An Amphisbaenidae from Northwestern Argentina, the oldest from South America (Early Pliocene)

RICARDO, MONTERO; GRACIELA ESTEBAN; NORMA NASIF; JUAN DAZA

New Orleans, Luisiana

Congreso; Joint Meeting of Ichthyologist and Herpetologists; 2016

Ichtyology and Herpetology Society

The large outcrops from Puerta de Corral Quemado, Catamarca, Argentina, areexceptional because of the abundant and diverse vertebrate fossils. However, theknowledge of fossils other than mammals is very scarce. Here we present preliminary data from an amphisbaenid lizard from the Andalhuala formation (Late Miocene - Early Pliocene). The specimen is an almost complete and articulated skull. This fossil can be attributed the family Amphisbaenidae based on the following combination of characters: solid and strong skull, parietal roofing completely and closing the braincase laterally, extensive basioccipital plate, sagittal crest, double occipital condyle; stout dentary. The fossil was temporary assigned to the genus Amphisbaena based on the presence of a lownumber of teeth, tooth crowns mostly straight, one enlarged tooth in the mandible, lack of retroarticular process, low saggital crest, columella with a large footplate directed lateroventrally. We cannot determine if this fossils belongs to any of the known species of the genus due to the anterior portion of the skull is missing (which would show characters that may define the species). The fossil was found in an upper layer of Andalhuala formation, and the estimated age ranges between 4.4 Ma and 3.66 + 0.05 Ma (Zancleano, Early Pliocene). This is the first record of an Amphisbenidae with exact chronestratrigrafic precedence and one of the oldest from South America.