The Echinoid Directory

Mortonella Pomel, 1883, p. 70

[pro Mortonia Desor 1858, p. 231 non Gray, 1851 ]

Diagnostic Features
  • Test with thick, rounded margin; circular in outline.
  • Petals broad and open distally.
  • Interambulacra continuous adorally but with extremely narrow contact between basicoronal and second plates.
  • Basicoronal circlet strongly pentastellate, with interambulacral plates projecting.
  • Periproct oral, midway between peristome and posterior margin; opening towards outer edge of first post-basicoronal interambulacral plates.
  • Food grooves with strong primary trunk that bifurcates at outer edge of second pair of ambulacral plates; branched distally.
Distribution
Late Eocene of South Eastern USA.
Name gender feminine
Type
Scutella quinquefaria Say, 1825, p. 228 (=Scutella rogersi Agassiz, 1841, non Morton, 1834), by subsequent designation ICZN 1955.
Species Included
Only the type species.
Classification and/or Status

Clypeasteroida; Scutellina; Scutelliformes; Protoscutellidae.

Monotypic.

Remarks

The thick, rounded margin is very reminiscent of laganids, but the bifurcating food grooves immediately distinguish this taxon. It differs from Periarchus only in having a thick rounded margin.

J. W. Durham 1955. Classification of clypeasteroid echinoids. University of California Publications in Geological Sciences 31(4), 73-198.

Pomel, A. 1883. Classification méthodique et genera des Échinides vivante et fossiles. Thèses présentées a la Faculté des Sciences de Paris pour obtenir le Grade de Docteur ès Sciences Naturelles, 503, 131 pp. Aldolphe Jourdan, Alger.