Ontogeny of the shell bones of embryos of Podocnemis unifilis (Troschel, 1848) (Testudines, Podocnemididae).

The aim of the present study was to investigate the sequence of shell bone formation in the embryos of the Pleurodira, Podocnemis unifilis. Their bones and cartilage were collected and cleared before staining. The shell was also examined by obtaining a series of histological slices.