New insights into the fossil record of the turtle genus Chelus Duméril, 1806 including new specimens with information on cervicals and limb bones

Edwin-Alberto CADENA, Andrés LINK, Andrés VANEGAS, Carlos A. Avellaneda-Otero, César PERDOMO, Diego A. Urueña-Carrillo, Rodolfo Sánchez, Rubén Dario VANEGAS, Torsten M. SCHEYER & Jorge Domingo CARRILLO-BRICEÑO

en Comptes Rendus Palevol 22 (34) - Pages 689-709

Published on 20 November 2023

Matamata turtles (Chelus Duméril, 1806) are composed of two extant species, Chelus fimbriata ­Schneider, 1783 and Chelus orinocensis Vargas-Ramírez, Caballero, Morales-Betancourt, Lasso, Amaya, Martínez, Silva-Viana, Vogt, Farias, Hrbek, Campbell & Fritz, 2020, inhabitants of the main freshwater drainages of northern South America. The systematics and palaeobiogeography of Chelus is still unresolved. Here, we describe several new fossil specimens from the Late Miocene of Urumaco (Venezuela) and Tatacoa (Colombia). The fossils are mostly complete, articulated shells that allow reestablishing validity of two extinct taxa, Chelus colombiana Wood, 1976 and Chelus lewisi Wood, 1976. One of the specimens of C. lewisi from Urumaco represents the first record within the genus for which autopodial bones (a left manus) and additional limb bones are preserved together with ashell, demonstrating evolutionary conservatism in limb anatomy for the genus. The specimen comes from the Socorro Formation, representing the earliest so far known record of Chelus for the Urumaco sequence. Additionally, one specimen from Tatacoa is the first fossil for which cervical and pectoral girdle elements are preserved. Phylogenetic analysis supports the existence of two separate clades inside of Chelus, one formed by the extinct species and the other by the extant ones.


Testudines, South America, Chelidae, Matamata, Miocene fossils

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