Early origins of turtles
In a letter to Nature this week the ancestral origins of turtles are believed to have been identified from fossils found in southwest China. The newly named fossilised species, Odontochelys semitestacea, may have lived in river deltas and shallow seas around 220 million years ago and had teeth and a long tail. However, it is the fact that this species only has a breastplate and some dorsal neural plate extension that is of interest. Previously recorded fossils are similar to the turtles in our oceans today, showing both a breastplate and carapace or shell. In those reported now, the breastplate is a bony extension of the ribs and the back is purely skin with no large bony structure. This corresponds to the early embryonic stages of turtle development today and is indicative of the formation of the shell from bone whereas previously it was thought it may have been formed by the fusion of hardened skin. These fabulous creatures can be seen on the shores of a number our wildlife holiday destinations including Costa Rica, Oman and India, whilst on Galapagos tours and cruises it is possible to swim with a variety of species of turtles.
Tags: evolution, Galapagos Island cruises, turtles
