A clade of Carinacea with:
Early Jurassic (Hettangian) to Recent; worldwide.
|Species Included||Includes the orders Phymosomatoida and Salenioida.|
|Classification and/or Status||Euechinoidea, Acroechinoidea, Carinacea (crown group)|
|Remarks||Gregory (1900) and later workers have used the term Calycina to encompass just the Salenioida. Here we follow Kroh & Smith's (2010) usage of the term. It unites groups that have a large apical disc in which periproctal plates are integrated with the ring of ocular and genital plates. In Echinacea, by contrast, periproctal plates do not form a tesselated pavement but are small and embedded in a membrane. The inner border of the genital and ocular ring is therefore smooth and circular whereas it is angular and indented in the Calycina.
Gregory, J. W. 1900. The Echinoidea. Pp. 282-332 in E. R. Lankester (ed.) A treatise on Zoology. Part III. The Echinoderma. London, Adam & Charles Black.
Kroh, A. & Smith, A. B. 2010. The phylogeny and classification of post-Palaeozoic echinoids. Journal of Systematic Palaeontology 8, 147-212.