Preliminary results of screenwashing in two Late Cretaceous outcrops of the Marilia Formation (Bauru Group) in the Triângulo Mineiro (Minas Gerais State, Brazil).

CARLOS R. CANDEIRO; AGUSTIN MARTINELLI; CECILIA PEREZ WINTER; LUIZ CARLOS RIBEIRO; LILIAN BERGQVIST

Rio de Janeiro

Simposio; 7° Simpósio Brasileiro de Paleontologia de Vertebrados; 2010

In this contribution we present the preliminary results of screenwashing carried out during the year 2009 in two localities of Uberaba municipality (Minas Gerais, Brazil). The screenwashing was developed with sediments from lacustrine and fluvial levels of the Marilia Formation outcropping in road cuts of the BR-050 near the city of Uberaba. About two tons of sediments were washed using four different screen types and at present only 1/3 of the concentrate was carefully analyzed. Among the recovered specimens the most remarkable are: isolated teeth of Lepisosteiformes, three different types of pectoral spines of Siluriformes, isolated teeth of Characiformes (Erythrinidae type), isolated teeth of Abelisauridae and Titanosauridae, and an isolated pedal phalanx of Aves. Despite the fossil vertebrate association of the Marilia Formation in the Peiropolis-Uberaba region is relatively well-documented and have been studied by several authors, the main goal of screenwashing in these localities is to look for previously unrecovered taxa. Among the recovered specimens, the isolated pedal phalanx 1 of left digit II, assigned only tentatively to Neornithes indet., is similar to the material recovered in Los Alamitos Formation (Late Cretaceous of Patagonia, Argentina), and constitutes the first occurrence of this group in this region. Systematized screen washing of sediments from lacustrine-fluvial levels of the Marilia Formation may bring novelties in the Late Cretaceous faunal composition of Brazil.