Pelagodiscus

Pelagodiscus
Scientific classification
Kingdom:	Animalia
Phylum:	Brachiopoda
Order:	Discinida
Family:	Discinidae
Genus:	Pelagodiscus
Species:	P. atlanticus
Binomial name
Pelagodiscus atlanticus

Pelagodiscus is a monospecific genus of discinid brachiopods. Silica tablets leave a distinctive tesselating imprint on the inner surface of its shell.

...
Wikipedia