The Echinoid Directory

No cladistic analysis of this group has yet been undertaken. However, Mintz (1968, text-fig. 6) did provide an unsupported phylogenetic tree suggesting possible derivation of Spatangoida and Holasteroida from amongst disasteroid taxa.

In the absence of a phylogenetic hypothesis the following pragmatic scheme is used here. It is not clear how many of these families will turn out to be paraphyletic grades.

Family Pygorhytidae Lambert, 1909 [a grade]

Genus Spatocyphus Pomel, 1883

Genus Pygorhytis Pomel, 1883

Genus Pygomalus Pomel, 1883

Family Disasteridae Gras, 1848

Genus Disaster Agassiz, 1835

Family Tithoniidae Solovjev, 1966

Genus Metaporinus Agassiz, 1844

Genus Tithonia Pomel, 1883

Genus Corytha Pomel, 1883

Genus Tetraromania Solovjev, 1971

Family Acrolusiidae Mintz, 1968

Genus Acrolusia Lambert, 1920

The following papers are key sources of primary data on this group:

Jesionek-Szynanska, W. 1963. Echinides irreguliers du Dogger de Pologne. Actes Palaeontologica Polonica 8(3), 293-396.

Mintz, L. W. 1968. Echinoids of the Mesozoic families Collyritidae d'Orbigny, 1853 and Disasteridae Gras, 1848. J ournal of Paleontology 42, 1272-1288.

Solovjev, A. 1971. Late Jurassic and Early Cretaceous disasterids of the USSR. Transactions of the Palaeontological Institute, Academy of Sciences of the USSR 131, 1-120, pls 1-16 [in Russian].