On Friday I gave you this object to identify:

As I suspected, you all worked out that it is the skull of a turtle, so well done all and particularly Jake, who got there first.
Turtle skulls are quite characteristic, in that they have a bill with no teeth and they have no openings apart from the obvious ones like the eye sockets and nose. Most other tetrapods have several openings in their skulls, something that is diagnostic for, and sometime provides the name for, major groups like the main ‘reptile’ group the Diapsida. This name that means two arches, which is a reference to two additional openings present in the skulls of this lineage (which includes the lizards, snakes, crocodiles and dinosaurs – including the birds). Turtles and tortoises are members of the Anapsida, which means without arches.
The characteristics of this skull are those of an Anapsid and the streamlined shape and quite large size (despite it being a youngish adult, as indicated by the unfused sutures) suggests that it is a sea-turtle. There are only 7 species of sea-turtle and the comments provide an example of features that can be used to distinguish this as a Continue reading →