The Echinoid Directory

Mimiosalenia Smith, 1995, p. 147

Diagnostic Features
  • Test flattened above and below; small (up to 15 mm).
  • Apical disc about half test diameter; thick, forming raised platform; dicyclic; plates firmly bound to corona. Genital plates pentagonal, projecting interradially; gonopores marginal; rising towards periproct, where there is an inner sunken ledge with one perianal tubercle on each plate. Ocular plates smaller and projecting. All plates smooth other than for the five perianal tubercles. Small sutural pits developed. Periproct subpentagonal.
  • Ambulacra straight and rather broad; pore-pairs small, uniserial, the two pores separated by a raised interporal knob; ambulacra remain uniserial to peristome.
  • Ambulacral plating mostly in diads with occasional interspersed simple plate; all elements extending to the perradial suture. Primary tubercle small, imperforate and non-crenulate, postitioned close to adradial margin. Wide perradial zone of smaller secondary tubercles and granules.
  • Interambulacral plates a little wider than tall; with a large primary tubercle on each; secondary tubercles and miliary granulation rather well developed interradially. Primary tubercles imperforate and non-crenulate, with distinct platform surrounding mamelon.
  • First interambulacral plate absent in adults.
  • Peristome subcircular, slightly sunken; buccal notches extremely feeble with no tag.
  • Spines and lantern unknown; no sphaeridial pits.
Distribution Cretaceous (Maastrichtian), Arabian Peninsula.
Name gender feminine
Type
Mimiosalenia quinquetuberculata Smith, 1995, p. 148, by original designation.
Species Included Only the type species.
Classification and/or Status

Echinacea, Arbacioida, Acropeltidae.

Monotypic.

Remarks

Very close to Glyphopneustes, from which it differs only in having predominantly bigeminate rather than trigeminate ambulacral plate compounding. No other acropeltid has a similar style of ambulacral plate compounding.

Smith, A. B. 1995. Late Campanian- Maastrichtian echinoids from the United Arab Emirates - Oman Borders Region. Bulletin of the Natural History Museum, London (Geology Series) 51(2), 121-240.