Systematics, biodiversity, and paleoecology of an early Danian decapod crustacean assemblage from Alabama, United States

2025  47  13 geodi e si as Geodi e si as es une e ue en lux con inu publiée pa les Publica ions scien i iques du Muséum, Pa is Geodi e si as is a as ack jou nal published by he Museum Science P ess, Pa is Les Publica ions scien i iques du Muséum publien aussi / The Museum Science P ess also publish: Adansonia, Zoosys ema, An h opozoologica, Eu opean Jou nal o Taxonomy, Na u ae, C yp ogamie sous-sec ions Algologie, B yologie, Mycologie, Comp es Rendus Pale ol Di usion – Publica ions scien i iques Muséum na ional d’His oi e na u elle CP 41 – 57 ue Cu ie F-75231 Pa is cedex 05 (F ance) Tél. : 33 (0)1 40 79 48 05 / Fax : 33 (0)1 40 79 38 40 [email p o ec ed] / h p://sciencep ess.mnhn. © Publica ions scien i iques du Muséum na ional d’His oi e na u elle, Pa is, 2025 ISSN (imp imé / p in ) : 1280-9659/ ISSN (élec onique / elec onic) : 1638-9395 Di ec eu De la publica ion / Publica ion di ec o : Gilles Bloch, P ésiden du Muséum na ional d’His oi e na u elle éDac eu en che / edi o -in-chie : Didie Me le assis an De éDac ion / assis an edi o : Emmanuel Cô ez ([email p o ec ed]) Mise en page / Page layou : Aud ina Ne eu, Pénélope Lau in coMi é scien i ique / scien i ic boa d : Ch is ine A go (Muséum na ional d’His oi e na u elle, Pa is) Bea ix Azanza (Museo Nacional de Ciencias Na u ales, Mad id) Raymond L. Be no (Howa d Uni e si y, Washing on DC) Henning Blom (Uppsala Uni e si y) Jean B ou in (So bonne Uni e si é, Pa is, e ai é) Gaël Clémen (Muséum na ional d’His oi e na u elle, Pa is) Ted Daeschle (Academy o Na u al Sciences, Philadelphie) G ego y D. Edgecombe (The Na u al His o y Museum, Lond es) U sula Göhlich (Na u al His o y Museum Vienna) Jin Meng (Ame ican Museum o Na u al His o y, New Yo k) B igi e Meye -Be haud (CIRAD, Mon pellie ) Zhu Min (Chinese Academy o Sciences, Pékin) Isabelle Rouge (Muséum na ional d’His oi e na u elle, Pa is) Se ke Sen (Muséum na ional d’His oi e na u elle, Pa is, e ai é) S anisla Š ambe g (Museum o Eas e n Bohemia, H adec K álo é) Paul Taylo (The Na u al His o y Museum, Lond es, e ai é) cou e u e / co e : Réalisée à pa i des Figu es de l’a icle/Made om he Figu es o he a icle. Geodi e si as es indexé dans / Geodi e si as is indexed in: – Science Ci a ion Index Expanded (SciSea ch®) – ISI Ale ing Se ices® – Cu en Con en s® / Physical, Chemical, and Ea h Sciences® – Scopus® Geodi e si as es dis ibué en e sion élec onique pa / Geodi e si as is dis ibu ed elec onically by: – BioOne® (h p://www.bioone.o g) Les a icles ainsi que les nou eau és nomencla u ales publiés dans Geodi e si as son é é encés pa / A icles and nomencla u al no el ies published in Geodi e si as a e e e enced by: – ZooBank® (h p://zoobank.o g) 577 GEODIVERSITAS • 2025 • 47 (13) © Publica ions scien i iques du Muséum na ional d’His oi e na u elle, Pa is. www.geodi e si as.com Sys ema ics, biodi e si y, and paleoecology o an ea ly Danian decapod c us acean assemblage om Alabama, Uni ed S a es Adiël A. KLOMPMAKER P. Geo ge MARTIN Depa men o Museum Resea ch and Collec ions & Alabama Museum o Na u al His o y, Uni e si y o Alabama, 500 Hackbe y Lane, Tuscaloosa, Alabama 35487 (Uni ed S a es) [email p o ec ed] (co esponding au ho ) [email p o ec ed] Ma úš HYŽNÝ Ea h Science Ins i u e, Slo ak Academy o Sciences, Dúb a ská ces a 9, SK-840 05 B a isla a (Slo akia) and Depa men o Geology and Paleon ology, Facul y o Na u al Sciences, Comenius Uni e si y, Ilko ičo a 6, SK-842 15 B a isla a (Slo akia) [email p o ec ed] And ew R. BOWMAN Geological Su ey o Alabama, P.O. Box 869999, 420 Hackbe y Lane, Tuscaloosa, Alabama 35486 (Uni ed S a es) [email p o ec ed] Geo ge E. PHILLIPS Mississippi Museum o Na u al Science, 2148 Ri e side D , Jackson, Mississippi 39202 (Uni ed S a es) [email p o ec ed] Roge W. PORTELL Flo ida Museum o Na u al His o y, Uni e si y o Flo ida, 1659 Museum Road, Gaines ille, Flo ida 32611 (Uni ed S a es) [email p o ec ed] Submi ed on 20 Sep embe 2024 | accep ed on 22 Decembe 2024 | published on 22 Sep embe 2025 u n:lsid:zoobank.o g:pub:F5144147-C045-48FD-8128-7F822CDE6B18 Klompmake A. A., Ma in P. G., Hyžný M., Bowman A. R., Phillips G. E. & Po ell R. W. 2025. — Sys ema ics, biodi e - si y, and paleoecology o an ea ly Danian decapod c us acean assemblage om Alabama, Uni ed S a es. Geodi e si as 47 (13): 577-622. h ps://doi.o g/10.5252/geodi e si as2024 47a13. h p://geodi e si as.com/47/13 ABSTRACT The ex en o which he C e aceous-Paleogene (K-Pg) ex inc ion e en impac ed decapod c us aceans has ye o be es ed igo ously due o a lack o s udies a he ou c op scale. We comp ehensi ely desc ibe an ea ly bu no ea lies Danian assemblage om Mussel C eek, cen al Alabama, Uni ed S a es, based on collec ing o decapod ca apaces and appendage emains a he oadcu pa o his si e since 2010. The specimens we e eco e ed chie ly om sil y, micaceous muds ones o he Pine Ba en Membe 578 GEODIVERSITAS • 2025 • 47 (13) Klompmake A. A. e al. INTRODUCTION The deg ee o which decapod c us aceans expe ienced ex inc- ion du ing he C e aceous-Paleogene mass ex inc ion e en emains an open ques ion as analyses ha e been done la gely a a global scale and a di e en axonomic le els (e.g., Schwei ze & Feldmann 2005, 2023; Klompmake e al. 2016). Ea ly Paleocene (Danian) decapod c us aceans p o ide insigh s in o hei biodi e si y a e his ex inc ion e en . Such assemblages ha e been desc ibed om mul iple con- inen s including An a c ica (Feldmann & Tshudy 1989), Eu ope (Jakobsen & Collins 1997; Robin e al. 2017), No h Ame ica (Ra hbun 1935a; Collins & Wienbe g Rasmussen 1992; A ms ong e al. 2009), and Sou h Ame ica (Feldmann e al. 1995). The s a ig aphic posi ion o hese assemblages wi hin he Danian is c i ical o e alua e he biodi e si y o decapods a e he mass ex inc ion. The Clay on Fo ma ion is a lowe Danian uni exposed in he sou heas e n Uni ed S a es known o yield deca- pods. Decapods o hei bu ows ha e been epo ed om he Clay on Fo ma ion om Illinois (Cope e al. 2005), A kansas (Ra hbun 1935a; Ma ínez-Díaz e al. 2016), and Alabama (Feldmann e al. 2014, 2019; Ma ínez-Díaz e al. 2016; Fos e e al. 2020), bu hese pape s ocused on selec ed axa o he pu poses o hei s udies o epo ed on a limi ed numbe o specimens. The goal o his pape is o comp ehensi ely desc ibe an ea ly Paleocene (ea ly Danian) decapod assemblage om he Pine Ba en Membe o he Clay on Fo ma ion in cen al Alabama, Uni ed S a es. Based on collec ing e o s spanning 15 yea s, we cla i y he axonomy o some p e iously epo ed axa; epo mul iple new eco ds and axa; and discuss he s a ig aphic and paleobiogeog aphic implica ions, paleoecol- ogy, and di e si y o his assemblage. wi hin he Clay on Fo ma ion, c. 8 m abo e he K-Pg bounda y. Mic o ossil analysis indica es ha he decapods o igina e om he lowe middle pa o he NP2 nanno ossil zone, c. 600-700 ka a e he K-Pg bounda y. Based on 354 iden i iable specimens, we ecognize eigh species: 1) ou B achyu a: Alahexapus ma ini (Feldmann, Schwei ze & Po ell, 2014) n. comb., Cos acopluma nicksabani n. sp., Raninoides danicus n. sp., and an inde e mina e ep esen a i e o Palaeoxan hopsidae Schwei ze , 2003; 2) h ee Axiidea: Alphacheles ze a (Ra hbun, 1936) n. comb., C enocheles sp., and Eucalliaxiopsis alabamensis (Ra hbun, 1935a) n. comb.; and 3) one Pagu oidea: “Pagu is es” johnsoni Ra hbun, 1935a. Two new gene a a e desc ibed: Alahexapus n. gen. and Alphacheles n. gen. The assemblage is domina ed by specimens o C. nicksabani n. sp. (52% o iden i iable specimens) and E.alabamensis n. comb. (31%). Th ee specimens o C. nicksabani n. sp. p ese e a e gonopods. A a e ac ion analysis indica es ha (nea ly) all species we e collec ed. This assemblage ep esen s he mos di e se ea ly Danian decapod assemblage om No h Ame ica hus a , and p o ides a basis o u he s udy o decapods ac oss he K-Pg bounda y. RÉSUMÉ Sys éma ique, biodi e si é e paléoécologie d’un assemblage de c us acés décapodes du Danien in é ieu de l’Alabama, É a s-Unis. L’ampleu de l’impac de l’ex inc ion du C é acé-Paléogène (K-Pg) su les c us acés décapodes n’a pas enco e é é igou eusemen é aluée en aison du manque d’é udes à l’échelle des a leu emen s. Nous déc i ons de maniè e exhaus i e un assemblage du Danien in é ieu , mais pas le plus ancien, p o enan de Mussel C eek, dans le cen e de l’Alabama, aux É a s-Unis, su la base de la collec e collec e de es es de ca apaces e d’appendices de décapodes dans un alus ou ie depuis 2010. Les spécimens on é é p incipalemen collec és dans des muds ones limoneux e micacés du Memb e Pine Ba en au sein de la Fo ma ion Clay on, à en i on 8 m au-dessus de la limi e K-Pg. L’analyse des mic o ossiles indique que les décapodes p o iennen de la pa ie in é ieu e moyenne de la zone à nanno ossiles NP2, en i on 600 à 700 ka ap ès la limi e K-Pg. Su la base de 354 spécimens iden- i iables, nous econnaissons hui espèces : 1) qua e B achyu a : Alahexapus ma ini (Feldmann, Schwei ze & Po ell, 2014) n. comb., Cos acopluma nicksabani n. sp., Raninoides danicus n. sp. e un ep ésen an indé e miné de la amille des Palaeoxan hopsidae Schwei ze , 2003 ; 2) ois Axiidea : Alphacheles ze a (Ra hbun, 1936) n. comb., C enocheles sp. e Eucalliaxiopsis alabamensis (Ra hbun, 1935a) n. comb. ; e 3) un Pagu oidea : “Pagu is es” johnsoni Ra hbun, 1935a. Deux nou eaux gen es son déc i s : Alahexapus n. gen. e Alphacheles n. gen. L’assemblage es dominé pa des spécimens de C. nicksabani n. sp. (52 % des spécimens iden i iables) e E. alabamensis n. comb. (31 %). T ois spécimens de C.nicksabani n. sp. conse en des gonopodes, ce qui es a e. Une analyse de a é- ac ion indique que (p esque) ou es les espèces on é é collec ées. Ce assemblage de décapodes du Danien in é ieu es le plus di e si ié d’Amé ique du No d connu à ce jou e ou ni une base pou la pou sui e des é udes su les décapodes à a e s la limi e K-Pg. MOTS CLÉS Alabama, Anomu a, Axiidea, B achyu a, C us acea, Danien, Decapoda, Paléocène, combinaisons nou elles, gen es nou eaux, espèces nou elles. KEY WORDS Alabama, Anomu a, Axiidea, B achyu a, C us acea, Danian, Decapoda, Paleocene, new combina ions, new gene a, new species. 579 Ea ly Danian decapods om Alabama, Uni ed S a es GEODIVERSITAS • 2025 • 47 (13) GEOLOGICAL SETTING The lowe Paleocene (Danian) Clay on Fo ma ion in Alabama is di ided in o a lowe (Pine Ba en) and uppe (McB yde Limes one) membe s in cen al Alabama. Toulmin (1977) i s documen ed he mac oin e eb a e con en o he Pine Ba en beds in Alabama (Bu le and Wilcox coun ies). Se e al locali ies o co es om cen al Alabama wi h Pine Ba en sedi- men s ha e been desc ibed including bu no limi ed o he An ioch Chu ch Co e (Schul e & Speije 2009), B aggs (e.g., Jones e al. 1987; B yan & Jones 1989; Zachos e al. 1989), Mooseland (La ina e al. 2016), Moscow Landing (e.g., Smi h 1997; Ha e al. 2013; Sa da e al. 2020), and Mussel C eek (Ha e al. 2013; Udga a & Sa da 2016). Thus, he age o hese sedimen s is gene ally well cons ained. The oadcu a Mussel C eek (ALMNH loc. 3) is in he sou he n pa o Lowndes Coun y, Alabama, Uni ed S a es (Fig. 1). He e, c. 5.5 m o sec ion o he lowe Danian Pine Ba en Membe o he Clay on Fo ma ion is exposed and ano he 1 m can cu en ly be co ed wi h an auge un il hi ing a limes one laye (Fig. 2). These sedimen s, all wi hin nanno ossil zone NP2, comp ise an al e na ion o g ay o an, ca bonaceous, glauconi ic calca e- ous, a iably sandy micaceous muds ones and ha de lime- o ma ls one laye s (Ha e al. 2013; Udga a & Sa da 2016). Udga a & Sa da (2016) in e p e ed hese laye s o ep esen a highs and sys ems ac , and hese limes ones o ha e o med diagene ically below ma ine looding su aces. Mac o ossils om his oadcu include plan emains, as e oid ossicles, bi al es, gas opods, a nau iloid, echinoid spines, b yozoans, a c inoid, decapods, sha k and ay ee h, holocephalan ee h, bony ish ee h and e eb ae, c ocodile bones and ee h, u le, and some ace ossils (Figs 3; 4). Among hese mac o ossils, ou deca- pod species (Feldmann e al. 2014, 2019) and wo lamni o m sha k species (Cicimu i e al. 2020; Ebe sole e al. 2024) we e o mally epo ed, bu many o he ossils emain o be s udied. Nea ly all decapod specimens s udied he ein o igina e om he lowe middle pa o NP2 nanno ossil zone (Fig. 2). Olde , ea lies Danian laye s exposed in he s eam cu o Mussel C eek ha e yielded epo ed mac o ossils such as echi- noids, bi al es, b yozoans, and bu ows such as Thalassinoides Eh enbe g, 1944 (Sa da 1993; Udga a & Sa da 2016; Zachos 2017). MATERIAL AND METHODS In o al, 354 iden i iable decapod specimens (excluding 30 Axiidean inde . and 25 Decapoda inde .) we e collec ed a he Mussel C eek oadcu (31°58’17”N, 86°42’15”W) in Lowndes Coun y, Alabama, om 2010-2024 du ing one o mul iple ips each yea . Mos specimens we e collec ed by PGM (2010-2024) and many o he s by AAK (2021-2024). The specimens we e o en ound loose on he su ace, ha ing wea he ed ou o he muds ones and limes ones; some speci- mens we e disco e ed embedded in he ock. The specimens we e la gely collec ed om he muds ones abo e and below he mos p ominen limes one laye (laye 13 in Figu e 2) cu en ly isible a he oadcu (laye 18 o Udga a & Sa da 2016), which is c. 8 m abo e he K-Pg bounda y exposed wi hin he c eek blu based on ou measu emen s. Specimens we e p epa ed using ai sc ibes and ha dened wi h Pa aloid B-72 as needed. Specimen pho og aphy was done using a Canon EOS 90D came a wi h a 60 mm lens in an O ech Pho o-e-Box Plus ligh box. Closeup pic u es we e made using a Swi cam 18 MP came a moun ed on a mic oscope and using an MP-E 65 mm lens on a Canon EOS 90D came a. Pos p ocessing o specimen images such as s acking occu ed in Adobe Pho oshop. A D3D-s (model S2) 3D scanne was used o c ea e 3D models o specimens o new species wi h he help o Polyga Poin Ki Scan so wa e. All specimens used a e eposi ed in he museum collec ions lis ed below. Specimens only iden i iable o high axonomic anks (Axiidea inde .: ALMNH:Paleo:5920 [3 specimens], ALMNH:Pa- leo:5922 [1 specimen], ALMNH:Paleo:13536 [1 specimen], ig. 1. — Images o he oadcu o Mussel C eek, Lowndes Coun y, Alabama, exposing he lowe Danian Pine Ba en Membe (Clay on Fo ma ion): A, Eas side; B, Wes side. Mos o he so , an laye s ha e g own o e since pho os we e aken in 2010. The main ha d limes one laye (laye 13, c. 8 m abo e he K-Pg bounda y in Figu e 2 co esponds o laye 18 o Udga a & Sa da 2016) is ba ely isible in he lowe le co ne o A bu clea ly isible in he lowe hi d o B. C edi s: pho os by P. Geo ge Ma in. AB 580 GEODIVERSITAS • 2025 • 47 (13) Klompmake A. A. e al. and ALMNH:Paleo:21556 [25 specimens]; Decapoda inde .: ALMNH:Paleo:21557 [21 specimens], UF 303812 [1 spec- imen], UF 303815 [1 specimen], UF 303819 [1 specimen], and UF 303866 [1 specimen]) a e no ea ed u he below. Coo dina es o locali ies, whe e a ailable, use he da um WGS 84 s anda d. Non-decapod mac o ossils we e iden i ied wi h he assis ance o compa a i e ma e ial in he ALMNH and MMNS collec- ions and mul iple e e ences (Ga dne 1935; Toulmin 1977; Cicimu i e al. 2020; Ga ie 2021; Ebe sole e al. 2024). In he discussion, we compa e he di e si y o ea ly Danian decapod assemblages globally. We ecognize he e a e younge Danian assemblages (e.g., uppe Danian Po e s C eek Fo - ma ion [Ra hbun 1935a]; middle Danian Faxe Fo ma ion [Jakobsen & Collins 1997; Jakobsen e al. 2020; Klompmake e al. 2022a]; uppe Danian Mexia Clay Membe o he Wills Poin Fo ma ion [A ms ong e al. 2009]), bu hey a e ou side he en isioned scope o he discussion. NaNNo ossil aNalyses Thi y- wo samples we e collec ed h oughou c. 6 m o ou - c op sec ion exposed a he oadcu o Mussel C eek. The samples we e ca e ully selec ed ac oss all li hologies; hus, samples we e collec ed in bo h he in e als o muds one and beds o limes one/ma l. The calca eous nanno ossils we e s udied unde c oss-pola ized ligh and phase con as a 1000X magni ica ion, using a Zeiss Axiopho ligh mic o- scope (LM). The samples we e p epa ed o LM obse a ion using a ou ine smea slide echnique. Samples we e analyzed quan i a i ely o iden i y bios a ig aphic e en s and es ab- lish a nanno ossil zona ion o he sec ion, and o documen nanno ossil-assemblage changes h oughou he ea ly Danian. Quan i a i e analysis in ol ed coun ing 300 nanno ossil specimens om andom ields o iew. In gene al, eaching a coun o 300 specimens equi ed obse a ion o be ween 1-2 a e ses. Howe e , samples ma ked by e y low nan- no ossil abundances would some imes equi e iewing o up o i e a e ses. The abundances o each species we e also eco ded using he ollowing ca ego ies: SA (supe -abun- dan ) = > 75 specimens, A (abundan ) = 21-75 specimens, C ( common) = 9-20 specimens, F ( ew) = 4-8 specimens, and R ( a e) = 1-3 specimens. The bios a ig aphic in e p e a ion o he samples u ilized he nanno ossil biozona ion o Ma ini (1971), and he associa ed nume ic ages o zonal bounda ies and nanno ossil bioe en s a e de i ed om G ads ein e al. (2012). We use he e ms “Base” o he i s o lowes s a ig aphic occu ence o a spe- cies, and “Top” o he las o highes s a ig aphic occu ence. The e minology o abundance-based bioe en s includes he ollowing: “inc ease” = equen -common; “in lux” = abundan ; “majo in lux” = supe -abundan ; “acme” = acme, o absolu e highes abundance. O axonomic and bios a ig aphic no e is ha al hough C uciplacoli hus enuis (S adne , 1961) is he adi ional and o icial index species ep esen ing Zone NP2, we acknowledge he se ious axonomic p oblem (e.g., c oss ba wi h “ ee -like” e mina ions) associa ed wi h he use o Base C. enuis as he zonal ma ke de ining NP2. In his s udy, we ollow he his o ical axonomic concep /bios a ig aphic app oach used by o he s (Pe ch-Nielsen 1985; Van Heck & P ins 1987; Va ol 1989; Bown e al. 2023). As such, we conside Base C uciplacoli hus in e medius Van Heck & P ins, 1987, he bioe en and subs i u e zonal ma ke de ining Zone NP2. We conside Zones NP1-NP2 o ep esen he “lowe ”/”ea ly” Danian he e in o mally. Slides wi h nanno ossils a e s o ed a he Geological Su ey o Alabama. iNs i u ioNal abb e ia ioNs ALMNH Alabama Museum o Na u al His o y paleon ol- ogy collec ion, Uni e si y o Alabama, Tuscaloosa, Alabama; GSA Geological Su ey o Alabama, Tuscaloosa, Alabama; MGSB Museu Geològic del Semina i de Ba celona, Ba celona; MMNS IP Mississippi Museum o Na u al Science In e eb a e Paleon ology collec ion, Jackson, Mississippi; NPL Non- e eb a e Paleon ology lab, Jackson School Museum o Ea h His o y, Uni e si y o Texas a Aus in, Aus in, Texas; UF Flo ida Museum o Na u al His o y (In e eb a e Paleon ology), Uni e si y o Flo ida, Gaines ille, Flo ida. SYSTEMATIC PALAEONTOLOGY O de DECAPODA La eille, 1802 In ao de AXIIDEA de Sain Lau en , 1979 Family C eNoChelidae Manning & Felde , 1991 iNCluded geNe a. — Ahazianassa Ka asawa, Kishimo o, Oha a & Ando, 2019; Alphacheles n. gen.; C enocheles Kishinouye, 1926; C e agou e ia Ossó, Cha bonnie , Hyžný, Van Bakel, De illez, Bo e -A nal & Mo eno-Bedma , 2024; C enocheloides Anke , 2010; Dawsonius Manning & Felde , 1991; Gou e ia de Sain Lau en , 1973; Kiic enocheloides Sakai, 2013; Lau en gou e ia Sakai, 2004; Pa agou e ia Sakai, 2004. Genus Alphacheles n. gen. u n:lsid:zoobank.o g:ac :D5A2F0B5-3E68-403C-A751-6951DE740D9F ype speCies. — Callianassa ze a Ra hbun, 1936 (Callianassa alpha Ra hbun, 1935a; non Callianassa alpha S enzel, 1935), by p esen designa ion. e ymology. — The genus name is a combina ion o “alpha”, e- e ing o he homonymous species name Callianassa alpha, and “cheles” meaning “claw”. Gende : masculine. diagNosis. — As o he ype species. ema ks Sho ly a e he desc ip ion o Callianassa alpha Ra hbun, 1935a, i was e ealed ha he name had al eady been used by S enzel (1935) o ye ano he ossil ghos sh imp assigned o Callianassa. A ec i ica ion was published in he ollowing yea , enaming C. alpha o C. ze a Ra hbun, 1936. 581 Ea ly Danian decapods om Alabama, Uni ed S a es GEODIVERSITAS • 2025 • 47 (13) Callianassa ze a di e s om all known ex an and ex inc ghos sh imp axa by i s ube cula e a ea (“densely punc a e exc escence” sensu Ra hbun [1935a]; “ iangula pa ch o g anules” sensu Feldmann e al. [2019]) a he base o he ixed inge which is p esen a he ou e and inne la e al su aces. This cha ac e has been conside ed a diagnos ic ea u e o his species (Ra hbun 1935a; Feldmann e al. 2019). I s axonomic signi icance is he ein ele a ed o he genus le el, and hence a new genus is p oposed o accommoda e his species. So a , only p opodi and dac yli a e known o Alphacheles ze a (Ra hbun, 1936) n. comb. Mos specimens ep esen majo claws, whe eas in one case also a mino claw is iden i- ied (Fig. 5O). Thei mo phology is a he close o ha o ex an species o Gou e ia and Pa agou e ia, based on which he new genus is classi ied wi hin he amily C enochelidae. Ne e heless, he amilial placemen o Alphacheles n. gen. should be conside ed p elimina y un il mo e comple e ma e ial is ound. Alphacheles n. gen. sha es wi h he abo e-men ioned gene a he ollowing se o cha ac e s: majo cheliped p opo- dus dis inc ly longe han high and sub ec angula in ou line, ela i ely long inge s exceeding hal o he p opodus palm leng h, and dac ylus occlusal su ace wi h simple den i ion (c . Le Loeu & In ès 1974; Sakai 2002, 2004; Ngoc-Ho 2003). These cha ac e s a e sha ed also wi h C e agou e ia, an exclusi ely ossil genus known om he Ea ly C e aceous (Albian) o Spain. This se o cha ac e s men ioned abo e is a ely seen in o he ghos sh imp amilies (Poo e & Ahyong 2023). As men ioned abo e, Alphacheles n. gen. di e s om all ghos sh imp gene a known o da e by he p esence o a ube cula e a ea a he base o he ixed inge . I di e s also om ye ano he exclusi ely ossil c enochelid genus, Ahazi- anassa, om he La e C e aceous (Maas ich ian) o Japan. Addi ionally, Alphacheles n. gen. possesses a mo e elonga e palm han Ahazianassa does. Besides Callianassa alpha, Ra hbun (1935a) desc ibed also “C. alpha a .” om he Uppe Eocene Jackson G oup o Mississippi. A new a ie y o C. alpha is based on a single incomple e p opodus and a pleon ound a he same locali y. ig. 2 . — S a ig aphic column o he Mussel C eek oadcu ela i e o he K-Pg bounda y wi hin he c eek, nanno ossil zona ion and key species based on mic o ossil samples ( ed do s), and laye s in which nea ly all decapods we e ound. 1 20 14 15 45 6 2 3 7 8 9 10 11 12 13 16 17 18 19 21 22 23 24 25 26 27 11 10 9 8 7 6 5 Heigh o sec ion (me e s abo e K-Pg bounda y) uppe NP2 middle NP2 lowe NP2 Base P aep inus dimo phosus [common] Base C uciplacoli hus p imus [supe -abundan /acme] Base C uciplacoli hus in e medius [common] Base P aep inus dimo phosus, Top Fu yania spp. [abundan ] Base Lan e ni hus duoca us [ equen ] Top Cyclagelosphae a al a [ equen ] Top Cyclagelosphae a al a [abundan ] Top Fu yania spp. [supe -abundan ], Top Fu yania a ewellii [acme], Top B aa udosphae a spp. [abundan ] Base P aep insius enuiculus, Base Neoc epidoli hus di imosus, Base Zeug habdo us sigmoides [common] Base C uciplacoli hus in e medius, Base Coccoli hus pelagicus, Base Fu yania spp. [supe -abundan ] 582 GEODIVERSITAS • 2025 • 47 (13) Klompmake A. A. e al. ig. 3 . — Non-decapod body mac o ossils om he lowe Danian Pine Ba en Membe (Clay on Fo ma ion) ound a he oadcu o Mussel C eek, Lowndes Coun y, Alabama: A, C ocodylia e eb a (ALMNH:Paleo:21546); B, C ocodylia os eode m agmen (ALMNH:Paleo:21538); C, C ocodylia oo h (ALMNH:Paleo:22081A); D, an e ola e al sha k oo h o Menne o odus mackayi Cicimu i, Ebe sole & Ma in, 2020 (ALMNH:Paleo:21532); E, (pa a-)symphyseal sha k oo h o Menne o odus mackayi (ALMNH:Paleo:21523); F, u le emu (ALMNH:Paleo:21547); G, wood agmen (ALMNH:Paleo:21534); H, la e al sha k oo h o Palaeohypo odus spe- ye i (Da e elle & Casie , 1943) (ALMNH:Paleo:21524); I, ome ine wi h some ee h o bony ish c . Pycnodus sp. (ALMNH:Paleo:21543); J, mola i o m oo h o bony ish c . Pycnodus sp. (ALMNH:Paleo:21522); K, e eb a o bony ish (ALMNH:Paleo:21545); L, bi al e Cucullaea (?) sp. (ALMNH:Paleo:21530); M, igh oys e al e o Os ea c enulima gina a Gabb, 1860 (ALMNH:Paleo:21520); N, le oys e al e o G yphaeos ea ome (Mo on, 1828) (ALMNH:Paleo:21533); O, igh oys e al e o G yphaeos ea ome (ALMNH:Paleo:21535); P, le al e o bi al e c . Eomil ha sp. (ALMNH:Paleo:21544); Q, bi al e Calloca dia sp. (ALMNH:Paleo:21541); R, bi al e Vene ica dia (Baluchica dia) sp. (ALMNH:Paleo:21519); S, bi al e C assa ella c . C. ioannes Ga dne , 1935 (ALMNH:Paleo:21539). Scale ba s: A, B, F, L, Q-S, 10.0 mm; C, D, G-I, K, M-P, 5.0 mm; E, J, 2.0 mm. C edi s: pho os by Adiël A. Klompmake . B C DE FG H IJKL MN O P QRS A 583 Ea ly Danian decapods om Alabama, Uni ed S a es GEODIVERSITAS • 2025 • 47 (13) ig. 4 . — Non-decapod body and ace mac o ossils om he lowe Danian Pine Ba en Membe (Clay on Fo ma ion) ound a he oadcu o Mussel C eek, Lowndes Coun y, Alabama: A, gas opod Kapalme ella sp. (ALMNH:Paleo:21526); B, gas opod Mesalia c . M. ha demanensis (Gabb, 1860) (ALMNH:Pa- leo:21515); C, gas opod S a icos a um (Paginacos a) sp. (ALMNH:Paleo:21516); D, gas opod Fasciola iidae G ay, 1853 (ALMNH:Paleo:21525); E, gas opod Volu oco bis c . V. uga us (Con ad, 1860) (ALMNH:Paleo:21521); F, gas opod Na icidae Guilding, 1834 (ALMNH:Paleo:21540); G, echinoid spine o Cida oida Claus, 1880 (ALMNH:Paleo:21537); H, I, C inoidea Mille , 1821 (ALMNH:Paleo:21527); J, B yozoan He e oconopeum damico nis (Canu & Bassle , 1920) (ALM- NH:Paleo:21531); K, Clionid sponge bo ing ace (in illing) En obia isp. (ALMNH:Paleo:21529); L, oys e G yphaeidae Vialo , 1936 (Pycnodon inae) wi h d ill hole (Oichnus pa aboloides B omley, 1981) by p eda o y gas opod (ALMNH:Paleo:21536); M, N, Nau iloid He coglossa sp. (ALMNH:Paleo:22082); O, ou ay ee h o Mylioba is sp. (ALMNH:Paleo:9737); P, Holocephalian Ischyodus williamsae Case, 1991 (ALMNH:Paleo: 9739). Scale ba s: A-C, E, F, J, K, P, 5.0 mm; D, M-O, 10.0 mm; G-I, L, 2.0 mm. C edi s: pho os by Adiël A. Klompmake . CD E F G HI J K L AB MN OP 590 GEODIVERSITAS • 2025 • 47 (13) Klompmake A. A. e al. desC ip ioN Cheliped me us o al in ou line, 1.6 imes as long as high; ou e la e al su ace wi h longi udinal idge a mid-heigh ; lowe ma gin dis inc ly con ex, smoo h. Cheliped ca pus 1.5 imes as high as leng h a uppe ma gin; p oximal ma gin ounded; dis ola e al ma gin squa e a lowe angle. Cheliped p opodus palm app oxima ely as high as leng h a uppe ma gin, highes p oximally; p oximo-lowe co - ne ounded; uppe and lowe ma gins ca ina e, ca inae accompanied wi h ows o se al po es on bo h sides (inne and ou e ), ca ina on lowe ma gin o ming mic oden i- cles dis ally (along ixed inge ); inne la e al su ace wi h nume ous se al po es concen a ed close o dis al ma gin and o ming sub e ical i egula ow; ou e la e al su ace wi h se al po es concen a ed dis ally, highes numbe o po es p esen close o junc ion wi h ixed inge ; dis al ma gin o ou e la e al su ace wi h blun oo h jus below a ic- ula ion wi h dac ylus. Fixed inge app oxima ely as long as uppe palm leng h, b oadly o al in c oss sec ion; ou e la e al su ace wi h oblique longi udinal idge, nume ous se al po es sca e ed below idge and in ow abo e i along en i e ixed inge leng h; ixed inge occlusal su ace wi h p oximal blun oo h, en i e occlusal su ace (incl. p oximal oo h) wi h nume ous equally sized den icles, ip sligh ly ben upwa d. Dac ylus uppe ma gin s aigh , ca ina e; ou e la e al su ace wi h ows o se al po e clus e s along uppe and occlusal ma gins; inne la e al su ace wi h se - e al se al po e clus e s along mid-leng h; occlusal su ace o obus dac ylus mo pho ype wi h p oximal blun oo h ollowed wi h inely den icula ed edge; occlusal su ace o slende dac ylus mo pho ype wi hou p oximal oo h; dac ylus ip sligh ly ben . ig. 10. — Eucalliaxiopsis alabamensis (Ra hbun, 1935a) n. comb. om he lowe Danian Pine Ba en Membe (Clay on Fo ma ion) a he oadcu o Mussel C eek, Lowndes Coun y, Alabama (MMNS IP-7251): A, igh majo cheliped wi h, om le o igh , he me us, ca pus, p opodus, and dac ylus; B, coun e pa . In si u nodule wi h specimen ound c. 9.8 m abo e K-Pg bounda y. Scale ba s: 10.0 mm. C edi s: pho os by Adiël A. Klompmake . A B 591 Ea ly Danian decapods om Alabama, Uni ed S a es GEODIVERSITAS • 2025 • 47 (13) ema ks Ra hbun (1935a: pl. 15.7-15.10) igu ed wo ype specimens, he dac ylus pa a ype, which ecei ed a new numbe subse- quen ly (USNM PAL 327231 A), bu she also men ioned he p esence o mo e specimens (20 p opodi and h ee inge s). Fi e addi ional specimens (USNM PAL 327231) a e lis ed as pa a ypes in he Smi hsonian Ins i u ion da abase and seen by AAK in 2018, bu ano he ca alog numbe used in Ra hbun (1935a) (371504) does no e u n any ma ch in hei da abase. Thus, he whe eabou s o 16 o iginal spec- imens is unce ain. Newly collec ed specimens ma ch he ype ma e ial in mos de ails. Sligh di e ences ela e o he mode o p ese a ion. The ype specimens a e pa ly ab aded hinde ing he obse a- ion o minu e de ails while he cu icula su aces a e be e p ese ed in he newly collec ed ma e ial. Fo ins ance, he de elopmen o mic oden icles on he lowe ma gin o he p opodus, he den i ion on he occlusal edges o inge s and mo phological de ails o se al po es a e no well obse able in he ype ma e ial. Se al po es a e a anged in clus e s; he clus e s a e o al, dis inc ly elonga e o V-shaped. Elonga e se al po e clus e s, o ien ed pe pendicula ly o he occlusal ma gin, a e p esen especially on he ou e la e al su ace o dac yli, whe eas V-shaped clus e s a e some imes p esen on he ou e la e al su ace o he ixed inge s. The numbe o se al po es/se al po e clus e s sligh ly a ies when compa ing he same pa s o a ious specimens. The e a e wo mo pho ypes o dac yli iden i ied in he newly collec ed ma e ial: he obus one, wi h he p oximal oo h on he occlusal su ace, and he slende one, wi hou he espec i e oo h. The slende mo pho ype is in e p e ed o belong o a mino claw, whe eas he obus mo pho ype is in e p e ed o belong o a majo claw; such di e ences in he mo phology o cheliped dac yli a e known also in ex an species o Eucalliacidae (Poo e 2021). Based on he p esence o a p oximal oo h on he occlusal su ace o he ixed inge , all s udied p opodi a ibu ed o E. alabamensis n. comb. a e in e p e ed o belong o majo claws only; such a p oximal oo h is missing in mino claws o eucalliacid sh imps (Hyžný 2012; Hyžný & Hudáčko á 2012; Poo e 2021). Majo chelipeds a e sexually dimo phic in ep esen a i es o Eucalliaxiopsis, wi h males ha ing he p opodus palm p opo ionally longe han ha o emales (Poo e 2021). The limi ed numbe o comple e p opodi does no allow an e alua ion o his dimo phism in E. alabamensis n. comb., al hough one p opodus (Fig. 8F, G) indeed appea s o be p opo ionally longe han o he s and migh ep esen a male indi idual. The newly p esen ed ma e ial o E. alabamensis n. comb. is he second epo o he species, o iginally desc ibed nea ly a cen u y ago (Ra hbun 1935a). I also adds u he de ails o he desc ip ion o he species, especially he mo phology o he ca pus and me us, p e iously unknown o his axon. The ange o he species is expanded om he la e Danian o he ea ly Danian. F om ossil congene s, Eucalliaxiopsis alabamensis n. comb. di e s om E. pseudo akosensis mainly in he na u e o majo dac ylus. In E. pseudo akosensis, he occlusal ma gin o he dac ylus is a med wi h a dis al oo h (Hyžný & Hudáčko á 2012), which is en i ely missing in E. alabamensis n. comb. In ao de ANOMURA MacLeay, 1838 Supe amily pagu oidea La eille, 1802 Family ?diogeNidae O mann, 1892 Genus ?Pagu is es Dana, 1851 ype speCies. — Pagu is es hi us Dana, 1851, by subsequen designa ion (S impson 1858: 235). “Pagu is es” johnsoni Ra hbun, 1935a (Fig. 11) Pagu is es johnsoni Ra hbun, 1935a: 78, pl. 14.13-14.18. — Cope e al. 2005: 101, pl. ig. 6.2. ype ma e ial . — Holo ype. Uni ed S a es • Alabama, Wilcox Coun y, P ai ie C eek and Pine Ba en sec ion; Po e s C eek Fo - ma ion; Paleocene (uppe Danian); USNM MO 371705 ( igh p opodus). Pa a ype. Uni ed S a es • 1 specimen; same as o he holo ype; USNM MO 371706 (le mino p opodus and dac ylus). addi ioNal ma e ial examiNed. — Uni ed S a es • 1 specimen; Alabama, Lowndes Coun y, Mussel C eek oadcu (31°58’17”N, 86°42’15”W), ALMNH loc. 3; Clay on Fo ma ion, Pine Ba en Membe , lowe middle NP2 nanno ossil zone; Paleocene (lowe Danian); ALMNH:Paleo:21483 ( igh p opodus + base o dac ylus) • 1 specimen; idem; ALMNH:Paleo:21484 (le dac ylus) • 1 speci- men; idem; ALMNH:Paleo:21485 ( igh dac ylus) • 1 specimen; idem; ALMNH:Paleo:21486 (?le ixed inge ) • 1 specimen; idem; ALMNH:Paleo:21487 ( igh dac ylus) • 1 specimen; idem; ALMN- H:Paleo:21555 (le me us) • 1 specimen; idem; UF 303860 ( igh dac ylus) • 1 specimen; Alabama, Sum e Coun y, Tombigbee Ri e , Black Blu (32°22’22”N, 88°2’38”W), ALMNH loc. 5; Po e s C eek Fo ma ion; Paleocene (uppe Danian); ALMNH:Paleo:21495 ( igh p opodus) • 1 specimen; idem; ALMNH:Paleo:21496 ( igh dac ylus) • 1 specimen; idem; GSA-I21012 ( igh dac ylus) • 1 speci- men; Alabama, Wilcox Coun y; Po e s C eek Fo ma ion; Paleocene (uppe Danian); GSA-I20984 ( igh p opodus). ype ho izoN. — Po e s C eek Fo ma ion (Suca noochee beds in Ra hbun 1935a), uppe Danian. ype loCali y. — P ai ie C eek and Pine Ba en sec ion, Wilcox Coun y, Alabama, Uni ed S a es. diagNosis. — Majo palm sho ; abou as long as high; ube cles wi h pi in cen e ; diamond-shaped in c oss-sec ion; wi h sha p, con ex uppe and lowe ma gins; uppe ma gin sho e han lowe ma gin; ounded idges on ou e and inne sides. Majo dac ylus wi h ube cles wi h pi in cen e and non- ube cula pa ches wi h se al po es on ou e , uppe , and pa o inne sides; occlusal su ace wi h a ew la ge ee h and a smalle oo h on ou e side o i s oo h p oximally, and a ow o connec ed small ee h owa d dis al end. measu emeN s. — Palm leng h (mm): ALMNH:Paleo:21483: 5.4 (as p ese ed); USNM MO 371705: 15.6; ALMNH:Paleo:21495: 10.4; GSA-I20984: 10.6 (as p ese ed). 592 GEODIVERSITAS • 2025 • 47 (13) Klompmake A. A. e al. desC ip ioN Re e ence is made o Ra hbun (1935a: 78). Addi ionally: majo dac ylus cu ed inwa d; ube cles wi h pi in cen e and non- ube cula pa ches wi h se al po es on ou e , uppe , and pa o inne sides; occlusal su ace wi h a ew la ge ee h and a smalle oo h on ou e side o i s oo h p oximally, and a ow o connec ed small ee h owa d dis al end. ema ks The single igh p opodus a ailable (ALMNH:Paleo:21483) om Mussel C eek is incomple e bu closely esembles he holo ype o Pagu is es johnsoni (USNM MO 371705, igh p opodus) and o he igh p opodi (ALMNH:Paleo:21495, igh p opodus; GSA-I20984, igh p opodus) om he uppe Danian Po e s C eek Fo ma ion in Alabama in e ms o o e all shape, size, and dis ibu ion o he o namen a ion, and he idge on he ou e su ace. The base o he dac ylus is p ese ed along wi h he p opo- dus om Mussel C eek (ALMNH:Paleo:21483), showing he base o he i s la ge oo h and an adjacen small accesso y oo h on he ou e side ha la ge oo h. This pa e n esem- bles o he isola ed dac yli om Mussel C eek and dac yli om he Po e s C eek Fo ma ion (ALMNH:Paleo:21496, GSA-I21012), which allows us o assign hese specimens o P. johnsoni as well. The sample also con ains an isola ed inge ha could be a ixed inge o his axon (Fig. 11I, J). I con- ains a ow o small ee h on he occlusal su ace and migh belong o he mino claw o his axon because la ge ee h on he occlusal su ace a e o en seen on bo h inge s o he majo claw in pagu oids, whe eas small ee h a e o en seen on he mino claw in pagu oids (e.g., Fo es e al. 2000). The oblique ow o small ee h on i s inne p oximal pa ma ches ha o he base o he ixed inge o he p opodus (ALMN- H:Paleo:21483). Dac yli o he majo claw we e unknown om his species hus a . A le me us possibly belonging o he same species was also ound (ALMNH:Paleo:21555). This species was b ie ly discussed in Bishop (1983: 419), ci ing a pe sonal communica ion wi h Jaques Fo es , who was in doub ha Pagu is es whi eni Bishop, 1983, and P.johnsoni could be assigned o Pagu is es o e en pagu oids. Tube cula p opodi do no necessa ily imply a pagu oid a ini y. Indeed, he p opodi o Pagu is es whi eni belong o ca apace specimens o he b achyu an c ab Dako icance aus alis Ra hbun, 1935a (see Ko necki e al. 2017), also common a he same locali y in Mississippi. We canno assign he ube cula elemen s he ein o a b achyu an ca a- pace om he same assemblage. The dac yli and p opodi a e oo la ge o Alahexapus ma ini (Feldmann, Schwei ze & Po ell, 2014) n. comb. and he (dis al) cheliped elemen s o o he b achyu an axa (see below) do no esemble he p opodi/dac yli o P. johnsoni. The cheliped elemen s also canno be linked o a b achyu an ca apace om he Po e s C eek Fo ma ion. Gi en he ex ensi e collec ing e o s a he Mussel C eek oadcu since 2010, he likelihood o inding o he b achyu an axa o which he claw elemen s could belong is low. We he e o e sugges ha he specimens ep esen a pagu oid. The ac ha he igh p opodus is la ge han he le p opodus (see Ra hbun 1935a: pl. 14.13-14.17), i bo h isola ed elemen s a e indeed om he same species, is incon- sis en wi h Diogenidae, membe s o which usually ha e a la ge le p opodus o (sub)equal p opodi (e.g., Tudge e al. 2012: 305), including Pagu is es, which is men ioned o ha e isochelous p opodi (F aaije e al. 2015: 590). An excep ion wi hin diogenids is Pe ochi us S impson, 1858, bu his axon has scab ous o namen a ion in he ype species Pe o- chi us diogenes (Linnaeus, 1758) (see Hyžný & Dulai 2021: ig. 43.7) no seen in P. johnsoni and a ious ossil Pe ochi us (Beschin e al. 2002, 2006, 2012). The dac yli he ein closely esemble a dac ylus iden i ied as Pe ochi us sp. om he Ea ly Miocene o Venezuela (Feldmann & Schwei ze 2004: pl. 1.2-1.4), bu his eco d has mo e ee h on he occlusal su ace. I is likely hese species belong o he same genus. We ha e no ound close ma ches wi h o he Pe ochi us spp. Mo e comple e ma e ial wi h bo h le and igh cheliped would be necessa y o u he e alua e he genus and amily placemen . Fo now, we ea he specimens as “Pagu is es” johnsoni wi hin Pagu oidea. The assignmen o ou ma e ial o P. johnsoni implies a ange ex ension in o he ea ly Danian in Alabama. Cope e al. (2005) asc ibed a p opodus om he Clay on Fo ma ion o sou he n Illinois o P. johnsoni. The le el o his specimen wi hin he Clay on Fo ma ion was no epo ed, bu po assium-a gon da ing on glauconi e on he oldes sample om he Clay on Fo ma ion e u ned a da e o 60.6 ± 1.3 Ma (Reed e al. 1977). This da e sugges s i is no he ea lies Danian and ha his p opodus om Illinois is p obably younge han he specimens he ein. In ao de BRACHYURA Linnaeus, 1758 Sec ion RANINOIDA De Haan, 1839 [in 1833-1850] Supe amily aNiNoidea De Haan, 1839 [in 1833-1850] Family aNiNidae De Haan, 1839 [in 1833-1850] Sub amily aNiNoidiNae Lő en hey in Lő en hey & Beu len, 1929 Genus Raninoides H. Milne Edwa ds, 1837 [in 1834-1840] ype speCies. — Ranina lae is La eille, 1825, by mono ypy. i NCluded speCies . — Ex an species: Raninoides benedic i Ra hbun, 1935b; R. bou ie i Capa , 1951; R. c osnie i Ribes, 1989; R.hende - soni Chop a, 1933; R. in e medius Dai & Xu, 1991; R.lae is (La eille, 1825); R. lama cki A. Milne Edwa ds & Bou ie , 1923; R.longi ons Chen & Tü kay, 2001; R. louisianensis Ra hbun, 1933; R.pe sona us Hende son, 1888. Exclusi ely ossil species: R.acan hocolus Sch- wei ze , Feldmann, González-Ba ba & Coso ic, 2006; R.a aucana (Philippi, 1887); R.aspe Ra hbun, 1926; R. bo ealis (Collins & Wienbe g Rasmussen, 1992); R. budapes iniensis (Lő en hey, 1897); R. danicus n. sp.; R.dicke soni Ra hbun, 1926; R. eugenensis Ra h- bun, 1926; R. abianii (Lő en hey in Lő en hey & Beu len, 1929); R. ulgidus Ra hbun, 1926; R. ulungensis Hu & Tao, 1999; R.glab a (Woodwa d, 1871); R.goede o um (Tucke , 1998); R.go schei (Böhm, 1927); R.g anulo ons Vega, Nybo g, Ga assino, Pasini, Aguila -Pé ez, Bo ges-Sellén, A ano-Ruiz, Quin e o- Vázquez & 593 Ea ly Danian decapods om Alabama, Uni ed S a es GEODIVERSITAS • 2025 • 47 (13) Gu ié ez-Domech, 2024; R. hollandica (Collins, F aaye, Jag & Van Knippenbe g, 1997); R. ja anus (Böhm, 1922); R.madu ensis Bee s, 1950; R. mexicanus Ra hbun, 1930; R. mo isi Collins, Lee & Noad, 2003; R. no opoides (Bi ne , 1883); R. o egonensis Ra hbun, 1926; R. pe a ma a (Glaessne , 1960); R.pliocenicus De Angeli, Ga assino & Pasini, 2009; R.p o acan hus Schwei ze , Feldmann, González-Ba ba & Coso ic, 2006; R. pulch a (Beschin, Busulini, De Angeli & Tessie , 1988); R. a hbunae Van S aelen, 1933; ig. 11 . — “Pagu is es” johnsoni Ra hbun, 1935a, om he lowe Danian Pine Ba en Membe (Clay on Fo ma ion) a he oadcu o Mussel C eek, Lowndes Coun y, Alabama (A-N), he uppe Danian Po e s C eek Fo ma ion a Black Blu , Sum e Coun y, Alabama (O, Q, R), and he uppe Danian Po e s C eek Fo ma ion in Wilcox Coun y, Alabama (P): A, B, ou e and inne iews o igh p opodus (ALMNH:Paleo:21483); C, D, bases o ixed inge and dac ylus (ALMNH:Paleo:21483); E-H, ou e , inne , occlusal, and uppe ma gin iews o igh dac ylus (ALMNH:Paleo:21487); I, J, inne and occlusal iews o possible le ixed inge (ALMNH:Paleo:21486); K-N, ou e , inne , lowe , and p oximal iews o le me us (ALMMH:Paleo:21555); O, P, ou e iews o igh p opodi (ALMNH:Paleo:21495 and GSA-I20984); Q, R, occlusal iews o igh dac yli (GSA-I21012 and ALMNH:Paleo:21496). Scale ba s: 2.0 mm. C edi s: pho os by Adiël A. Klompmake . ABC D EFG H KL MN OPQ R IJ 594 GEODIVERSITAS • 2025 • 47 (13) Klompmake A. A. e al. R. io u biensis Schwei ze , Feldmann, Casadío & Raising, 2012; R.sinuosus (Collins & Mo is, 1978); R. slaki Squi es, 2001; R. elde- naesensis Collins & Jakobsen, 2003; R. ade ensis Ra hbun, 1926 (Lae i anina lewisana Ra hbun, 1926); R. oehoepae (Van S aelen, 1924); R.washbu nei Ra hbun, 1926. diagNosis. — See Ka asawa e al. (2014: 258). Raninoides danicus n. sp. (Figs 12; 13; Appendices 1I, J; 2) u n:lsid:zoobank.o g:ac :6B1972E9-782E-4B4C-AC4A-2BEAA49CC8CE Giulianoly eidus johnsoni (Ra hbun, 1935a). — Feldmann e al. 2019: 285, ig. 5. ype ma e ial . — Holo ype. Uni ed S a es • 1 specimen; Alabama, Lowndes Coun y, Mussel C eek oadcu (31°58’17”N, 86°42’15”W), ALMNH loc. 3; Clay on Fo ma ion, Pine Ba en Membe , lowe middle NP2 nanno ossil zone; Paleocene (lowe Danian); ALMN- H:Paleo:21488. Pa a ypes. Uni ed S a es • 1 specimen; same as o he holo ype; ALMNH:Paleo:5919 • 1 specimen; idem; ALMNH:Paleo:21489 • 1 specimen; idem; ALMNH:Paleo:21490 • 1 specimen; idem; ALMNH:Paleo:21491 • 1 specimen; idem; ALMNH:Paleo:21492. e ymology. — danicus e e s o he i s species o Raninoides ecognized om he Danian. addi ioNal ma e ial examiNed. — Uni ed S a es • 5 specimens; Alabama, Lowndes Coun y, Mussel C eek oadcu (31°58’17”N, 86°42’15”W), ALMNH loc. 3; Clay on Fo ma ion, Pine Ba en Membe , lowe middle NP2 nanno ossil zone; Paleocene (lowe Danian); ALMNH:Paleo:21493 • 1 specimen; idem; ALMNH:Pa- leo:21494 • 2 specimens; idem; MMNS IP-7252 • 4 specimens; idem; MMNS IP-7253 • 1 specimen; idem; MMNS IP-8792 • 1 specimen; idem; UF 303873. ype ho izoN. — Pine Ba en Membe o he Clay on Fo ma ion, middle NP2 nanno ossil zone, lowe Danian. ype loCali y. — ALMNH loc. 3: Mussel C eek oadcu (31°58’17”N, 86°42’15”W), Lowndes Coun y, Alabama, Uni ed S a es. diagNosis. — Ca apace leng h-wid h a io c. 1.45 wi hou os- um and spines. F on o-o bi al wid h c. 70% o maximum wid h; pos e io ma gin 70% o maximum wid h. F on wi h ou e o bi al spine cu ing inwa d o o m s aigh pa , lined wi h ube cles; in- a-o bi al spine su ounded by deep issu es, ou e pa op o spine s eep-sided and lined wi h ube cles; ou e mos pa os al sec ion o on conca e, lined wi h ube cles. An e ola e al ma gin wi h one s ong spine nea ou e o bi al angle and di ec ed an e ola e ally, o he wise mos ly s aigh and lined wi h ube cles. Sinuous band o ube cles jus pos e io o on al ma gin. S e ni e 4 longe han wide. measu emeN s. — Maximum ca apace wid h (mm): ALMNH:Pa- leo:21488: 12.3, ALMNH:Paleo:5919: 14.7, ALMNH:Paleo:21490: 12.3, MMNS IP-7252.1: 15.1, MMNS IP-7253.1: 8.8. desC ip ioN Ca apace longe han wide (l/w a io c. 1.45 wi hou os um and spines), mode a ely aul ed ans e sely, weakly aul ed longi udinally, wides a ound hi d o leng h. F on o-o bi al wid h c. 70% o maximum wid h; pos e io ma gin 70% o maximum wid h. F on incomple ely known, bu wi h ou e o bi al spine cu ing inwa d o o m s aigh pa , lined wi h ube cles; in a-o bi al spine su ounded by deep issu es, ou e pa op o spine s eep-sided and lined wi h ube cles; ou e mos pa os al sec ion o on conca e, lined wi h ube cles. Subo bi al ma gin lined wi h ube - cles, mos ly s aigh excep nea ou e o bi al spines and wi h single deep issu e. O bi wide han all. An e ola e al ma gin wi h one s ong spine nea ou e o bi al angle and di ec ed an e ola e ally, o he wise mos ly s aigh and lined wi h ube cles; con ex ansi ion o mos ly s aigh and longe pos e ola e al ma gin lined wi h ube cles. Con ex ansi ion om pos e ola e al ma gin o pos e io ma gin, which exhibi s a sligh conca i y axially and is smoo h- immed. Axis o ca apace wi h weak, ounded idge. Ca apace egions unde ined, excep o la e al pa s o ca diac egion in be ween conca e-ou wa d b anchioca diac g oo es. Pai o pos e io gas ic pi s in on o b anchioca diac g oo es. Cu icle o do sal ca apace wi h widely spaced deep pi s and mo e dense shallow pi s, bu wi h sinuous band o ube cles jus pos e io o on al ma gin. P e ygos ome wi h gen le idge an e io ly, widening an e io ly, wi h sinuous buccal colla , wi h ube cula cu icle, unin e up ed ansi ion o b anchios egi e. S e ni e 3 small, ounded la e ally, wi h sha p ip and s eep on ; s e ni e 4 longe han wide, wi h conca e la e al sides, epis e ni es ounded; s e ni e 5 abou equally long as wide, widening owa d s e ni e 4, wi h axial g oo e; s e ni e 6 widening pos e io ly, wi h conca e pos e io ma gin on ei he side o axis, wi h axial g oo e. S e ni es 3-4 cu icula su ace pi ed bu wi h ube cles along ma gins; ube cles on la e almos pa s o s e ni es 5 and 6 in do sal iew, and on ansi ion om s e ni e 5 o 6. Pleu- i es 4-7 pa ly isible ex e nally, smoo h cu icula su ace excep o pleu i e 4 and spines on pleu i es 4-7 con aining ube cles; pleu i es wi h ims a ound pe eiopod a achmen s. Coxae o maxilliped 3 cu ed o wa d, adjacen o la e al sides s e ni e 3. O al a achmen o cheliped pai o en e , ci cula o second pe eiopod pai . Ros um, pleon, and appendages no p ese ed. ema ks Feldmann e al. (2019) asc ibed h ee ca apaces (MMNS IP-7252 [2 specimens] and MMNS IP-8792) o Giuliano- ly eidus johnsoni wi hin Ly eidinae Guino , 1993. The do sal ca apace is close o his species i s desc ibed om he uppe Danian Po e s C eek Fo ma ion o Alabama (Ra hbun 1935a: pl. 17.12-17.17 [as Syme his johnsoni]; Bishop & Whi mo e 1986: ig. 1K [no 1G, 1H, 1J]; Waugh e al. 2009: ig. 11; Ka asawa e al. 2014: ig. 12C, D) and la e om he uppe Danian Mexia Clay Membe o he Wills Poin Fo ma ion in Texas (A ms ong e al. 2009: ig. 4.1-4.2 [as Mac oa- caena johnsoni] [iden i ica ion e i ied by AAK]), bu he axial idge is mo e p ominen and he pi s on he cu icula su ace a e la ge in G. johnsoni. Mo eo e , he en al side o mul iple new specimens (ALMNH:Paleo:5919, ALMN- H:Paleo:21488-21490, ALMNH:Paleo:21494) and MMNS IP-8792 show ma ked di e ences, e ealing an axial g oo e 595 Ea ly Danian decapods om Alabama, Uni ed S a es GEODIVERSITAS • 2025 • 47 (13) on s e ni es 5 and 6 (Figs 12B; 13A, which G. johnsoni lacks (Ra hbun 1935a: pl. 17.12). Compa able do sal and en al su aces a e ound among Raninoidinae, such as No osceles Bou ne, 1922, and Raninoides. The main di e ences be ween hese gene a in ol e he de elopmen o he os um, o bi al issu es, and he ou e o bi al spines (diagnoses in Ka asawa ig. 12. — Raninoides danicus n. sp. om he lowe Danian Pine Ba en Membe (Clay on Fo ma ion) ound a he oadcu o Mussel C eek, Lowndes Coun y, Alabama: A-D, do sal, en al, igh la e al, and on al iews o holo ype ALMNH:Paleo:21488; E, do sal iew o pa a ype ALMNH:Paleo:21492; F, do sal iew, ocused on he le on al ma gin, o pa a ype ALMNH:Paleo:21491; G-I, igh o bi al, uppe o bi al ma gin, and lowe o bi al ma gin iews o pa a ype ALMN- H:Paleo:5919. Scale ba s: A-E, 5.0 mm; G-I, 2.0 mm. C edi s: pho os by Adiël A. Klompmake . EF G HI ABC D 596 GEODIVERSITAS • 2025 • 47 (13) Klompmake A. A. e al. e al. 2014, and Schwei ze e al. 2018b), bu hese ea u es a e no well- p ese ed in he specimens om Mussel C eek. Ka asawa e al. (2014) diagnosed ha No osceles exhibi s sho open issu es, bu one specimen he ein (ALMNH:Paleo:21491) exhibi s ai ly deep issu es (Fig. 12F). An addi ional di e - ence we no ed is ha he an e ola e al spine is subs an ially la ge and mo e an e ola e ally di ec ed in Raninoides han in No osceles, in which a small spine is consis en ly mo e o wa dly di ec ed ac oss all species (see ex an species and No osceles bou nei Ra hbun, 1928, om he Paleocene o Texas, Alabama, and A kansas, see Ra hbun 1935a). Many ex an and ossil Raninoides ha e a s ong an e ola e ally di ec ed spine, consis en wi h ou specimens. This genus is diagnosed o exhibi a bi id ou e o bi al spine (Ka asawa e al. 2014; Schwei ze e al. 2018b), bu his does no apply o all species assigned o his genus because se e al membe s ha e a s aigh pla eau inwa d om a single spine a he han ano he spine (e.g., Paleocene R.bo ealis, ex an R. c osnie i, ex an R. longi ons, and ex an R.pe sona us). None o he ossil specimens s udied he e ha e he ip o he ou e o bi al spine p ese ed, bu wo specimens show a s aigh pla eau inwa d in addi ion o he base o he ou e o bi al spine (ALMNH:Paleo:5919 and MMNS-IP7253.2). Thus, we assign he specimens o Raninoides wi h con idence. Reasons o species sepa a ion o en include he o ien a ion, size, and loca ion o he an e ola e al spine; he de elopmen o he on al ma gin and pos - on al idge, and ca apace p opo ions (e.g., Collins e al. 2003; Schwei ze e al. 2006, 2012; De Angeli e al. 2009). The ea ly Danian Raninoides danicus n. sp. di e s om all o he species. The s a ig aphi- cally closes species a e R. bo ealis om he middle Paleocene (Selandian) o Wes G eenland and R. g anulo ons om he la e Campanian-ea ly Maas ich ian o Cuba. Based on a s udy o he ype ma e ial by AAK, R. bo ealis bea s an an e ola e al spine ha may be a he om he ou e o bi al ma gin, his spine is o ien ed mo e o wa d, and he in a-o bi al spine is mo e ounded. Raninoides g anulo ons bea s an in a-o bi al spine ha is mo e ounded on op, and he p ese ed base o he an e ola e al spine is smalle , men ioned o be sho by Vega e al. (2024). We also compa ed his species o Eocene species, using he pape s in which hose species we e i s desc ibed and o he pape s as needed. Raninoides acan hocolus bea s a sho e an e ola e al spine u he back on he an e ola e al ma gin and he uppe ma gin o he in ao bi al spine slopes inwa d (Schwei ze e al. 2006: ig. 2.7). Raninoides a aucana bea s a smalle an e ola e al spine (Philippi 1887: pl. 50.6). Raninoides budapes iniensis has an an e ola e al spine u he back on he an e ola e al ma gin and a s onge pos on al idge (Lő en hey 1898: pl. 1.2). Raninoides dicke soni, only known om a en e , has a wide spine on s e ni e 5 (Ra h- bun 1926: pl. 20.5). Raninoides abianii appa en ly lacks an e ola e al spines (Lő en hey & Beu len 1929: pl. 4.10). Raninoides ulgidus has a p opo ionally smalle an e ola - e al spine (Ra hbun 1926: pl. 23.6; ALMNH:Paleo:5937). Raninoides glab a has he axial g oo e mo e o wa d on o he pos e io pa o s e ni e 4 (nea he cen e o epis e ni e 4) and s e ni e 4 is p opo ionally longe (see Van Bakel e al. 2012: ig. 44c, d). Raninoides goede o um and R.no opoides exhibi smalle and mo e o wa dly o ien ed an e ola e al spines (Tucke 1998: ig. 13; Hyžný & Zo n 2016: pl. 9.3). Raninoides go schei has a smalle an e ola e al spine (Glaess- ne & Wi he s 1931: pls 20.1-2, 21.1). Raninoides pe a ma a and R. a hbunae ha e p opo ionally sho e s e ni es 4 (Feld- mann 1991: igs 2, 4; Feldmann & Schwei ze 2004: ig. 1B). Raninoides p o acan hus bea s a much smalle an e ola e al spine (Feldmann & Schwei ze 2004: ig. 2.8). Raninoides pulch a exhibi s an an e ola e al spine ha is bi id nea i s base (Beschin e al. 1988: pl. 4.1-3). Raninoides io u biensis has a longe in ao bi al spine na owing o he on and he base o he an e ola e al spine is smalle (Schwei ze e al. 2012: ig. 4). Raninoides sinuosus exhibi s a smalle base o he an e ola e al spine and s e ni e 4 is p opo ionally sho e (Collins & Mo is 1978: pl. 116.4-6). Raninoides slaki has a bi id in a-o bi al spine and he maximum ca apace wid h is loca ed u he pos e io ly (Squi es 2001: igs 47-55). Raninoides eldenaesensis bea s a smalle an e ola e al spine and s e ni e 4 is p opo ionally sho e (Collins & Jakobsen 2003: ig. 4, pl. 3.5). Raninoides ade ensis appea s close bu i s an e ola e al spine is o ien ed mo e o wa dly (Ra h- bun 1926: pl. 22.5; Tucke 1998: ig. 17; Gus a son 2023: igs 16-19). Raninoides washbu nei has a mo e o wa dly o ien ed an e ola e al spine and i s ca apace is p opo ion- ally wide (Ra hbun 1926: pl. 22.6). We did no compa e he new species o pos -Eocene species because b achyu an species anging o >32 million yea s a e ex emely unlikely and unknown o us. Sec ion EUBRACHYURA de Sain Lau en , 1980 Subsec ion HETEROTREMATA Guino , 1977 Supe amily e oplumoidea Gill, 1894 Family e oplumidae Gill, 1894 Genus Cos acopluma Collins & Mo is, 1975 ype speCies. — Cos acopluma conca a Collins & Mo is, 1975, by o iginal designa ion. iNCluded speCies. — Cos acopluma aus alis Feldmann, Casadío, Chi ino-Gál ez & Agui e-U e a, 1995; C. bi ida Collins, Higgs & Co i ula, 1994; C. bishopi Vega & Feldmann, 1992; C.binodosa Collins & Wienbe g Rasmussen, 1992; C. conca a Collins & Mo - is, 1975; C. g ayi Feldmann & Po ell, 2007; C.ma occana Ossó- Mo ales, A al & Vega, 2010; C. mexicana Vega-Ve a & Pe illia , 1989; C. mame hioupamei Hyžný, Pe ie , Robin, Ma in & Sa , 2016; C.nicksabani n. sp.; C. no des ina Feldmann & Ma ins-Ne o, 1995; C. salamanca Feldmann, Rod iguez, Ma inez & Agui e- U e a, 1997; C. squi esi Nybo g, Vega & Filko n, 2023; C. exana A ms ong, Nybo g, Bishop, Ossó-Mo ales & Vega, 2009; C. sen- egalensis (Rémy in Go odiski & Rémy, 1959). diagNosis. — Small ec angula o o oid ca apace, wide han long; ca apace su ace dis inc ly la ened and a e sed by h ee ele a ed, g anula idges, he an e io mos being comple e and o en bicon ex o wa ds; pos e io wo idges con e ging axially de ining dep essed, iangula o ec ilinea , smoo h mesob anchial egion. Ros um gene ally na ow, down u ned, bilobed. Ca apace lanks dis inc , 597 Ea ly Danian decapods om Alabama, Uni ed S a es GEODIVERSITAS • 2025 • 47 (13) abou pe pendicula o do sal su ace and sepa a ed om i by beaded im. S e num b oad, wi h well-de ined s e ni es; s e ni es 5-7 each wi h p ominen ans e se, beaded idge; male s e nopleonal ca i y deep, eaching end o s e ni e 4. T ans e se idges also p esen on pleonal somi es. Pe eiopod 5 subdo sal, educed. Emended om Feldmann e al. (2014: 137). ig. 13. — Raninoides danicus n. sp. om he lowe Danian Pine Ba en Membe (Clay on Fo ma ion) ound a he oadcu o Mussel C eek, Lowndes Coun y, Alabama: A, en al iew o MMNS IP-8792; B, do sal iew o MMNS IP-7252.1; C, do sal iew o MMNS IP-7253.1; D, igh pos e ola e al iew o holo ype ALMNH:Paleo:21488; E, en al iew ocused on s e ni es 3-4 o pa a ype ALMNH:Paleo:21490; F, le pos e ola e al iew o pa a ype ALMNH:Paleo:21489; G, on al iew o s e ni e 3 o pa a ype ALMNH:Paleo:21490. Scale ba s: 5.0 mm. C edi s: pho os by Adiël A. Klompmake . AB C D E F G 598 GEODIVERSITAS • 2025 • 47 (13) Klompmake A. A. e al. Cos acopluma g ayi Feldmann & Po ell, 2007 (Figs 14; 15; Table 1; Appendix 1F) Cos acopluma g ayi Feldmann & Po ell, 2007: 92, igs 2, 3. — A ms ong e al. 2009: ig. 6.2-6.3. — Ma ínez-Díaz e al. 2016: ig. 5.9-5.10. non Cos acopluma g ayi – Feldmann e al. 2014: 137, pls 1, 2. (Cos a- copluma nicksabani n. sp.). — Ma ínez-Díaz e al. 2016: igs 5.1- 5.8; 6.4. (Cos acopluma nicksabani n. sp.). — Ma ínez-Díaz e al. 2016: igs 4; 6.4. — Vega e al. 2016: ig. 4G, H. ype ma e ial . — Holo ype. Uni ed S a es • 1 specimen; Alabama, Co ing on Coun y, Below Poin A Dam (31°21’32”N, 86°31’11”W), ALMNH loc. 4; Tallaha a Fo ma ion, NP14 nanno ossil zone; Eocene (uppe Yp esianlowe Lu e ian); UF 113749. Pa a ypes. Uni ed S a es • 1 specimen; same as o he holo ype; UF 113748 • 1 specimen; idem; UF 113750 • 1 specimen; idem; UF 114747 • 1 specimen; idem; UF 115672 • 1 specimen; idem; UF 115793 • 1 specimen; idem; UF 115794 • 1 specimen; idem; UF 115795 • 1 specimen; idem; UF 115796. addi ioNal ma e ial examiNed. — Uni ed S a es • 2 specimens; Alabama, Co ing on Coun y, Below Poin A Dam (31°21’32”N, 86°31’11”W), ALMNH loc. 4; Tallaha a Fo ma ion, NP14 nanno os- sil zone; Eocene (uppe Yp esianlowe Lu e ian); ALMNH:Paleo:20598 • 1 specimen; idem; ALMNH:Paleo:21440 • 3 specimens; idem; MMNS IP-6491 • 1 specimen; idem; MMNS IP-6492 • 2 specimens; idem; MMNS IP-10046 • 1 specimen; idem; MMNS IP-11213 • 1 specimen; idem; UF 116615 • 1 specimen; idem; UF 116619 • 1 specimen; idem; UF 142615 • 1 specimen; idem; UF 142616 • 1 specimen; idem; UF 116691 • 1 specimen; idem; UF 171033 • 1 specimen; idem; UF 171034 • 1 specimen; idem; UF 256410 • 1 specimen; Alabama, Conecuh Coun y, Pigeon C eek (T5N, R14E, Sec. 20, NE¼, NE¼); Tallaha a Fo ma ion, NP14 nanno ossil zone; Eocene (uppe Yp esianlowe Lu e ian); UF 287265 • 1 speci- men; idem; UF 287266 • 1 specimen; idem; UF 349284-349310. ype ho izoN. — Tallaha a Fo ma ion, NP14 nanno ossil zone, Eocene (uppe Yp esianlowe Lu e ian). ype loCali y. — Below Poin A Dam (31°21’32”N, 86°31’11”W), Co ing on Coun y, Alabama, Uni ed S a es. A B C D EF GH ig. 14. — Cos acopluma g ayi Feldmann & Po ell, 2007, om he Eocene (uppe Yp esian-lowe Lu e ian) Tallaha a Fo ma ion in Alabama: A-C, do sal iews o ALMNH:Paleo:20598B, MMNS IP-10046.1, and MMNS IP-11213; D, igh p opodus and dac ylus o UF 287266; E, F, on al iews o UF 171033 and ALMN- H:Paleo:20598B; G, H, en al iews including male pleon o MMNS IP-11213. Scale ba s: 5.0 mm. C edi s: pho os by Adiël A. Klompmake . 599 Ea ly Danian decapods om Alabama, Uni ed S a es GEODIVERSITAS • 2025 • 47 (13) d iagNosis . — Ca apace ela i ely small (<15 mm maximum wid h), sub ec angula , wide han long (l/w a io c. 0.9), wides poin pos e io o mid-leng h. F on o-o bi al ma gin c. 70% o maximum wid h; la e al ma gins somewha di e ging pos e io ly, ai ly s aigh , bu mo e con ex pos e io ly; pos e io ma gin nea ly s aigh . Ros um inclined downwa d, sligh ly longe han wide, minimum wid h in do sal iew c. 4% o maximum ca apace wid h. Ou e o bi al spine small, iangula , di ec ed o wa d. Do sal ca apace con aining h ee ube cula ans e se idges o na ow wid h on a e age, wi h ound- ed ops; an e io idge sinuous, unin e up ed, diminishes owa d bu eaches la e al ma gins. Ca diac egion aised, ube cula , wi h con ex and la ened idge an e io ly and aised ex ension axially di ec ed pos e io ly. Gen le swellings wi h ube cles jus an e io o inne mos pa o pos e ola e al ma gins. measu emeN s. — See Table 1. desC ip ioN Re e al is made o Feldmann & Po ell (2007: 92). Addi- ional specimens allow o imp o ed desc ip ion o os um, ou e o bi al spine, pos e io ma gin, cheliped, s e num, and pleon. Ou e o bi al spine small, appea s di ec ed o wa d (UF 115796). Pa ial os um na ow, minimally c.4% o maximum ca apace wid h in do sal iew. Pos e io ma gin wi h one ow o small ube cles on op o im, cu ing some- wha o wa d in la e al pa s, nea ly s aigh o e y sligh ly conca e in axial pa (MMNS IP-11213, UF 171033). Ou e side p opodus (UF 287266) wi hou ube cles as p ese ed, wi h a g oo e nea base ex ending on o ixed inge , wi h a leas ou pi s on ixed inge close o occlusal su ace. Male s e ni e 4 wi h dis inc , ube cula im on ou e side; less dis inc im on inne side, ma king deep s e nopleonal ca i y o elson; gene ally smoo h on cu icula su ace in be ween. Somi es male pleon un used, wi h ans e se, ube cula keels; elson wi h ounded ip. ema ks Se e al pape s asc ibed ea ly Danian and Maas ich ian speci- mens o his species (Feldmann e al. 2014; Vega e al. 2016; Ma ínez-Díaz e al. 2016), bu he e a e se e al mo phological di e ences be ween he specimens om he Eocene and hese c.18-19 million yea s olde specimens ha wa an species-le el sepa a ion. Fo he ea ly Danian specimens, e e al is made o he new species e ec ed below. The Maas ich ian specimens also ep esen a di e en species o Cos acopluma no ea ed u he he ein: hey ha e an ou e o bi al spine di ec ed an e- ola e ally ins ead o o wa d as in C. g ayi (UF 115796), a e p opo ionally wide , and ha e a g ea e maximum size (see Vega e al. 2016; Ma ínez-Díaz e al. 2016). Specimens wi h ligh o da k b own cu icle a e embedded in an/ligh b own ine sedimen wi h some sand. O he s occu in an-b own sedimen wi h mo e sand embedded, and a e y da k b own cu icle. Finally, some occu in da k g ay sedimen and ha e da k b own cu icle. This applies o specimens om Poin A Dam and Pigeon C eek. Some a e lis ed as ound insi u (UF 116615, UF 116619, UF 116691) o ound in bed 5 o Copeland (1966) (UF 171033, UF 171034, ype se ies), bu he p ese a ion s yle di e s. I is likely ha speci- mens unde wen somewha di e en aphonomic his o ies. Some specimens (MMNS IP-11213 and MMNS IP-10046) a e lis ed o ha e come om he basal Lisbon Fo ma ion in “Bed 5” o Copeland (1966), which Feldmann & Po ell (2007) in e p e ed o be he Tallaha a Fo ma ion (see also Sa da e al. 2010). Addi ional specimens we e b ie ly men ioned in a pape ocused on he e eb a e auna o Poin A Dam (Clay on e al. 2013). Un o una ely, he whe eabou s o hose c abs is unce ain (pe s. comm. AAK wi h he Chuck Ciampaglio, No embe 2023). Cos acopluma exana A ms ong, Nybo g, Bishop, Ossó-Mo ales & Vega, 2009 (Fig. 16; Table 1; Appendix 1G, H) Cos acopluma exana A ms ong, Nybo g, Bishop, Ossó-Mo ales & Vega, 2009: 756, igs 5.14-5.20; 6.1. — Ma ínez-Díaz e al. 2016: igs 5.14, 6.6. ype ma e ial. — Holo ype. Uni ed S a es • 1 specimen; Texas, Limes one Coun y, qua y c. 2 miles wes o Mexia (c. 31°40’12”N, ig. 15. — Ca apace a ios o Cos acopluma spp. e sus specimen size: A, leng h-wid h a ios; B, os al wid h-maximum ca apace wid h a ios. See Table 1 o measu emen s. 0.12 0.11 0.10 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 6.07.0 8.09.0 10.0 11.0 12.0 13.0 14.0 1.00 0.98 0.96 0.94 0.92 0.90 0.88 0.86 0.84 6.07.0 8.09.0 10.0 11.0 12.0 13.0 14.0 AB Maximum ca apace wid h ( mm )Maximum ca apace wid h ( mm ) Ros al wid h-maximum wid h a io Lengh -wid h a io Cos acopluma g ayi (ea ly Eocene) C. nicksabani n. sp. (ea ly Danian) C. exana (la e Danian) Cos acopluma g ayi (ea ly Eocene) C. nicksabani n. sp. (ea ly Danian) C. exana (la e Danian) 606 GEODIVERSITAS • 2025 • 47 (13) Klompmake A. A. e al. has a signi ican ly highe leng h-wid h a io (Mann-Whi ney p = 0.0005; Figs 15-18; Table 1), appea s o exhibi a hicke uppe o bi al im (Fig. 15G, I s Fig. 16D, G; 17B), has an o al-shaped o iduc a he han subci cula in C. nicksabani n. sp. (Fig. 16K s Fig. 17M), he ans e se idges on s e n- i es 5-6 a e alle in a leas emales, he ou e la e al ma gins o s e ni e 4 appea mo e la ed up on a e age, and he p ess bu on on males is la ge (Fig. 16L s Fig. 18N). We did no obse e ob ious on ogene ic a ia ion, pe haps because o he limi ed size ange o specimens. Sexual dimo - phism is no obse ed on he do sal ca apace, bu i is e iden on he en al side (wide emale pleon and o he cha ac e s, see desc ip ion). In aspeci ic a ia ion is limi ed despi e he high numbe o specimens. Fo lesse p ese ed specimens wi h cu icle, he ube cles on he ans e se idges a e less ob ious. Ca apace o na- men a ion is di icul o disce n on in e nal molds (ALMN- H:Paleo:21497A, 1 specimen o UF 235569). The sedimen su ounding Mussel C eek specimens a ies om an o da k g ay and om iable o ully li hi ied. This obse a ion may indica e di e ing aphonomic condi ions. The gonopods p ese ed in h ee specimens o Cos acopluma nicksabani n. sp. (ALMNH:Paleo:21457, MMNS IP-7940.1, UF 303806; Fig. 16I, M) esemble hose in ex an e oplumids (de Sain Lau en 1989). The p ese a ion o gonopods in ossil b achyu ans is uncommon (e.g., Ka asawa & Schwei ze 2006: 42; Ga assino e al. 2013: 356), and hey had no been ecognized wi hin Cos acopluma and ossil Re oplumidae un il his pape . These small pleonal appendages, o en ax- onomically impo an o ex an c abs, a e less calci ied han walking appendages and claws and end o be co e ed by he pleon wi hin he s e nopleonal ca i y. Fossil b achyu an species wi h hese s uc u es ha e been mo e equen ly ecog- nized o e he las decade, mos ly in specimens ha ha e he pleonal somi es incomple ely p ese ed exposing s uc u es unde nea h (Smi no 1929; Sec é an 1975; Ka asawa & Ka o 2001, 2019; Guino & B e on 2006; Ka asawa & Schwei ze 2006; A al e al. 2008; Feldmann e al. 2011; Schwei ze & Feldmann 2015; Luque e al. 2018, 2019; Pe ey a e al. 2019; Lima e al. 2020; Pe ey a & Ve de 2020; Hyžný e al. 2022; Ko alchuk e al. 2023). The p ese a ion o delica e ips o gonopods he ein is e en a e . Supe amily Ca pilioidea O mann, 1893 Family palaeoxaN hopsidae Schwei ze , 2003 Palaeoxan hopsidae inde . (Fig. 19) ma e ial examiNed. — Uni ed S a es • 1 specimen; Alabama, Lowndes Coun y, Mussel C eek oadcu (31°58’17”N, 86°42’15”W), ALMNH loc. 3; Clay on Fo ma ion, Pine Ba en Membe , lowe middle NP2 nanno ossil zone; Paleocene (lowe Danian); ALMNH:Pa- leo:21482 (ca apace) • 51 specimens; idem; ALMNH:Paleo:21497 (51 ca apaces/ en e s) • 1 specimen; idem; ALMNH:Paleo:21505 ( ixed inge ) • 2 specimens; idem; ALMNH:Paleo:21506 ( ixed inge s) • 1 specimen; idem; MMNS IP-7256.1 ( ixed inge ) • 1 specimen; idem; UF 303867 ( ixed inge ) • 1 specimen; idem; UF 303870 ( ixed inge ) • 1 specimen; idem; ALMNH:Paleo:21507 (dac ylus) • 4 specimens; idem; ALMNH:Paleo:21508 (dac yli) • 1 specimen; idem; MMNS IP-7256.2 (dac ylus) • 1 specimen; idem; UF 303868 (dac ylus) • 1 specimen; idem; UF 303869 (dac ylus) • 1 specimen; idem; UF 303871 (dac ylus) • 1 specimen; idem; UF 303872 (dac ylus). measu emeN s. — Maximum ca apace wid h (mm): ALMN- H:Paleo:21482: 24.6 desC ip ioN P ese ed ca apace c.24.6 mm wide wi hou an e ola e al p ojec ions, weakly aul ed ans e sely, mode a ely aul ed longi udinally. F on o-o bi al wid h c.55% o maximum wid h. An e ola e al ma gin wi h bases o ou p ojec ions. Ca apace wi h i e la ge p o ube ances, one ma king base o mesogas ic egion, wo adjacen o an e io pa o mesogas ic egion, and wo la e al o ce ical g oo e a le el o mesogas ic egion base. T ans e se ow o small bumps an e ola e ally o pos e io mos se o p o ube ances. On cu icle, ube cles on p o ube ances and in on o an e io mos p o ube ances. Pi p esen in on o each side o pos e io pa o mesogas ic egion. Flanks s eep. P ese ed p e ygos ome appea s sub ian- gula . S e ni e 3 wide han long, sepa a ed om s e ni e 4 by a conca e g oo e. S e ni e 4 in e sec ed by na ow s e nople- onal ca i y, bo h sides appea squa e-shaped. Coxa and basis o pe eiopod 1, and pa s o maxilliped 3 p ese ed. S e num and appendages co e ed by ube cles, excep o g oo es and s e nopleonal ca i y. Ros um, pos e io ca apace, mos o en al side, pleon, and appendages missing. Fixed inge obus ; cu ed inwa d; wi h ow o o al ube - cles, a iably sized, diminishing in size o ip on a e age; ou e and inne la e al sides wi h ow o pi s. Dac ylus cu ed; wi h s ong ube cle on ou e side o occlusal su ace nea base, ollowed by smalle , simila -sized ube cles owa d ip. ema ks The single ca apace lacks he pos e io po ion, he on al egion including he o bi al s uc u e and he os um, and he p ojec ions on he an e ola e al ma gins. The p ese ed cha ac e s i hose o Palaeoxan hopsidae (e.g., Schwei ze 2003; Schwei ze e al. 2018a, 2025; Vega e al. 2018), includ - ing he loca ion o he sphe ical swellings on he ca apace and he an e ola e al ma gins wi h bases o p ojec ions. Specimens o he Maas ich ian gene a Palaeoxan hopsis Beu len, 1958, and Pa azan hopsis Vega, Feldmann, Ga cía-Ba e a, Filko n, Pimen el & A endano, 2001, a e mo phologically close o he single, incomple e ca apace specimen he ein. The collec ion o mo e comple e ca apaces is necessa y o iden i ica ion beyond he amily le el. We also ound a ious inge s a ibu able o Palaeoxan hop - sidae. Bo h ixed inge s and dac yli con o m well o hose seen in Palaeoxan hopsidae such as Pa a e ucoides alabamen- sis (Ra hbun, 1935a) om he uppe Danian Po e s C eek Fo ma ion o Alabama (GSA-I21006 and GSA-I21010) and Lobula a lobula a (Feldmann, Casadio, Chi ino-Gal ez & Agui e-U e a, 1995), om he Maas ich ian-Danian o 607 Ea ly Danian decapods om Alabama, Uni ed S a es GEODIVERSITAS • 2025 • 47 (13) A gen ina ( hei ig. 7.6). I is e y likely ha hese isola ed inge s belong o he same species as he ca apace, bu asso- cia ed chelipeds wi h a ca apace a e needed o e i ica ion. Supe amily hexapodoidea Mie s, 1886 Family hexapodidae Mie s, 1886 iNCluded geNe a. — Bellhexapus De Angeli, Guino & Ga assino, 2010; Eohexapus De Angeli, Guino & Ga assino, 2010; Eu ohexa- pus De Angeli, Guino & Ga assino, 2010; Goniocypoda Wood- wa d, 1867; Headonipus Quayle & Collins, 2012; Hexalaughlia Guino , 2006; Hexapinus Manning & Hol huis, 1981; Hexaplax Do lein, 1904; Hexapus De Haan, 1835 [in 1833-1850]; Hol hui- sea Guino , De Angeli & Ga assino, 2010; Lambdophallus Alcock, 1900; La ohexapus Huang, Hsueh & Ng, 2002; Lucahexapus De Angeli & Capo iondo, 2022; Ma iaplax Rahayu & Ng, 2014; Paeduma Ra hbun, 1897; Palaeopinnixa Vía, 1966; Pa ahexapus Balss, 1922; Pseudohexapus Monod, 1956; Rayapinus Rahayu & Ng, 2014; Rodneyellus Lima, Alcân a a, Aguile a & Ta a es, 2025; Spi oplax Manning & Hol huis, 1981; S e ea Manning & Hol huis, 1981; Thaumas oplax Mie s, 1881; Theoxapus Rahayu & Ng, 2014; T i oplax Manning & Hol huis, 1981. ig. 19. — Palaeoxan hopsidae inde . om he lowe Danian Pine Ba en Membe (Clay on Fo ma ion) ound a he oadcu o Mussel C eek, Lowndes Coun y, Alabama: A-D, do sal, igh la e al, on al, and en al iews o ALMNH:Paleo:21482; E-H, ou e , inne , lowe ma ginal, and occlusal iews o ixed inge o UF 303867; I-L, ou e , inne , uppe ma ginal, and occlusal iews o dac ylus o ALMNH:Paleo:21507. Scale ba s: A-D, 10.0 mm; E-L, 5.0 mm. C edi s: pho os by Adiël A. Klompmake . AB C D E FGH IJKL 608 GEODIVERSITAS • 2025 • 47 (13) Klompmake A. A. e al. Genus Alahexapus n. gen. u n:lsid:zoobank.o g:ac :C230B4E9-59C4-4322-9057-5513F4722A93 ype speCies. — S e ea ma ini Feldmann, Schwei ze & Po ell, 2014, by p esen designa ion. e ymology. — Ala- e e s o Alabama and -hexapus e e s o he ype genus o Hexapodidae. Gende : masculine. diagNosis. — As o he ype species. ema ks S e ea ma ini was asc ibed o S e ea based on a limi ed numbe o specimens hen a ailable wi hou male and emale pleons. Two addi ional specimens collec ed since 2014 wi h male and emale pleons p ese ed sugges assignmen o his genus is no enable. Speci ically, he emale pleon om he only specimen o S e ea williamsi, he ype and sole ex an species o S e ea, was demons a ed o be na ow and ha e somi es 2-6 used (Guino e al. 2010), whe eas he emale indi idual o Alahexapus ma ini n. comb. has p opo ion- ally wide pleonal somi es 4-6 and hese somi es a e un used. Addi ional di e ences include he an e ola e al bo de s passing below he ou e o bi al angle a he han joining he ou e o bi al angle as in A. ma ini n. comb., he os um has a conca e bo de a he han a s aigh bo de as in A. ma ini n. comb., and he os um is widening dis ally a he han being s aigh la e ally (UF 254042). The deg ee o usion o pleonal somi es and he pleonal wid h a e conside ed impo an cha ac e s dis inguishing be ween gene a among ex an hexapodids (Rahayu & Ng 2014). O he cha ac e s equen ly used in ha pape o genus diagnoses a e ca apace leng h-wid h a ios, cu icle o namen a ion, g oo e de elop- men on he ca apace, an e ola e al ma gin shape, eye size, maxilliped mo phology, o namen a ion including s idula- o y s iae on he p e ygos ome, cheliped mo phology, he deg ee o s e ni e and somi e usion, he shape o he pleon, and he shape and each o he s e nopleonal ca i y. Many o he same cha ac e s a e used o de ine gene a p esen in he ossil eco d when p ese ed, bu also o he cha ac e s ela ed o he ca apace ha e been used including he wides poin o he ca apace, he on al ma gin mo phology and ela i e dimensions, and he o bi al ca i y size and shape (e.g., De Angeli e al. 2010; Schwei ze e al. 2022). Key di e ences be ween Alahexapus n. gen. and exclusi ely ossil gene a exis . Bellhexapus is wides a he pos e io ma - gin, male somi e 6 is longe , and male somi es 3-5 a e no used (De Angeli e al. 2010: igs 2, 3). In Eohexapus, he o bi s a e ci cula a he han o al and he do sal ca apace is smoo h a he han showing some g oo es (De Angeli e al. 2010: igs 4-6). Eu ohexapus exhibi s a ca apace abou as long as wide a he han wide han long, i s on o-o bi al wid h is g ea e (c.65% o maximum wid h s 50% o Alahexapus n. gen.), and male somi es 2-6 a e used (De Angeli e al. 2010: igs 7-9). Goniocypoda has a ela i ely wide on o-o bi al wid h (c.65% o maximum wid h s c.50% o Alahexapus n. gen.) (Schwei ze & Feldmann 2001: 335). Fo Headonipus, he “g oo es cu ing om he base o he ca diac egion o he middle o he coxigeal incisions isola e elonga ed in es- inal lobes” (Quayle & Collins 2012: 40), a e no obse ed in Alahexapus n. gen. Mo eo e , he pos e io mos po ion o he ca apace o Headonipus appea s much mo e dep essed and he o bi s a e subci cula a he han o al (Quayle & Collins 2012: pl. 3.9-3.10; Schwei ze e al. 2022: ig. 7.5). Fo Hol huisea, ca apace g oo es a e absen and male somi es 3-6 a e used a he han somi es 3-5 only (Guino e al. 2010: igs 2-4). Lucahexapus has a p opo ionally g ea e on o-o bi al wid h (c.67% o maximum ca apace wid h s c.50%) and he ce ical g oo e is much wide (De Angeli & Capo iondo 2022: igs 2.5, 3.5). Fo Palaeopinnixa, he ca apace is wides jus an e io o pos e ola e al een an s (e.g., Hyžný & A al 2018; Schwei ze e al. 2022; Gus a son 2023), bu Alahexapus n. gen. is wides abou mid-leng h and does no widen owa d he pos e io ca apace. Mo eo e , somi es 5-6 in emales a e used o he ype species P. a hbunae and his species does no exhibi s idula ing appa a us/s iae on he p e ygos ome (Schwei ze e al. 2000: 57). Rodneyellus lacks a U-shaped ce ical g oo e and has a lowe a io o on o-o bi al wid h o maximum ca apace wid h (0.37 s 0.50). Key di e ences also exis wi h ex an gene a o he han S e ea as discussed abo e, p ima ily using diagnoses in Manning & Hol huis (1981), Guino (2006), and Rahayu & Ng (2014). Hexalaughlia exhibi s a p e ygos ome wi hou a ow o s idu- la o y s iae, and male somi e 6 is much longe . Hexapinus has a ca apace widening pos e io ly, he ca apace egions a e no dema ca ed excep o a poo ly de ined ca diac egion, he o bi s a e much smalle , and male somi e 6 is longe . Fo Hexaplax, he ca apace egions a e mo e indis inc , he o bi s a e la ge and a e subci cula a he han o al. Fo Hexapus, he ca apace egions a e less dis inc , and he o bi s a e much smalle . Lambdophallus bea s much smalle o bi s and exhibi s a male ans e se s e nal g oo e ex ending la e ally om he s e nopleonal ca i y no seen in Alahexapus n. gen. La ohexa- pus has much mo e dis inc ca apace egions and i s ca apace widens pos e io ly. Ma iaplax has a ca apace widening pos e i- o ly, smalle o bi s, and a much sho e male elson. Paeduma exhibi s a much longe male somi e 6 and ca apace g oo es a e absen o e y ain . Pa ahexapus bea s a much longe male somi e 6 ha is na owe han male somi es 3-5, and has o bi s ha a e smalle . Fo Pseudohexapus, he p e ygos- ome lacks a ow o oblique s iae. Rayapinus has a ca apace wi hou clea g oo es, bea s a ela i ely na ow emale pleon, has emale somi es 1-5 used, and has a male elson almos as long as somi e 6. Spi oplax exhibi s a ca apace ha is widen- ing pos e io ly, and has a much b oade male pleon wi h a iangula elson. Fo Thaumas oplax, he p e ygos ome lacks a ow o oblique s iae, he o bi s a e smalle and ci cula , and he ca apace egions a e indis inc . Theoxapus has much smalle o bi s and a p opo ionally longe male somi e 6. T i oplax has a male elson wi h a iangula ip, a male pleonal somi e 6 ha is di ided longi udinally, and appa en ly smalle o bi s. As none o he diagnoses o ossil and ex an gene a ma ch he species unde s udy, we e ec Alahexapus n. gen. I is pos- sible addi ional ossil species may belong o he new genus. 609 Ea ly Danian decapods om Alabama, Uni ed S a es GEODIVERSITAS • 2025 • 47 (13) Fo example, Palaeopinnixa ocaensis (Feldmann, Casadío, Chi ino-Gál ez & Agui e-U e a, 1995), om he Danian o sou he n A gen ina does no widen owa d o pos e io ca a- pace as o he genus diagnosis o Palaeopinnixa ( Schwei ze & Feldmann 2001). The on o-o bi al wid h is simila (45% o maximum wid h s c.50% o Alahexapus n. gen.), he ou line is simila , he lanks o bo h axa a e s aigh , he leng h-wid h a io is simila (0.71 s c.0.67 o Alahexapus n. gen.) (Feldmann e al. 1995: igs 14, 15). Un o una ely, no cu icle is p ese ed no any en al cha ac e s, which hinde s u he e alua ion. Alahexapus ma ini (Feldmann, Schwei ze & Po ell, 2014) n. comb. (Fig. 20; Appendix 1K, L) S e ea ma ini Feldmann, Schwei ze & Po ell, 2014: 142, pl. 3. ype ma e ial . — Holo ype. Uni ed S a es • 1 specimen; Alabama, Lowndes Coun y, Mussel C eek oadcu (31°58’17”N, 86°42’15”W), ALMNH loc. 3; Clay on Fo ma ion, Pine Ba en Membe , lowe middle NP2 nanno ossil zone; Paleocene (lowe Danian); UF 228988. Pa a ype. Uni ed S a es • 1 specimen; same as o he holo ype; UF 235561. addi ioNal ma e ial examiNed. — Uni ed S a es • 1 specimen; Alabama, Lowndes Coun y, Mussel C eek oadcu (31°58’17”N, 86°42’15”W), ALMNH loc. 3; Clay on Fo ma ion, Pine Ba en Membe , lowe middle NP2 nanno ossil zone; Paleocene (lowe Danian); ALMNH:Paleo:5915 • 1 specimen; idem; ALMNH:Pa- leo:21464 • 1 specimen; idem; MMNS IP-7939 • 1 specimen; idem; UF 254040 • 1 specimen; idem; UF 254041 • 1 specimen; idem; UF 254042 • 1 specimen; idem; UF 303801. ype ho izoN. — Pine Ba en Membe o he Clay on Fo ma ion, lowe middle NP2 nanno ossil zone, lowe Danian. ype loCali y. — ALMNH loc. 3: Mussel C eek oadcu (31°58’17”N, 86°42’15”W), Lowndes Coun y, Alabama, Uni ed S a es. diagNosis. — Ca apace leng h-wid h a io c. 0.67, wides abou mid-leng h. F on o-o bi al wid h c. 50% o maximum ca apace wid h. O bi s o mode a e size, o al-shaped. Ce ical g oo e wide- ly U-shaped bu di e ging, ai ly dis inc , diminishing nea o bi s. B anchioca diac g oo es weake , de ining ca diac egion la e ally. Cu icle o ca apace wi h densely co e ed ine g anules. P e ygos ome exhibi ing s idula ing appa a us wi h c. 15 s iae. Female pleon wi h un used, much wide han long somi es; iangula elson wi h ounded ip; wi h gen le axial keel; pi ed cu icula su ace. S e nopleonal ca i y o emale appea s o each dis al po ion o s e ni e 3. Male pleon na ow, gene ally na owing dis ally; elson longe han wide wi h ounded ip; somi e 6 sligh ly wide han long, appea s un used, hexagonal, wi h immed la e al ma gins; so- mi es 3-5 appea used bu wi h dis inc su u e ma king bounda ies; wi h pi ed cu icula su ace. S e nopleonal ca i y o male appea s o each dis al po ion o s e ni e 4. measu emeN s. — Maximum ca apace wid h (mm): ALMNH:Paleo:5915: 7.1, ALMNH:Paleo:21464: 11.1. UF 228988: 11.1, UF 254041: 8.9, MMNS IP-7939: 11.4. desC ip ioN Re e al is made o Feldmann e al. (2014: 142-143). Some addi ional and e ised cha ac e s a e no ed in new specimens. Ca apace leng h-wid h a io c.0.67. F on o-o bi al wid h c.50% o maximum ca apace wid h. S e ni es wi h ube cula and pi ed cu icula su ace; pleonal s e ni e 2 na ow; s e - ni es 3-4 used; s e ni e 4 wi h cu ed, an e ola e ally di ec ed spine sepa a ed by sulcus. Female pleon wi h un used, much wide han long somi es; iangula elson wi h ounded ip; maximum wid h pleon c.30% o maximum ca apace wid h; wi h gen le axial keel; pi ed cu icula su ace. Female pleonal somi es 1-3 no p ese ed. S e nopleonal ca i y o emale appea s o each dis al po ion o s e ni e 3; wi h small p ess bu on on s e ni e 5 on uppe pa o slope nea s e ni e 4; wi h subci cula o iduc on s e ni e 6, adjacen o base o s e nopleonal ca i y. Male pleon na ow, gene ally na owing dis ally; elson longe han wide wi h ounded ip; somi e 6 sligh ly wide han long, appea s un used, hexagonal, wi h immed la e al ma gins; somi es 3-5 appea used bu wi h dis inc line ma k- ing bounda ies; wi h pi ed cu icula su ace. S e nopleonal ca i y o male appea s o each dis al po ion o s e ni e 4. Thi d maxilliped pa ly p ese ed, wi h elonga ed exopod; boo -shaped, ube cula ischium, and abou equally wide and long, ounded me us. Appendages no p ese ed. ema ks This species is a e wi h only nine indi iduals epo ed he ein a e c.15 yea s o collec ing. This a i y is no p ima ily caused by he small size o he specimens, making hem po en ially mo e di icul o ind, because many small specimens o o he species we e ound (see abo e). Recen ly, Schwei ze (2024) asc ibed ou specimens o S e ea ma ini om a si e nea S ee man, F ees one Coun y, Texas, Uni ed S a es, o igina ing om he uppe Danian-Selandian Wills Poin Fo ma ion (see A ms ong e al. 2009, o age). Howe e , he ube cles on he do sal ca apace a e coa se on a e age and mo e uni o m in he Texan specimens based on all a ailable specimens; s e ni e 4 has a wide , hexagonal-shaped ex ension as p ese ed a he han an e ola e ally di ec ed, cu ed spines as in A. ma ini n. comb. (compa e Schwei ze 2024: ig. 3.2 s Fig. 20E); and he p e ygos ome does no appea o bea he s idula ing appa a us (Schwei ze 2024: ig. 3.6) cha ac e is ic o A. ma ini n. comb. (Fig. 20L; Feld- mann e al. 2014: pl. 3.2) hough di e en ial p ese a ion may play a ole he e. Thus, he specimens om Texas may ep e- sen a di e en hexapodid species wa an ing u he s udy. DISCUSSION bios a ig aphy aNd age The li hos a ig aphic sec ion analyzed in his s udy belongs o calca eous nanno ossil Zone NP2. The base o NP2 occu s c.2.75 m below he base o he sec ion shown in Figu e 2, wi h he i s occu ence/base o C uciplacoli hus in e medius (and o he bioe en s such as he i s occu ences o Coccoli hus pelagicus (Wallich, 1877) and Fu yania spp. [supe -abundan ]). A nume ic age o 65.50 Ma is assigned o he base o NP2, ollowing he global ages om G ads ein e al. (2012). The sec ion has been subdi ided in o lowe -middle-uppe NP2 610 GEODIVERSITAS • 2025 • 47 (13) Klompmake A. A. e al. ig. 20 . — Alahexapus ma ini (Feldmann, Schwei ze & Po ell, 2014) n. comb. om he lowe Danian Pine Ba en Membe (Clay on Fo ma ion) ound a he oadcu o Mussel C eek, Lowndes Coun y, Alabama: A-C, do sal, on al, le la e al iews o ALMNH:Paleo:5915; D-F, on al, pa ial en al, and do sal iews o UF 254041; G, en al iew o MMNS IP-7939 wi h emale pleon; H, en al iew o ALMNH:Paleo:21464; I, closeup o maxilliped 3 o MMNS IP-7939; J, K, en al iews o UF 254040 wi h male pleon; L, iew o pa ially p ese ed s idula ing appa a us ( e ical idges a anged diagonally) o MMNS IP-7939; M, do sal iew o ALMNH:Paleo:21464. Scale ba s: 2.0 mm. C edi s: pho os by Adiël A. Klompmake . AB C D E F GH I J K L M 611 Ea ly Danian decapods om Alabama, Uni ed S a es GEODIVERSITAS • 2025 • 47 (13) based on he iden i ica ion o bios a ig aphically use ul nanno ossil-e en s used in he zona ion schemes o Va ol (1989) and Bown e al. (2023). The deepes sample analyzed in his s udy belongs o lowe NP2, wi h he i s occu ence/ base o P aep insius enuiculus (Okada & Thie s ein, 1979) (Fig. 2). The middle NP2 is based on he las occu ence/ op o Fu yania spp. [supe -abundan ], whe eas uppe NP2 is de ined by he i s occu ence/base o P aep insius dimo phosus (Pe ch-Nielsen, 1977) [common/inc ease] (Fig. 2). The base o NP3 (64.81 Ma, G ads ein e al. 2012) was no obse ed, as he uppe mos sample analyzed is wi hin uppe NP2. The lowe middle NP2 nanno ossil zone assigned o nea ly all decapods and o he ossils om he Mussel C eek ou c op, allows us o e alua e he absolu e age o he assemblage. Using he as onomically calib a ed NP zona ion o H id e al. (2021: ig. 12) and an age model coupled wi h he NP zona- ion in Bown e al. (2023), we in e an absolu e age o 65.4- 65.3 Ma o he assemblage. This in e ence implies he auna li ed c.600-700k yea s a e he K-Pg bounda y (66.0 Ma). s a ig aphiC aNd paleobiogeog aphiC impliCa ioNs o he deCapod assemblage Raninoides danicus n. sp. is he s a ig aphically second o oldes species known o he genus a e R. g anulo ons, om he la e Campanian-ea ly Maas ich ian o Cuba. This genus has no been epo ed p e iously om he ossil eco d o he sou heas e n Uni ed S a es. Eucalliaxiopsis alabamensis n. comb., C enocheles sp., and Palaeoxan hopsidae we e unknown om he ea ly Danian o Alabama hus a , bu hey ha e been epo ed om he uppe Danian Po e s C eek Fo ma ion o he s a e (Ra hbun, 1935a). deCapod paleoeCology All decapods appea o ha e li ed in o on he bo om o he muddy subs a e. A leas one decapod axon in ou assem- blage was a likely du ophagous p eda o . Mul iple species o Palaeoxan hopsidae, such as Pa a e ucoides alabamensis, Lobula a lobula a, and he inde e mina e species in he Mussel C eek assemblage, bea mola i o m ee h on he ixed inge and a la ge oo h p ojec ing inwa d on he dac ylus, loca ed mo e on he ou e han inne side o he occlusal su ace. This oo h is eminiscen o he mo e cu ed and la ge oo h ha calappid c abs use o b eak shells (Shoup 1968). Such cha ac- e s ha e been asc ibed o shell-p eying c abs (Schwei ze & Feldmann 2010); hus, we sugges Palaeoxan hopsidae we e likely molluscan p eda o s. Mollusks a e common a Mussel C eek (Figs 3; 4). The h ee axiidean species we e bu owe s (e.g., Hyžný & Klompmake 2015: able 1), and bu ows a e commonly ound a he Mussel C eek oadcu . As ex an hexapodids ha e been ound in bu ows (Rahayu & Ng 2014; Na use 2020), Alahexapus ma ini n. comb. may ha e had a simila li es yle. As o ex an e oplumids (de Sain Lau en 1989), Cos acopluma nicksabani n. sp. likely li ed on he muddy bo om o bu owed, eeding on o ganic pa icles wi hin he sedimen . As o nea ly all Cenozoic pagu oids (e.g., F aaije & Polkowsky 2016; Pasini e al. 2020), specimens o “Pagu is es” johnsoni likely elied on gas opod shells as a domicile, which we e common a Mussel C eek (Fig. 4). The ca apace shape o Raninoides danicus n. sp. sugges s i was likely bu ying in he sedimen (e.g., Van Bakel e al. 2012). Li le is known abou he die o aninoidans, bu Ranina anina Linnaeus, 1758, appea s o be a sca enge (Baylon & Ti o 2012). E idence o p ese ed p eda ion in lic ed on decapods is gene ally a e in he ossil eco d (Klompmake e al. 2013, o a summa y). One o he Raninoides danicus n. sp. speci- mens (MMNS IP-7252.2) igu ed in Feldmann e al. (2019: ig. 5B) bea s wo elonga ed dep essions diagonally ac oss he ca apace. All cu icle is p esen wi hin hese dep essions and he e is no sign o a oo h imp ession. They we e unsu e bu sugges ed bi ing o c ushing by a p eda o as one explana ion. These aces do no ma ch known aces a ibu ed o p eda- ion in ossil decapods. We, oo, a e unsu e abou he cause. able 2. — Numbe o specimens pe axon. Ca apaces and isola ed appendage elemen s a e all coun ed as one indi idual. Taxon To al # specimens Ca apaces/ en e s wi h o wi hou appendages P opodi wi h o wi hou dac ylus Fixed inge s Fixed inge and associa ed dac ylus Dac yli Me i Cheliped Finge inde . Alphacheles ze a (Ra hbun, 1936) n. comb. 6 – 6 – – – – – – C enocheles sp. 1 – – – – – – – 1 Eucalliaxiopsis alabamensis (Ra hbun, 1935) n. comb. 111 – 1 31 2 76 – 1 – “Pagu is es” johnsoni Ra hbun, 1935 7 – 1 – 1 4 1 – – Raninoides danicus n. sp. 20 20 – – – – – – – Cos acopluma nicksabani n. sp. 183 174 5 1 – – 2 1 – Palaeoxan hopsidae inde . 17 1 – 6 – 10 – – – Alahexapus ma ini (Feldmann, Schwei ze & Po ell, 2014) n. comb. 9 9 – – – – – – – 612 GEODIVERSITAS • 2025 • 47 (13) Klompmake A. A. e al. None o he specimens s udied show e idence o Kan- hyloma c us a Klompmake , A al, Van Bakel, F aaije & Jag , 2014, he ace ossil a ibu ed o pa asi ism in he b anchial chambe by an epica idean isopod (see also Klompmake e al. 2022b). Thus, le els o his ype o pa asi ism we e low. di e si y o ea ly daNiaN deCapod assemblages All o nea ly all decapod species o he ea ly Danian Mus- sel C eek assemblage ha e been collec ed as sugges ed by a a e ac ion analysis (Fig. 21; Table 2). The eigh species ecognized he ein make i one o he mos di e se ea ly Danian assemblages known ela i ely soon a e he C e a- ceous-Paleogene mass ex inc ion. This is pa ly because o he lack o s udies on such assemblages, bu also because bios a ig aphic da a is no always a ailable o place assem- blages wi hin a pa o he Danian (e.g., Feldmann e al. 1993; Robin e al. 2017). F om he lowe Danian Roca Fo ma ion a Ce os Bayos in sou he n A gen ina (NP1 nanno ossil zone), i e decapod species we e epo ed (Feldmann e al. 1995). They also epo ed one species om he ea ly Danian Gene al Roca ou c op, bu eigh o he species came no h om he e, implying he p ecise age wi hin he Danian is unce ain. F om he ea ly Danian Clay on Fo ma ion in Illinois, Uni ed S a es, ou species we e epo ed (Cope e al. 2005). Finally, Jensen (2013) in o mally epo ed on an ea ly Danian assemblage om Sangs up in Denma k, consis ing o 15 species. Al hough a mo e ho ough s udy on Sangs up ma e ial is ongoing, alpha di e si y appea s o be highe han in he assemblage o Mussel C eek. Acknowledgemen s Aus in Hendy and Julie Hook (bo h Na u al His o y Museum o Los Angeles Coun y, Cali o nia, Uni ed S a es) a e hanked o a loan o specimens asc ibed o Cos acopluma squi esi and To ey Nybo g (Loma Linda Uni e si y, Cali o nia, Uni ed S a es) o pho os o his species as well as pho os o C. exana. Lia h Apple on (Uni e si y o Texas a Aus in) a anged a loan o specimens o C. exana. S en Jakobsen (Geomuseum Faxe, Faxe, Denma k) p o ided a cas o C.binodosa o compa ison. A den Bash o and Lau a Co on (Na u al His o y Museum o Denma k, Copenhagen, Denma k) g an ed access o hei collec ion o compa a i e pu poses, as did Ke in Koco (Uni e si y o Alabama) o access o he ma ine decapod in e eb a e zoology collec ion and Lynn Ha ell (Geological Su ey o Alabama) o he ossil deca- pod collec ion. Yusuke Ando (Mizunami Fossil Museum, Japan) p o ided a high- esolu ion e sion o Cope e al. (2005: ig. 6) o compa ison. Pe e Ng (Na ional Uni e - si y o Singapo e) cla i ied ICZN ules ega ding Alphacheles ze a (Ra hbun, 1936) n. comb. We hank Je Shaw and he Nolan amily o si e access. We hank collec o s and dono s (Adam A ms ong, Ga y Biele eld, B e Boyd, Jim B aswell, Bill Deu sch, Vic Fa ie ia B uce Thiel, Ma k G ay, Ramsey G eene, Ron Judy, B uce Relihan, Jason Sei z, Ikeji i Take- hi o, Helen Whisle ) o s udied specimens. This s udy was suppo ed by a 2022 Paleon ological Socie y A hu J. Bouco Resea ch g an o AAK. The esea ch o MH was suppo ed by VEGA 2/0106/23 and he Slo ak Resea ch and De elop- men Agency unde con ac no. APVV-22-0523. We hank he wo e iewe s (Àlex Ossó and an anonymous e iewe ) o hei help ul commen s, and Aud ina Ne eu o much app ecia ed edi o ial wo k on he page p oo s. REFERENCES alCoCk a. 1896. — Ma e ials o a ca cinological auna o India, no. 2. The B achyu a Oxys oma. Jou nal o he Asia ic Socie y o Bengal 65 (2): 134-296, pls VI-VIII. h ps://doi.o g/10.5962/ bhl. i le.16033 alCoCk a. 1900. — Ma e ial o a ca cinological auna o India. No. 6: he B achyu a Ca ome opa, o G apsoidea. Jou nal on he Asia ic Socie y o Bengal 69 (2): 279-456. h ps://doi.o g/10.5962/ bhl. i le.15344 aNke a. 2010. — C enocheloides a enbo oughi n. gen., n. sp. (C us acea: Decapoda: Axiidea: C enochelidae), a new ghos sh imp wi h pec ina e claw inge s om Madagasca . Jou - nal o Na u al His o y 44 (29-30): 1789-1805. h ps://doi. o g/10.1080/00222931003633219 a ms oNg a., Nybo g ., bishop g. a., ossó-mo ales À. & ega . J. 2009. — Decapod c us aceans om he Paleocene o Cen al Texas, USA. Re is a mexicana de ciencias geológicas 26 (3): 745-763. a al p., g uiNo d., aN b akel b. & C as illo J. 2008. — Ibe i- canc idae, a new dako icanc oid amily (Decapoda, B achyu a, Podo ema a) om he uppe Campanian (Uppe C e aceous) o Spain. Zoo axa 1907 (1): 1-27. h ps://doi.o g/10.11646/ zoo axa.1907.1.1 ahyoNg s. . 2009. — The polychelidan lobs e s: phylogeny and sys ema ics (Polychelida: Polychelidae). C us acean Issues 18: 369-396. ig. 21. — Ra e ac ion analysis using PAST 4.17 (Hamme e al. 2001) based on specimens iden i ied a low axonomic anks ( amily-le el and lowe ). The ed (middle) cu e ep esen s he expec ed numbe o species o a smalle sample size, whe eas he op and bo om (blue) cu es ep esen he 95% uncondi ional con idence in e als. See Table 2 o da a. 50 100 150200 250300 35 0 Specimens 0 1 2 3 4 5 6 7 8 9 Species (95% con idence) 613 Ea ly Danian decapods om Alabama, Uni ed S a es GEODIVERSITAS • 2025 • 47 (13) balss h. 1922. — C us acea VII: Decapoda B achyu a (Oxy hyncha bis B achy hyncha) und geog aphische Übe sich übe C us acea Decapoda, in miChaelseN W. (ed.), Bei äge zu Kenn nis de Mee es auna Wes a ikas. Band III, Lie e ung 3. L. F iede ichsen & Co, Hambu g: 72-110. ba e C. s. 1888. — Repo on he C us acea Mac u a collec ed by he Challenge du ing he yea s 1873-76. Repo on he Scien i ic Resul s o he Voyage o H.M.S. Challenge Du ing he Yea s 1873- 76. Zoology 24 (pa 52): i-xc, 1-942, pls 1-150. bayloN J. C. & i o o. d. 2012. — Na u al die and eeding habi s o he ed og c ab (Ranina anina) om Sou hwes e n Mindanao, Philippines. Philippine Ag icul u al Scien is 95 (4): 370-377. h ps://doi.o g/10.33997/j.a s.2012.25.2.001 bee s C. 1950. — On ossil b achyu an c abs om he Eas Indies. Ve handelingen an he Koninklijk Nede lands Geologisch Mijn- bouwkundig Genoo schap, (Geologische se ie) 15: 349-354, 1 pl. besChiN C., busuliNi a., de aNgeli a. & essie g. 1988. — Raninidae del Te zia io Be ico-Lessineo (I alia se en ionale). La o i - Socie à eneziana di Scienze na u ali 13: 155-215. besChiN C., busuliNi a., de aNgeli a. & essie g. 2002. — Aggio namen o ai c os acei eocenici di ca a “Main” di A zignano (Vicenza-I alia se en ionale) (C us acea, Decapoda): S udi e Rice che, Associazione Amici del Museo. Museo Ci ico “G. Zan- na o” (Mon ecchio Maggio e) 2002: 7-28. besChiN C., de aNgeli a., CheCChi a. & mie o p. 2006. — C os acei del P iaboniano di P iabona (Vicenza-I alia se en i- onale). La o i-Socie à Veneziana di Scienze Na u ali 31: 95-112. besChiN C., de aNgeli a., CheCChi a. & za aN oNello g. 2012. — C os acei del giacimen o eocenico di G ola p esso Spagnago di Co nedo Vicen ino (Vicenza, I alia se en ionale) (Decapoda, S oma opoda, Isopoda). Museo di A cheologia e Scienze Na u ali “G. Zanna o,” Mon ecchio Maggio e (Vicenza) 2012: 5-99. beu leN k. 1928. — Die Decapoden des schwäbischen Ju a mi Ausnahme de aus den obe ju assischen Pla enkalken s am- menden. Palaeon og aphica 70 (2-6): 115-278, pls 6-8. beu leN k. 1958. — Dois c us aceos do C e áceo supe io do no des e do B asil (Decapoda, B achyu a). Bole im do Museu Nacional, Rio de Janei o, (no a sé ie) 26: 1-23. bi a . a. 1970. — Th ee new species o callianassid sh imp (Decapoda, Thalassinidea) om he wes e n A lan ic. P oceedings o he Biological Socie y o Washing on 83: 35-50. bishop g. a. 1983. — Fossil decapod C us acea om he La e C e aceous Coon C eek Fo ma ion, Union Coun y, Missis- sippi. Jou nal o C us acean Biology 3 (3): 417-430. h ps://doi. o g/10.1163/193724083X00076 bishop g. a. & Whi mo e J. l. 1986. — The Paleogene c abs o No h Ame ica: occu ence, p ese a ion, and dis ibu ion, in ex o is D. A. (ed.), SEPM Field Guidebooks Sou heas e n Uni ed S a es, Thi d Annual Midyea Mee ing, 1986, Raleigh, No h Ca olina. Socie y o Economic Paleon ologis s and Min- e alogis s, Tulsa: 297-306. bi Ne a. 1883. — Neue Bei äge zu Kenn nis de B achyu en- Fauna des Al e iä s on Vicenza und Ve ona. Denksch i en de Kaise lichen Akademie de Wissenscha en, (Ma hema ischna u wis- senscha liche Klasse) 46: 299-316, pl. 1. böhm J. 1922. — A h opoda. C us acea, in ma iN K. (ed.), Die Fossilien on Ja a. Sammlungen des Geologischen Reichsmuseums in Leiden, (neue Folge). Vol. 2. E. J. B ill, Leiden: 521-535, pl. 63. böhm J. 1927. — Raninellopsis Go schei no . gen. n. sp. Jah buch de P eussischen Geologischen Landesans al und Be gakademie in Be lin 48: 563-566, pls 1, 2. bosque J. 1854. — Les C us acés ossiles du Te ain C é acé du Limbou g. Ve handelingen ui gege en doo de commissie belas me he e aa digen eene geologische besch ij ing en kaa an Nede land 2: 1-127. bou Ne g. C. 1922. — The Raninidae: a s udy in ca cinology. Jou nal o he Linnean Socie y o London, Zoology 35 (231): 25-79, pls 4-7. h ps://doi.o g/10.1111/j.1096-3642.1922. b01495.x boWN p. ., kim h. & gibbs s. J. 2023. — Danian calca eous nanno ossil e olu ion and axonomy wi h ocus on si es om he No h A lan ic Ocean (IODP Expedi ion 342, Si es U1403 and U1407). Jou nal o Nannoplank on Resea ch 41 (2): 110-157. h ps://doi.o g/10.58998/jn 3943 b omley . g. 1981. — Concep s in ichno axonomy illus a ed by small ound holes in shells. Ac a Geológica Hispánica 16 (1): 55-64. b uCe a. J. 1989. — Thaumas ochelopsis wa di, gen. e . sp. no ., a new blind deep-sea lobs e om he co al sea (C us acea : Decapoda : Neph opidea). In e eb a e Sys ema ics 2 (7): 903- 914. h ps://doi.o g/10.1071/IT9880903 b yaN J. . & J oNes d. s. 1989. — Fab ic o he C e aceous- Te ia y ma ine mac o aunal ansi ion a B aggs, Alabama. Palaeogeog aphy, Palaeoclima ology, Palaeoecology 69: 279-301. h ps://doi.o g/10.1016/0031-0182(89)90170-3 CaNu . & bassle . s. 1920. — No h Ame ican Ea ly Te ia y B yozoa. Uni ed S a es Na ional Museum Bulle in 106: 1-879. h ps://doi.o g/10.5962/bhl. i le.1142 Capa a. 1951. — C us aces Decapodes B achyu es. Expédi ion océanog aphique belge dans les eaux cô iè es a icaines de l’A lan ique sud (1948-1949) 3 (1): 13-205. Case g. . 1991. — A new species o chimae oid ish om he Uppe Paleocene (Thane ian) o Ma yland, USA. Palaeo e e- b a a 21 (1-2): 85-94. Cha boNNie s., audo d., ga assiNo a. & hyžNý m. 2017. — Fossil C us acea o Lebanon. Muséum na ional d’His oi e na u- elle (Mémoi es du Muséum na ional d’His oi e na u elle; 210), Pa is, 252 p. CheN h. & ü kay m. 2001. — A new species o Raninoides (C us acea: Decapoda: Raninidae) om o he Sou heas e n coas o Hainan Island and Nansha Islands. Chinese Jou nal o Oceanology and Limnology 19 (4): 332-336. h ps://doi. o g/10.1007/BF02850737 Chop a b. 1933. — Fu he no es on C us acea Decapoda in he Indian Museum. III.—On he decapod C us acea collec ed by he Bengal Pilo Se ice o he mou h o he Ri e Hugli. D omiacea and Oxys oma a. Reco ds o he Indian Museum 35 (1): 25-52. h ps://doi.o g/10.26515/ zsi/ 35/i1/1933/162600 CiCimu i d. J., ebe sole J. a. & ma iN g. 2020. — Two new species o Menne o odus Zhelezko, 1994 (Chond ich hyes: Lamni o mes: Odon aspididae), om he Paleogene o he sou h- eas e n Uni ed S a es. Fossil Reco d 23 (2): 117-140. h ps://doi. o g/10.5194/ -23-117-2020 Claus C. . W. 1880. — G undzüge de Zoologie : zum Wissen- scha lichen Geb auche. 2 ols. - 4 du chaus umgea b. und e b. Au l. N. G. El e , Ma bu g, 821 p. h ps://doi.o g/10.5962/ bhl. i le.1113 Clay oN a. a., Ciampaglio C. N. & CiCimu i d. J. 2013. — An inqui y in o he s a ig aphic occu ence o a Claibo nian (Eocene) e eb a e auna om Co ing on Coun y, Alabama. Bulle in o he Alabama Museum o Na u al His o y 31 (2): 60-73. ColliNs J. s. h. & JakobseN s. l. 2003. — New c abs (C us acea, Decapoda) om he Eocene (Yp esian/Lu e ian) Lillebæl Clay Fo ma ion o Ju land, Denma k. Bulle in o he Mizunami Fossil Museum 30: 63-96. C olliNs J. s. h. & m o is s. . 1975. — A new c ab, Cos acopluma conca a, om he Uppe C e aceous o Nige ia. Palaeon ology 18 (4): 823-829. ColliNs J. s. h. & mo is s. . 1978. — New Lowe Te ia y c abs om Pakis an. Palaeon ology 21: 957-981. ColliNs J. s. h. & WieNbe g asmusseN h. 1992. — Uppe C e aceous-Lowe Te ia y decapod c us aceans om Wes G een- land. Bulle in a G ønlands geologiske Unde søgelse 162: 1-46. C olliNs J. s. h., h iggs . & C o iCula b. 1994. — A new c ab, Cos acopluma bi ida (C us acea, Decapoda) om he Paleocene o Venezuela. Bulle in o he Mizunami Fossil Museum 21: 29-34. 614 GEODIVERSITAS • 2025 • 47 (13) Klompmake A. A. e al. ColliNs J. s. h., aaye . h. b., Jag J. W. m. & aN kNip- peNbe g p. h. m. 1997. — Lae i anina hollandica, a new La e Oligocene (?) aninid c ab (C us acea, Decapoda) om he Ne he lands. Te ia y Resea ch 18: 1-5. ColliNs J. s. h., lee C. & Noad J. 2003. — Miocene and Pleis- ocene c abs (C us acea, Decapoda) om Sabah and Sa awak. Jou nal o Sys ema ic Palaeon ology 1 (3): 187-226. h ps://doi. o g/10.1017/S1477201903001068 CoN ad . a. 1860. — Desc ip ion o new species o C e aceous and Eocene ossils om Mississippi and Alabama. Jou nal o he Academy o Na u al Sciences o Philadelphia, second se ies 4: 275-298. Cope k. h., u gaa d J. e., mas e s J. m. & eldmaNN . m. 2005. — The auna o he Clay on Fo ma ion (Paleocene, Danian) o sou he n Illinois: a case o K/P su i o ship and Danian eco e y. Bulle in o he Mizunami Fossil Museum 32: 97-108. CopelaNd C. W. 1966. — Facies changes in he Alabama Te ia y. Guidebook o he Fou h Annual Field T ip o he Alabama Geo- logical Socie y. Alabama Geological Socie y, Tuscaloosa, 103 p. dai a. y. & xu z. 1991. — A p elimina y s udy o he c abs o he Nansha Islands, China [in Chinese]. Con ibu ions on Ma ine Biological Resea ch o he Nansha Islands and Neighbou - ing Wa e s 3: 1-47. daNa J. d. 1851. — Conspec us c us aceo um quae in o bis e - a um ci cumna i ga ione, Ca olo Wilkes e classe Reipublicae Foede a ae Duce, lexi e desc ipsi . Pagu idea. P oceedings o he Academy o Na u al Sciences o Philadelphia 5: 267-272. daNa J. d. 1852. — Conspec us c us aceo um, e c. Conspec us o he C us acea o he explo ing expedi ion unde Cap . C. Wilkes, U.S.N. Mac ou a. P oceedings o he Academy o Na u al Sciences o Philadelphia 6: 10-28. da e elle e. & Casie e. 1943. — Les poissons ossiles du Bas Congo e des égions oisines. Annales du Musée du Congo Belge, Sé ie A (Miné alogie Géologie, Paléon ologie) 3: 1-200. de aNgeli a. & Capo ioNdo . 2022. — Gli Hexapodidae (C us- acea, Decapoda) dell’Eocene del Vene o (I alia no do ien ale), con la desc izione di un nuo o gene e e due nuo e specie. La o i - Socie à Veneziana di Scienze Na u ali 47: 107-115. de aNgeli a., ga assiNo a. & pasiNi g. 2009. — New epo s o anomu ans and b achyu ans om he Cenozoic o Tuscany (I aly). A i della Socie à i aliana di Scienze na u ali e del Museo ci ico di S o ia na u ale di Milano 150 (2): 163-196. de aNgeli a., guiNo d. & ga assiNo a. 2010. — New hexa- podid c abs om he Eocene o Vicenza (NE I aly) (C us acea, Decapoda, B achyu a, Hexapodidae). A i della Socie à i aliana di Scienze na u ali e del Museo ci ico di S o ia na u ale in Milano 151 (1): 51-75. d e h aaN W. 1833-1850. — C us acea, in oN s iebold P. F. (ed.), Fauna Japonica si e Desc ip io Animalium, quae in I ine e pe Japoniam, Jussu e Auspiciis Supe io um, qui summum in India Ba a a Impe ium Tenen , Suscep o, Annis 1823-1830 Collegi , No is, Obse a ionibus e Adumb a ionibus Illus a i . J. Mülle e Co., Lugduni Ba a o um: i-x ii, i-xxxi, ix-x i, 1-243, pls A-J, L-Q, 1-55, ci c. able 2. de s aiN l au eN m. 1973. — Su la sys éma ique e la phylogénie des Thalassinidea : dé ini ion des amilles des Callianassidae e des Upogebiidae e diagnose de cinq gen es nou eaux. Comp es Rendus Hebdomadai es de Séances de l’Académie des Sciences, Pa is 277: 513-516. de saiN lau eN m. 1979. — Ve s une nou elle classi ica ion des C us acés Décapodes Rep an ia. Bulle in de l’O ice Na ionale de Pêche de Tunisie 3: 15-31. de saiN lau eN m. 1980. — Su la classi ica ion e la phylo- génie des C us acés Décapodes B achyou es. I. Podo ema a Guino , 1977, e Eub achyu a sec . no . Comp es endus heb- domadai es des Seances de l’Academie des Sciences, sciences, sé ie III 290: 1265-1268. de s aiN l au eN m. 1989. — La nou elle supe amille des Re oplumoidea Gill, 1894 (Decapoda, B achyu a): sys éma- ique, a ini és e é olu ion. Muséum na ion d’His oi e na u elle (coll. Mémoi es du Muséum na ional d’His oi e na u elle; 144), Pa is: 103-179. do leiN . 1904. — B achyu a. In: Wissenscha liche E gebnisse de Deu schen Tie see-Expedi ion au dem Damp e ‘Valdi ia’ 1898- 1899. Band VI. Gus a Fische , Jena, xi + 314 p., 58 pls. ebe sole J. a., CiCimu i d. J. & ha ell J . l. 2024. — A new species o Palaeohypo odus Glückman, 1964 (Chond ich hyes, Lamni o mes) om he lowe Paleocene (Danian) Po e s C eek Fo ma ion, Wilcox Coun y, Alabama, USA. Fossil Reco d 27 (1): 111-134. h ps://doi.o g/10.3897/ .27.e112800 eh eNbe g k. 1944. — E gänzende Beme kungen zu den seine zei aus dem Miozän on Bu gschleini z besch iebenen Gangke nen und Bau en dekapode K ebse. Paläon ologis- che Zei sch i 23 (3-4): 354-359. h ps://doi.o g/10.1007/ BF03160443 eldmaNN . m. 1991. — Decapod C us acea om he Tapui Glauconi ic Sands one (Bo onian: Middle Eocene) in he Wai aki alley, Sou h Island, New Zealand. New Zealand Jou nal o Geology and Geophysics 34 (1): 17-22. h ps://doi.o g/10.108 0/00288306.1991.9514435 eldmaNN . m. & ma iNs-Ne o . g. 1995. — Cos aco- pluma no des ina n. sp. (Decapoda: Re oplumidae) om he Ma ia Fa inha Fo ma ion (Paleocene) o B azil. Jou nal o Paleon ology 69 (3): 610-611. h ps://doi.o g/10.1017/ S0022336000035071 eldmaNN . m. & po ell . W. 2007. — Fi s epo o Cos acopluma Collins and Mo is, 1975 (Decapoda: B ach- yu a: Re oplumidae) om he Eocene o Alabama, U.S.A. Jou nal o C us acean Biology 27 (1): 90-96. h ps://doi. o g/10.1651/S-2712.1 eldmaNN . m. & sChWei ze C. e. 2004. — Decapod c us- aceans om he lowe Miocene o no h-wes e n Venezuela (Ce o la C uz, Cas illo Fo ma ion). Special Pape s in Palaeon- ology 71: 7-22. eldmaNN . m. & shudy d. m. 1989. — E olu iona y pa - e ns in mac u ous decapod c us aceans om C e aceous o ea ly Cenozoic ocks o he James Ross Island egion, An a c ica. Geological Socie y, London, Special Publica ions 47 (1): 183-195. h ps://doi.o g/10.1144/GSL.SP.1989.047.01.14 eldmaNN . m., shudy d. m. & homsoN m. . a. 1993. — La e C e aceous and Paleocene decapod c us aceans om James Ross Basin, An a c ic Peninsula. Jou nal o Paleon ology 67 (S28): 1-41. h ps://doi.o g/10.1017/s0022336000062077 eldmaNN . m., Casadío s., Chi iNo-gál ez l. & agui e- u e a m. 1995. — Fossil decapod c us aceans om he Jagüel and Roca Fo ma ions (Maas ich ian-Danian) o he Neuquén Basin, A gen ina. Jou nal o Paleon ology 69 (S43): 1-22. h ps:// doi.o g/10.1017/S0022336000061060 eldmaNN . m., od iguez m. ., ma iNez g. a. & agui e- u e a m. 1997. — Cos acopluma salamanca new species (Decapoda, Re oplumidae) om he Salamanca Fo ma ion (Danian) o Pa agonia, A gen ina. Jou nal o Paleon ology 71 (1): 125-130. h ps://doi.o g/10.1017/S0022336000039019 eldmaNN . m., sChWei ze C. e., Casadío s. & g i iN m. 2011. — New Miocene Decapoda (Thalassinidea; B achyu a) om Tie a Del Fuego, A gen ina: paleobiogeog aphic implica- ions. Annals o Ca negie Museum 79 (2): 91-123. h ps://doi. o g/10.2992/007.079.0202 eldmaNN . m., sChWei ze C. e. & po ell . W. 2014. — C abs (Decapoda, B achyu a) om he lowe Paleocene o Ala- bama, USA. Sc ip a Geologica 147: 135-151. eldmaNN . m., sChWei ze C. e. & phillips g. 2019. — Paleogene Decapoda (Ca idea, Anomu a, Axiidea, B achyu a) om Alabama and Mississippi, USA. Jou nal o C us acean Biology 39 (3): 279-302. h ps://doi.o g/10.1093/jcbiol/ uz002 615 Ea ly Danian decapods om Alabama, Uni ed S a es GEODIVERSITAS • 2025 • 47 (13) o es J., de saiN lau eN m., mClaughliN p. a. & lemai- e . 2000. — The ma ine auna o New Zealand: Pagu idea (Decapoda: Anomu a) exclusi e o he Li hodidae. NIWA Bio- di e si y Memoi 114: 1-250. os e C., s a da C. e., d eme z e. & s aNdliN W. 2020. — Fi mg ound c us acean bu ow sys ems (Glossi ungi es ichno acies) in ma ine shel deposi s, Paleocene Clay on Fo - ma ion, Alabama, USA. Le haia 53 (4): 500-514. h ps://doi. o g/10.1111/le .12372 aaiJe . h. b. & polkoWsky s. 2016. — Da danus colosseus, a new pagu oid om he Eocene o Aus ia p ese ed in i s hos gas opod shell. Neues Jah buch ü Geologie und Paläon- ologie - Abhandlungen 279 (1): 57-62. h ps://doi.o g/10.1127/ njgpa/2016/0540 aaiJe . h. b., aN bakel b. W. m., Jag J. W. m. & m aChalski m. 2015. — A new he mi c ab (Anomu a, Pagu oidea) om he uppe Albian (C e aceous) o Annopol, Poland. Zoo axa 3955 (4): 588-594. h ps://doi.o g/10.11646/ zoo axa.3955.4.9 g abb W. m. 1860. — Desc ip ions o new species o Ame ican Te ia y and C e aceous ossils. Jou nal o he Academy o Na u al Sciences o Philadelphia se ie 2 4 (4): 375-406, pls 67-69. ga assiNo a., ega . J., Cal illo-CaNadell l., Ce allos- e iz s. . & Cou iño m. a. 2013. — New decapod c us a- cean assemblage om he Uppe C e aceous (Cenomanian) o Chiapas, Mexico. Neues Jah buch ü Geologie und Paläon ologie- Abhandlungen 269 (3): 261-270. h ps://doi.o g/10.1127/0077- 7749/2013/0349 ga dNe J. a. 1935. — The Midway G oup o Texas. Uni e si y o Texas Bulle in 3301: 1-403. ga ie C. l. 2021. — The mac o auna o he Tehuacana Limes one Membe (Danian, Kincaid Fo ma ion) o cen al Texas, wi h he desc ip ion o a ew new axa om he Pisgah Membe . Bulle ins o Ame ican Paleon ology 399-400: 1-292. gill . 1894. — A new bassalian ype o c abs. Ame ican Na u al- is 28: 1043-1045. glaessNe m. . 1960. — The ossil decapod C us acea o New Zealand and he e olu ion o he o de Decapoda. New Zealand Geological Su ey Paleon ological Bulle in 31: 3-63, pls 1-7. glaessNe m. . & Wi he s . h. 1931. — LXVI.— On London Clay c abs o he amily Raninidæ. Annals and Magazine o Na u al His o y 8 (47): 484-493. h ps://doi. o g/10.1080/00222933108673427 go odiski a. & émy J. m. 1959. — Su les Décapodes éocènes du Sénégal occiden al. Bulle in de la Socié é Géologique de F ance S7-I (3): 315-319. h ps://doi.o g/10.2113/gssg bull.S7-I.3.315 g ads eiN . m., ogg J. g., sChmi z m. d. & ogg g. (eds) 2012. — The Geologic Time Scale 2012. Else ie , Ams e dam, 1144 p. g ay J. e. 1853. — On he di ision o c enob anchous gas e o- podous Mollusca in o la ge g oups and amilies. Annals and Magazine o Na u al His o y, Se ies 2 11 (62): 124-132. h ps:// doi.o g/10.1080/03745485609496511 guildiNg l. 1834. — Obse a ions on Na icina and Den alium, wo gene a o molluscous animals. T ansac ions o he Linnean Socie y o London 17 (1): 29-35, pl. 3. guiNo d. 1977. — P oposi ions pou une nou elle classi ica- ion des C us acés, Décapodes, B achyou es. Comp es Rendus Hebdomai es des Seances de I’Academie des Sciences, Pa is, se ie D 285: 1049-1052. guiNo d. 1993. — Données nou elles su les Raninoidea de Haan, 1841 (C us acea Decapoda B achyu a Podo ema a). Comp es endus de l’Académie des sciences. Sé ie 3, Sciences de la ie 316 (11): 1324-1331. g uiNo d. 2006. — Redisco e y o he holo ype o Paeduma cylind aceum (Bell, 1859) and desc ip ion o a new genus o Hexapodidae (Decapoda, B achyu a). Zoosys ema 28 (2): 553-571. guiNo d. & b e oN g. 2006. — Li hophylax ige i A. Milne- Edwa ds & B occhi, 1879 om he F ench C e aceous (Cenoma- nian) and placemen o he amily Li hophylacidae Van S aelen, 1936 (C us acea, Decapoda, B achyu a). Geodi e si as 28 (4): 591-633. guiNo d., de aNgeli a. & ga assiNo a. 2010. — Hol huisea, a new genus om he Eocene o I aly (Decapoda, B achyu a, Hexapodidae), in aNseN C., d e g a e s. & N g P. (eds), S udies on Malacos aca: Lipke Bijdeley Hol huis Memo ial Volume. B ill, Leiden: 283-304. h ps://doi.o g/10.1163/9789047427759_019 gus a soN e. p. 2023. — The ea ly Eocene decapod c us acean auna o he Lookingglass Fo ma ion, O egon. The Bulle in o he Museum o Na u al His o y o he Uni e si y o O egon 31: 1-45. hamme Ø., ha pe d. a. & yaN p. d. 2001. — PAST: pale- on ological s a is ics so wa e package o educa ion and da a analysis. Palaeon ologia Elec onica 4 (1): 1-4. ha m. b., ha ies p. J. & Cá deNas a. l. 2013. — The C e a- ceous/Paleogene bounda y e en s in he Gul Coas : compa isons be ween Alabama and Texas. Gul Coas Associa ion o Geological Socie ies, T ansac ions 63: 235-255. heNde soN J. . 1888. — Repo on he Anomu a collec ed by H.M.S. Challenge du ing he yea s 1873-76. Repo on he Sci- en i ic Resul s o he Voyage o H.M.S. Challenge du ing he Yea s 1873-76. Zoology. 27 (pa 69): i-xi, 1-221, pls 1-21. h ps://doi. o g/10.5962/bhl. i le.6513 h u C.-h. & ao h.-J. 1999. — Cenozoic c ab ossils om Taiwan island. Pe oleum Geology o Taiwan 33: 217-240. huaNg J.- ., Ng p. k. l. & hsueh p.-W. 2002. — C abs o he amily Hexapodidae (Decapoda: B achyu a) om Taiwan, wi h desc ip ion o a new genus and new species. Jou nal o C us acean Biology 22 (3): 651-660. h ps://doi.o g/10.1163/20021975- 99990277 h id J. m., aN buChem ., aNd easeN ., sheldoN e. & ab iCius i. l. 2021. — S a ig aphy and pe ophysical cha ac- e is ics o Lowe Paleocene cool-wa e ca bona es, Faxe qua y, Denma k. Bulle in o he Geological Socie y o Denma k 69: 97-121. h ps://doi.o g/10.37570/bgsd-2021-69-07 hyžNý m. 2012. — Calliaxina chalmasii (B occhi, 1883) comb. no . (Decapoda: Axiidea: Callianassidae: Eucalliacinae), a ghos sh imp om he Middle Miocene o Eu ope, wi h eapp aisal o he ossil eco d o Eucalliacinae. Zoo axa 3492 (1): 49-64. h ps://doi.o g/10.11646/zoo axa.3492.1.3 hyžNý m. & a al p. 2018. — Re ision and edesc ip ion o Pal- aeopinnixa my ilicola Vía Boada, 1966 (Malacos aca: Decapoda: B achyu a) om he Miocene (Langhian) o Spain, wi h an app aisal o he genus Palaeopinnixa. PalZ 92 (4): 577-586. h ps://doi.o g/10.1007/s12542-018-0414-8 h yžNý m. & d ulai a. 2014. — Deep-wa e osso ial sh imps om he Oligocene Kiscell Clay o Hunga y: axonomy and palaeoecology. Ac a Palaeon ologica Polonica 59 (4): 947-965. h ps://doi.o g/10.4202/app.2012.0078 hyžNý m. & dulai a. 2021. — Badenian decapods o Hunga y. Szeged, GeoLi e a Publishing House, Ins i u e o Geosciences, Uni e si y o Szeged, Hunga y, 290 p. h yžNý m. & g ašpa i Č . 2014. — Ghos sh imp Calliax de Sain Lau en , 1973 (Decapoda: Axiidea: Callianassidae) in he ossil eco d: sys ema ics, palaeoecology and palaeobioge- og aphy. Zoo axa 3821 (1): 37-57. h ps://doi.o g/10.11646/ zoo axa.3821.1.3 hyžNý m. & hudá Č ko á N. 2012. — Redesc ip ion o wo ghos sh imps (Decapoda: Axiidea: Callianassidae) om he Middle Miocene o he Cen al Pa a e hys: sys ema ics, in aspeci ic a i- a ion, and in si u p ese a ion. Zoo axa 3210 (1): 1-25. h ps:// doi.o g/10.11646/zoo axa.3210.1.1 h yžNý m. & k lompmake a. a. 2015. — Sys ema ics, phylogeny, and aphonomy o ghos sh imps (Decapoda): a pe spec i e om he ossil eco d. A h opod Sys ema ics& Phylogeny 73 (3): 401- 437. h ps://doi.o g/10.3897/asp.73.e31829 622 GEODIVERSITAS • 2025 • 47 (13) Klompmake A. A. e al. appenDix 2 . — Link o he 3D model o he holo ype o Raninoides danicus n. sp. (ALMNH:Paleo:21488): h ps://zenodo.o g/ eco ds/17065577 appenDix 3 . — Link o he 3D model o he holo ype o Cos acopluma nicksabani n. sp. (ALMNH:Paleo:21453): h ps://doi.o g/10.5281/zenodo.17065590