The Echinoid Directory

Cassidulus Lamarck, 1801, p. 348

Diagnostic Features
  • Test small, low, elongate oval; broader posteriorly, base more or less flat
  • Apical system anterior; monobasal with four gonopores
  • Petals moderately developed, straight, the two poriferous zones of the same petal usually unequal in length
  • Ambulacra plates beyond petals single pored
  • Periproct supramarginal, subrounded, with short groove on subanal ledge extending from periproct to posterior margin
  • Peristome pentagonal, transverse, anterior, with vertical-walled entrance
  • Bourrelets confined to vertical sides of peristome, basicoronal plates short, very slightly inflated at outer edge
  • Phyllodes single pored, with slight crowding of pores, one or two occluded pores in some ambulacra but for the most part forming a single series widening slightly towards the peristome
  • Three or four sphaeridial pits perradially in phyllodes and partially enclosed
  • Buccal pores present
  • Adorally tubercles much larger, scrobicules often polygonal, with bosses eccentric anteriorly; adorally, naked, pitted area in interambulacrum 5, ambulacrum III
Upper Eocene to Recent; worldwide distribution in the tropics
Name gender masculine
Cassidulus caribaearum Lamarck, 1801, p. 349.
Species Included
  • C. caribaearum Lamarck, 1801; Recent, West Indies, Bahamas to Barbados
  • C. infidus Mortensen, 1948; Recent, Bahia, east coast of South America
  • C. malayanus Mortensen, 1948; Recent, Kei Islands
  • C. mitis Krau, 1954: Recent, Brazil
  • C. trojanus Cooke, 1942; Upper Eocene, Florida, USA
    Kier (1962) also included the following species:
    C. californicus Anderson, 1905; Upper Eocene, California, USA
    C. ellipticus Kew, 1920; Lower Miocene, California, USA
    C. ynezensis Kew, 1920; Lower Miocene, California, USA
Classification and/or Status
Irregularia; Cassiduloida; Cassidulidae

Cassidulus is distinguished from Rhyncholampas by its smaller, more elongate test, narrower, non-lanceolate petals, generally less posterior periproct. However, these differences are largely size related and it is not clear that there is sufficient evidence to merit keeping the two genera separate.

P. M. Kier. 1962. Revision of the cassiduloid echinoids. Smithsonian Miscellaneous Collections 144 (3), 262 pp.

Lamarck, J. B. P. M. d. 1801. Système des animaux sans vertèbres, ou Tableau général des classes, des ordres et des genres des ces animaux, 432 pp. Deterville, Paris.