Sawfishes and Other Elasmobranch Assemblages from the Mio-Pliocene of the South Caribbean (Urumaco Sequence, Northwestern Venezuela).
The Urumaco stratigraphic sequence, western Venezuela, preserves a variety of paleoenvironments that include terrestrial, riverine, lacustrine and marine facies. A wide range of fossil vertebrates associated with these facies supports the hypothesis of an estuary in that geographic area connected with a hydrographic system that flowed from western Amazonia up to the Proto-Caribbean Sea during the Miocene. Here the elasmobranch assemblages of the middle Miocene to middle Pliocene section of the Urumaco sequence (Socorro, Urumaco and Codore formations) are described. Based on new findings, we document at least 21 taxa of the Lamniformes, Carcharhiniformes, Myliobatiformes and Rajiformes, and describe a new carcharhiniform species (†Carcharhinus caquetius sp. nov.). Moreover, the Urumaco Formation has a high number of well-preserved fossil Pristis rostra, for which we provide a detailed taxonomic revision, and referral in the context of the global Miocene record of Pristis as well as extant species. Using the habitat preference of the living representatives, we hypothesize that the fossil chondrichthyan assemblages from the Urumaco sequence are evidence for marine shallow waters and estuarine habitats.
Paleontological Institute and Museum, University of Zurich, Zürich, Switzerland.
Jorge D
JD
Carrillo-Briceño
Staatliches Museum für Naturkunde, Stuttgart, Germany.
Erin
E
Maxwell
Universidade Federal Fluminense, Instituto de Biologia, Campus do Valonguinho, Outeiro São João Batista, Niterói, Rio de Janeiro, Brasil.
Orangel A
OA
Aguilera
Museo Paleontológico de Urumaco, Urumaco, estado Falcón, Venezuela.
Rodolfo
R
Sánchez
Paleontological Institute and Museum, University of Zurich, Zürich, Switzerland.
Marcelo R
MR
Sánchez-Villagra
D000818:Animals; D005075:Biological Evolution; D017691:Caribbean Region; D018940:Elasmobranchii / Q000033:anatomy & histology* / Q000145:classification*; D005580:Fossils; D010802:Phylogeny; D014687:Venezuela