Mio-pliocene crustaceans from the Canary Islands, Spain

MIO-PLIOCENE CRUSTACEANS FROM THE CANARY ISLANDS, SPAIN JUAN FRANCISCO BETANCORT1, ALEJANDRO LOMOSCHITZ2& JOAQUIN MECO1 Received: August 04, 2014; accepted: October 24, 2014 Key words : Neogene, Miocene-Pliocene, North Atlantic, Canary Islands, crustacean, decapod, cirriped. Abstract . There are few previous references to fossil crustaceans for the Neogene marine layers of the Canary Islands (Spain). The Mio-Pliocene marine sedimentary layers in the eastern islands (Gran Canaria, Fuerteventura and Lanzarote) were previously characterised by the presence of numerous fossil fauna, mainly anthozoans and molluscs, which correspond to an equatorial-type palaeoclimate, warmer than the present climate. This Mio-Pliocene transition dated between 9.3 and 4.1 Ma. In this paper, 12 fossil crustacean taxa are identified and classified, including decapods and barnacles: Balanus concavus Bronn, 1831, Balanus spongicola Brown, 1827, Balanus perforatus BruguieÁre, 1789, Chenolobia testudinaria LinneÁ, 1767, Tetraclita cf. rubescens Darwin, 1854, Callianassa matsoni Rathbun, 1935, Callianassa sp., Upogebia sp, Eriphia aff. verrucosa (Forskal, 1775) , Maja sp., Scylla michelini Milne-Edwards, 1861 and Ocypode sp. Some of these taxa mean new references for the Atlantic islands and the North African Atlantic and definitely enlarge the palaeographic distribution of Neogene crustaceans beyond the Mediterranean region, extending it to the North Atlantic. Particularly significant are the presence of Tetraclita cf. rubescens , this being the first reported fossil occurrence of this barnacle outside the North America Pacific coasts, and Chenolobia testudinaria , indicating for the first time the existence of marine turtles in these islands during the Neogene. These results are coherent with previous research hypothesising the existence of a flow of surface water between the Pacific and Atlantic in the Mio-Pliocene transition (Central American Seaway, CAS) which explains the arrival of organisms, in larval stage, from Central America to the Canary Islands. Introduction Fossil fauna from the Canary Islands of the MioPliocene age plays an important role in understanding climate evolution in the North African Atlantic. The very few crustacean fossil records for the Canaries come from the XIX century (Rothpletz & Simonelli 1890) [PMM collection: Pala Èontologisches Museum Mu Ènchen, Germany] and the ULPGC-Pal collection [Palaeontology Laboratory of the Universidad de Las Palmas de Gran Canaria, Spain]. However, other fossil fauna groups of Mio-Pliocene sedimentary layers in the Canaries have been studied by Buch (1825), Lyell (1865), Rothpletz & Simonelli (1890) and more recently by Meco (1975). These layers appear in the eastern Canary Islands (NE of Gran Canaria, S and W of Fuerteventura and S of Lanzarote) at varying elevations above more than 140 km of the present-day coastline (Fig. 1). The chronostratigraphic position of the fossiliferous sedimentary layers corresponds to the Late Miocene and Early Pliocene and was determined by Lietz & Schmincke (1975), Meco & Stearns (1981), and Meco et al. (2007) from K/Ar radiometric dating of lava flows and submarine pillow lavas. Recently, a Mio-Pliocene fauna association was determined from a study of the ULPGC-Pal collection by Meco et al. (2005, 2007). They established a group of three main fossils and a group of three accompanying fossils (all anthozoans and molluscs) to characterise the Mio-Pliocene layers of the eastern Canary Islands from a chronostratigraphic perspective. In palaeoclimatic terms, these layers importantly indicate temperatures typical of tropical-type warm waters, which are higher than those of the present day are. The new findings and systematic classification of fossil crustaceans in the sedimentary strata of the Neogene in the Canary Islands contribute to augmenting the palaeontological record and to a better understanding of Rivista Italiana di Paleontologia e Stratigrafia volume 120 no. 3 1 pl. pp. 337-349 December 2014 1 Departamento de BiologõÂa, Campus Universitario de Tafira, Universidad de Las Palmas de Gran Canaria, 35017 Las Palmas de Gran Canaria, Spain. E-mail: [email protected]pgc.es; [email protected]pgc.es 2 Instituto de OceanografõÂa y Cambio Global (IOCAG), Campus Universitario de Tafira, Universidad de Las Palmas de Gran Canaria, 35017 Las Palmas de Gran Canaria, Spain. E-mail: [email protected] palaeoecological conditions during this period in the North African Atlantic region. There are very few previous references to fossil crustaceans for these marine layers in the Canaries. Rothpletz & Simonelli (1890) mentioned the presence of Balanus perforatus BruguieÁre, 1789 and defined the new species Chenolobia hemisphaerica . As for accompanying fauna, Meco et al. (2005) defined a group of species of stratigraphic and palaeoclimatic interest, divided into an first triad that characterises these layers in the Canaries ( Gryphaea virleti Deshayes, 1832, Nerita emiliana Mayer, 1872 and Strombus coronatus Defrance, 1827) and a second triad of chronostratigraphic confirmation ( Ancilla glandiformis Lamarck, 1822, Rothpletzia rudista Simonelli, 1890 and Siderastraea miocenica Osasco, 1897). This fauna not only provides stratigraphic contextual information corresponding to the Miocene-Pliocene transition, consistent with the different existing radiometric dating, but also additionally informs us of climate conditions different to those of the present day. Geological and stratigraphic setting The Canary Islands comprise seven main volcanic islands and several islets and are located in the Eastern Atlantic Ocean between N 27ë and N 30ë latitudes, forming a chain that extends latitudinally about 450 km; with the easternmost point just over 100 km off the north-western African coast (Fig. 1). The islands have a complex geological history, with volcanic formations over 20 million years old, but they also include extensive sedimentary deposits. Fossil marine fauna of the Mio-Pliocene are found in coastal deposits on the eastern Canary Islands (NE of Gran Canaria, S and W of Fuerteventura and S of Lanzarote) at varying elevations above the present-day coastline (Fig. 1). They are always composed of layers of two materials: (1) reddish conglomerate (rubefacted conglomerates as a result of Fe oxidation), consisting of coarse gravel, cobble and medium to coarse size sand, and (2) grey to white sands, medium to fine in size, with bioturbation structures, which constitute reference layers (or strata) in the local stratigraphy of each island. The original conglomerates, comprised of cobbles and sands with a wide variety of fossils (anthozoans, brachiopods, molluscs, crustaceans, echinoderms, fishes, etc.), were deposited on wave-cut platforms tens of kilometres long. Subsequently, withdrawal of the sea saw oxidation of pebbles and fossil remains, because of contact with freshwaters. These reddish sandy conglomerates as a whole are considered regional key layers, in both a stratigraphic and palaeontological sense (Lomoschitz et al. 2011). In order to establish a general time interval, the fossil specimens previously studied from these deposits dated to a Late Miocene and Early Pliocene age (Fig. 2). This agrees with K/Ar ages obtained from pillow lavas emplaced in the marine deposits (ca 4.1 Ma in Gran Canaria, ca 4.8 Ma in Fuerteventura) and from underlying (ca 9.3 Ma in Gran Canaria) or overlying (ca 8.9 Ma in Lanzarote) lava flows (Meco et al. 2007). Consequently, it is consistent to consider a time interval between 9.3 and 4.1 Ma for Neogene marine deposits in the eastern Canary Islands as a whole. Another important aspect of the fossiliferous sedimentary layers is the varying height above present sea level (apsl) of the different outcrops in the Canaries. These range from 9 to 57 m apsl in Fuerteventura, from 21 to 69 m apsl in Lanzarote and from 50 to 120 m apsl in Gran Canaria. These variations in height have been Betancort J. F., Lomoschitz A. & Meco J. 338 Fig. 1 - Sedimentary layers (black lines) with Mio-Pliocene marine fossils and main sites from the eastern Canary Islands. Selected sites where the stratigraphical sections were made (in bold). interpreted as being related to tectonic readjustments in the different island edifices (Meco et al. 2007). In addition, from a palaeoclimatic perspective these raised marine deposits in the eastern Canary Islands have been interpreted as warming episodes within Plio-Quaternary climate variations. Stratigraphic sections The fossil crustacean specimens were found in the sedimentary layers, consisting of old coastal and marine deposits which outcrop along more than a hundred kilometres, if all the different stretches are considered together. As these layers show many lateral variations along the outcrops, eight sections have been selected to be representative of the whole area: Janubio and Los Ajaches from S. Lanzarote Is., Aljibe de la Cueva and AjuõÂ from W Fuerteventura Is. (Fig. 3), and Guiniguada, Barranco Seco, Arenales-Chil and Quintanilla from NE Gran Canaria Island (Fig. 4, Fig. 5A). 1 - Janubio section Location: SW Lanzarote Is. Latitude: 28ë55'57.48'', longitude: 13ë49'17.72'', height: 36 m (apsl) This section comprises three units, which are (top to bottom): 3) Basaltic lava flows (3 m). These are thin layers of rock with intercalations of pyroclasts, horizontally displayed and slightly weathered. They are of Early Pleistocene age according to IGME (2005) and Meco et al. (2007). 2) Reddish conglomerate with fossils (0.5 m). This is composed of sub-rounded basaltic pebbles and cobbles with a matrix of fine gravel and sand, partially cemented by calcite. 1) Basaltic lava flows (20-30 m). These are a succession of predominant lava flows and beds of scoria and buried tephra cones, which are densely crossed by dykes. All these materials are intensely weathered. They are of Middle to Late Miocene age, according to IGME (2005). 2 - Los Ajaches section Location: SE Lanzarote Is. Latitude: 28ë50'32.04'', longitude: 13ë47'16.63'', height: 21 m (apsl). This section comprises four units, which are (top to bottom): 4) Sandy gravel colluvium (0.5 m) of Holocene age. 3) White dune sand (3 m). Aeolianite composed of carbonate grains of medium to fine sand, with a characteristic cross-bedding internal structure. 2) Reddish conglomerate with fossils (1.5 m). This is composed of rounded to sub-angular basaltic pebbles, cobbles and some boulders with a matrix of fine gravel and sand, partially cemented by calcite. 1) Basaltic lava flows (35 m). These are massive and very thick layers of basalts, with columnar jointing. They are composed of dark basalt of aphanite matrix, with weathered olivine (iddingsite) and pyroxene crystals. They are of Late Miocene age, according to IGME (2005). 3 - Aljibe de la Cueva section Location: NW Fuerteventura Is. Latitude 28ë39 ' 56.39'', longitude: 14ë00'43.22'', height: 17 m (apsl). This section comprises four units, which are (top to bottom): 4) White sand dunes (2 m). Aeolianite composed of carbonate grains of fine sand. 3) Basaltic lava flows and tephra (2 m). These are part of a succession of thin layers of olivine basalt, rather weathered, with some intercalated layers of pyroclasts. They are of Late Pliocene age, according to IGME (2006). 2) Reddish conglomerate with fossils (0.5-2 m). As a whole, it is composed of conglomerate and sand layers. The conglomerate layer has sub-rounded basaltic pebbles and cobbles with a matrix of gravel and sand, partially cemented by calcite. The sand layer is comprised of grey coarse sands with slightly defined planar lamination. They correspond to the Pliocene coast platform described in IGME (2006). 1) Basaltic lava flows and dykes (5 m). These are highly weathered rocks with olivine and pyroxene crystals and secondary filling of calcite and zeolite. Basaltic and trachytic dykes also densely cross them. This formation is of Early Miocene age, according to IGME (2006). 4 - AjuõÂsection Location: W Fuerteventura Is. Latitude: 28ë24 ' 03.86'', Longitude: 14ë09 ' 21.20'', height: 7 m (apsl). This section comprises five units, which are (top to bottom): 5) Sandy gravel colluvium (1 m) of Holocene age. Mio-Pliocene crustaceans from the Canary Islands, Spain 339 Fig. 2 - Volcanic chronostratigraphy of the eastern Canary Islands and K/Ar ages (*) Ma of Mio-Pliocene marine deposits from underlying and overlying lava flows. Datings from (+) Guillou et al. (2004) and (++) Meco et al. (2007). 4) White sand dunes (2 m). Aeolianite composed of carbonate grains of medium to fine sand, with a characteristic cross-bedding internal structure. 3) Basaltic pillow lavas and hyaloclastites (3 m). These come from olivine basaltic lava flows that erupted about 9 km inland. This formation is of Early Pliocene age, according to IGME (2006) and Meco et al. (2007). 2) Reddish conglomerate with fossils (1.5 m). This is mainly composed of basaltic sub-rounded pebbles, gravels and cobbles with sandy matrix. It is part of the Pliocene marine platform described in IGME (2006). 1) Basaltic lava flows and dykes (8 m). These are badly defined layers of basaltic materials: lava flows, breccias, tuffs and hyaloclastites. They are highly weathered rocks and densely crossed by dykes. As a whole, they are part of the ``basal complex'' of Fuerteventura that is of Oligocene age, according to IGME (2006). 5 - Guiniguada section (Las Palmas) Location: NE Gran Canaria Is. Latitude: 28ë06 ' 03.91'', longitude: 15ë25 ' 54.96'', height: 92 m (apsl). This section comprises five units, which are (top to bottom): 5) Heterogeneous sandy conglomerate of phonolitic and basaltic pebbles (> 15 m). This is a mixture of coarse gravel with sand, cobbles and boulders, angular to sub-round in shape and slightly horizontally layered. It is an alluvial fan deposit of Pliocene age. 4) Reddish conglomerate with fossils (1.5 m). This is composed of sub-rounded phonolitic pebbles and cobbles with a matrix of fine gravel and sand, partially cemented by calcite. It is a Lower Pliocene deposit and was formed in a tidal environment of a coastal platform. 3) Reddish phonolitic lava flow (1-12 m). The variable outcropping thickness of this layer is due to coastal erosion that occurred on an old phonolite cliff. A later exposure to fresh water caused the red colour, which is common in weathering processes. 2) Heterogeneous sandy conglomerate of phonolitic pebbles (510 m). This is a mixture of coarse gravel, pebbles and cobbles with a matrix of coarse sand and fine gravel. Their clasts are sub-angular to sub-round in shape. It corresponds to a Miocene alluvial fan. 1) Phonolitic non-welded ignimbrite (> 15 m). This has a homogeneous appearance and is composed of thick layers of yellow to white rocks. It corresponds to the Miocene of Gran Canaria. Betancort J. F., Lomoschitz A. & Meco J. 340 Fig. 3 - Stratigraphical sections on Lanzarote and Fuerteventura islands where the fossil crustaceans have been found. K/Ar dating ages (*) from (-) Coello et al. (1992) and (++) Meco et al. (2007). Fig. 4 - Stratigraphical sections on NE Gran Canaria where the fossil crustaceans have been found. Modified from GabaldoÂn et al. (1989) and Meco et al. (2005). K/Ar dating ages (*) from (+) Guillou et al. (2004) and (++) Meco et al. (2007). 6 - Barranco Seco section (Las Palmas) Location: NE Gran Canaria Is. Latitude: 28ë05 ' 25.40'', longitude: 15ë25 ' 40.25'', height: 85 m (apsl). This section comprises six units, which are (top to bottom): 6) Heterogeneous sandy conglomerate of phonolitic and basaltic pebbles (20-25 m). It is similar to unit 5 of the Guiniguada section, described above. 5) White sand dunes (5-10 m). Aeolianite composed of carbonate grains of fine to medium sand, with a characteristic cross-bedding internal structure. 4) Grey sand with bioturbation structures (3-8 m). This is a deposit of medium to fine sand, which originated in a foreshore environment. 3) Reddish conglomerate with fossils (2 m). It is similar to unit 3 of the Guiniguada section, described above. 2) Heterogeneous sandy conglomerate of phonolitic pebbles (20-25 m). It is similar to unit 2 of the Guiniguada section, described above. 1) Phonolitic non-welded ignimbrite (>15 m). It is similar to unit 1 of the Guiniguada section, described above. 7 - Arenales-Chil section (Las Palmas) Location: NE Gran Canaria Is. Latitude: 28ë06 ' 43.63'', longitude: 15ë25 ' 35.62'', height: 47 m (apsl). This section comprises five units, which are (top to bottom): 5) Heterogeneous sandy conglomerate of phonolitic and basaltic pebbles (20-25 m). It is similar to unit 5 of the Guiniguada section and unit 6 of the Barranco Seco section, described above. 4) Grey sand with bioturbation structures (5 m). This is a deposit of medium to fine sand, which originated in a foreshore environment. 3) Reddish conglomerate with fossils (2-3 m). It is similar to unit 3 of the Guiniguada and Barranco Seco sections, described above. 2) Heterogeneous sandy conglomerate of phonolitic pebbles (20-25 m). It is similar to units 2 of the Guiniguada and Barranco Seco sections, described above. 1) Phonolitic lava flow (>12 m). This is composed of a hard rock, dark green in color and with homogeneous appearance. It corresponds to the Miocene of Gran Canaria, which are of Late Miocene age. 8 - Quintanilla section Location: NE Gran Canaria Is. Latitude: 28ë07'12.84'', longitude: 15ë27 ' 30.75'', height: 97 m (apsl). This section comprises six units, which are (top to bottom): 6) Basaltic lava flows (25 m). These are horizontally displayed layers, with scoriaceous layers at their top. They are of Early Pleistocene age according to ITGE (1990). 5) Basanitic lava flows and pillow lavas (40 m). These form a monotonous layer, about 25 m thick, that is only disturbed at their bottom, where lava flows (originally aerial) turn to pillow lavas and hyaloclastites (submarine) with an average thickness of 15 m. They are of Early Pliocene age according to ITGE (1992) and Meco et al. (2007). 4) White silt and sand (0.5-1.5 m). This is an easily distinguishable layer because of its light colour. In detail, it is composed of 2-3 thin layers, which correspond to specific sedimentary facies: white silt with planar lamination; grey coarse sand with undulated lamination and grey coarse to fine sand with planar lamination. It most probably originated in a quiet and shallow offshore environment, e.g. a small bay. 3) Reddish conglomerate with fossils (0.5-2 m). This is similar to unit 3 of the other Las Palmas sections, described above. 2) Heterogeneous sandy conglomerate of phonolitic pebbles (12-15 m). This is similar to unit 2 of the other Las Palmas sections, described above. 1) Phonolitic non-welded ignimbrite (15-20 m). This is similar to unit 1 of the Guiniguada and Barranco Seco sections, described above. Canary Island Neogene Crustaceans Twelve taxa have been identified in the different outcrops of the deposits in the islands, corresponding to both decapod and cirriped crustaceans. These Neogene fossil crustaceans are shown in the following list: 1. Balanus concavus Bronn, 1831 2. Balanus spongicola Brown, 1827 3. Balanus perforatus BruguieÁre, 1789 4. Chenolobia testudinaria LinneÁ, 1767 5. Tetraclita cf. rubescens Darwin, 1854 6. Callianassa matsoni Rathbun, 1935 7. Callianassa sp. 8. Upogebia sp. 9. Eriphia aff. verrucossa (Forskal, 1775) 10. Maja sp. 11. Scylla michelini Milne-Edwards, 1861 12. Ocypode sp. Systematic Palaeontology Phylum Arthropoda Latreille, 1829 Subphylum Crustacea Pennat, 1777 Class Maxillopoda Dahl, 1956 Infraclass Cirripedia Burmeister, 1834 Superorder Thoracica Darwin, 1854 Order Sessilia Lamarck, 1818 Suborder Balanomorpha Pilsbry, 1916 Superfamily Balanoidea Leach, 1817 Family Balanidae Leach, 1817 Genus Balanus Da Costa, 1778 Balanus concavus Bronn, 1831 Pl. 1, figs A1, A2, A3 1854 Balanus concavus Darwin, p. 235, pl. 4, fig. 4a-e. 1906 Balanus concavus - Alessandri, p. 295, pl. XVI, figs 21-25; pl. XVII, figs 1-4. 1952 Balanus concavus - Davadie, p. 17, pl. I, figs 1-2; pl. II, figs 1-2; pl. III, figs 1-2, pl. IV, figs 1-2; pl. V, figs 1-2. 1963 Balanus (Balanus) concavus ± Davadie, p. 52, pl. XXIV, figs 8-9. Balanus concavus - Menesini, p. 110, pl. IV, figs 2-6; pl. VI, figs 1-4; pl. X, figs 7-8; pl. XI, figs 1-2; pl. XVII, figs 3-8; pl. XIX, figs 1-3. Balanus concavus - Cuerda and Sacares, p. 115, pl, II, fig. 1a-b; fig. 2. Mio-Pliocene crustaceans from the Canary Islands, Spain 341 1979 Balanus concavus concavus - D'Alessandro et al., p. 94, pl. 18, figs 4-5; pl. 19, figs 1-3. Material : Many free scutum and a few shells attached to bivalves ( Chama sp.) Locality : Fuerteventura: JandõÂa (Costa Calma) (Fig.1), Costa de Barlovento. Gran Canaria: Barranco de Mata, Las Rehoyas-El PolvorõÂn, San JoseÂ, Ban Äaderos. Remarks. Reported for the Oligocene of Hungary and Algeria. Found at sites of Miocene age in Germany, Austria, France, Italy, Algeria, Portugal and even the Atlantic coasts of North America. During the Pliocene, it is very abundant in Italy, Algeria, Spain and England. Currently found in the Caribbean, Panama, Peru, the Philippine archipelago and Australia (Darwin 1854; Menesini 1964), but extinct in the Mediterranean (D'Alessandro et al. 1979). Displays a high degree of polymorphism, with a slender and angular scutum , the design of which has grooves, or vertical and horizontal lines, which criss-cross in a highly characteristic pattern. Balanus perforatus BruguieÁre, 1789 Pl. 1, fig. B1 1873 Balanus perforatus ± Seguenza, p. 28, pl. I, fig. 2-2a. 1906 Balanus perforatus ± Alessandri, p. 294, pl. XVI, figs 1720. 1952 BalanusperforatesDavadie,p.20,pl.III,fig.3;pl.IV,fig.1. 1963 Balanus (Balanus) perforates - Davadie, p. 38, pl. XI, figs 5-8. 1964 Balanus perforatus perforatus ± Menesini, p. 95, pl. I, figs 10, 12, 13; pl. II, figs 1-6; pl. VIII, figs 5-8; pl. XII, fig. 8; pl. XIV, figs 15. 1976 Balanus (Balanus) perforatus angustus - Pajaud, p. 483, fig. 1a-b; fig. 2. Material : Large number of specimens forming aggregates. Locality : Fuerteventura: Cofete (Cofete, Risco del Moro). Remarks. Reported in the Miocene and Pliocene levels of the Indian Ocean and Mediterranean Seas. Found today in the Mediterranean and Atlantic, along the French coast, England and west coast of Africa (Menesini 1964). Balanus spongicola Brown, 1827 Pl. 1, fig. C1, C2 1854 Balanus spongicola ± Darwin, p. 225, pl. 4, fig. 1a-d. 1873 Balanus spongicola var. pliocenica Seguenza, pl. IX, fig 917. 1906 Balanus spongicola ± Alessandri, p. 290, pl. XVI, figs 6-13. 1963 Balanus (Balanus) spongicola - Davadie, p. 49, pl. XXIV, figs 1-7. 1965 Balanus spongicola ± Menesini, p. 106, pl. III, figs 2-14; pl. IV, fig. 1-1a; pl. X, figs 1-6; pl. XVII, figs 1-2. Material : Fragments of various large-sized scuta . Localitiy : Fuerteventura: Costa de Barlovento (Barranco de la Cruz). Gran Canaria: Arenales (Fig. 1). Remarks. Reported in the Miocene of England, Italy, Sardinia, France, Spain, Algeria, Tunisia, and Egypt. Very common during the Pliocene and Pleistocene of Italy, Portugal and Algeria. Currently found in the Mediterranean, Cape of Good Hope and south of England. It is characterised by its large-sized scuta with grooved or parallel line decoration. Genus Chelonibia ( Chenolobia ) Leach, 1817 Chelonibia testudinaria LinneÁ, 1758 Pl. 1, fig. D1, D2 1854 Chelonobia testudinaria - Darwin, pl. 14, fig. 1 a-d, fig. 5; pl. 15, fig. 1. 1906 Chelonibia testudinaria - Alessandri, p. 314, pl. XVIII, figs 6-7. 1980 Chelonibia testudinaria (Linnaeus, 1758). Morris et al., p. 516, fig. 149. Material : A single fragment of rostrum . Locality : Gran Canaria: Mata ravine. Betancort J. F., Lomoschitz A. & Meco J. 342 PLATE 1 Fossil crustaceans remains of the Mio-Pliocene transition in the eastern Canary Islands. ABalanus concavus Bronn, 1831. A1) Specimen from Costa Calma, Fuerteventura. A2) Scutum, Costa Calma, Fuerteventura. A3) Specimens attached to the upper valve of Chama sp. BBalanus perforatus BruguieÁre, 1789. B1) Cofete, Fuerteventura. CBalanus spongicola Brown, 1827. C1 & C2) Scutum . Barlovento coast, Fuerteventura. DChenolobia testudinaria LinneÁ, 1767. D1) interior view and D2) exterior view. Las Rehoyas-El PolvorõÂn, Gran Canaria. ETetraclita cf. rubescens Darwin 1854. E1) T. cf. rubescens Darwin, 1854 attached to an upper valve of Gryphaea virleti Deshayes, 1832. Aljibe de la Cueva, Fuerteventura. E2) & E3) Top view. E4) Side view. Aljibe de la Cueva, Fuerteventura. FCallianassa matsoni Rathbun, 1935. F1) Right chela. Aljibe de la Cueva, Fuerteventura. GCallianassa sp. G1) Right chela, exterior view, G2) Interior view. Barranco de Esquinzo, Fuerteventura. HUpogebia sp. H1) Left Chela. Las Rehoyas-El PolvorõÂn, Gran Canaria. IScylla michelini Milne-Edwards, 1861. I1) & I2) Dactylus. Aljibe de la Cueva, Fuerteventura. JMaja sp. J1) Dactylus. Aljibe de la Cueva, Fuerteventura. KEriphia aff. verrucossa (Forskal, 1775). K1) interior view, K2) exterior view. Papagayo cliff, Lanzarote. LOcypode sp. L1 Right chela, exterior view, L2) interior view, L3) meropodite fragments. Cofete, Fuerteventura. Mio-Pliocene crustaceans from the Canary Islands, Spain 343 Remarks. Reported in the Pliocene of the Mediterranean (Italy) and currently found in the Mediterranean, Atlantic and Pacific (Mexico and northern Australia), it is always associated with the presence of marine turtles. Epibiont barnacle on turtle shells. Reaches a maximum diameter of 8 cm (Morris et al. 1980), low height, smooth shell on the outside with only slight inclination. Rostrum consisting of three fused plates. Superfamily Tetraclitoidea Gruvel, 1903 Family Tetraclitidae Gruvel, 1903 Subfamily Tetraclitinae Gruvel, 1903 Genus Tetraclita Schumacher, 1817 Tetraclita aff . rubescens Darwin, 1854 Pl. 1, fig. E1, E2, E3, E4 1854 Tetraclita porosa v ar. rubescens Darwin, p. 382, pl. 10, fig. 1b. 1916 Tetraclita squamosa rubescens ± Pilsbry, p. 250, pl. 61, fig. 1a-c. 1980 Tetraclita rubescens - Morris et al., p. 157, pl. 150. Material : Very abundant. Large-sized complete specimens and fragments of specimens found attached to bivalves ( Gryphaea virleti Deshayes, 1832). Locality : Lanzarote: Papagayo, Costa de Los Ajaches (Punta Gorda, La Colorada). Fuerteventura: Costa de Barlovento (between Los Molinos and Santa IneÂs), JandõÂa (Costa Calma ± Costa Esmeralda), Aljibe de la Cueva. Gran Canaria: Ciudad JardõÂn, Guiniguada (Fig. 1). Remarks. Limited in both its fossil (Pliocene and Pleistocene) and present-day form from Cape San Lucas, Baja California, Mexico, to San Francisco Bay (Pilsbry 1916). Exterior decorated with very marked grooves. The region of the orifice of these barnacles tends to be eroded and so is seen enlarged. They grow in intertidal habitats, in exposed and quite wave-beaten areas. They occasionally appear in the subtidal region, in this case attached to shells, mainly to Haliotis (Morris et al. 1980). Subphylum Crustracea Bru Ènnich, 1772 Class Malacostracea Latreille, 1803 Subclass Eumalacostraca Grobben, 1892 Order Decapoda Latreille, 1803 Suborder Pleocyemata Burkenroad, 1963 Infraorder Thalassinidae Latreille, 1831 Superfamily Thalassnoidea Latreille, 1831 Family Callianassidae Dana, 1852 Genus Callianassa Leach, 1814 Callianassa cf. matsoni Rathbun, 1935 Pl. 1, fig. F1 1935 Callianassa matsoni Rathbun, p. 24, figs 23-28. Material : Two chelas without dactylopodites with different degrees of preservation. One corresponds to a right pincer with a fragment of finger and the other to a left pincer with the two ends broken. Locality : Fuerteventura: Aljibe de la Cueva (Fig.1, Fig.3). Gran Canaria: Chil (Fig. 1). Remarks. Present in Florida Miocene deposits. Pincer of subrectangular form with smooth edges and convex appearance, which has a narrow fixed finger. The distal edge of the pincer where the dactylopodite is inserted is oblique or perpendicular. The outer surface is convex in a vertical direction. A deep, highly characteristic U-shaped sinus is observed at the base of the lower finger. Callianassa sp. Pl. 1, fig. G1, G2 Material : Two right chelas, one complete but with dactylopodite insertion point broken and eroded, the other in bad condition with complete fixed finger. Locality : Costa de Barlovento (Barranco de Esquinzo) and JandõÂa (Costa Calma), Fuerteventura (Fig.1). Remarks. Two chelas (manus and dactylus ) with similar taxonomic features to those seen in the genus Callianassa Leach, 1814. These two chelas have the following characteristics: rectangular shaped, slender and narrow, slightly bulging. Concave interior and convex exterior. Long and inward-curving fingers. Very pronounced beak-like curvature of the fingertips. In the interior region of both the movable and fixed finger, a fine keel-like ridge (carina) extends over the finger from virtually the tip to the end giving it a blade-like appearance. This fine carina follows both the upper and lower edges of the chela and appears much more pronounced at the distal vertices, with a slight continuation noticeable towards the joint. A slight semi-circular depression is observed in the mid-interior region of the chela at the distal end where the joint is situated. C. candida (Olivi, 1792), presently found in the Mediterranean, has the interior or cutting edges of the two fingers serrated, whereas they are smooth in Callianassa sp. The upper finger is notably more robust in the present day species and displays a series of tubercles on the interior edge which are absent in the Mio-Pliocene species. Family Upogebiidae Borradaile, 1903 Genus Upogebia Leach, 1814 Betancort J. F., Lomoschitz A. & Meco J. 344 Upogebia sp. Pl. 1, fig. H1 Material : Partially broken left pincer. Locality : Gran Canaria: Las Rehoyas - El PolvorõÂn. Remarks. Rectangular left chela, slightly concave interior and markedly convex exterior. Smooth external surface. Fine lower margin, finely and evenly serrated, with very small and flat, triangular shaped spines. Superior and anterior edge encrusted with sand. Superior or movable finger absent, as is its insertion. Fixed finger well preserved, small in size, very curved and interior edge with a carina that runs along its length. Infraorder Brachyura Latreille, 1802 Section Eubrachyura Saint Laurent, 1980 Subsection Heterotremata Guinot, 1977 Superfamily Eriphioidea MacLeay, 1838 Family Eriphiidae MacLeay, 1838 Genus Eriphia Latreille, 1817 Eriphia aff. verrucosa (Forskal, 1775) Pl. 1, fig. K1, K2 Material : Fragment of left pincer, broken at both joints and with encrustation of fine sands on both the interior and surface. Locality : Papagayo coast, Lanzarote (Fig. 1, Fig. 5C). Remarks. Small squared chela with fixed finger and cusps. Smooth interior face, exterior face covered with rounded tubercles, moderately aligned longitudinally, that extend to the upper edge and slightly beyond to the interior face. They are of a larger size in the upper half. Fixed finger with a slight rectangular depression in the exterior surface. There is a strong resemblance between this chela and that shown by Varola (1981) and classified as Eriphia verrucosa (Forskal, 1775) for the Neogene deposits (Miocene and Pliocene) of Sicily. Baldanza et al. (2013) quote this genus in the deposits of the lower Pleistocene of Siena Basin, Tuscany, Italy. This crab is presently found in the Mediterranean Sea, West Africa and Canary Islands coasts (GonzaÂlez PeÂrez, 1995). Superfamily Majoidea Samouelle, 1819 Family Majidae Samouelle, 1819 Genus Maja Lamarck, 1801 Maja sp. Pl. 1, fig. J1 Material : Two dactylopodite fragments of different length and different states of preservation. Locality : Fuerteventura: Aljibe de la Cueva (Fig 1, Fig. 3). Remarks. Reported for the levels of the Lower Pliocene of England, Upper Pliocene of Italy and the Pleistocene of Italy and Sicily (Varola 1981). Slender, curved cone-shaped dactylopodites with smooth surface. The fragments are very similar to the dactylopodite of Maja squinado (Herbst, 1788) of the Neogene of southern Italy (Varola 1981). Superfamily Portunoidea Rafinesque, 1815 Family Portunidae Rafinesque, 1815 Subfamily Portuninae Rafinesque, 1815 Genus Scylla de Hann, 1833 Scylla michelini Milne-Edwards, 1861 Pl. 1, fig. K1, K2 1861 Scylla michelini Milne-Edwards, p. 262, pl. 3, fig. 3. Material : Numerous pincer fragments (dactylopodites and propodites), varying in size from 0.9 to 3.85 cm. Locality : Fuerteventura: Aljibe de la Cueva. Gran Canaria: Chil (Fig. 1, Fig. 3). Remarks. Reported for the Miocene of Ajou, France. According to Milne-Edwards (1861) the difference in pincers between the S. michelini Milne-Edwards, 1861 and the Scylla serrata (Forskal, 1775) is minimal. Complete carapaces need to be examined for a full classification. Section Thoracotremata Guinot, 1977 Superfamily Ocypodoidea Rafinesque, 1815 Family Ocypodidae Rafinesque, 1815 Subfamily Ocypodinae Rafinesque, 1815 Genus Ocypode Weber, 1795 Ocypode sp. Pl. 1, fig. L1, L2, L3 Material : Numerous stray fragments in compacted sands, fragments of legs, carapace and pincers, attributable to several individuals. Locality : Cofete, Fuerteventura (Fig. 1, Fig. 5B). Remarks. Robust and quadrangular-oval pincer with convex exterior and concave interior. Surface covered with granules, more pronounced in the distal region and the region near the fixed finger. In the interior side there is a rounded and prominent insertion point for the joint, with a well-defined sinus which tapers the chela to the insertion point in a highly characteristic form. Both upper and lower edges have a row of short Mio-Pliocene crustaceans from the Canary Islands, Spain 345