Diagnostic Features
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- Test large and relatively thin plated; adambulacral suture appears to be imbricate.
- Apical disc and aboral surface unknown.
- Interambulacra with 7-8 plates in a series to the ambitus (estimated 12-16 in total). Primary tubercles perforate and crenulate; areoles ovate and confluent over entire oral surface.
- Scrobicular tubercles undifferentiated; adradial and interradial bands of secondary tubercles.
- Ambulacra narrow and straight. Pore zones not incised; pore-pairs not conjugate with narrow interporal ridge. Ambulacra trigeminate Every third plate enlarged and with a primary tubercle, other plates reduced and with secondary tubercles only. Primary ambulacral tubercles perforate.
- Peristomial plates well developed, in double series in each column.
- Lantern with grooved teeth; perignathic girdle not seen.
- Primary spines long and cylindrical; neck moderately long; shaft smooth and glassy.
- Secondary spines not flattened, not adpressed.
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Distribution
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Lower Jurassic; Europe; ? Upper Triassic, New Zealand. |
Name gender |
feminine |
Type |
Cidaris edwardsi Wright, 1858, p. 26, by subsequent designation of Mortensen, 1928, p. 482. |
Species Included |
- P. edwardsi (Wright, 1858); Pliensbachian, England.
- P. lobatum (Wright, 1878); Hettangian, Sinemurian, England.
- Other species may belong here but are incompletely known and are basically indeterminate
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Classification and/or Status |
Cidaroida; stem group (miocidarids).
?
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Remarks |
Distinguished by its perforate primary ambulacral tubercles and smooth primary spines.
Pomel, A. 1883. Classification methodique et genera des echinides vivants et fossiles. Thesis presentees a la Faculte des Sciences de Paris. A. Jourdan, Alger, 131 pp. |