NEW RECORD OF A SQUAMATE LIZARD (DIAPSIDA; LEPIDOSAURIA) FROM THE LATE CRETACEOUS ADAMANTINA FORMATION, SÃO PAULO STATE, BRAZIL

NAVA, WILLIAM R.; CANDEIRO, C. ROBERTO A.; MARTINELLI, AGUSTÍN G; FORASIEPI, ANALÍA; SCANFERLA, C. AGUSTÍN; MUZZOPAPPA, PAULA

Neuquén, Provincia de Neuquén, Argentina

Congreso; III Congreso Latinoamericano de Paleontología de Vertebrados; 2008

Universidad Nacional del Comahue

A new record of a non-ophidian squamate from the Late Cretaceous of Brazil is herein described. The specimen was found about 10km south of Marília city (São Paulo State) in outcrops of the Adamantina Formation (Bauru Group; Turonian-Santonian). The material consists of 10 articulated dorsal vertebrae with a total length of 14mm and seven right incomplete ribs. The vertebrae are slender, procoelous, with a broad intervertebral foramen, without evidence of intercentra, with a single synapophysis. The ribs are unicapitate. This material is assigned to Squamata due to the presence of procoelous vertebrae, the absence of intercentra in the dorsal vertebrae, and the presence of single-headed ribs (Hoffstetter and Gasc, 1969; Estes et al., 1988). In addition, it is excluded from the snake?s group owing to the absence of separated diapophyses and parapophyses, the lack of clearly triangular centra in ventral view, and, if present, the reduced zygosphene-zygantrum articular complex. Previous squamate remains from the Bauru Group comprise mid-posterior trunk vertebrae of an anilioid snake (General Salgado, São Paulo State) from the Adamantina/Vale do Rio Peixe Formation (Zaher et al., 2003). It was interpreted as an anilioid snake due to the presence of dorso-ventrally compressed neural arches and poorly developed neural spines; both features are absent in the specimen described here. The other record is Pristiguana brasiliensis (Estes and Price, 1973), found near the Peirópolis town (Uberaba, Minas Gerais State) in the Marília Formation (Maastrichtian). It consists of cranial bones and left humerus of a single individual and does not possess vertebral remains, hindering any comparison with the specimen presented here. Despite an accurate taxonomic identification of the material was not possible, it represents the first non-ophidian squamate from the Adamantina Formation, enlarging the record of squamates in the Bauru Group (Brazil), and indicating the presence of very small-sized non-ophidian squamate taxa, which are scarce in the South American fossil record.