The Echinoid Directory

• Test cordiform with deep anterior sulcus; posterior face truncate. Test as wide as long; domed in profile; lower face weakly convex.
• Apical disc not preserved.
• Anterior ambulacrum deeply sunken from apex to peristome; lateral walls vertical on upper surface. Pore pairs uniserial and presumably supporting funnel-building tube-feet; broad granular perradial zone.
• Anterior petals widely divergent; deeply sunken, with well-developed conjugate pore-pairs in distal part. However, towards apex pore-pairs in both columns become rudimentary.
• Posterior petals very different; short, narrow, almost flush, with simple small pore-pairs which do not enlarge towards the base.
• Peristome close to anterior border and facing forward into frontal groove. Labrum projecting to cover peristome in oral view.
• Plastron plating with symmetical sternal plates.
• Periproct on posterior truncate face.
• Peripetalous and lateroanal fascioles present; peripetalous fasciole indented behind anterior petals.

Paleocene (Danian) of southern France.

Dipneustes aturicus Arnaud, in Cotteau, 1891, p. 624, by original designation.

• Only the type species.

Spatangoida, Schizasterina, Schizasteridae.

Monotypic (one specimen). Nomen dubium.

Differs from Linthia by having anterior and posterior petals markedly different in length. Lambert & Thiery (1921, p. 521), suspected that this represent a pathological individual. It was distinguished from other schizasterids by the very marked difference between anterior and posterior paired petals: in this genus the anterior petals are well developed distally while the posterior petals have small simple rudimentary pore-pairs only. The reduced posterior petals is reminiscent of Kina [=Diploporaster], but this taxon differs in having a more subcentral apical disc and pore-pairs in the anterior ambulacrum uniserial rather than biserial in each column.

McNamara & Philip (1980, p. 57) attributed a Miocene species to this genus but their species Dipneustes fosteri would seem closer to Kina Henderson, 1975 in form.

Cotteau, G. 1891. Echinides nouveaux ou peu connus. Memoires de la Societe zoologique de France 6, 620-631