- Test plating rather fragile, although plating effectively sutured throughout (adapical interradial suture may be slightly flexible).
- Apical disc monocyclic with ocular plates broadly insert. Large circular periproct; genital plates projecting interradially. Periproctal plates typically intercalated into the ring of ocular and genital plates.
- Ambulacra narrow and straight; pore-pairs non-conjugate, in weakly offset triads.
- Ambulacral plating trigeminate with single large primary tubercle per plate.
- Interambulacral zone about two to three times wider than ambulacral zone. Ambital plates pentagonal.
- Single primary tubercle on interambulacral plate filling full plate height; usually with small secondary tubercles on adradial and interradial sides. Tubercles perforate and crenulate.
- Peristome about same size as apical disc, with shallow, rounded buccal notches associated with adradial tags.
- Spines very long and slender; hollow, with verticillate ornament.
Late Cretaceous (Santonian) to Recent; western Europe, Indo-Pacific, Atlantic and Mediterranean.
Diadema longispina Philippi, 1845, by original designation.
- C. longispina (Philippi, 1845); Recent, Mediterranean and East Atlantic.
- C. rodgersii (Agassiz, 1863); Recent, Australia.
- C. asteriscus Agassiz & Clark, 1907; Recent, Hawaii and the Malay archipelago.
- C. coronatus (Verrill, 1867); Recent, Gulf of California.
- C. nitidus Koehler, 1927; Recent, Maldives.
- C. rubricingulus H. L. Clark, 1921; Recent, Caribbean.
- C. tenuispinus H. L. Clark, 1914; Recent, West Australia.
- C. fragile (Wiltshire, in Wright, 1882); Late Cretaceous, Santonian, of England; ?Maastrichtian and Danian of The Netherlands and Denmark.
|Classification and/or Status
?Paraphyletic (lacks autapomorphies).
Differs from most other diadematoids in having a single enlarged primary tubercle on interambulacral plates. Culozoma has a single large tubercle on each plate, but in that genus the areoles are large and confluent, the apical disc opening is large and the peristome is deeply notched by broad U-shaped buccal notches.
Mortensen, T. 1940. A monograph of the Echinoidea. Volume III. 1, Aulodonta. C.A. Reitzel, Copenhagen.
Peters, W. K. H. 1855. Ueber die an der Kuste von Mossambique beobachten Seeigel und isbesondere uber die Gruppe von Diademen. Koenig Akademie der Wissensch