Gryphaea arcuata

Gryphaea arcuata is an extinct species of foam oyster, a bivalve mollusc in the family Gryphaeidae from the Early Jurassic of Europe.

Gryphaea arcuata Temporal range: Hettangian–Bajocian PreꞒ Ꞓ O S D C P T J K Pg N
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Bivalvia
Order:	Ostreida
Family:	Gryphaeidae
Genus:	†Gryphaea
Species:	†G. arcuata
Binomial name
†Gryphaea arcuata Lamarck, 1801

It is commonly referred to in English folklore as the 'devils toenail' due to its supposed resemblance to the devil's 'cloven hoof'.

Sources

• Paleontology portal

• Gryphaea arcuata in the Paleobiology Database
• Fossils (Smithsonian Handbooks) by David Ward (Page 101)