The Echinoid Directory

Ravenelia McCrady, 1859, p. 283

Diagnostic Features
  • Test of medium size, elongate. anterior margin rounded, posterior truncated, adapically low, only slightly inflated, adoral surface flattened to slightly depressed saggitally
  • Apical system anterior, monobasal, with four gonopores
  • Petals broad, interporiferous zones only slightly wider than poriferous, poriferous zones wide, tapering distally but remaining open. Pores conjugate, outer pore more elongate transversely than inner pore, ambulacral plates beyond petals with single pores
  • Peristome anterior, subpentagonal, longer than wide; with vertical-walled entrance
  • Periproct supramarginal, transverse, groove extending from opening to posterior margin; adapical surface overhanging opening, faint adoral sulcus
  • Bourrelets: basicoronal plates short but with slight swellings; dense tuberculation extend laterally along bourrelets as well as on vertical-walled entrance to peristome
  • Phyllodes broad, single pored, arranged in two series in each half ambulacrum
  • Buccal pores present; sphaeridial pits well developed, forming double perradial series
  • Tubercles on adoral surface much larger than on adapical, with sunken areoles and large high boss located anteriorly
  • Broad naked zone with deep irregularly shaped pits in adoral ambulacrum III and interambulacrum 5
  • Middle Eocene of North and South Carolina, USA
Name gender feminine
Pygorhynchus rugosa Ravenel, 1848, p. 4; by subsequent designation of Lambert & Thiery, 1921, p. 365.
Species Included
  • Only the type species
Classification and/or Status

Irregularia; Cassiduloida; Cassidulidae

Subjective junior synonym of Eurhodia Haime in d'Archiac & Haime, 1853.


Ravenelia is very similar to Eurhodia, the type species of both genera having an elongate, low shape, with a supramarginal transverse, periproct, high peristome and strikingly similar floscelle (Kier, 1962, p. 216). Ravenelia differs in that it has deep irregularly shaped pits in adoral ambulacrum III and interambulacrum 5, these areas being typically less deeply pitted in the type species of Eurhodia. Such a character is not worthy of generic distinction as varying degrees of this character are present throughout the species of Eurhodia. Distinguished from Cassidulus and Rhyncholampas by its longitudinally elongate peristome.

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