Psephoderma

Name: Psephoderma ‭(‬Pebbly skin‭)‬.
Phonetic: Sef-oh-der-mah.
Named By: Christian Erich Hermann von Meyer‭ ‬-‭ ‬1858.
Classification: Chordata,‭ ‬Reptilia,‭ ‬Sauropterygia,‭ ‬Placodontia,‭ ‬Placohelyidae.
Species: P.‭ ‬alpinum‭ (‬type‭)‬,‭ ‬P.‭ ‬anglicum.
Diet: Shellfish.
Size: 180‭ ‬centimetres long.
Known locations: Europe.
Time period: Norian of the Triassic.
Fossil representation: Few specimens.

       With two body shells Psephoderma was very similar to Cyamodus although it was much larger.‭ ‬It is also these shells,‭ ‬or rather the pebbly appearance of them that was the inspiration of the name that means‭ ‘‬pebbly skin‭’‬.‭ ‬Psephoderma was one of the larger placodonts,‭ ‬particularly of the shelled variety.‭ ‬This may be because Psephoderma lived more towards the end of the Triassic when marine predators such as reptiles and sharks were also growing bigger.‭ ‬Like other placodonts,‭ ‬Psephoderma was well adapted to eating shellfish.‭ ‬Rather than having forward facing teeth however,‭ ‬Psephoderma’s mouth was shaped like a beak.‭ ‬This could pick out shellfish from between rocks and other submerged debris so that the crushing teeth further back in the mouth could crush the shell.

Further reading
- The dermal armor of the cyamodontoid placodonts (Reptilia, Sauropterygia): morphology and systematic value. - Fieldiana Geology: New Series 46:1-41. - O. Rieppel - 2002.

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