The Echinoid Directory

• Test small, subglobular; plating non-imbricate.
• Apical disc large and plates not bound to the corona; plating unknown.
• Ambulacra narrow and almost straight; composed of simple plates throughout.
• Pore-pairs small and non-conjugate. Perradial tuberculate zone very narrow (equal to pore-pair in width); with primary tubercle on each plate.
• Interambulacral zones with about 6 pentagonal plates in a column.
• Single large primary interambulacral tubercle on each plate; mamelon very large and imperforate, increasing in size adapically.
• Weakly differentiated scrobicular circle of enlarged tubercles; small heterogeneous extrascrobicular granules best developed interradially.
• Feeble buccal notches possibly present.
• Slight swelling at adradial edge of ambulacra proximally forming incipient lantern attachments.

Late Triassic (Carnian); Italy.

Levicidaris zardini Kier, 1977, p. 21, by original designation.

• Levicidaris zardini Kier, 1977; Carnian, Italy.
• L. furlani Kier, 1984; Carnian, Italy.
• L. pfaifferi Kier, 1984; Carnian, Italy.

?Euechinoidea stem group; Triadocidaridae.

Monophyletic.

Levicidaris differs from Megaporocidaris in having much lower and more closely packed ambulacral plates with larger contiguous tubercles and densely packed pore-pairs. The mamelons in Levicidaris increase in size adapically, but are largest at the ambitus and decrease adapically in Megaporocidaris.

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

Kier, P. M. 1984. Echinoids from the Triassic (St Cassian) of Italy, their lantern supports, and a revised phylogeny of Triassic echinoids. Smithsonian Contributions to Paleobiology 56, 1-41.