The Echinoid Directory

Serpianotiaris Jeannet, in Peyer, 1933, p. 1

Diagnostic Features
  • Test small (diameter less than 20 mm); depressed above and below.
  • Interambulacral plating more or less firmly sutured; ambulacral-interambulacral suture strongly imbricate.
  • Apical disc slightly less than half test diameter; more or less dicyclic with oculars just exsert. Genital plates large with single small gonopore. Ocular plates triangular. Periproctal zone of small plates about half apical disc diameter. All plates covered in fine uniform granulation.
  • Ambulacra narrow and almost straight. Pore-pairs uniserial to ambitus but expanded to form biserial phyllodes adorally. Plates pseudocompound often in triads, with larger elements bearing a large primary tubercle alternating with smaller elements with smaller tubercles, but can be more irregularly developed. Towards peristome a primary tubercle only on inner series of plates.
  • Pore-pairs laterally elongate but non-conjugate.
  • Interambulacral zones wide with two columns of plates. Adapical plates with a single large primary tubercle surrounded by a sunken areole and well defined scrobicular circle. On oral surface scrobicular circles less well defined and large secondary tubercles, two or three to a plate, occur along the adradial margin.
  • Primary tubercles perforate and crenulate.
  • Interior of interambulacral zone along adradial margin strongly denticulate.
  • Peristome larger than apical disc, circular; no buccal notches.
  • Perignathic girdle well developed, consisting of a small interradial knob and auricle-like flanges at the adradial edges of interambulacral plates.
  • Primary spines stout, cylindrical, more than half the test diameter in length; shaft smooth, no neck, no cortex. Scrobicular spines present, somewhat flattened.
  • Lantern with flat unkeeled teeth; pyramids with shallow foramen magnum, less than 20% pyramid height.
Distribution
Middle to Late Triassic (Anisian - Carnian); Europe.
Name gender feminine
Type
Miocidaris (Serpianotiaris) hescheleri Jeannet, 1933, p. 1 [=Cidarites coava Quenstedt, 1873, p. 55], by monotypy.
Species Included
  • S. coava (Quenstedt, 1873); Anisian to Carnian; Europe [=S. hescheleri Jeannet, 1933; Ladinian, Switzerland].
Classification and/or Status

?Euechinoidea stem group; Serpianotiaridae.

Monotypic.

Remarks

The genus was described in admirable detail based on excellent new material by Hagdorn (1995). Kier (1977) refigured the type.

Close to Triadotiaris in adoral ambulacral structure but differing from that genus in having less elongate interambulacral plates and non-confluent areoles, in having simple uniserial plating aborally, and in having a distinctly different perignathic girdle (Triadotiaris has a well developed girdle of apophyses). Hagdorn (1995) provides a full and detailed description.

Jeannet, A. 1933. Die Triasfauna der Tessiner Kalkalpen, VI: Note sur un Miocidaris nouveau. Abhandlungen der Schweizerischen Palaeontologischen Gesellschaf 53, 1-7, pl. 30.

Kier, P.M. 1977. Triassic echinoids. Smithsonian Contributions to Paleobiology 30, 1-88.

Hagdorn, H. 1995. Die Seeigel des germanischen oberen Muschelkalks. Geologische und Palaontologische Mitteilungen, Innsbruck. 20, 245-281.