Echinocyamidae

Echinocyamidae Temporal range: 9 –0 Ma PreЄ Є O S D C P T J K Pg N Miocene to Recent
Echinocyamus pusillus
Scientific classification
Domain:	Eukarya
Kingdom:	Animalia
Phylum:	Echinodermata
Class:	Echinoidea
Subclass:	Euechinoidea
Superorder:	Gnathostomata
Order:	Clypeasteroida
Suborder:	Scutellina
Infraorder:	Laganiformes
Family:	Echinocyamidae Lambert & Thiéry, 1914
Genera
Echinocyamus †Leniechinus Mortonia

Echinocyamidae is a family of sand dollars. They are found mostly off the coast of Britain and Ireland and the North Sea, with scattered populations in the tropics.

Description

The are Laganiformes with:

• simple radial internal buttresses along interambulacral margins;
• periproct close to peristome and opening bounded by first and second paired post-basicoronal interambulacral plates
• interambulacral zones terminating adapically in one or two single small plates
• basicoronal circlet small and unspecialized
• no food grooves