Holectypoida

The Holectypoida are an order of sea urchins related to the sand dollars. The order consists of just two living genera, but was once more diverse.

Holectypoida
Temporal range: Lower Jurassic–recent
Echinoneus cyclostomus.jpg
Echinoneus cyclostomus
Scientific classification
Kingdom:
Phylum:
Class:
Superorder:
Order:
Holectypoida

Duncan, 1889
Family:
Echinoneidae

Agassiz, 1847
Genera

Echinoneus
Micropetalon

Description and characteristicsEdit

In appearance, the living holectypoids are similar to sand dollars, but with less flattened bodies and an oval outline. They also lack the petal-like patterns found on the bodies of sand dollars.

TaxonomyEdit

According to World Register of Marine Species :

ReferencesEdit

  • Barnes, Robert D. (1982). Invertebrate Zoology. Philadelphia, PA: Holt-Saunders International. p. 981. ISBN 0-03-056747-5.