A new specimen of Toxodontidae (Notoungulata) from the Urumaco Formation (Upper Miocene) of Venezuela

BOND, MARIANO; MADDEN, RICHARD; CARLINI, ALFREDO A.

Journal of Systematic Palaeontology

University Press

Lugar: Cambridge, UK; Año: 2006 vol. 4 p. 285 - 291

1477-2019

SYNOPSIS A new specimen of Toxodontidae, consisting of a partial mandibular ramus with three molars, is described from the Middle Member of the Urumaco Formation and compared with type and referred material from all four taxa previously reported from Venezuela and with several better known taxa of advanced Toxodontidae. Incomplete preservation and postmortem distortion make an assessment of its morphology difficult. Despite these shortcomings, the new material does not appear to represent any of the Venezuelan taxa previously described. The specimen shows a unique combination of characters including a pattern of lingual enamel folds, weakly developed metaentoconid and well-developed ento-hypoconid fold (m1 andm2, not inm3), subrounded and lingually expanded trigonid, transversely broad hypoconid and open labial enamel fold. In this combination of features, the newspecimenmost closely resembles the types of Trigodonops lopesi and Mixotoxodon larensis. KEY WORDS Urumaco Formation, fossil mammal, Neogene, South America