Holectypoida
{{Short description|Order of sea urchins}}
{{Automatic taxobox
| fossil_range = {{Fossil range|Lower Jurassic|recent}}
| display_parents = 2
| taxon = Holectypoida
| authority = Duncan, 1889
| subdivision_ranks = Families
| subdivision = See text
| subdivision_ref = {{cite WoRMS |title=Holectypoida |id=196233 |access-date=29 July 2024}}
}}
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.
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.{{cite book |author= Barnes, Robert D. |year=1982 |title= Invertebrate Zoology |publisher= Holt-Saunders International |location= Philadelphia, PA|page= 981|isbn= 0-03-056747-5}}
Taxonomy
According to World Register of Marine Species:
{{Linked taxon list
| {{extinct}}Anorthopygidae | Wagner & Durham, 1966
| {{extinct}}Coenholectypidae | Smith & Wright, 1999
| Discoididae | Lambert, 1900
| {{extinct}}Holectypidae | Lambert, 1900
}}
References
{{Reflist}}
{{Taxonbar|from=Q1037576}}
Category:Extant Early Jurassic first appearances
Category:Taxa described in 1889
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