The Echinoid Directory

Unifascia Cooke, 1959, p. 79

Diagnostic Features
  • Test ovate with convex anterior; rather inflated in profile, weakly convex orally.
  • Apical disc ethmolytic with four gonopores, left and right pairs being rather widely separated; anterior. Genital plate 2 extends between the posterior oculars.
  • Frontal ambulacrum flattened or very slightly depressed adapically. Pore-pairs small and widely spaced.
  • Petals long, parallel-sided and straight; extending almost to ambitus. Anterior pair very widely divergent, almost at 180 degrees. Interporiferous zone as wide as pore-pairs in petals.
  • Peristome well away from anterior; D-shaped.
  • Plastron rather wide; plating unknown.
  • Periproct on posterior truncate face.
  • Single fasciole present, passing above the periproct posteriorly, well below the ends of the anterior petals and inframarginally around the anterior.
  • Tuberculation rather coarse and heterogeneous aborally.
Distribution
Middle Eocene, south eastern USA.
Name gender feminine
Type
Macropneustes carolinensis Clark, in Clark & Twitchell, 1915, p. 154, by original designation.
Species Included
  • Only the type species.
Classification and/or Status

Spatangoida, Paleopneustina, Prenasteridae.

Monotypic.

Remarks

Cooke (1959) described Unifascia as having a marginal fasciole, because it passes around the ambitus in the anterior part of the test and is removed from the ends of the petals. However, the fasciole passes between the periproct and apical system and is thus a hybrid semipetalous and marginal fasciole. It differs from Prenaster in lacking the lateroanal portion of the marginal fasciole and in having heterogeneous aboral tuberculation.

Cooke, C. W. 1959. Cenozoic echinoids of Eastern United States. United States Geological Survey Professional Paper 321, 1-103, pls 1-43.

Kier, P. M. 1980. The echinoids of the Middle Eocene Warley Hill Formation, Santee Limestone, and Castle Hayne Limestone of North and South Carolina. Smithsonian Contributions to Paleobiology 39, 1-102.