Subfamily Arachnoidinae Duncan 1889 (sand dollar)
Echinoidea - Clypeasteroida - Clypeasteridae
Alternative spelling: Arachnoididae
Full reference: P. M. Duncan. 1889. A revision of the genera and great groups of the Echinoidea. Journal of the Linnean Society, Zoology 23:1-311
Parent taxon: Clypeasteridae according to A. Kroh and A. B. Smith 2010
See also Clark 1914, Durham 1955 and Durham 1966
Sister taxa: Ammotrophinae, Clypeaster, Clypeasterinae, Diplothecanthus
Subtaxa: Arachnoides Fellaster Fossulaster
Ecology: slow-moving semi-infaunal detritivore
Distribution:
• Quaternary of New Zealand (1 collection)
• Pliocene of New Zealand (2)
Total: 3 collections each including a single occurrence