Journal of South American Earth Sciences 51 (2014) 76e90 Contents lists available at ScienceDirect Journal of South American Earth Sciences journal homepage: www.elsevier.com/locate/jsames Fossil Chondrichthyes from the central eastern Pacific Ocean and their paleoceanographic significance Jorge D. Carrillo-Briceño a,*, Orangel A. Aguilera b, Félix Rodriguez c a Paleontological Institute and Museum, University of Zurich, Karl-Schmid-Strasse 4, CH-8006 Zurich, Switzerland b Universidade Federal Fluminense, Instituto de Biologia, Departamento de Biologia Marinha, Programa de Pos-graduacao em Biologia Marinha, Campus do Valonguinho, Outeiro São João Batista, s/n, CEP: 24020-14 1Niterói, Rio de Janeiro, Brazil c Smithsonian Tropical Research Institute, PO Box 0843-03092, Balboa, Panama article info abstract Article history: The study of the chondrichthyan fauna from the Angostura, Onzole, Canoa and Jama formations, in the Received 8 November 2013 Neogene of Bordón and Manabí basins, Ecuador, reveals the presence of 30 taxa, including the deep Accepted 2 January 2014 water shark yChlamydoselachus landinii sp. nov. The assemblages are dominated by tropical shallow and deep water chondrichthyans, suggesting paleoenvironments associated with a short platform shelf Keywords: bordering a deep margin. These assemblages are the most diverse shark and ray association known from Neogene the Tropical Central Eastern Pacific Ocean in the South American coastal basin, and provide new infor- Tropical America mation on the paleoecology and paleodiversity of Neogene chondrichthyans. Ecuador Ó Sharks 2014 Elsevier Ltd. All rights reserved. Rays Paleoenviroments 1. Introduction seaway (Hoernle et al., 2002; Pindell et al., 2005), related to the uplift of the Isthmus of Panama (Coates and Obando, 1996; O’Dea Fossil chondrichthyan assemblages from the eastern Pacific et al., 2007; Coates and Stallard, 2013), the Andean uplift Ocean are still poorly known in spite of several publications on the (Garzione et al., 2008; Martinoid et al., 2010), the Ecuadorian subject, including: Longbottom (1979) and Aguilera et al. (2011) on subduction, the submarine trench system (Lonsdale, 1978; Ratzov Ecuador; De Muizon and Devries (1985), Kindlimann (1990), Apolín et al., 2010) and the oceanographic dynamic (Fiedler and Talley, et al. (2004) and Avalán et al. (2007) on Perú; Long (1993a), Suárez 2006) derived in successions of neritic to depth sea paleoenviron- and Marquardt (2003), Suárez et al. (2006) and Carrillo-Briceño ment changes. Longbottom (1979) described the early chon- et al. (2013) on Chile; Laurito (2004), and Laurito and Valerio drichthyan fauna assemblage from the Miocene of the Onzole (2008) on Central America, and Long (1993b), González-Barba Formation and Aguilera et al. (2011) reported the presence of and Thies (2000), and Boessenecker (2011) on North America. additional Miocene-Pleistocene taxa from the Angostura, Onzole These previous contributions are not uniform in terms of sampling and Jama formations from Ecuador. Teleostean records from the and geochronological control, preventing comparative quantitative Neogene basin in Ecuador are known from otoliths reported from analyses among faunas. However, the faunal assemblages along the the Onzole and Canoa formations (Landini et al., 2002a, 2002b; tropical eastern Pacific coast have been the subject of studies about Aguilera et al., 2011; Carnevale et al., 2011). faunal distribution in Tropical America and the proto-Caribbean In this work we provide a taxonomic revision of the chon- area (Iturralde-Vinent and MacPhee, 1999; Landini et al., 2002a, drichthyan fauna from Ecuador, resulting in an increased fossil re- 2002b; Aguilera et al., 2011; Carnevale et al., 2011). cord for the region and a better understanding of the Neogene In terms of regional relevance, the central eastern Pacific Ocean shark and ray associations in Tropical America, especially along the represents a geographic and oceanographic complex influenced by eastern Pacific coast of South America. geologic and tectonic events along the Panamanian AtlanticePacific 2. Methods * Corresponding author. The chondrichthyan assemblages (Table 1) were collected from E-mail addresses: [email protected], [email protected] (J. D. Carrillo-Briceño), [email protected] (O.A. Aguilera), RodriguezF@si. nine localities (Fig. 1) of four Neogene geological units in Ecuador, 0 00 0 00 edu (F. Rodriguez). including: Cayapas River [Telembí (0 58 57 N, 78 51 42 W)], 0895-9811/$ e see front matter Ó 2014 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.jsames.2014.01.001 J.D. Carrillo-Briceño et al. / Journal of South American Earth Sciences 51 (2014) 76e90 77 Table 1 Chondrichthyan assemblages from the Neogene of Ecuador. Superorder Order Family Species Geological formations Angostura Onzole Canoa Jama (EPI) Onzole Longbottom (1979) (MM-LM) (LM-EP) (LP-PI) Squalomorphii Hexanchiformes Chlamydoselachidae yChlamydoselachus landinii sp. nov. X Squaliformes Centrophoridae Centrophorus sp. X X Dalatiidae yIsistius cf. triangulus XX Pristiophoriformes Pristiophoridae Pristiophorus sp. X Squatiniformes Squatinidae Squatina sp. X Galeomorphi Orectolobiformes Ginglymostomatidae Ginglymostoma sp. X Lamniformes Odontaspididae yCarcharias acutissima X yOtodontidae yMegaselachus megalodon X Carcharhiniformes Hemigaleidae yHemipristis serra XX Paragaleus sp. X Carcharhinidae yGaleocerdo aduncus X Rhizoprionodon longurio XX Rhizoprionodon taxandriae XXX Rhizoprionodon sp. X X X X Carcharhinus albimarginatus X Carcharhinus brachyurus XX yCarcharhinus egertoni X Carcharhinus obscurus XX yCarcharhinus priscus X Carcharhinus cf. porosus X Carcharhinus sp. X X X X Negaprion brevirostris X yNegaprion eurybathrodon X Sphyrnidae Sphyrna media XX Batomorphii Myliobatiformes Dasyatidae Dasyatidae indet. X Myliobatidae Aetobatus sp. X Myliobatis sp. X Rhinopteridae Rhinoptera sp. X Mobulidae Mobula sp. X cf. Mobula XX Batomorphii Indet. X Abbreviations: Middle Miocene (MM), Late Miocene (LM), Early Pliocene (EP), Late Pliocene (LP), Pleistocene (PL), Early Pleistocene (EPL). Fig. 1. Location map and localities. 78 J.D. Carrillo-Briceño et al. / Journal of South American Earth Sciences 51 (2014) 76e90 Flavio Alfaro road (0 440 1900 N, 79 560 3900 W), Punta Verde (0 350 Experimental Francisco de Miranda, Coro, Venezuela (UNEFM-PF). 5500 N, 80 250 4700 W) and Santiago River [Cueva de Angostura, Palo Taxonomic abbreviations are: h (height), w (width) l (length), and palo, Playa de Oro (0 530 N, 78 500 W)] in the Angostura Formation these are used for the entire tooth including the root. (Middle-Late Miocene); Camarones River (0 580 0400 N, 79 360 4700 In this work we use the term “Tropical America” (Neotropics) to W) in the Onzole Formation (Late Miocene-Early Pliocene); Punta refer the geographic area of the western hemisphere located be- Canoa (0 260 4300 N, 80 280 0800 W) in the Canoa Formation (Late tween the Tropic of Cancer (23 270 N) and the Tropic of Capricorn Pliocene-Pleistocene); and Jama [Punta Ballena (0 100 2100 N, 80 (23 270 S). “Southern South America” is a region composed of the 190 3100 W)] in the Jama Formation (Early Pleistocene). The assem- southernmost areas of South America, south of the Tropic of blages are represented by a total of 91 specimens and 23 taxa. The Capricorn and this includes Argentina, Chile, Paraguay and specimens were collected during a field trip between June 11e23 in Uruguay, and “North America” includes Canada, the USA and the 1999, to the Bordón and Manabí basins in Ecuador (Figs. 1 and 2)by northern part of Mexico (north of the Tropic of Cancer). Only the one of the authors (O.A.A.) as part of the Panama Paleontology countries with fossil records of Neogene chondrichthyan have been Project at the Smithsonian Tropical Research Institute, Panama included in the tables. (STRI). These were collected directly on the outcrop and screen washed in bulk samples (10 Kg each) using a 2 mm diameter mesh. 3. Geological setting All specimens described here are deposited at STRI (STRI-PPP-T catalogue). The classifications follow Compagno (1973, 1977) and The Angostura Formation is located in the western Borbón Ba- Cappetta (2012), and the terminology is based on Pfeil (1983) and sin, on the northwestern coast of Ecuador, and this has been Cappetta (2012). Photographs of shark and ray teeth were made assigned to the Middle-Late Miocene (Cantalamessa et al., 2007). with a Leica M205A multifocal stereomicroscope. Images from The Angostura Formation overlies the Lower-Middle Miocene Viche small teeth were made with a Scanning Electronic Microscope Formation, and its lithology consists principally of muddy, fine- (SEM). grained sandstones with abundant mollusk shells (Baldock, 1982; The identification was based on the comparative analysis with Cantalamessa et al., 2007). An integrated analysis of facies and fossil and extant specimens in the following collections: Departa- paleontological content of this geological unit suggests shore-face mento Nacional de Pesquisas Minerais, Brazil (DNPM); Museo and inner-shelf paleoenvironments (Cantalamessa et al., 2007). Nacional de Historia Natural de Santiago, Chile (SGO-PV); Natural The Onzole Formation is assigned to the Late Miocene-Early History Museum of Basel (NMB), Paleontological collections of the Pliocene (Schulman et al., 1965; Whittaker, 1988; Carnevale et al., Alcaldía Bolivariana de Urumaco, Falcon, Venezuela (AMU-CURS); 2011). Whittaker (1988) subdivided the Onzole Formation