The Echinoid Directory

• Test shape unknown; plating moderately thick and weakly imbricate.
• Apical disc small; plating unknown.
• Ambulacra more or less straight and narrow; quadriserial except close to apex where plating may become biserial. Every second or third plate larger and extending from adradial to perradial suture; other plates smaller and demiplates.
• Ambulacral plates with small undifferentiated pore-pair; pore-pairs forming irregular adradial band.
• Larger ambulacral plates with perradial primary tubercle with perforate mamelon.
• Ambulacral plates without internal flanges (radial water vessel internal).
• Interambulacral zones wide; composed of up to 7 regular columns of polygonal plates.
• All interambulacral plates with a relatively large perforate, non-crenulate primary tubercle surrounded by well marked areole; irregular scrobicular circle of tubercles developed and extra-scrobicular tuberculation also present.
• Peristome small, plating unknown.
• Lantern unknown.
• Spines short and relatively stout, without cortex.

Lower Carboniferous, USA.

Lepidocidaris squamosa Meek & Worthen, 1873, p. 478, by original designation.

Only the type species.

Stem group Echinoidea; Archaeocidaridae.

Monotypic.

Distinguished from Archaeocidaris by its more heterogeneous ambulacral plating and by its more than four columns of interambulacral plates. Polytaxicidaris also has more than four columns of plates but its ambulacra are more uniform and its interambulacral plates do not have such a pronounced deeply sunken areole and raised extra-areolar zone.

Jackson, R. T. 1912. Phylogeny of the Echini, with a revision of Paleozoic species Memoirs of the Boston Society of Natural History 7, 491 pp. 76 pls.