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Stratigraphic chart of the lower Permian (partial) Content updated October 16, 2005
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CLAUDIOSAURUS GERMAINI Eureptilia-Diapsida
Claudiosaurus Germaini, described as possible plesiosaur ancestor by Carroll (1981), is now considered a stem diapsid more basal than Youngina (but see J. Muller 2003) and less basal than Araeoscelids. This well preserved specimen comes, as the Carroll's ones, from the Lower Sakamena Formation of Upper Permian of Madagascar. This specimen, though without skull, is interesting because it is an adult individual with the clavicles and the tarsus well exposed. In the specimens of Carroll the clavicles were not well exposed but he described them as narrow. Narrow clavicles is considered a synapomorphy shared by Claudiosaurus, Younginiforms and Saurians by Laurin and Gauthier (Autapomorphies of Diapsid Clades in Tree of Life Web Project), but in this specimen the clavicles seem not narrow. Tibio-astragalar joint is considered a synapomorphy shared by Araeoscelids and Younginiforms by Laurin and Reisz (1995). Perhaps, the tibio-astragalar joint could be expected also in Claudiosaurus, but in this specimen the tibio-astragalar joint is not present. 2) Claudiosaurus (same skeleton): enlargement of clavicle 3) Claudiosaurus (same skeleton): enlargement of the pes 4) Claudiosaurus (same skeleton): enlargement of the tarsus
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