The Echinoid Directory

Jeronia Seunes, 1888, p. 809

Diagnostic Features
  • Test ovate, tapering posteriorly to a relatively sharp point. Upper surface domed, lower surface with keeled sternum and sunken around anterior of peristome.
  • Thick-shelled.
  • No anterior sulcus.
  • Apical disc elongate with three gonopores; no gonopore in genital plate 2.
  • Paired ambulacra flush, with small, undifferentiated pore-pairs set strongly oblique to the horizontal.
  • Peristome circular and facing downwards.
  • Plastron meridosternous, with a single symmetrical sternal plate following the labrum; subsequent plating biserial.
  • Periproct inframarginal, at end of posterior point. Bounded orally by interambulacral plates 4b/4a.
  • Enlarged primary tubercles around ambitus on either side of the test.
  • No fascioles.
Distribution
Palaeocene (Danian); western Pyrenees.
Name gender feminine
Type
Jeronia pyrenaica Seunes, 1888, p. 810, by original designation.
Species Included
  • Only the type species.
Classification and/or Status

Holasteroida, basal Meridosternata.

Monotypic.

Remarks

The distinctive shape and ambital band of enlarged tubercles makes this genus instanty recognizable. It differs from Echinocorys in apical disc structure, position of periproct and tuberculation. One species of Galeola with a pointed and projecting anal rostrum approaches Jeronia in shape, but Galeola has four gonopores, and no enlarged ambital tuberculation.

Seunes, J. 1888. Note sur le Crétacé supérieur des Pyrénées occidentales. Bulletin de la Societe geologique de France, Serie 3, 16, 779-790.

A. B. Smith, J. Gallemi. C. H. Jeffery, G. Ernst & P. D. Ward 1999. Late Cretaceous-early Tertiary echinoids from northern Spain: implications for the Cretaceous-Tertiary extinction event. Bulletin of the Natural History Museum, London (Geology Series) 55, 81-137.