The Echinoid Directory

Parmulechinus Lambert, 1906, p. 63.

[=Stenaster Lambert, 1905, non Billings, 1858 (objective) ]

Diagnostic Features
  • Test extremely flat with sharp edges. Outline broadly indented at ambulacra, especially posteriorly.
  • Apical disc central, monobasal, with four gonopores.
  • Petals bowed and converging distally, but remaining open. Less than half the radius in length.
  • Ambulacral zones about twice the width of interambulacral zones at ambitus.
  • Food grooves bifurcating immediately distal to the basicoronal plates and are branched distally. Food grooves and ambulacral pores extend onto interambulacral plates.
  • Periproct marginal, opening between fourth paired post-basicoronal plates.
  • Interambulacra continuous, but with very narrow contact between basicoronal plate and subsequent plates. Basicoronal interambulacral plates not projecting.
  • Internal partitioning present but arrangement unreported.
Distribution
Oligocene and Lower Miocene, southern Europe and the Mediterranean.
Name gender masculine
Type
Stenaster labrei Lambert, 1905, p. 140 [= Scutella agassizi Oppenheim, 1902], by original designation.
Species Included
  • P. agassizi (Oppenheim, 1902); Oligocene, France.
  • P. subtetragona (Grateloup, 1936); Lower Oligocene, France.
  • P. parisiense (Tournouer, 1869); Lower Oligocene, France.
Classification and/or Status

Clypeasteroida; Scutellina; Scutelliformes; Scutellidea, Scutellidae.

Subjective junior synonym of Scutulum Lambert, 1910.

Remarks

Abertella has a similarly thin-margined test with strong posterior ambulacral indentations, but differs in having a distinct anal notch and in having disjunct interambulacral plating on the oral surface. The continuous interambulacra also differentiates Parmulechinus from Scaphechinus as does its much thinner test that is uniformly domed aborally. Parmulechinus differs from Parascutella in having shorter petals and narrower interambulacral zones at the ambitus and an altogether thiner test construction, but is otherwise very similar.

Lambert, J. 1906. Revue de Paleozoologie 10, p. 63.

J. W. Durham 1955. Classification of clypeasteroid echinoids. University of California Publications in Geological Sciences 31(4), 73-192.