Fossil dipsadid snakes from the Guadeloupe Islands (French West-Indies) and their interactions with past human populations

2019 ● 41 ● 12 geodiversitas M e m o r i a l J e a n - C l a u d e R a g e – A l i f e o f p a l e o - h e r p e t o l o g i s t – Geodiversitas est une revue en flux continu publiée par les Publications scientifiques du Muséum, Paris Geodiversitas is a fast track journal published by the Museum Science Press, Paris Les Publications scientifiques du Muséum publient aussi / The Museum Science Press also publish: Adansonia, Zoosystema, Anthropozoologica, European Journal of Taxonomy, Naturae, Cryptogamie sous-sections Algologie, Bryologie, Mycologie. Diffusion – Publications scientifiques Muséum national d’Histoire naturelle CP 41 – 57 rue Cuvier F-75231 Paris cedex 05 (France) Tél. : 33 (0)1 40 79 48 05 / Fax : 33 (0)1 40 79 38 40 [email protected] / http://sciencepress.mnhn.fr © Publications scientifiques du Muséum national d’Histoire naturelle, Paris, 2019 ISSN (imprimé / print) : 1280-9659/ ISSN (électronique / electronic) : 1638-9395 Directeur De la publication : Bruno David, Président du Muséum national d’Histoire naturelle réDacteur en chef / Editor-in-chiEf : Didier Merle assistants De réDaction / AssistAnt Editors : Emmanuel Côtez ([email protected]) ; Anne Mabille Mise en page / PAgE lAyout : Emmanuel Côtez coMité scientifique / sciEntific boArd : Christine Argot (MNHN, Paris) Beatrix Azanza (Museo Nacional de Ciencias Naturales, Madrid) Raymond L. Bernor (Howard University, Washington DC) Alain Blieck (chercheur CNRS retraité, Haubourdin) Henning Blom (Uppsala University) Jean Broutin (UPMC, Paris) Gaël Clément (MNHN, Paris) Ted Daeschler (Academy of Natural Sciences, Philadelphie) Bruno David (MNHN, Paris) Gregory D. Edgecombe (The Natural History Museum, Londres) Ursula Göhlich (Natural History Museum Vienna) Jin Meng (American Museum of Natural History, New York) Brigitte Meyer-Berthaud (CIRAD, Montpellier) Zhu Min (Chinese Academy of Sciences, Pékin) Isabelle Rouget (UPMC, Paris) Sevket Sen (MNHN, Paris) Stanislav Štamberg (Museum of Eastern Bohemia, Hradec Králové) Paul Taylor (The Natural History Museum, Londres) couverture / cover : Background: made from the Figures of the article; medallion: Jean-Claude Rage, to whom this issue is dedicated. Geodiversitas est indexé dans / Geodiversitas is indexed in: – Science Citation Index Expanded (SciSearch®) – ISI Alerting Services® – Current Contents® / Physical, Chemical, and Earth Sciences® – Scopus® Geodiversitas est distribué en version électronique par / Geodiversitas is distributed electronically by: – BioOne® (http://www.bioone.org) Les articles ainsi que les nouveautés nomenclaturales publiés dans Geodiversitas sont référencés par / Articles and nomenclatural novelties published in Geodiversitas are referenced by: – ZooBank® (http://zoobank.org) 501 GEODIVERSITAS • 2019 • 41 (12) © Publications scientifiques du Muséum national d’Histoire naturelle, Paris. www.geodiversitas.com Corentin BOCHATON Max Planck Institute for the Science of Human History, Kahlaische Straße 10, D-07745, Jena (Germany) and Laboratoire Archéozoologie et Archéobotanique : Sociétés, Pratiques et Environnements , UMR 7209 – CNRS, MNHN – Muséum national d’Histoire naturelle, Sorbonne Université, case postale 56, 57 rue Cuvier, F-75231 Paris cedex 05 (France) and Institut de Systématique, Évolution, Biodiversité ISYEB UMR 7205 – CNRS, MNHN, EPHE – Muséum national d’Histoire naturelle, Sorbonne Université, 57 rue Cuvier, case postale 30, F-75231 Paris cedex 05 (France) [email protected] (corresponding author) Renaud BOISTEL Institut international de Paléoprimatologie et de Paléontologie humaine, UMR 7262 – CNRS, Université de Poitiers, UFR SFA – Bât. B35, 6 rue Michel Brunet, TSA 51106, F-86073 Poitiers (France) Sandrine GROUARD Laboratoire Archéozoologie et Archéobotanique : Sociétés, Pratiques et Environnements , UMR 7209 – CNRS, MNHN – Muséum national d’Histoire naturelle, Sorbonne Université, case postale 56, 57 rue Cuvier, F-75231 Paris cedex 05 (France) Ivan INEICH Institut de Systématique, Évolution, Biodiversité ISYEB – UMR 7205 – CNRS, MNHN, EPHE, Muséum national d’Histoire naturelle, Sorbonne Université, 57 rue Cuvier, case postale 30, F-75231 Paris cedex 05 (France) Anne TRESSET† Salvador BAILON Laboratoire Archéozoologie et Archéobotanique : Sociétés, Pratiques et Environnements , UMR 7209 – CNRS, MNHN – Muséum national d’Histoire naturelle, Sorbonne Université, case postale 56, 57 rue Cuvier, F-75231 Paris cedex 05 (France) Submitted on 12 July 2018 | accepted on 28 January 2019 | published on 20 June 2019 Fossil dipsadid snakes from the Guadeloupe Islands (French West-Indies) and their interactions with past human populations urn:lsid:zoobank.org:pub:B0131324-1E7D-4D4E-97EA-AA812A5F7B94 Bochaton C., Boistel R., Grouard S., Ineich I., Tresset A. & Bailon S. 2019. — Fossil dipsadid snakes from the Guadeloupe Islands (French West-Indies) and their interactions with past human populations., in Steyer J.-S., Augé M. L. & Métais G. (eds), Memorial Jean-Claude Rage: A life of paleo-herpetologist. Geodiversitas 41 (12): 501-523. https://doi.org/10.5252/geodiversitas2019v41a12. http://geodiversitas.com/41/12 ABSTRACT Snakes of the family Dipsadidae Bonaparte, 1838 still occur on most of the Lesser Antillean islands, although they have been strongly impacted by modern and historical anthropogenic disturbances as it has been demonstrated for many squamate taxa worldwide. However, these observations mostly rely on modern assemblages, whereas the fossil record of dipsadid snakes, which is the most direct 502 GEODIVERSITAS • 2019 • 41 (12) Bochaton C. et al. MOTS CLÉS Colubroidae, Caraïbe, Amérindien, archéozoologie, extinction, ostéologie, paléontologie. way to assess their past diversity, remains largely understudied. In order to fill this gap we performed a comprehensive review of the dipsadid snake fossils recovered on the Guadeloupe Islands. We identify the fossils on the basis of both qualitative osteological criteria and a morphometric study of the vertebrae. These approaches allow us to recognize three different dipsadid snake taxa, two of which still occur nowadays in Guadeloupe, but have been partly extirpated: Alsophis antillensis (Schlegel, 1837) and Erythrolamprus juliae cf. copeae (Parker, 1936), and a third one that is now extinct (Alsophis sp. 2). In addition, we evaluate previous interpretations of occurrences of snake remains in archaeological deposits. Our conclusions raise questions about the putative consumption of snake meat by past Amerindian populations, which is still far from being clearly demonstrated. RÉSUMÉ Les serpents dipsadidés fossiles des îles de Guadeloupe (Antilles françaises) et leurs interactions avec les populations humaines du passé. Les serpents de la famille des Dipsadidae Bonaparte, 1838 sont encore présents sur de nombreuses îles des Petites Antilles bien qu’ayant été, comme de nombreux squamates dans le monde, fortement impactés par les perturbations anthropiques actuelles et historiques. Cependant, en ce qui concerne les dipsadidés, l’évaluation de cet impact repose essentiellement sur les données issues des faunes actuelles, et le registre fossile de ces animaux, qui serait le plus à même de documenter leur diversité passée, demeure largement sous-évalué. Cette étude tente de contribuer à combler ce manque grâce à une large révision du matériel fossile de Dipsadidae découvert dans les îles de l’archipel de Guadeloupe. Nous tentons d’identifier ces restes fossiles par des approches en ostéologie qualitative et une étude morphométrique des vertèbres. Ces approches permettent la mise en évidence de trois taxons de Dipsadidae. Deux d’entre eux existent encore en Guadeloupe aujourd’hui, malgré des disparitions locales : Alsophis antillensis (Schlegel, 1837) et Erythrolamprus juliae cf. copeae (Parker, 1936). Le troisième étant éteint de nos jours (Alsophis sp. 2). Nous avons, de plus, conduit une étude archéozoologique dans le but de discuter les interprétations possibles de la présence de restes de serpents dans les dépôts archéologiques. Nos conclusions mettent en doute la possibilité d’une consommation des serpents par les populations précolombiennes de Guadeloupe. KEY WORDS Colubroidae, Caribbean, Amerindian, zooarchaeology, extinction, osteology, palaeontology. INTRODUCTION The current biodiversity crisis impacting worldwide faunas is now broadly accepted as a reality (Barnosky et al. 2011; Ceballos et al. 2015), as is its strong negative impact on insular faunas (Case et al. 1992; Steadman et al. 2015; Johnson et al. 2017). The extent of this phenomenon is difficult to quantify for extinctions that could have occurred in the past before contemporary recording and description of taxa. This is especially true for fragile insular ecosystems that are strongly impacted by numerous anthropic phenomena. One of the ways to asses these putative past extinctions is to study historical sources describing past biodiversity and/or available fossil evidence. Concerning fossil remains, the study of animal remains collected in archaeological deposits allows, in addition to documenting past fauna and its geographical distribution, the investigation of past interactions between humans and animals. This material is thus of crucial interest for studying how of human populations have reshaped past and current biodiversity (Vigne 1992; Crabtree 2016). These questions have already been extensively studied on the Guadeloupe Islands (French West-Indies) where archaeological and paleontological deposits have providedevidence of the minor impact on past faunas by the pre-Columbian Amerindians, followed by the numerous extirpations and/or extinctions events occurring after the colonization of the Guadeloupe Islands by European settlers (Grouard 2001a; Boudadi-Maligne et al. 2016; Stoetzel et al. 2016; Bochaton et al. 2019). Among all taxonomic groups that occurred in the past on Guadeloupe Islands, squamates are the most investigated and a significant amount of data concerning their past diversity exist from both historical (Du Tertre 1654; de Rochefort 1658) and paleontological (Bochaton et al. 2016a, b; 2017a) sources. However, our understanding of Guadeloupe’s past squamate biodiversity and of its interactions with past human populations is incomplete, because the putative rich Guadeloupe past snake diversity remains poorly investigated. Indeed, although historical texts describing the past Guadeloupe snake fauna exist (see review in Breuil 2002), the morphology of their fossil remains as well as the interactions of these taxa with past Guadeloupe human populations have never been fully investigated. The sole exception to this lack of investigation concerns the remains of the boid snake, Boa blanchardensis Bochaton & Bailon, 2018, recovered in Pleistocene layers on Marie-Galante Island (Bochaton & Bailon 2018). Preliminary morphological studies of recently discovered dipsadid remains on La Désirade (Boudadi-Maligne et al. 2016) and Marie-Galante islands (Bailon et al. 2015; Bochaton et al. 2015) have already been carried out. However, most of these snake remains could not be identified at the species level. This makes dipsadid snakes, although being mentioned in several studies, among the less known groups having a fossil record on the Guadeloupe Islands. This is especially problematic considering that comparisons of historical sources with current biodiversity data raise several questions about past 503 Fossil dispadids from the Guadeloupe Islands GEODIVERSITAS • 2019 • 41 (12) Guadeloupe snake diversity. Indeed, the snake fauna seems to have been far more diverse in the 17th century than nowadays. The text of R. P. Jean-Baptiste Du Tertre (1654), a French pastor who provided one of the first descriptions of Lesser Antillean fauna, indicates the occurrence of three different forms of possible dipsadid snakes on the Guadeloupe Islands. However, the situation nowadays is very different because, among the six main islands of this archipelago, three lack any dipsadid snakes (Marie-Galante, and La Désirade islands, and Petite-Terre islets), one is occupied by a single species (Les Saintes islets), and two are occupied by two species (Grande-Terre and Basse-Terre islands) (Powell & Henderson 2012). Striking differences between historical and modern data could be another demonstration of the severe extinction crisis impacting Guadeloupe squamates during modern times. However, historical accounts often lack precision, which makes it challenging to deduce what happened to Guadeloupe snakes during the last centuries. The aim of this study is to fill the scientific gap between historical accounts and modern snake diversity data, in order to improve our understanding of how Guadeloupe snake faunas have changed acrossthe last thirty millennia. To achieve this goal we review dipsadid snake fossil remains collected in all known archaeological and paleontological deposits on Guadeloupe Islands, and provide detailed descriptions and rigorous taxonomic identifications. We also provide new data concerning the relationships between past snake fauna and pre-Columbian human populations by studying assemblages of bones discovered in several archaeological contexts. REGIONAL SETTING Guadeloupe islands The Guadeloupe Islands are located in the Lesser Antilles, north of Dominica and south of Montserrat Islands (Fig. 1A). This archipelago (Fig. 1B) is composed of two large islands, BasseTerre (848.1 km²) and Grande-Terre (585.7 km²), separated by a 70 m wide marine channel 5-10 meters deep. Other islands nowadays are separated from the two main islands: La Désirade (21.1 km²), Petite-Terre islets (1.5 km²), MarieGalante (157.5 km²), and Les Saintes (14.2 km²) (Fig. 1B). These islands have different geological histories but, during interval covered by this study (Late Pleistocene to present), the configuration of the archipelago was similar to today except that Basse-Terre, Grande-Terre, La Désirade, and Petite-Terre islands were connected to form a unique landmass during the Late Pleistocene, when the sea level was 200 m lower (Fig. 1B) (Münch et al. 2013). Basse-Terre Grande-Terre Marie-Galante La Désirade Petite-Terre Les Saintes 10 km Caribbean Sea N Atlantic Ocean 100 km A B Guadeloupe Islands 200 m 200 m 200 m 200 m 200 m Colombie bank 1 2 3 5 6 8911 12 13 15 16 17 19 10 14 18 20 47 fig. 1. — A, Map of the Lesser Antilles indicating the position of the Guadeloupe archipelago; B, Map of the Guadeloupe Islands with isobaths (–200 m) from Münch et al. (2013) and locations of the studied sites: 1, cathédrale de Basse-Terre; 2, gare maritime de Basse-Terre; 3, Sainte-Rose la Ramée; 4,Trou Lolo; 5, Anse à l’Écu cave; 6, Bambous cave; 7, Morel; 8, Anse à la Gourde cave; 9, Anse à la Gourde; 10, Pointe du Helleux; 11, Anse Petite Rivière; 12, Pointe Gros Rempart 6; 13, Caille à Bélasse; 14, Jean-François gully cave; 15, Morne Rita; 16, Tourlourous – Stade José Bade; 17, Blanchard cave; 18, Cadet 2 cave; 19, Cadet 3 shelter; 20, Grande-Anse de Terre de Bas. 504 GEODIVERSITAS • 2019 • 41 (12) Bochaton C. et al. Guadeloupe dipsadid snakes Concerning the Guadeloupe snake fauna, three dipsadid species currently occurs in the archipelago. The first species, Alsophis antillensis (Schlegel, 1837) is a medium sized snake reaching a maximum total length of 129 cm (Duméril et al. 1854). This species currently occurs on Grande-Terre and Basse-Terre Islands (Breuil et al. 2009; Powell & Henderson 2012). A specimen of this species was also collected in 1839 by Hotessier (MNHN-RA-0.3555) on Marie-Galante from where it is absent nowadays (Breuil 2002). This snake is also described by Du Tertre (1654, 1667) who reported the occurrence of three different non-venomous snakes on the Guadeloupe Islands during the 17th century. One of these snakes is described as a grass snake about five (160 cm) or six (190 cm) feet in length with a black and yellow back, and a grey and yellow belly. This snake probably corresponds to A. antillensis. That species includes two varieties that only differ by their coloration according to Duméril et al. (1854). The “A variety” is similar to the one described by Du Tertre (1667) but the “B variety” is completely black (Duméril et al. 1854). This fact become interesting in regard with the second snake described by Du Tertre (1667) in Guadeloupe, a large snake measuring more than seven feet (224 cm) in total length and completely black just as the “B variety” of A. antillensis. Still, the small size of the black A. antillensis (120 cm of total length) does not match the size of the large snake described by Du Tertre (1667). The second species currently occurring on Guadeloupe is Alsophis sanctonum Barbour, 1915, a species only reported from Les Saintes islands. This species was long considered a subspecies of A. antillensis, but was elevated to species level by Breuil (2002). The last dipsadid species currently occurring in Guadeloupe is Erythrolamprus juliae (Cope, 1879). This snake still occurs nowadays on Grande-Terre and Basse-Terre islands where it is represented by the subspecies E. j. copeae (Parker, 1936). This snake historically also occurred on MarieGalante where a specimen of a distinct endemic sub-species was described as E. j. mariae (Barbour, 1914), but apparently went extinct during the 19th century (Henderson 1992; Breuil 2002). This taxon was also probably described by Du Tertre who wrote about a small grey grass snake never exceeding two feet (64 cm) or two feet and half (81 cm) of length and occurring throughout the Guadeloupe Islands (Du Tertre 1654, 1667). The two dipsadid genera occurring on Guadeloupe have different geographical origins, with Alsophis Fitzinger, 1843 having colonized the Lesser Antilles from the Greater Antilles and Erythrolamprus from continental South America (Hedges 1996; Hedges et al. 2009). Guadeloupe past human peoplinG The oldest direct evidence for the occurrence of humans on Guadeloupe is provided by the archaeological site of Morel Zero on Grande-Terre Island (Paulet-Locard & Stouvenot 2005), dated to around 1500 BC (Mesoindian or Archaic Age), but indirect evidences of far older human occupation are dated to around 3000 BC on Marie-Galante Island (Stouvenot et al. 2014; Siegel et al. 2015). The oldest site containing ceramic remains is the site of Morel I on GrandeTerre. It is dated from around 80 AD, and is attributed to the Saladoid cultures (Neoindian or Early Ceramic Age) (Clerc table 1 . — Number of fossil bones and taxonomic attribution of dipsadid snakes bones collected in each archaeological and paleontological deposit on the Guadeloupe Islands. Islands Archaeological/ Palaeontological sites Alsophis antillensis (Schlegel, 1837) Alsophis sp. 2 Alsophis sp. Erythrolamprus juliae cf. copeae Colubroidea ind. Total Les Saintes Grande Anse Terre de Bas 88 16 71 0 0 175 Grande-Terre Anse à la Gourde 42 1 4 0 3 50 Anse à l’Écu Cave 3 0 9 4 5 21 Anse à la Gourde Cave 20 0 3 0 11 34 Bambous Cave 55 0 0 0 0 55 Morel 6 6 9 0 0 21 Pointe du Helleux 4 3 1 0 0 8 Trou Lolo 2 1 0 1 0 4 Basse-Terre Cathédrale de Basse-Terre 19 1 2 0 1 23 Gare Maritime de Basse-Terre 69 0 1 0 2 72 Sainte-Rose La Ramée 16 0 5 1 0 22 La Désirade Anse Petite Rivière 11 2 9 0 0 22 Pointe Gros Rempart 6 57 0 11 0 10 78 Petite-Terre Caille à Bélasse 4 0 4 0 4 12 Marie-Galante Cadet 2 Cave 72 2 76 0 0 150 Cadet 3 Shelter 64 4 54 0 4 126 Blanchard Cave 227 12 722 0 78 1039 Morne Rita Cave 66 0 52 0 9 127 Jean-Francois gully Cave 1 0 1 0 0 2 Tourlourous, Stade José Bade 14 3 15 0 1 33 Total 840 51 1049 6 128 2074 505 Fossil dispadids from the Guadeloupe Islands GEODIVERSITAS • 2019 • 41 (12) 1964; Hofman et al. 1999; Bérard 2013; Fitzpatrick 2015). This first ceramic culture later developed into Troumassoid cultures (900 AD-1500 AD) (Late Ceramic Age) (Bonnissent 2008; Keegan et al. 2013; Honoré 2014). After a period of cohabitation with Amerindians, the French colonization of Guadeloupe started in 1635 and led to the disappearance of Left lateral view Dorsal view Ventral view Left lateral view Dorsal view A B C D Ventral view Alsophis rijgersmaei MNHN-UMR7209 406 Alsophis rijgersmaei MNHN-ZA-AC 2016-9 Left lateral view Dorsal view Ventral view Left lateral view Dorsal view Ventral view Alsophis antillensis variety A MNHN-UMR7209 601 Alsophis antillensis variety B MNHN-RA-0.3556 fig. 2. — Morphological variability among four specimens of Alsophis Fitzinger, 1843. From left-to-right: smallest and largest available specimens of Alsophis rijgersmaei Cope, 1869 and Alsophis antillensis (Schlegel, 1837) varieties A and B (of Duméril et al. 1854). The two figured vertebrae for each specimen correspond to the most different morphologies observed among the trunk vertebrae (anterior vertebra on the left and median vertebra on the right). 506 GEODIVERSITAS • 2019 • 41 (12) Bochaton C. et al. Amerindian populations (Saunders 2005; Keegan et al. 2013) and to the industrialization of the islands. As a consequence, nearly all primary forests on the islands were destroyed in the 18th century (Lasserre 1961). MATERIAL AND METHODS Fossil dipsadid material and anatomical nomenclature Studied fossil material consist of 2 074 dipsadid snake remains collected from 20 archaeological and paleontological deposits located on most of the islands of Guadeloupe (Fig. 1B). These deposits are mostly dated from pre-Columbian times with the exception of Marie-Galante paleontological deposits (Cadet 2 cave, Cadet 3 shelter and Blanchard cave) which contain layers dated from the Late Pleistocene to Late Holocene. The sites of Jean-François gully, Bambous, and Trou Lolo caves are modern deposits. Details and bibliographies concerning these deposits can be found in supplementary materials. The studied fossil material is stored in the repository of the “Service régional de l’archéologie de Guadeloupe” (BasseTerre/Guadeloupe) at the exception of the material from Blanchard Cave that is stored in the “Musée archéologique Edgard Clerc” (Grande-Terre/Guadeloupe). As it is the standard for archaeological faunal remains, bones were not be given an individual collection number but are ordered in the collections following their site of origin and their stratigraphic position. For this reason we indicated the site and the stratigraphic origin of each pictured specimen. The anatomical nomenclature used mostly follows Cundall & Irish (2008) for the skull. The nomenclature for vertebrae follows Hoffstetter & Gasc (1969) and Szyndlar (1984). comparative material oF modern dipsadid snakes The comparative sample used in this study consists of 18 museum specimens of Lesser-Antillean dipsadid snakes belonging to three Alsophis species, one Clelia species, and two Erythrolamprus species from: the Museum of Comparative Zoology (Boston, USA) (MCZ), Florida Museum of Natural History, University of Florida (Gainesville, USA) (UF), and the Muséum national d’Histoire naturelle (Paris, France) Herpetology (MNHN-RA), Comparative Anatomy (MNHN-ZA-AC), and UMR7209 Laboratory (coll. UMR7209) collections (see Appendix 1). In addition we performed an X-Ray Microtomography (XMT) of the type specimen of the now-extinct “B variety” of Alsophis antillensis collected in Guadeloupe (MNHN-RA-0.3556). The specimen of A. antillensis (coll. UMR7209 601) was the sole specimen for which we had pictures before osteological preparation. It corresponds to the previously defined “A variety” of the species. The scarcity of skeletons of Lesser Antillean dipsadid snakes in museum collections did not allow including more comparative specimens in this study. In order to observe the intra-individual and ontogenetic variability of the trunk vertebrae in the genus Alsophis, we selected four specimens corresponding to two closely related species (Fig. 2), Alsophis rijgersmaei Cope, 1869 (coll. UMR7209 406 and MNHN-ZA-AC 2016-9) and Alsophis antillensis (coll. UMR7209 601 and MNHN-RA-0.3556). This choice was strongly constrained by the limited availability of comparative specimens. The full ontogenetic variability could not be described using specimens of a single species. X-ray microtomography (XMT) The XMT of Alsophis antillensis (MNHN-RA-0.3556: Fig. 2) was performed according to the protocols reported in the literature (Boistel et al. 2011; Lauridsen et al. 2011; Zanette et al. 2013). We used an EasyTom XL duo RX solution scanner at the Centre for Microtomography of the University of Poitiers (France). Scans were performed at 100 kV and 34/32 mA. The geometry was set to obtain a 38.59 μm voxel size in the reconstructed three-dimensional images. The reconstruction was performed using the FDK algorithms of Xact ver. 1.1 (revision = 6663M, RXsolution, acceleration in GPU). The dataset consists of 4320 projections taken over 360° on the whole body of the specimen. Direct volume rendering was used to visualize the sub-set of selected voxels of the skeleton in AVIZO v. 7.1 and 6.1 (FEI Visualization Sciences Group, http://www.fei.com) after having used the software IMAGEJ to mask the anatomical structures not useful for the present study. Morphometric analysis A maximum of eight measurements (depending on bone fragmentation) were taken on modern and fossil dipsadid snakes trunk vertebrae by a single user (CB) using a dial caliper (Mitutoyo IP 67). These measurements (Fig. 3) are mostly taken from Szyndlar (1984), Rage (2001), and Albino (2011) and are widely used in snake vertebral studies. Subsequent statistical analyses were performed using the R software (cran.r-project.org). Log-shape ratios (Mosimann & James 1979) were calculated on the log10 transformed measurements. This manipulation allows the separation of shape and size components of the variables. A Principal Component Analysis (PCA) was then performed to explore the data. Linear Discriminant Analyses (LDA) and Mahalanobis distance trees were performed to observe the morphological distance separating the investigated taxa. These analyses were conducted using the R libraries MASS (Ripley et al. 2016) and Ape (Paradis & Schliep 2018). Manova analyses were also performed using basic R Stats library. All probability values (p. value) were considered significant when inferior to 0.01. Two set of analyses using different numbers of fossil vertebrae were performed depending on the number of measurements available for fossil elements. For each comparative modern specimen, a maximum of 15 vertebrae representing all the morphological variability of trunk vertebrae were chosen on the basis of their morphology to be measured, except for some specimens for which only a limited number of vertebrae were available. We carried out a first analysis using the maximum number of fossil specimens (312) and 507 Fossil dispadids from the Guadeloupe Islands GEODIVERSITAS • 2019 • 41 (12) the minimum number of variables (four variables: CL, MLV, WIC, and Wp). The second analysis was performed using the minimum number of fossil specimens (100) and the maximum number of measurements (eight variables: CL, MLV, WIC, Wp, Wa, PRW, GH, and LNS). The first analysis focused on the distinction between Alsophis and Erythrolamprus vertebrae. It includes, in addition of all fossil specimens, the following comparative specimens: Alsophis antillensis morphotype A (coll. UMR7209 601), Alsophis rijgersmaei (coll. UMR7209 406, MNHN-ZA-AC 2016-9), Alsophis rufiventris (Duméril, Bibron & Duméril, 1854) (MCZ R-76665, UF 15495), Erythrolamprus juliae copeae (MNHN-RA-1998.485) and Erythrolamprus perfuscus (Cope, 1862) (MCZ 78620). This first analysis is the only one including fossil and modern Erythrolamprus, because all measurements could not be obtained from fossil Erythrolamprus vertebrae. The second analysis using all the measurements is more focused on Alsophis vertebrae and only includes the above mentioned comparative specimens of this genus. The CT-scan of Alsophis antillensis morphotype B (MNHN-RA-0.3556) is not included in our morphometric analyses, because measurements could not be acquired using the same methodology as for other specimens and, thus, the data were not comparable. RESULTS morpholoGical variability oF trunk vertebrae within Alsophis (FiG. 2) Medial constriction of the vertebrae varies within individuals along the vertebral column. The most striking differences appear on the zygosphene anterior margin, which can be trilobed or concave within the same individual. The length and height of the neural spine are also variable to some extent. In ventral view, the centrum may have more or less deep subcentral depressions, and the hemal keel can be of constant width or is wider in its posterior half. In lateral view, the ventral margin of the hemal keel can be nearly straight to strongly stepped. Centrum length (CL) of the trunk vertebrae in the same individual is also variable, with the largest vertebra being 115% of the CL of the smallest. Comparison of individuals of different sizes shows that the morphology of the prezygapophyseal processes undergoes an ontogenetic change from being slender and pointed on smaller specimens to being larger and blunted on larger specimens. The neural spine also changes ontogenetically. In lateral view, this structure is high and short on the smallest specimens and lower and longer on the largest specimens. The anterior and posterior margins of the neural spine also more strongly overhang the centrum on the largest specimens. In dorsal view, prezygapophyseal facets are more rounded on small specimens, versus ovoid on large specimens. In ventral view, the ventral edge of the hemal keel changes from sharp on small specimens to blunt on large specimens. These observations also demonstrate that clear morphological differences, free of potential intra-specific variability, between the vertebrae of Alsophis antillensis A and B varieties are absent. SYSTEMATIC PALAEONTOLOGY Order SQUAMATA Oppel, 1811 Suborder SERPENTES Linnaeus, 1758 Family dipsadidae Bonaparte, 1838 Subfamily Xenodontinae Cope, 1895 Genus Alsophis Fitzinger, 1843 Alsophis antillensis (Schlegel, 1837) eXamined material. — A total of 840 bones from all 20 sites and six islands are attributed to Alsophis antillensis (Table 1). Among these are 82 cervical and caudal vertebrae that could not be unambiguously identified because of their strong morphological variability. These elements, which are not described in this study, were associated with A. antillensis on the basis of their sizes, and the taxonomic composition of the snake material of the different sites. CL MLV Ventral view Wa PRW Wp WIC Dorsal view GH Lateral view LNS fig. 3. — Measurements taken of snake vertebrae: CL, greatest centrum length; GH, greatest height of the vertebra; LNS, greatest length of the neural spine; MLV, maximum length of vertebra; PRW, prezygapophyseal width; WIC, width of interzygapophyseal constriction (= NAW sensu Szyndlar 1984); Wa, greatest width of the anterior part of the neural arch; Wp, greatest width of the posterior part of the neural arch (= PO-PO sensu Szyndlar 1984). 514 GEODIVERSITAS • 2019 • 41 (12) Bochaton C. et al. physis are slightly more separated than in Alsophis morphotypes, but their relative positions are similar. The diapophysis is clearly larger than the parapophysis. Ventrally, a long and shallow hemal keel with a straight ventral edge and a slight posterior projection is visible. In anterior view, the cotyle is circular and it is bordered laterally by paracotylar foramina and deep paracotylar depressions. In posterior view, the condyle is circular and the neural arch is dorsally flattened. The centrum is cylindrical in transverse section. In ventral view, the centrum has weakly marked subcentral ridges and lacks the precondylar constriction occurring in Alsophis fossil vertebrae. The hemal keel is shaped like a gladius shape and its width is constant along its whole length. Two subcentral depressions of shallow depth and limited extent are visible on the anterior part of the centrum below the synapophysis. Sub-cotylar tubercles occur ventral to the cotyle on some specimens. remarks These vertebrae present two characters occurring in Erythrolamprus and not in Alsophis: the vertebra is clearly longer than wide and the neural spine is anteroposteriorly elongate and low. These same fossils also exhibit several differences with our two comparative extant specimens of Erythrolamprus perfuscus: lack of a strongly trilobed anterior margin of the zygosphene in dorsal view; cylindrical shape of the centrum with weakly defined lateral margins; lack of precondylar constriction separating the centrum from the condyle; and narrowness of the postero-medial notch in the neural arch forming an angle clearly less than 90° in dorsal view. All these characters that do not occur in E. perfuscus occur on our unique individual of E. juliae copeae (MNHN-RA-1998.485). Still, some differences exist between this last individual and the fossil vertebrae. Most notably, in our modern individual, the prezygapophyseal processes are wider and shorter and the zygosphene is narrower than in some fossils. In addition, the hemal keel in the modern individual is shorter and its posterior end is enlarged in ventral view, and the cotyle is ovoid in anterior view. Considering the strong morphological affinities between the fossil vertebrae and our modern specimen of E. j. copeae and the fact that this sub-species currently occurs on the Guadeloupe Islands, the fossils may belong to that sub-species. However, because comparative specimens of Erythrolamprus juliae are scarce (n = 5) we are unable to determine if the observed morphological differ - ences between fossils and our modern specimens are reliably diagnostic at the sub-species level. We thus conservatively identify these six fossil vertebrae as Erythrolamprus juliae cf. copeae. A gross comparison of the centrum length of fossil vertebrae with modern specimens indicates fossils snakes were about 44-54 cm in total length, a size similar to the modern individuals of E. j. copeae (see Breuil 2002). Superfamily colubroidea Oppel, 1811 eXamined material. — 128 bone elements all representing colubridae (sensu lato) fragmented pre-cloacal and post-cloacal vertebrae could not be identified to the genus level. MORPHOMETRIC ANALYSIS OF MODERN AND FOSSIL VERTEBRAE The first analysis was conducted on only four variables (CL, MLV, WIC, and WP) and includes all fossil morphotypes described above (n=312 specimens). The two first axes of the PCA (Fig. 7A) reflect the significant differences occuring between modern Alsophis and Erythrolamprus (Manova, p. val<0.01), which do not exhibit any morphological overlap in the PCA. Fossil Erythrolamprus vertebrae do not significantly differ from modern Erythrolamprus (Manova, p.val>0.01), but they do differ significantly from both fossil (Manova, p. val<0.01) and modern (Manova, p.val<0.01) Alsophis. The morphology of fossil Erythrolamprus seems intermediate between our two modern Erythrolamprus species, but the limited number of available variables and comparative specimens do not allow for a specific attribution for the Erythrolamprus fossils. Still, morphometric data confirm the generic attribution made on the basis of morphological criteria. Concerning Alsophis, this analysis reveals no significant differences between modern A. antillensis and A. rufiventris (Manova, p.val>0.01); these two species thus are considered together in subsequent analyses. The results reveal significant differences between the two fossil Alsophis morphotypes (Manova, p.val<0.01) and between the modern A. antillensis/rijgersmaei and A. rufiventris (Manova, p.val<0.01). Fossil A. antillensis vertebrae, although being significantly different from modern A. rufiventris (Manova, p.val<0.01), not significantly differ from modern A. antillensis/rijgersmaei (Manova, p.val>0.01). Our second fossil Alsophis morphotype, however, is significantly different from all modern taxa (Manova, p.val>0.01). The Mahalanobis distance tree constructed on the results of a LDA performed on the axes of the above mentioned PCA (Fig. 7B) confirms the intermediate position of fossil Erythrolamprus between modern E. juliae copeae and E. perfuscus, as well as the morphological similarities between modern and fossil Alsophis. The second analysis performed on all the variables and limited to Alsophis fossil and modern vertebrae reveals that most of fossil Alsophis antillensis vertebrae fall in the range of variability of modern A. antillensis and A. rijgersmaei (Fig. 7C). Alsophis antillensis fossil vertebrae do not significantly differ from modern A. antillensis and A. rijgersmaei considered as a single group (Manova, p.val>0.01), but differ from both modern species taken individually (Manova, p.val<0.01). The position of Alsophis sp. 2 vertebrae on the two first axis of the PCA is intermediate between the three modern Alsophis species included in our study (A. antillensis, A. rijgersmaei, and A. rufiventris). It slightly overlaps the morphological diversity of fossil Alsophis antillensis and A. rufiventris. Manova tests indicate that Alsophis sp. 2 vertebrae significantly differ from all fossil and modern groups (Manova, p.val<0.01). However, the small number of Alsophis sp. 2 specimens available to conduct the statistical tests makes the results difficult to 515 Fossil dispadids from the Guadeloupe Islands GEODIVERSITAS • 2019 • 41 (12) interpret. The Mahalanobis distance tree (Fig. 7D) further confirms the morphological similarities between modern A. rufiventris and fossil Alsophis sp. 2, which are closer to each other than with other species of the sample. In the same analysis, fossil Alsophis antillensis is as distant from A. rufiventris as from A. rijgersmaei. This distance is similar to that between Alsophis sp. 2 and A. rufiventris. Our two morphometric analyses confirm the results of the morphological observations, but fail to provide further resolution for the taxonomic affinities of the fossil vertebrae. This likely was due to the small number of available modern specimens, which fail to capture the full morphological variability within each taxon. Concerning only fossil A. antillensis vertebrae, the analysis conducted on four variables indicates significant differences (Manova, p.val<0.01) between vertebrae collected on the different Guadeloupe Islands, but these differences are no longer significant if the analysis is conducted on eight variables (Manova, p.val>0.01). Considering the small number of available specimens in the eight variables analysis and the possible bias impacting the analysis conducted on four variables we are unable to state whether the observed differences represent true morphological differences that reflect taxonomic differences. The analysis of four variables also indicates no differences between vertebrae collected in Pleistocene and Holocene layers on Marie-Galante Island -4 -2 0 2 4 6 8 -2 -1 0 1 2 3 4 Axis 1 (58.32%) Axis 2 (18.06%) Fossil Alsophis antillensis Modern Alsophis antillensis Fossil Alsophis sp. 2 Modern Alsophis rijgersmaei Modern Alsophis rufiventris (Duméril, Bibron & Duméril, 1854) A C B D Modern Alsophis rufiventris1 Fossil Alsophis sp. 2 2 Modern Alsophis antillensis 3 Fossil Alsophis antillensis 4 Modern Alsophis rijgersmaei 5 1 2 3 4 5 1 2 Modern Alsophis rufiventris1 Fossil Alsophis sp. 2 2 Modern Alsophis antillensis/rijgersmaei 3 Fossil Alsophis antillensis 4 Erythrolamprus perfuscus 5 Fossil Erythrolamprus juliae cf. copeae 6 Erythrolamprus juliae copeae 7 5 6 7 3 4 -4 -2 0 2 4 6 –4 –3 –2 –1 0 1 2 Axis 1 (66.95%) Axis 2 (24.65%) Fossil Alsophis antillensis (Schlegel, 1837) Modern Alsophis antillensis Modern Erythrolamprus juliae copeae Fossil Erythrolamprus juliae cf. copeae (Parker, 1936)Fossil Alsophis sp. 2 Modern Erythrolamprus perfuscus (Cope, 1862) Modern Alsophis rijgersmaei Cope, 1869 Modern Alsophis rufiventris fig. 7. — Results of statistical analyses of fossil and modern dipsadid snake vertebrae on the Guadeloupe Islands: A, two first axes of the PCA conducted on the maximum number of specimens (first analysis); B, Mahalanobis distance tree obtained from the results of the LDA (first analysis); C, two first axes of the PCA conducted on the maximum number of measurements (second analysis); D, Mahalanobis distance tree obtained from the results of the LDA (second analysis). 516 GEODIVERSITAS • 2019 • 41 (12) Bochaton C. et al. (Manova, p.val>0.01); however, the samples are too small to test potential morphological difference between vertebrae collected in archaeological and natural deposits. ZooarchaeoloGical analysis The 438 snake bones recovered from archaeological deposits (Table 1) are mostly vertebrae. With the exception of the Grande-Anse de Terre-de-Bas site, the number of specimens collected from each archaeological site does not exceed 72 and is below 50 for most of them (Table 1). Considering the number of vertebrae occurring in a complete Alsophis antillensis specimen (more than 280 – pers. obs.), the minimal number of individuals (MNI) of each site never exceeds one, making occurrences of snake fossils, although nearly ubiquitous, a minor component in archaeological sites. Among vertebrae collected from archaeological deposits, only four sites (Anse Petite-Rivière, Sainte-Rose La Ramée, Anse à la Gourde, and Tourlourous) yielded specimens exhibiting burning traces. No cut marks were observed on any specimens included in our study. The size distribution of vertebrae (centrum length) in archaeological sites (Fig. 8A) is partly similar to that in natural deposits (Fig. 8B), although it is significantly different (t. test, p.val<0.01). The main difference concerns the lack of specimens less than 3 mm long in archaeological sites. This clearly reflects a recovery bias, because mesh size used to recover small bones are mostly 2.7 mm² for archaeological deposits versus 2 mm² or less for natural deposits. Aside from that difference, both types of sites have a good representation of vertebrae between 3 and 4 mm long and a decreasing proportion of vertebrae between 4 and 6.5 mm long. This similarity is confirmed by the t. test, which demonstrates that size distributions at both types of site is no longer significantly different if specimens below 3 mm are removed (t. test, p.val>0.01). Both kinds of sites tend to lack vertebrae from large-sized snakes. This bias could be explained in natural deposits where raptors, possibly being the accumulator agents, may avoid the largest snakes. In archaeological deposits, the absence of large specimens could indicate mutual avoidance between large snakes and humans. DISCUSSION past Guadeloupe dipsadid snake diversity Morphological and morphometric evidences demonstrate the occurrence of three distinct dipsadid snake fossil morphotypes on the Guadeloupe Islands. The first morphotype corresponds to Alsophis antillensis, an endemic snake of the Guadeloupe Islands currently occurring on Basse-Terre and Grande-Terre islands. Fossil evidence demonstrates this species occurred on all islands of the Guadeloupe archipelago in the past (Fig. 9), at least during Amerindian occupation. Fossil data supports the historical writings of Jean-Baptiste Du Tertre (1654, 1667), who stated this snake occurred on all Guadeloupe islands in the 17th century. However, the maximum size of our fossils (around 150 cm of total length) is clearly lower than the maximum size described by Du Tertre (190 cm). This is raises questions about how representative the fossil assemblages are, if larger specimens may be excluded from the fossil record. We also attribute the fossil vertebrae collected on Les Saintes Islets to A. antillensis. However, although we did not observe differences between fossils vertebrae collected on Les Saintes and other Guadeloupe islands, the vertebral morphology of the species occurring nowadays in Les Saintes islands, A. sanctonum, remains unknown. This raises the possibility that at least some specimens from Les Saintes may pertain to A. sanctonum. The second fossil morphotype corresponds to a member of the genus Erythrolamprus (E. juliae cf. copeae). This morphotype is far scarcer in the fossil assemblages and only occurs on Basse-Terre and Grande-Terre Islands in Amerindian deposits (Fig. 9). This constitutes the first fossil report of this genus in the archipelago. Nowadays, E. juliae occurs in Basse-Terre and Grande-Terre islands, but is absent from all others islands (Powell & Henderson 2012), with the exception of Marie-Galante where it is reported as having gone extinct (Henderson 1992; Breuil 2002). This snake also was probably mentioned by Du Tertre (1667) who signaled its occurrence on all Guadeloupe islands. The scarcity of this snake in fossil deposits possibly Frequency 3 4 5 6 0 10 20 30 40 N = 106 0 10 20 30 2.5 6.5 Centrum Length (CL) in mm 3 4 5 61.5 6.5 Centrum Length (CL) in mm 2 Frequency N = 134 AB fig. 8. — Distribution of size (centrum length) of snake vertebrae from archaeological deposits (A) and natural deposits (B) on the Guadeloupe Islands. 517 Fossil dispadids from the Guadeloupe Islands GEODIVERSITAS • 2019 • 41 (12) provides a distorted image of its past distribution in Guadeloupe. However, the absence of Erythrolamprus in the Marie-Galante fossil record is difficult to explain considering the large numbers of snake vertebrae discovered in the rich fossil bearing deposits on this island. The only physical evidence for the past occurrence of Erythrolamprus on Marie-Galante Island are old museum specimens collected in 1886 prior to the putative extinction of the genus on this island, which occurred around 1880 following Henderson (1992) or later, as hypothesized by Breuil (2002). Fossil and archaeological data however do not confirm the past occurrence of this snake on Marie-Galante. The third fossil dipsadid snake corresponds to an unidentified member of the genus Alsophis, which occurred in the past on all Guadeloupe islands. This small fossil snake shares morphological similarities with A. rufiventris, but has proved impossible to identify at species level due to the lack of data regarding the osteology of modern Alsophis. Only two species of Alsophis, A. antillensis and A. sanctonum, are known to have occurred on the Guadeloupe Islands and these fossil elements are the first evidence for the past occurrence of another species that is nowadays extinct. Interestingly, this snake does not correspond to the third enigmatic black snake described by Du Tertre (1654, 1667) that is reported to reach around seven feet (224 cm) in total length, making it far larger than our fossil Alsophis sp. 2 (max. 120 cm in total length). Should the snake described by Du Tertre really have existed in the past, it is possible than four species of dipsadid snakes occurred in the Guadeloupe Islands. are paleontoloGical and archaeoloGical deposits an accurate tool to appreciate past Guadeloupe snake biodiversity? Snakes remains are often found in archaeological deposits. In our opinion, there is no clear evidence for any selection and consumption of these animals by Amerindians populations for the following reasons: 1) lack of large specimens; 2) similar size distributions of snakes in both archaeological and natural deposits; 3) scarcity of burning traces; and 4) total absence of butchering marks. At least one historical account supports this idea. The Anonymous of Carpentras (1618), who described the daily life of Lesser Antillean Amerindians from Dominica and la Martinique at the beginning of the 17th century, stated that Amerindians “do not catch nor consumed eels because they are sisters of snakes” (Anonymous of Carpentras 1618: 146, translated from French). This could be interpreted as a culinary taboo or fear related to snakes and snake-like animals such as eels. The low occurrence of snake bones in archaeological deposits might be explained by these animals opportunistically feeding on insects and small lizards, which are known to be part of their diet (Henderson & Bourgeois 1993; Henderson & Sajdak 1996), attracted by food waste left by Amerindians in the vicinity of their villages. The fact that snakes were not hunted and consumed by Amerindians could explain that large snakes, if any was present in Guadeloupe as suggested by Du Tertre (1667), were not discovered in archaeological sites. Probably also because they were more exposed to be killed by humans if found near their settlement places, compared to their more harmless smaller congeners. Regardless of the reason(s) why fig. 9. — Fossil and modern occurrences of the three dipsadid species identified on the Guadeloupe Islands at the different chronological intervals. Les Saintes Late Pleistocene Pre-anthropic Holocene Amerindian periods Nowadays Alsophis antillensis and sanctonum Present Present Alsophis sp. 2 Present Absent Erythrolamprus juliae ssp. Absent Absent Grande-Terre Alsophis antillensis Present Present Alsophis sp. 2 Present Absent Erythrolamprus juliae cf. copeae Present Present Basse-Terre Alsophis antillensis Present Present Alsophis sp. 2 Present Absent Erythrolamprus juliae cf. copeae Present Present La Désirade Alsophis antillensis Present Absent Alsophis sp. 2 Present Absent Erythrolamprus juliae ssp. Absent Absent Petite-Terre Alsophis antillensis Present Absent Alsophis sp. 2 Absent Absent Erythrolamprus juliae ssp. Absent Absent Marie-Galante Alsophis antillensis Present Present Present Absent Alsophis sp. 2 Present Present Present Absent Erythrolamprus juliae ssp. Absent Absent Absent Absent No Data No Data No Data No Data No Data No Data No Data No Data No Data No Data No Data No Data No Data No Data No Data 518 GEODIVERSITAS • 2019 • 41 (12) Bochaton C. et al. large-sized snakes are underrepresented in archaeological sites, it is evident that archaeological assemblages incompletely document past biodiversity. Currently available fossil material is thus unsuitable to discard the possible past occurrence of more snakes than those we observed in the deposits. The image of the snake past diversity that we provided should thus be considered a minimum estimation of what it could have been during the last millennia. Following from the above, a report of a non-xenodontine snakes in the region observe commentary. The genus Clelia Fitzinger, 1826, for which the hypothesis of it having occurred in Guadeloupe is only based on the historical description of the large black snake by Du Tertre (see Breuil 2002). Clelia currently only occurs on the southern Islands of Grenada and Sainte-Lucia (Henderson & Powell 2009) and there is no fossil evidence of its occurrence in Guadeloupe. Citations in the PhD work of Grouard (2001b) mentioned the occurrence of fossil Clelia in Guadeloupe, but specimens of this snake were never identified or mentioned by Grouard. The sole report of Clelia in the Lesser Antilles based on a fossil was a vertebra described by Auffenberg (1958) from Barbuda. As mentioned in our account for Alsophis sp. 2 this specimen is lost and likely pertains instead to Alsophis. The last argument for the occurrence of Clelia in Guadeloupe concerns a museum specimen of the continental species Clelia clelia (MNHN-RA-0.169) indicated as originating from Guadeloupe, but for which provenance was considered as “undoubtedly erroneous” by Underwood (1993). In summary, there is no compelling evidence for Clelia in Guadeloupe. evolution oF Guadeloupe dipsadid snake biodiversity throuGh time Our results provide new insight regarding the evolution of snake biodiversity on the Guadeloupe Islands through time. Concerning, the putative effect of the Pleistocene/Holocene transition on snake biodiversity can only be assessed for Marie-Galante Island, because that is the sole island for which a Pleistocene and early Holocene fossil record is available. Based on our reidentification of Colubroidea sp. 2 of Bochaton et al. (2015), and of Colubridae sp. 2 of Bailon et al. (2015) as Alsophis sp. 2, we can exclude those earlier identified taxa as having gone extinct. Here we report examples of (Alsophis sp. 2) in one of the Marie-Galante pre-Columbian archaeological deposit (Tourlourous/Stade José Bade). Based on current evidence and identifications, the sole squamate extinction occurring at the end of the Pleistocene on Marie-Galante seems to be that of Boa blanchardensis (see Bochaton & Bailon 2018). During pre-Columbian times, we demonstrate the occurrence of at least three dipsadid taxa on the Guadeloupe Islands (Fig. 9): Alsophis antillensis (on all six islands), Alsophis sp. 2 (on five islands), and Erythrolamprus juliae cf. copeae (on at least two islands) (Fig. 9). Fossil and archaeological data combined with current snake biodiversity in Guadeloupe provide evidence for several extirpations and extinctions during modern times. Alsophis antillensis/sanctonum nowadays only occurs on BasseTerre, Grande-Terre, and Les Saintes islands, although historically having been present also on La Désirade, Petite-Terre, and Marie-Galante Islands (Fig. 9). Nowadays, Erythrolamprus juliae only occurs on Basse-Terre and Grande-Terre Islands, from where fossils of this species were discovered (Table 1; Fig. 9). However, this species possibly underwent extirpation on Marie-Galante islands (Barbour 1914; Henderson 1992; Breuil 2002) although we did not identify any fossils on this island. This taxon is scarce in fossil deposits and there is a possibility that past populations may have existed on La Désirade, Petite-Terre, and Les Saintes islands, although this currently lacks any fossil evidence. Our Alsophis sp. 2 occurred on nearly all islands during pre-Columbian times, but is no longer present in Guadeloupe (Fig. 9). In summary, dipsadid snakes underwent at least one extinction (Alsophis sp. 2), at least three extirpations of Alsophis antillensis, and one extirpation of Erythrolamprus juliae during modern time. The obtained global extinction/extirpation rate for dipsadid snake species occurring in Guadeloupe before the 17th century is 61%. This rate may be even higher (70%) if past dipsadid snakes described in historical reports, but not yet confirmed by fossil remains, are included. The global extinction rate of snakes during the Holocene is slightly impacted by adding non-dipsadid Guadeloupe snake taxa. Fossil typhlopid snakes remains were discovered on Basse-Terre, Grande-Terre and Marie-Galante Islands (CB pers. obs.; Bochaton et al. 2015; Bailon et al. 2015) but this taxon is only nowadays extinct on the last island (Powell & Henderson 2012; Breuil 2002). Considering boid snakes, although fossils of Boa were discovered in Pleistocene layers on Marie-Galante Island, there remains no strong evidence of the occurrence of a native Boa during Holocene on the Guadeloupe islands. Consequently the minimal global extinction/extirpation rate for snakes during the Holocene on the Guadeloupe Islands would be of 56%. This rate is similar to the one observed for lizards on MarieGalante Island (57%, see Bailon et al. 2015). Extinction rates of squamates on Marie-Galante Island are difficult to compare to other Lesser Antillean islands, because the later often lack informative fossil records. Still, a comparison can be made with the squamates of Antigua and Barbuda Islands, which are well documented from a paleontological point of view (Etheridge 1964; Steadman et al. 1984; Pregill et al. 1988). Paleontological and modern data indicated squamate extinction rates of 40% for Antigua and Barbuda but, higher rates of 66% (four of six species) for snakes (Etheridge 1964; Steadman et al. 1984; Pregill et al. 1988; Powell & Henderson 2012). The similar results observed on these islands demonstrate the strong impact of anthropic phenomenon on snakes during the last centuries. This strong extinction rate of snakes could have several explanations including systematic hunting by Man, predation by exogenous mammalian predators, destruction of their habitats, or a combination of those factors. The strong extinction rate of squamates, however, is not surprising considering the numerous extinction events also recorded for other West Indian taxa such as mammals (litt. rev. in Cooke et al. 2017) and birds (see e.g. Steadman et al. 2015). Our results demonstrate how fossil data can help evaluate the extinction rates of insular snake faunas in response to anthropic modifications and reveal the vulnerability of 519 Fossil dispadids from the Guadeloupe Islands GEODIVERSITAS • 2019 • 41 (12) snakes to extinction phenomenon. Human impact on snake biodiversity in the Lesser Antilles is most likely still largely underestimated considering the lack of fossil data on most islands and the gap in the distribution of some taxa (e.g. Boa) across islands. Another difficulty concerns the specific identification of fossil snakes, which is made more complex by the lack of comparative specimens (Bell & Mead 2014) although it is possible using the appropriate reference sample (see e.g. Mead & Steadman 2017). Consequently, it is likely that several other now extinct fossil snakes still wait to be discovered and described in the Lesser Antilles. However, this can only be done by conducting fieldwork on the numerous islands lacking a fossil record and by devoting much more attention to the exhaustively documenting the osteological morphology of modern taxa. Acknowledgements The authors are extremely grateful to James Gardner who reviewed and provided several comments regarding this study along with an extensive revision of the English of this paper. We are also grateful to Marc Augé who evaluated this work and provided several comments helping us to improve this study. We sincerely thank the Museum of Comparative Zoology (J. Rosado), and the Muséum national d’Histoire naturelle (N. Vidal) for the loan of museum specimens. We thank C. Sheehy for allowing us the access to the collections of the Florida Museum of Natural History. We are also grateful to the team of CeMIM (USM 0504, Department RDDM, MNHN) for access to their three-dimensional workstation. X-ray CT at the University of Poitiers, which was supported by grants from the Poitou-Charentes Région (16-17-79-86). We also wish to thank all the excavation directors of the studied sites: P. Bodu, D. Bonnissent, M. Boudadi-Maligne, F. Casagrande, A. Chancerel, E. Clerc, C. Colas, P. Courtaud, A. Delpuech, P. Fouéré, J. Gagnepain, C. Hofman, M. Hoogland, A. Lenoble, M.-A. Paulet-Locart, T. Romon, N. Sellier-Segard, N. Serrand, C. Stouvenot, and M. de Waal. The main contributor of this work (CB) is funded by a fellowship granted by the FYSSEN foundation. REFERENCES albino a. m. 2011. — Morfología vertebral de Boa constrictor (Serpentes: Boidae) y la validez del género mioceno Pseudoepicrates Auffenberg, 1923. Ameghiniana 48 (1): 53‑62. https://doi. org/10.5710/AMGH.v48i1(302) a nonymous oF c arpentras 1618. — Relation d’un Voyage infortuné fait aux Indes Occidentales par le Capitaine Fleury avec la Description de quelques Isles qu’on y rencontre, par l’un de ceux de la Compagnie qui fit le Voyage, in moreau J. P. (ed.), Un flibustier français dans la mer des Antilles 1618-1620. Petite bibliothèque Payot, Paris, 328 p. https://gallica.bnf.fr/ark:/12148/btv1b53184366n auFFenberG w. 1958. — A small fossil herpetofauna from Barbuda, Leeward Islands, with the description of a new species of Hyla. Quarterly Journal of the Florida Academy of Science 21: 248‑254. http://www.biodiversitylibrary.org/page/41494603 b ailon s., b ochaton c. & l enoble a. 2015. — New data on Pleistocene and Holocene herpetofauna of Marie-Galante (Blanchard Cave, Guadeloupe Islands, French West Indies): Insular faunal turnover and human impact. Quaternary Science Reviews 128: 127‑137. https://doi.org/10.1016/j.quascirev.2015.09.023 barbour t. 1915. — Recent notes regarding West Indian reptiles and amphibians. Proceedings of the Biological Society of Washington 28: 71‑78. http://www.biodiversitylibrary.org/page/3338480 barbour t. 1914. — A Contribution to the Zoögeography of the West Indies, with Especial Reference to Amphibians and Reptiles. Harvard Universitary Press, Cambridge, 174 p. https://doi.org/10.5962/ bhl.title.49187 barnosky a. d., matZke n., tomiya s., woGan G. o. u., swartZ b., Quental t. b., marshall c., mcGuire J. l., lindsey e. l., maGuire k. c., mersey b. & Ferrer e. a. 2011. — Has the Earth’s sixth mass extinction already arrived? Nature 471 (7336): 51‑57. https://doi.org/10.1038/nature09678 beets c. J., troelstra s. r., Grootes p. m., nadeau m.-J., borG k. van der, JonG a. F. m. de, hoFman c. l. & hooGland m. l. p. 2006. — Climate and pre-Columbian settlement at Anse à la Gourde, Guadeloupe, Northeastern Caribbean. Geoarchaeology 21 (3): 271-280. https://doi.org/10.1002/gea.20096 bell c. J. & mead J. i. 2014. — Not enough skeletons in the closet: collections-based anatomical research in an age of conservation conscience. The Anatomical Record 297 (3): 344‑348. https:// doi.org/10.1002/ar.22852 bérard b. 2013. — The Saladoid, in keeGan w. F., hoFman c. l. & ramos r. r. (eds), The Oxford Handbook of Caribbean Archaeology. Oxford University Press, Oxford: 184‑197. https://doi. org/10.1093/oxfordhb/9780195392302.013.0065 bochaton c. & bailon s. 2018. — A new fossil species of Boa Linnaeus, 1758 (Squamata, Boidae) from the Pleistocene of MarieGalante Island (French West Indies). Journal of Vertebrate Paleontology 38 (3). https://doi.org/10.1080/02724634.2018.1462829 bochaton c., Grouard s., cornette r., ineich i., tresset a. & bailon s. 2015. — Fossil and subfossil herpetofauna from Cadet 2 Cave (Marie-Galante, Guadeloupe Islands, F. W. I.): Evolution of an insular herpetofauna since the Late Pleistocene. Comptes Rendus Palévol 14 (2): 101‑110. https://doi.org/10.1016/j.crpv.2014.10.005 bochaton c., bailon s., ineich i., breuil m., tresset a. & G rouard s. 2016a. — From a thriving past to an uncertain future: Zooarchaeological evidence of two millennia of human impact on a large emblematic lizard (Iguana delicatissima) on the Guadeloupe Islands (French West Indies). Quaternary Science Reviews 150: 172‑183. https://doi.org/10.1016/j.quascirev.2016.08.017 bochaton c., boistel r., cassaGrande F., Grouard s. & bailon s. 2016b. — A fossil Diploglossus (Squamata, Anguidae) lizard from Basse-Terre and Grande-Terre islands (Guadeloupe, French West-Indies). Scientific Report 28475 (6): 1‑12. https:// doi.org/10.1038/srep28475 b ochaton c., b ailon s., h errel a., G rouard s., i neich i., tresset a. & cornette r. 2017. — Human impacts reduce morphological diversity in an insular species of lizard. Proceedings of the Royal Society B: Biological Sciences 284 (1857): 20170921. https://doi.org/10.1098/rspb.2017.0921 bochaton c., boistel r., Grouard s., ineich i., tresset a. & bailon s. 2019. — Evolution, diversity and interactions with past human populations of recently extinct Pholidoscelis lizards (Squamata: Teiidae) from the Guadeloupe Islands (French WestIndies). Historical Biology 31 (2): 140-146. https://doi.org/10.1 080/08912963.2017.1343824 bodu p. 1984. — Rapport sur les deux ateliers de débitage en Désirade. Conseil Général Guadeloupe, Basse-Terre (Guadeloupe). b odu p. 1985. — Rapport de fouille « les Sables », Beauséjour, la Désirade. Conseil Général Guadeloupe, Basse-Terre (Guadeloupe). boistel r., herrel a., lebrun r., daGhFous G., taFForeau p., l osos J. b. & v anhooydonck b. 2011. — Shake rattle and roll: the bony labyrinth and aerial descent in squamates. Integrative and Comparative Biology 56 (4): 957‑968. https:// doi.org/10.1093/icb/icr034 520 GEODIVERSITAS • 2019 • 41 (12) Bochaton C. et al. bonaparte c. l. 1838. — Synopsis vertebratorum systematis. Amphibiorum Tabula Analytica. Nuovi Annali delle Scienze Naturali 1: 391‑397. https://biodiversitylibrary.org/page/9326555 b onnissent d. 2008. — Archéologie précolombienne de l’île de Saint-Martin, Petites Antilles (3300 BP-1600 AD). Université Aix-Marseille, Aix-Marseille, 617 p. https://tel.archives-ouvertes. fr/tel-00403026 bonnissent d. & romon t. 2004. — Fouille de la Cathédrale de Basse-Terre. INRAP, Service régional de l’archéologie de Guadeloupe, Basse-Terre, 51 p. boudadi-maliGne m., bailon s., bochaton c., cassaGrande F., G rouard s., s errand n. & l enoble a. 2016. — Evidence for historical human-induced extinctions of vertebrate species on La Désirade (French West Indies). Quaternary Research 85 (1): 54‑65. https://doi.org/10.1016/j.yqres.2015.11.001 breuil m. 2002. — Histoire naturelle des Amphibiens et Reptiles terrestres de l’archipel Guadeloupéen : Guadeloupe, Saint-Martin, Saint-Barthélémy. Muséum national d’Histoire naturelle, Paris, 348 p. (Patrimoines naturels ; 54). b reuil m., G uiouGou F., Q uestel k. & i béné b. 2009. — Modifications du peuplement herpétologique dans les Antilles françaises, disparitions et espèces allochtones 2ème partie : reptiles. Le Courrier de la Nature 251: 36‑43. casaGrande F., hildebrand m., serrand n. & Grouard s. 2010. — Sainte Rose la Ramée, in Bilan Scientifique Guadeloupe 2007. Ministère de la culture, Direction du patrimoine, Sousdirection de l’archéologie, Paris: 85-90. case t., bolGer d. & richman a. 1992. — Reptilian Extinctions: The Last Ten Thousand Years, in Fiedler p. & Jain S. (eds), Conservation Biology. Springer, Boston: 91‑125. https:// doi.org/10.1007/978-1-4684-6426-9_5 ceballos G., ehrlich p. r., barnosky a. d., García a., prinGle r. m. & palmer t. m. 2015. — Accelerated modern human-induced species losses: entering the sixth mass extinction. Science Advances 1 (5): e1400253. https://doi.org/10.1126/sciadv.1400253 c lerc e. 1964. — Le peuplement précolombien des Antilles et ses vestiges en Guadeloupe. Bulletin de la Société d’Histoire de la Guadeloupe 2: 18‑32. https://doi.org/10.7202/1044237ar colas c., bertran p., chancerel a., chancerel G. & richard J.-m. 2002. — Le Tourlourous. INRAP, Service régional de l’archéologie de Guadeloupe, Marie-Galante. cooke s. b., dávalos l. m., mychaJliw a. m., turvey s. t. & upham n. s. 2017. — Anthropogenic extinction dominates Holocene declines of West Indian mammals. Annual Review of Ecology, Evolution, and Systematics 48 (1): 301‑327. https://doi. org/10.1146/annurev-ecolsys-110316-022754 cope e. d. 1895. — The classification of the ophidia. Transactions of the American Philosophical Society 18: 186‑219. https://doi. org/10.2307/1005387 cope e. d. 1879. — Eleventh contribution to the herpetology of tropical America. Proceedings of the American Philosophical Society 18 (104): 261‑277. http://www.biodiversitylibrary.org/ page/7337315 crabtree p. J. 2016. — Zooarchaeology in Oceania: An overview. Archaeology in Oceania 51 (1): 1‑6. https://doi.org/10.1002/ arco.5089 c undall d. & i rish F. 2008. — The snake skull, in G ans c., G aunt a. s. & a dler k. (eds), The Skull of Lepidosauria. Society for the Study of Amphibians and Reptiles, New-York: 349‑362. delpuech a., hoFman c. & hooGland m. 1997. — Fouilles sur le site précolombien de l’Anse à la Gourde (Saint-François, Guadeloupe). Journal de la Société des Américanistes 83 (1): 279-282. delpuech a., hoFman c. l. & hooGland m. l. p. 2001. — Excavations at the site of Anse à la Gourde, Guadeloupe. Organization, history and environmental setting, in Proceedings of the XVIIIth Congress for Caribbean Archaeology. IACA, Grenada: 156-161. d elpuech a., h oFman c. l. & h ooGland m. l. 2003. — Premiers horticulteurs amérindiens dans l’archipel Guadeloupéen : Morel I (Le Moule) et la question Huecan/Cedrosan Saladoïde, in d elpuech a., G iraud J. p. & h esse A. (eds), Archéologie précolombienne et coloniale des Caraïbes, Actes du 123e Congrès national des sociétés historiques et scientifiques. Éditions du CTHS, Paris: 127-139. de rocheFort c. d. 1658. — Histoire naturelle et morale des Îles Antilles de l’Amérique. Histoire générale des Antilles habitées par les Français. Arnould Liers, Rotterdam, 558 p. https://doi. org/10.5962/bhl.title.61244 de waal m. s. 2006. — Pre-Columbian Social Organization and Interaction Interpreted through the Study of Settlement Patterns: an Archaeological Case-Study of the Pointe des Châteaux, La Désirade and les Îles de la Petite-Terre Micro-Region, Guadeloupe, F.W.I. Leiden University, Leiden, 419 p. du tertre J.-b. (r. p.) 1654. — Histoire générale des isles de S. Christophe, de la Guadeloupe, de la Martinique, et autres dans l’Amérique. Chez Jacques Langlois et Emmanuel Langlois, Paris, 542 p. https://doi.org/10.5962/bhl.title.61174 d u t ertre J.-b. (r. p.) 1667. — Histoire générale des Antilles habitées par les François. T. Jolly, Paris, 551 p. https://doi.org/10.5962/ bhl.title.119250 duméril a. m. c., bibron G. & duméril a. h. a. 1854. — Erpétologie générale ou histoire naturelle complète des reptiles, Tome VII. Librairie encyclopédique de Roret, Paris, 780 p. https://doi. org/10.5962/bhl.title.45973 etheridGe r. 1964. — Late Pleistocene lizards from Barbuda, British West Indies. Bulletin of the Florida State Museum 9 (2): 43‑76. FitZinGer l. 1843. — Systema reptilium. Braumüller & Seidel, Germany, 106 p. https://doi.org/10.5962/bhl.title.4694 FitZpatrick s. m. 2015. — The pre-columbian Caribbean: colonization, population dispersal, and island adaptations. PaleoAmerica 1 (4): 305‑331. https://doi.org/10.1179/2055557115Y.0000000010 Fouéré p., bailon s., bonnissent d., chancerel a., courtaud p., Grouard s., lenoble a., mora p., pinçon k. & QueFFelec a. 2011. — La grotte du Morne Rita (Commune de Capesterre de Marie-Galante, Guadeloupe). INRAP, Service régional de l’archéologie de Guadeloupe, Marie-Galante, Guadeloupe, 92 p. Fouéré p., chancerel a., courtaud p., Grouard s., lenoble a., monney J., mora p., pinçon k., QueFFelec a. & tomadini n. 2012. — La grotte du Morne Rita (Commune de Capesterre de Marie-Galante, Guadeloupe). INRAP, Service régional de l’archéologie de Guadeloupe, Marie-Galante, Guadeloupe, 161 p. GaGnepain J., luZi c., serrand n. & stouvenot c. 2007. — Première approche du site de Caille à Bélasse : Campagne de 20062007. Direction régionale des affaires culturelle de Guadeloupe, Basse-Terre, Guadeloupe, 65 p. Grouard s. 1999. — Interprétations sur la présence des espèces de vertébrés et de crustacés du site de la Pointe du Helleux-GrandeTerre-Guadeloupe. True Blue, Grenada, 10 p. Grouard s. 2001a. — Faunal remains associated with late Saladoïd and post-Saladoïd occupations at Anse à la Gourde, Guadeloupe, West Indies: Preliminary Results. Archaeofauna 10: 71‑98. G rouard s. 2001b. — Subsistance, systèmes techniques et gestion territoriale en milieu insulaire antillais précolombien – Exploitation des Vertébrés et des Crustacés aux époques Saladoïdes et Troumassoïdes de Guadeloupe (400 av. J.-C. à 1500 ap. J.-C.). Université Paris X, Paris, 1073 p. Grouard s., debue k., Franel y., lenoble a., QueFFelec a. & serrand n. 2014. — Abri de l’Anse à la Gourde, Saint-François, Grande-Terre (niveaux amérindiens et historiques), in Bilan Scientifique Guadeloupe 2010. Ministère de la Culture, Direction du Patrimoine, Sous-Dir. Archéologie, Paris, 59 p. h edGes s. b. 1996. — Historical biogeography of West Indian vertebrates. Annual Review of Ecology and Systematics 27 (2): 163‑196. https://doi.org/10.1146/annurev.ecolsys.27.1.163 hedGes s. b., coulouX a. & vidal n. 2009. — Molecular phylogeny, classification, and biogeography of West Indian racer snakes of the Tribe Alsophiini (Squamata, Dipsadidae, Xenodontinae). Zootaxa 2067: 1‑28. 521 Fossil dispadids from the Guadeloupe Islands GEODIVERSITAS • 2019 • 41 (12) henderson r. 1992. — Consequences of predator introductions and habitat destruction on amphibians and reptiles in the post-columbus West Indies. Caribbean Journal of Science 28 (1‑2): 1‑10. h enderson r. & p owell r. 2009. — Natural History of West Indian Reptiles and Amphibians. University Press of Florida, Gainesville, 496 p. h enderson r. w. & b ourGeois e. 1993. — Notes on the diets of West Indian Liophis (Serpentes: Colubridae). Caribbean Journal of Science 29: 253‑254. henderson r. w. & saJdak r. a. 1996. — Diets of West Indian racers (Colubridae: Alsophis): composition and biogeographic implications, in powell r. & henderson R. W. (eds), Contribution to West Indian herpetology: a Tribute to Albert Schwartz. Society for the Study of Amphibians and Reptiles, New-York:. 327‑338. hoFFstetter r. & Gasc J. p. 1969. — Vertebrae and ribs of modern reptiles, in Gans C. (ed.), Biology of the Reptilia, Volume 1: Morphology. Academic Press, London: 201‑310. hoFman c. l. & hooGland m. l. p. 1994. — Le site de GrandeAnse (Terre-de-Bas, Les Saintes). Direction régionale des affaires culturelle de Guadeloupe, 17 p. h oFman c. l., h ooGland m. l. p. & d elpuech a. 1999. — New perspectives on a Huecan Saladoïd assemblage on Guadeloupe: the case of Morel I, in hoFman c. l. & hooGland m. l. p. (eds), Archaeological Investigations on St. Martin (Lesser Antilles). The sites of Norman Estate, Anse des Pères and Hope Estate, with a contribution to the “la Hueca problem”. Leiden UniversityPress, Leiden: 303‑312. http://hdl.handle.net/1887/13508 holman J. a. 2000. — Fossil Snakes of North America: Origin, Evolution, Distribution, Paleoecology. Indiana University Press, Bloumington, 412 p. hooGland m. l. & hoFman c. 1994. — Pointe du Helleux, site n° 97128001, (Guadeloupe, Sainte-Anne), prospection et sondages 1994. DRAC Guadeloupe, Service régional de l’Archéologie, 20 p. honoré s. 2014. — Évaluation du potentiel archéologique du site de l’Anse du Coq, Marie-Galante, Guadeloupe, in Actes du XXIVe Congrès de l’Association internationale d’Archéologie de la Caraïbe. AIAC, Fort-de-France: 240‑248. hsiou a. s. & albino a. m. 2010. — New snake remains from the Miocene of northern South America. The Herpetological Journal 20 (4): 249‑259. J ohnson c. n., b almFord a., b rook b. w., b uettel J. c., G aletti m., G uanGchun l. & w ilmshurst J. m. 2017. — Biodiversity losses and conservation responses in the Anthropocene. Science 356 (6335): 270‑275. https://doi.org/10.1126/science.aam9317 keeGan w. F., hoFman c. l. & ramos r. r. 2013. — The Oxford Handbook of Caribbean Archaeology. Oxford University Press, Oxford, 617 p. https://doi.org/10.1093/oxfordhb/9780195392302.001.0001 lasserre G. 1961. — La Guadeloupe : étude géographique. Tome 1 : Le milieu naturel et l’héritage du passé. Union française d’impression, Bordeaux, 448 p. lauridsen h., hansen k., wanG t., aGGer p., andersen J., knudsen p. s., rasmussen a. s., uhrenholt l. & pedersen m. 2011. — Inside out: modern imaging techniques to reveal animal anatomy. PLoS ONE 6 (3). https://doi.org/10.1371/ journal.pone.0017879 lenoble a. 2016. — Grotte des Bambous, Le Moule, in Bilan scientifique 2014 SRA Guadeloupe. Service régional de l’Archéologie, Direction régionale des affaires culturelles d’Ile-de-France, BasseTerre: 33-34. lenoble a., Grouard s., cassaGrande F., serrand n. & romon t. 2008. — Faune fossile des cavités de Guadeloupe. Service régional de l’archéologie de Guadeloupe, Basse-Terre, Guadeloupe, 38 p. lenoble a., Grouard s., Fouéré p. & coutaud p. 2010. — Cavités naturelles de Guadeloupe – aspects géologiques, fauniques et archéologiques. Service régional de l’Archéologie de Guadeloupe Direction régionale de l’Environnement de la Guadeloupe, Service Patrimoine de la Région Guadeloupe, Basse-Terre, 234 p. linnaeus c. 1758. — Systema Naturae per Regna tria Naturae, secundum Classes, Ordines, Genera, Species, cum characteribus, differentiis, synonymous, locis ed. 10. Volume 1. Laurentii Salvii, Holmiae, Stockholm, 828 p. https://doi.org/10.5962/bhl.title.559 m arX h. & r abb G. b. 1972. — Phyletic analysis of fifty characters of advanced snakes. Field Museum of Natural History 63: 1‑321. https://doi.org/10.5962/bhl.title.2981 mead J. i. & steadman d. w. 2017. — Late Pleistocene snakes (Squamata: Serpentes) from Abaco, The Bahamas. Geobios 50 (5): 431‑440. https://doi.org/10.1016/j.geobios.2017.09.001 m osimann J. e. & J ames F. c. 1979. — New Statistical Methods for Allometry with Application to Florida Red-Winged Blackbirds. Evolution 33 (1): 444‑459. https://doi.org/10.2307/2407633 münch p., lebrun J.-F., cornée J.-J., thinon i., Guennoc p., marcaillou b., b eGot J., b ertrand G., b erc s. b. d. & b iscarrat k. 2013. — Pliocene to Pleistocene carbonate systems of the Guadeloupe archipelago, French Lesser Antilles: a land and sea study (the KaShallow project). Bulletin de la Société géologique de France 184 (1): 99‑110. https://doi.org/10.2113/gssgfbull.184.1-2.99 oppel m. 1811. — Die ordnungen, familien und gattungen der reptilien als prodrom einer naturgeschichte derselben. Joseph Lindauer, Munich, 87 p. https://doi.org/10.5962/bhl.title.4911 paradis e. & schliep k. 2018. — Ape 5.0: an environment for modern phylogenetics and evolutionary analyses in R. Bioinformatics 35: 526-528. https://doi.org/10.1093/bioinformatics/ bty633 parker h. w. 1936. — Some extinct snakes of the West Indies. Annals and Magazine of Natural History 18 (104): 227‑233. https://doi.org/10.1080/00222933608655187 paulet-locard m.-a. & stouvenot c. 2005. — Guadeloupe: Bilan et orientation de la recherche archéologique. Bilan Scientifique Régional 2005: 5‑7. paulet-locard m.-a. & chancerel a. 2005. — Basse-Terre, Gare Maritime, Diagnostic archeologique. SRA Guadeloupe, 15 p. powell r. & henderson r. w. 2012. — Island list of West Indian amphibians and reptiles. Bulletin of Florida Museum of Natural History 51 (2): 85-166. preGill G. k., steadman d. w., olson s. l. & Grady F. v. 1988. — Late Holocene fossil vertebrates from Burma Quarry, Antigua, Lesser Antilles. Smithsonia Contribution to Zoology 463: 1‑27. https://doi.org/10.5479/si.00810282.463 raGe J. c. 1984. — Serpentes, in Handbuch der Paläoherpetologie. Volume 11. Gustav Fischer, Stuttgart, 80 p. raGe J. c. 2001. — Fossil snakes from the Palaeocene of São Jose de Itaborai, Brazil. Part 2. Boidae. Palaeovertebrata 30 (3‑4): 111‑150. r ipley b., v enables b., b ates d. m., h ornick k., G ebhardt a. & F irth d. 2016. — MASS: Support Functions and Datasets for Venables and Ripley’s MASS. https://rdrr.io/cran/MASS/ romon t. 2001. — Cathédrale de Basse-Terre (Guadeloupe). AFAN Grand sud-ouest, SRA Guadeloupe, DRAC. r omon t., b ertran p., F ouéré p., h ildebrand m., s errand n. & vallet c. 2006. — Fouille préventive de la gare maritime de Basse-Terre. INRAP, Service régional de l’archéologie de Guadeloupe, Basse-Terre, 457 p. royer a., malaiZé b., lécuyer c., QueFFelec a., charlier k., caley t. & lenoble a. 2017. — A high-resolution temporal record of environmental changes in the Eastern Caribbean (Guadeloupe) from 40 to 10 ka BP. Quaternary Science Reviews 155: 198-212. https://doi.org/10.1016/j.quascirev.2016.11.010 s aunders n. J. 2005. — The Peoples of the Caribbean: an Encyclopedia of Archaeology and Traditional Culture. ABC CLIO, Denver, 423 p. schleGel h. 1837. — Essai sur la physionomie des serpents – Partie descriptive. M. H. Schonekat, Libraire-Editeur, Amsterdam, 606 p. https://doi.org/10.5962/bhl.title.4273 serrand n., bonnissent d., Fouilloud c., sellier-seGard n. & a udouit F. 2010. — Tourlourous, Stade josé Bade. INRAP, Service régional de l’archéologie de Guadeloupe, Marie-Galante, 64 p. sieGel p. e., Jones J. G., pearsall d. m., dunninG n. p., Farrell p., duncan n. a., curtis J. h. & sinGh s. k. 2015. — 522 GEODIVERSITAS • 2019 • 41 (12) Bochaton C. et al. Paleoenvironmental evidence for first human colonization of the eastern Caribbean. Quaternary Science Reviews 129: 275‑295. https://doi.org/10.1016/j.quascirev.2015.10.014 steadman d. w., albury n. a., kakuk b., mead J. i., sotocenteno J. a., sinGleton h. m. & Franklin J. 2015. — Vertebrate community on an ice-age Caribbean island. Proceedings of the National Academy of Sciences 112 (44): E5963‑E5971. https://doi.org/10.1073/pnas.1516490112 steadman d. w., preGill G. k. & olson s. l. 1984. — Fossil vertebrates from Antigua, Lesser Antilles: evidence for late Holocene human-caused extinctions in the West Indies. Proceedings of the National Academy of Sciences of the United States of America 81: 4448‑4451. https://doi.org/10.1073/pnas.81.14.4448 stoetZel e., royer a., cochard d. & lenoble a. 2016. — Late Quaternary changes in bat palaeobiodiversity and palaeobiogeography under climatic and anthropogenic pressure: new insights from Marie-Galante, Lesser Antilles. Quaternary Science Reviews 143: 150‑174. https://doi.org/10.1016/j.quascirev.2016.05.013 stouvenot c., Grouard s., bailon s., bonnissent d., lenoble a., serrand n. & sierpe v. 2014. — L’abri sous roche Cadet 3 (Marie-Galante) : un gisement à accumulations de faune et à vestiges archéologiques, in bérard b. & losier c. (eds), Archéologie Caraïbe. Sidestone Press, Leiden: 77‑102. sZyndlar Z. 1984. — Fossil snakes from Poland. Acta Zoologica Cracoviensia 1 (28): 1‑156. underwood G. 1993. — A new snake from St Lucia, West Indies. Bulletin of the Natural History Museum (Zool.) 59: 1‑9. http:// www.biodiversitylibrary.org/page/41149592 viGne J.-d. 1992. — Zooarchaeology and the biogeographical history of the mammals of Corsica and Sardinia since the last ice age. Mammal Review 22 (2): 87‑96. https://doi. org/10.1111/j.1365-2907.1992.tb00124.x waGler J. 1830. — Natürliches System der Amphibien, mit vorangehender Classification der Säugthiere und Vögel. Cotta, Munich, Stuttgart, Tübingen, 354 p. https://doi.org/10.5962/ bhl.title.58730 Zanette i., daGhFous G., weitkamp t., Gillet b., adriaens d., lanGer m., cloetens p., helFen l., bravin a., peyrin F., baumbach t., dischler J.-m., loo d. v., praet t., poirier-Quinot m. & boistel r. 2013. — Looking inside marine organisms with magnetic resonance and x-ray imaging, in reynaud EG. (ed.), Imaging Marine Life. Wiley-VCH, Weinheim: 122‑184. https://doi.org/10.1002/9783527675418.ch7 Submitted on 12 July 2018; accepted on 28 January 2019; published on 20 June 2019. APPENDICES appenDix 1 . — List of extant comparative specimens used. Abbreviations: MCZ, Museum of Comparative Zoology (Boston, Massachusetts; UF, Florida Museum of Natural History (Gainesville, Florida; MNHN-RA, Muséum national d’Histoire naturelle, herpetology collection (Paris); MNHN-ZA-AC, Muséum national d’Histoire naturelle, comparative anatomy collection (Paris); coll. UMR7209, Muséum national d’Histoire naturelle, UMR 7209 laboratory collection (Paris). Alsophis antillensis (Schlegel, 1837) (unknown variety): MCZ R-29785; MCZ R-42181; MCZ R-61072; MCZ R-61073. Alsophis antillensis (“A variety”): coll. UMR7209 601. Alsophis rijgersmaei Cope, 1869: MNHN-ZA-AC 2016-9; coll. UMR7209 406. Alsophis rufiventris: MCZ R-6129; MCZ R-6130; MCZ R-76665; UF 15495. Clelia clelia: MNHN-RA-1989.3087. Erythrolamprus juliae mariae: MCZ R-6138; MCZ R-32055; MCZ R-177411. Erythrolamprus juliae juliae: MCZ R-57819. Erythrolamprus juliae copeae: MNHN-RA-1998.485. Erythrolamprus perfuscus (Cope, 1862): MCZ R-78619; MCZ R-78620. 523 Fossil dispadids from the Guadeloupe Islands GEODIVERSITAS • 2019 • 41 (12) appenDix 2 . — List of the studied sites that have yielded fossils of dipsadid snakes on the Guadeloupe Islands, with their names, type of deposit, cultural attribution. Archaic, 2000–500 BC; Early Saladoid, 500 BC-500 AD; Late Saladoid, 500-850 AD; Early Troumassoid, 750-1000 AD; Late Troumassoid, 1000-1600 AD; Colonial Modern, XV-XVIII century; Contemporary, XIX century-Present day. Excavation director: RE, rescue excavations; PE, programmed excavations, D, diagnostic [year], and main publications and/or unpublished reports. Island Site Type of deposit Cultural period Excavation Reference Les Saintes Grande-Anse de Terre de Bas Archaeological Late Troumassoid Hofman & Hoogland (RE) [1994] Hofman & Hoogland 1994 GrandeTerre Anse à la Gourde Archaeological Late Saladoid-Early & Late Troumassoid Delpuech, Hofman & Hoogland (PE) [1995-2002] Delpuech et al. 1997; Hofman et al. 1999; Delpuech et al. 2001; Grouard 2001a; Beets et al. 2006 Anse à la Gourde Cave Natural Colonial Modern Grouard (PE) [2010] Grouard et al. 2014 Anse à l’Ecu Cave Natural Colonial Modern Lenoble (PE) [2009] Lenoble et al. 2010 Bambous Cave Natural Colonial Modern Lenoble (PE) [2014] Lenoble 2016 Morel Archaeological Early Saladoid (Morel I, II) – Troumassoid (Morel III, IV) Clerc (PE) [1964]; Delpuech, Hofman & Hoogland (RE) [1999] Hofman et al. 1999; Delpuech et al. 2003 Pointe du Helleux Archaeological Late Troumassoid Hoogland & Hofman (RE) [1994], [1997] Hoogland & Hofman 1994; Grouard 1999 Trou Lolo Natural Colonial Modern Lenoble (PE) [2008] Lenoble et al. 2008 Basse-Terre Cathédrale de Basse-Terre Archaeological Early Saladoid Romon (D) [2001]; Bonnissent & Romon (RE) [2002] Romon 2001; Bonnissent & Romon 2004 Gare Maritime de Basse-Terre Archaeological Early Saladoid Paulet-Locart and Chancerel (D) [2005]; Romon (RE) [2006] Paulet-Locard & Chancerel 2005; Romon et al. 2006 Sainte-Rose La Ramée Archaeological Early Troumassoid Casagrande (RE) [2006] Casagrande et al. 2010 La Désirade Petite Rivière Archaeological Late Saladoid –Early Troumassoid Bodu (RE) [1984] ; de Waal [1995] Bodu 1984; Bodu 1985; de Waal 2006 Pointe Gros Rempart 6 Archaeological Colonial Modern Boudadi-Maligne (PE) [2011] Boudadi-Maligne et al. 2016 Petite-Terre islets Caille à Bélasse Archaeological Late Troumassoid Gagnepain (PE) [2006-2007] Gagnepain et al. 2007 MarieGalante Cadet 2 Cave Natural/ Archaeological Late Troumassoid Courtaud (PE) [2005]; Grouard (PE) [2010] Bochaton et al. 2015 Abri Cadet 3 Natural/ Archaeological Archaic, Late Troumassoid Stouvenot (PE) [2007] Stouvenot et al. 2014 Blanchard Cave Natural/ Archaeological Pleistocene-Late Troumassoid Lenoble (PE) [2008 & Courtaud (PE) [2011] Bailon et al. 2015; Stoetzel et al. 2016; Royer et al. 2017 Morne Rita Cave Archaeological Archaic Saladoid Fouéré (PE) [2011-2014] Fouéré et al. 2011; Fouéré et al. 2012; Jean-François gully Cave Archaeological Colonial Modern Lenoble (PE) [2010] Lenoble et al. 2010 Tourlourous - Stade José Bade Archaeological Late Saladoid-Early and Late Troumassoid Colas (RE) [2002]; Serrand (RE) [2010; 2012] Colas et al. 2002; Serrand et al. 2010