Gaining clues on the role of bone fusions in the simplification of the early tetrapod skull

The tetrapod skull has repeatedly lost bones throughout its evolutionary history. This is a well-documented, yet poorly studied convergent trend that has occurred independently in several different tetrapod lineages. This project aims to use histological data to find evidence for bone loss via fusion. We will search for evidence of fusions in the temporal and median series of the dermatocranium in several different early tetrapods. This will include stem amniotes, as well as the two groups that have been alternatively proposed as stem-lissamphibians; the temnospondyls and lepospondyls. The specimens also possess varying degrees of completeness of the temporal series, which is the most variable region of the dermatocranium. By including these specimens and sampling both the temporal and neighbouring median series, we will be able to see if there is evidence that suggests temporal series bones were lost by fusing with neighbouring temporal or median bones.