Evolution of post-cranium and intra and interespecific variations in Pleurodiromorpha (Chelonii)

Abstract

New pleurodiran taxa have been described based on fragmented or uncompleted post-cranial materials. At the same time, based on a non-verified hypothesis that the chelonian post-cranium (especially the shell) are very homoplastic, most of the pleurodiran phylogenetic analysis are poor in post-cranial characters. This contradiction reflects a lack of knowledge of the chelonian post-cranium, especially in the Pleurodira lineage. The primary master degree project on which this BEPE project are attached aims to investigate the previous mentioned subject. Beginning with the osteological study of extant pleurodiran specimens, we intend to identify and to distinguish the observed variation between intra- and interspecific kinds. Therefore, the project is divided in two fronts: one aims to review problematic fossil species, known only by post-cranial bones; and the other intends to generate more post-cranial phylogenetic characters, to incorporate them in a character supermatrix alongside with other author's cranial characters, and to run this supermatrix in a cladistics analysis. This apprenticeship, with a duration of six months, will be sponsored by Dr. Juliana Sterli, and will have its physical basis on the "Museo Paleontológico Egidio Feruglio", Trelew, Argentina. The experience will be important to the project, allowing access to Argentinian colections containing chelonian fossils (of great importance to this study) and allowing contact to one of the most important researchers in this area of paleontology. Moreover, it will be very significant to the academic development of the candidate, which will sense the different work routine of a very important paleontological museum, and will learn new techniques on fossil preparation and data analysis, bringing this new knowledge to Brazil, at the end of the apprenticeship. (AU)