Reevaluation of the extinct lizard Propodinema and remains of Tupinambis from Miocene-Pliocene deposits of Argentina

BRIZUELA, S.; ALBINO, A. M.

Ciudad de Buenos Aires

Congreso; XI Congreso Argentino de Herpetología; 2010

Asociación Herpetológica Argentina

The presence of lizard remains in the Miocene - Pliocene deposits of the provinces of Entre Ríos and Córdoba has been acknowledge for a long time in the literature. Only the remains from Entre Ríos (Ituzaingó Formation) have been described in detail as support of the erection of two species of the extinct lizard Propodinema, posteriorly referred to Tupinambis. These fossils are now lost preventing direct comparisons. On the other hand, a maxilla from Córdoba (La Playa Formation) was assigned to Tupinambis merianae, although lacking a formal description and discussion of characters. The results of direct observations on the material from La Playa Formation and discussion of the characters given in the original description of Propodinema, are presented here. A assignation to the genus Tupinambis is well supported in both cases, although, contrary to previous claims, no specific determination is possible. Additional data from the La Playa Formation indicate a more humid environment during the Miocene - early Pliocene, contrasting with the present xeric conditions that allow the presence of only T. rufescens in the area of the fossil locality allocation. However, the exploitation of humid environments by other species of Tupinambis does not contradict the palaeoenvironmental assumption.