Belongs within: Cidaroida.
The Rhabdocidarinae are a group of cidaroid urchins known from the Lower Jurassic to the present (Fell 1966).
Characters (Fell 1966): Test robust, without sutural grooves. Pores conjugate or subconjugate. Primary spines large, robust.
<==RhabdocidarinaeF66
|--Actinocidaris Mortensen 1928F66
| `--*A. thomasi (Agassiz & Clark 1907) [=Phyllacanthus thomasi]F66
|--Chondrocidaris Agassiz 1863F66
| `--*C. gigantea Agassiz 1863F66
|--Megacidaris Thiéry 1928F66
| `--*M. horrida (Merian 1880) [=Cidarites horrida]F66
|--Parhabdocidaris Thiéry 1928 [=Parrhabdocidaris Mortensen 1928]F66
| `--*P. varusensis (Cotteau 1880) [=Rhabdocidaris varusensis]F66
|--Plococidaris Mortensen 1909F66
| `--*P. verticillata (Lamarck 1816) [=Cidarites verticillata]F66
|--Porocidaris Desor 1855 [=Procidaris Pávay 1875]F66
| `--*P. schmidelii (Münster 1843) [=Cidarites schmidelii]F66
|--Rhabdocidaris Desor 1855F66 [=Rhabdocrinus (l. c.) non Wright 1944WR78]
| |--*R. orbignyana [=Cidaris orbignyana]F66
| |--R. copeoidesF66
| `--R. rhodaniF66
|--Prionocidaris Agassiz 1863 (see below for synonymy)F66
| |--*P. pistillaris (Lamarck 1816) [=Cidarites pistillaris]F66
| |--P. baculosa (Lamarck 1816)MG-H11
| |--P. bispinosa (Lamarck 1816)SM15
| |--P. canaliculataF66
| |--‘*Schleinitzia’ crenularis Studer 1880F66
| |--P. marshalliF66
| |--P. mitchelliF66
| |--P. sismondaiF66
| `--P. verticillata (Lamarck 1816)SM15
`--Phyllacanthus Brandt 1835 (see below for synonymy)F66
|--*P. dubius (Brandt 1835) [=Cidarites (*Phyllacanthus) dubia]F66
|--P. annuliferaH04
|--‘Leiocidaris’ australe [incl. Cidaris striatus]H86
|--P. baculosaH04
|--‘Cidarites’ depressus Risso 1826R26
|--‘Cidaris’ imperialis Lamarck 1816 [=*Leiocidaris imperialis]F66
|--‘Cidarites’ judaicus Risso 1826R26
|--‘*Aulacocidaris’ lamberti (Savin 1903)F66
|--P. longispinus Mortensen 1918SM15
|--P. magnificus Clark 1914MG-H11
|--P. parvispinusF67
|--P. titanF66
`--P. wellmanaeF66
Phyllacanthus Brandt 1835 (nom. cons.) [incl. Aulacocidaris Lambert 1903, Cidarites Lamarck 1816, Leiocidaris Desor 1855]F66
Prionocidaris Agassiz 1863 [incl. Pleurocidaris Pomel 1883, Schleinitzia Studer 1880, Stephanocidaris Agassiz 1872 non Agassiz 1863]F66
*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.
[F67] Fell, H. B. 1967. Echinoderm ontogeny. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt S. Echinodermata 1. General characters. Homalozoa—Crinozoa (except Crinoidea) vol. 1 pp. S60–S85. The Geological Society of America, Inc., and The University of Kansas: Lawrence (Kansas).
[H04] Haeckel, E. 1899–1904. Kunstformen der Natur. Bibliographisches Institut: Leipzig und Wien.
[H86] Hutton, F. W. 1886. Notes on some Australian Tertiary fossils. Proceedings of the Linnean Society of New South Wales, series 2, 1 (2): 481–482.
[MG-H11] McEnnulty, F. R., K. L. Gowlett-Holmes, A. Williams, F. Althaus, J. Fromont, G. C. B. Poore, T. D. O’Hara, L. Marsh, P. Kott, S. Slack-Smith, P. Alderslade & M. V. Kitahara. 2011. The deepwater megabenthic invertebrates on the western continental margin of Australia (100–1100 m depths): composition, distribution and novelty. Records of the Western Australian Museum Supplement 80: 1–191.
[SM15] Sampey, A., & L. M. Marsh. 2015. Kimberley marine biota. Historical data: echinoderms. Records of the Western Australian Museum Supplement 84: 207–246.
[WR78] Wienberg Rasmussen, H. 1978. Articulata. In: Moore, R. C., & C. Teichert (eds) Treatise on Invertebrate Paleontology pt T. Echinodermata 2. Crinoidea vol. 3 pp. T813–T927. The Geological Society of America, Inc.: Boulder (Colorado), and The University of Kansas: Lawrence (Kansas).