Belongs within: Cidaroida.
The Ctenocidarinae are a group of echinoids found in the Antarctic and South Pacific (Fell 1966).
Characters (Fell 1966): Primary tubercles noncrenulate on oral hemisphere, subcrenulate or noncrenulate on aboral hemisphere. No horizontal sutural grooves. Ambulacral pore pairs placed obliquely on plate; two pores confluent or separated by very narrow wall, thickness of which does not exceed 0.5 of pore diameter. No tridentate pedieellariae. Large and small globiferous pedicellariae present.
Ctenocidarinae [Ctenocidarina]F66
|--Ctenocidaris Mortensen 1910F66
| `--*C. speciosa Mortensen 1910F66
|--Aporocidaris Agassiz & Clark 1907F66
| `--*A. milleri (Agassiz 1898) [=Porocidaris milleri]F66
|--Austrocidaris Clark 1907F66
| `--*A. canaliculata (Agassiz 1863) [=Temnocidaris canaliculata]F66
|--Eurocidaris Mortensen 1909F66
| `--*E. nutrix (Wyville Thomson 1876) [=Cidaris nutrix]F66
|--Homalocidaris Mortensen 1928F66
| `--*H. gigantea (Clark 1925) [=Austrocidaris gigantea]F66
|--Notocidaris Mortensen 1909F66
| `--*N. mortenseni (Koehler 1900) [=Goniocidaris mortenseni]F66
|--Ogmocidaris Mortensen 1921F66
| `--*O. benhami Mortensen 1921F66
`--Rhynchocidaris Mortensen 1909F66
`--*R. triplopora Mortensen 1909F66
*Type species of generic name indicated
References
[F66] Fell, H. B. 1966. Cidaroids. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt U. Echinodermata 3 vol. 1 pp. U312–U339. The Geological Society of America, Inc., and The University of Kansas Press.