Helicoplacoidea
Helicoplacoidea Temporal range:
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The holotype specimen of Helicoplacus guthi[1] | |
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Echinodermata |
Class: | †Helicoplacoidea
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Helicoplacoidea is an extinct
Description
Helicoplacoid skeletons consist of small platelets arranged like those of
Fossils and taxonomy
Most of the fossils are from White Mountains, Nevada. The rarity of fossils and general poor preservation of them has made it hard to determine any kind of phylogeny for them, though three genera (Helicoplacus, Polyplacus and Waucobella) are currently recognized.[5] Also due to this, it is difficult to establish a conclusive taxonomic classification of the Helicoplacoidea.
A list of helicoplacoid genera, as recognized by the Paleobiology Database, is as follows:[5]
- Family †Helicoplacidae
- †Helicoplacus Durham & Caster, 1963
- †Polyplacus Durham, 1967
- †Waucobella Durham, 1967
- Family †Helicoplacidae
Helicoplacus guthi, one of two species of Helicoplacus, was named after the fossil's discoverer, Peter Guth. However, Wilbur (2006) suggests that this specimen is actually a poorly preserved specimen of Helicoplacus gilberti. This fossil measured 3.3 cm, and comes from the Cambrian formation of Poleta, California.[6]
References
- ^ S2CID 33443660.
- ^ Fossilworks: Helicoplacoidea. fossilworks.org. Retrieved 2021-01-13.
- ^ a b University of Berkeley: Helicoplacoidea. ucmp.berkeley.edu. Retrieved 2021-01-15.
- ^ Palaeos: Helicoplacoidea: Armor-Plated Spirals
- ^ a b Paleobiology Database: Helicoplacoidea. paleobiodb.org. Retrieved 2021-01-15.
- .