The Echinoid Directory

• Test weakly cordate in outline; depressed and slightly wedge-shaped in profile.
• Apical disc tetrabasal and disjunct. Ocular plates II and IV meeting behind genital plate 2. Genital plates 1 and 4 relatively small and wedge-shaped towards posterior. Interambulacral series 1 and 4 meet without catenal plates between the anterior and posterior parts of the apical disc.
• Posterior ocular plates small; boundaries not distinct. Posterior ambulacra about mid-way between periproct and anterior part of apical disc.
• Anterior ambulacrum sunken and slightly bowed adapically; continuing as shallow sulcus to ambitus and adorally. Adapical pore-pairs distinctly enlarged compared to ambital pore-pairs.
• Paired ambulacra subpetaloid, flush, narrow, with circumflexed pore-pairs; the two pores being somewhat elongate.
• Peristome anterior of centre, subcircular; facing downwards.
• Plastron plating impossible to make out except at very rear.
• Periproct small, tear-drop-shaped towards top of short posterior truncate face.
• Tuberculation fine, scattered tubercles set in groundmass of granules.

Lower Cretaceous (Berriasian), North Africa.

Proholaster auberti Gauthier, 1896, p. 18. Holotype: Museum National d'Histoire Naturelle, Paris J01430.

• P. auberti Gauthier, 1896; Berriasian, Tunisia.

Irregularia, Stem group Atelostomata, Collyritidae.

Monotypic.

Distinguished from Cardiopelta by having the pore-pairs of the anterior ambulacrum differentiated adapically and in having subpetaloid paired ambulacra. Also there are no catinal plates in this species.

Gauthier, V. 1896. Echinides jurassiques. Exploration scientifique de la Tunisie, Géologie, Paléontologie. Imprimerie Nationale, Paris.

Solovjev (1971) made this the only member of his subfamily Proholasterinae Solovjev, 1966.

Solovjev, A. 1971. Late Jurassic and Early Cretaceous disasterids of the USSR. Transactions of the Palaeontological Institute, Academy of Sciences of the USSR 131, 1-120, pls 1-16 [in Russian].