Basic info Taxonomic history Classification Included Taxa
Morphology Ecology and taphonomy External Literature Search Age range and collections

Helicoplacidae

Helicoplacoidea - Helicoplacidae

Taxonomy
Helicoplacidae was named by Durham and Caster (1966).

It was assigned to Helicoplacida by Durham (1993); and to Helicoplacoidea by Wilbur (2006).

Synonymy list
YearName and author
1966Helicoplacidae Durham and Caster
1993Helicoplacidae Durham p. 600
2006Helicoplacidae Wilbur p. 290

Is something missing? Join the Paleobiology Database and enter the data

RankNameAuthor
kingdomAnimalia()
Bilateria
EubilateriaAx 1987
Life
Deuterostomia
RankNameAuthor
Ambulacraria
phylumEchinodermata
classHelicoplacoidea
familyHelicoplacidaeDurham and Caster 1966
familyHelicoplacidaeDurham and Caster 1966

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.

Fm. †Helicoplacidae Durham and Caster 1966
show all | hide all
G. †Helicoplacus Durham and Caster 1963
hide
Helicoplacus gilberti Durham and Caster 1963
hide
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
hide
Polyplacus kilmeri Durham 1967
G. †Waucobella Durham 1967
hide
Waucobella nelsoni Durham 1967
Diagnosis
ReferenceDiagnosis
J. W. Durham 1993Paired grooves for tubefeet in opposing margins of contemporaneous ambulacral plates. Plates of medial column of interambulacra pustulose or with longitudinal ridges. In each volution eight interambulacral areas adoral to primary ambu- lacrum.
B. C. Wilbur 2006Echinoderm with a spindle to bulb-shaped theca composed of left-handed spiraling interambulacral pleats composed of ridge and accessory plates, which allowed for expansion and contraction of the test. Three ambulacral branches are imbedded within interambulacral pleats and extend away from a mediolateral mouth; two separated by one to three interambulacral pleats extend toward the upper pole, and one toward the lower pole. Ambulacra are comprised of biserial floor-plates and sheets of coverplates. The ambulacral groove have sutural gaps between laterally adjacent floorplates, which form compensation space for the ampullae of tube feet.