The Holectypoida are an
order of
sea urchins related to the
sand dollar
Sand dollars (also known as a sea cookie or snapper biscuit in New Zealand, or pansy shell in South Africa) are species of flat, burrowing sea urchins belonging to the order Clypeasteroida. Some species within the order, not quite as flat, are k ...
s. The order consists of just two living genera, but was once more diverse.
Description and characteristics
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.
Taxonomy
According to
World Register of Marine Species
The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive list of names of marine organisms.
Content
The content of the registry is edited and maintained by scientific specialis ...
:
* family
Anorthopygidae Wagner & Durham, 1966b †
* family
Coenholectypidae Smith & Wright, 1999 †
* family
Discoididae Lambert, 1900
* family
Holectypidae Lambert, 1900 †
References
*
Gnathostomata (echinoid)
Extant Early Jurassic first appearances
{{echinoidea-stub