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Helicoplacoidea

Helicoplacoidea

Synonyms
Synonymy list
YearName and author
1963Helicoplacoidea Durham and Caster
1993Westgardellidae Durham p. 601
2002Helicoplacoidea Sepkoski

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RankNameAuthor
kingdomAnimalia()
Bilateria
EubilateriaAx 1987
Life
Deuterostomia
RankNameAuthor
Ambulacraria
phylumEchinodermata
classHelicoplacoidea
classHelicoplacoidea

If no rank is listed, the taxon is considered an unranked clade in modern classifications. Ranks may be repeated or presented in the wrong order because authors working on different parts of the classification may disagree about how to rank taxa.

Cl. †Helicoplacoidea Durham and Caster 1963
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Fm. †Helicoplacidae Durham and Caster 1966
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G. †Helicoplacus Durham and Caster 1963
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Helicoplacus gilberti Durham and Caster 1963
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Invalid names: Helicoplacus casteri Durham 1993 [synonym], Helicoplacus curtisi Durham and Caster 1963 [synonym], Helicoplacus everndeni Durham 1967 [synonym], Helicoplacus guthi Durham 1993 [synonym], Westgardella blancoensis Durham 1993 [synonym], Westgardella firbyi Durham 1967 [synonym]
Invalid names: Westgardella Durham 1993 [synonym]
G. †Polyplacus Durham 1967
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Polyplacus kilmeri Durham 1967
G. †Waucobella Durham 1967
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Waucobella nelsoni Durham 1967
Invalid names: Helicoplacida Durham 1967 [empty], Polyplacida Durham 1967 [empty], Westgardellidae Durham 1993 [invalid subgroup]
Diagnosis
ReferenceDiagnosis
J. W. Durham and K. E. Caster 1963Free living, fusiform placoid echinoderms with spirally pleated, expansible test; apical and oral poles at opposite extremities; columns of plates arranged in a spiral; ambulacra and "inter ambulacra" present; new "interambulacral" plates originating at apical pole and becoming more oral in position as subsequent plates are added (origin of ambulacral plates obscure). Lower Cambrian, California