Holectypoida

Holectypoida
Temporal range:
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Echinodermata
Class: Echinoidea
Subclass: Euechinoidea
Infraclass: Irregularia
Order: Holectypoida
Duncan, 1889
Families

See text

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.