The Echinoid Directory

• Based on single fragment of interambulacrum (about 4 plates, possibly adoral).
• Interambulacral plates weakly tongue and grooved; adradial suture denticulate (and thus imbricate).
• Interambulacral plate with two large primary tubercles in a row plus two small adradial tubercles aligned vertically.
• All tubercles perforate and non-crenulate.

Middle Triassic (Carnian); Hungary.

Hemipedina incipiens Bather, 1909, p. 76, by original designation. Type presumed to be in the Hungarian Geological Survey collections.

• Only the type species.

Indeterminate.

Monotypic.

Both Bather (1909) and Kier (1977) treated this fragment as indeterminate, but Vadet (2000) created a new species and genus for it. So little is known about it that it is indeterminate even to subclass level. Serpianotiaris is vaguely similar, but in that taxon there is only ever one primary tubercle , not the two as seen here, and the tubercles are obviously crenulated. Kieritiaris, another taxon based on a fragment of test is probably synonymous.

The unique specimen is not in the Natural History Museum, London, contrary to the statement in Kier (1977).

Bather, F. A. 1909. Triassic echinoids from Bakony. Result. wiss. Erforsch. Balaton. 1, 1-286.

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

Vadet, A. 2001. Revision des echinides de Saint Cassian et evolution des echinides post-carboniferes. Memoires de la Societe Academique du Boulonnais 20, 1-116.