The Echinoid Directory

• Test cordiform with anterior sulcus; posterior face truncate.
• Apical disc central; ethmophract; with four gonopores.
• Anterior ambulacrum in shallow sulcus from apex to peristome. Pore-pairs differentiated aborally; non-petaloid.
• Other ambulacra forming straight, shallowly sunken petals aborally; pore-pairs elongate; perradial line grooved.
• Peristome close to anterior margin; facing forward and completely covered by the labral plate in oral view.
• Labral plate longitudinally elongate; sternal plates symmetical; episternal plates not narrowing.
• Periproct at top of steeply truncated posterior face.
• Aboral tuberculation of uniform small tubercles set in a fine groundmass of granules.
• Subanal fasciole present.

Upper Cretaceous (Santonian to Campanian), Europe.

Micraster coranguinum var. latior Rowe, 1899, p. 539 [= Spatangus coranguinum Leske, 1778 p. 221] by original designation.

• M. latior (Rowe, 1899); Santonian, Europe.
• M. cracoviensis Maczynska, 1968; Campanian, Poland.

Spatangoida, Micrasterina, Micrasteridae.

Objective synonym of Micraster Agassiz, 1836.

Maczynska (1968) distinguished this taxon from Micraster citing its more granular subanal region and more stretched plastronal plating. He cited Rowe's Micraster coranguinum var. latior as type species. However, there is little to distinguish Rowe's variety from the type Micraster coranguinum other than test width. Furthermore, it is likely that Maczynska's Campanian M. latior is not synonymous with Rowe's Lower Santonian species. The former has meridoplacous lateral interambulacra while the latter has amphiplacous lateral interambulacra.

Maczynska, S. S. 1968. Echinoids of the genus Micraster L. Agassiz from the Upper Cretaceous of the Cracow-Miechow area. Prace Muzeum Ziemi 12, 87-168, pls 1-28.