The Echinoid Directory

Plesiohemipneustes Smith & Wright, 2003, p. 483

Diagnostic Features	Test cordate with shallow anterior sulcus from apex to peristome; depressed in profile with relatively flat base and top. Apical disc subcentral with four gonopores; hydropores extending over anterior ocular and genital plates. Paired ambulacra petaloid with moderately elongate pore-pairs. In anterior petals the anterior column of pore-pairs distinctly narrower than the posterior column. Peristome oval, facing obliquely towards the anterior. Plastron plating protosternous: labral plate with horn that extends to meet second sternal plate (plate 5.a.2). No primary tubercles except for a band bordering the frontal groove. No fascioles.
Distribution	Cretaceous (Upper Albian - Cenomanian), western Europe.
Name gender	feminine
Type	Holaster revestensis Lambert in Lambert & Thiery, 1924, p. 404, by original designation.
Species Included	Only the type species.
Classification and/or Status	Holasteroida, Hemipneustidae. Monotypic.
Remarks	Very close to Pseudholaster, differing only in having hydropores extending over the anterior three ocular plates and genital plates 2 and 3. It differs from Hemipneustes and Opisopneustes in having the two columns of pore-pairs in its petals subequally developed. It differs from Pseudananchys (Zumoffenia) in having a shallow but well defined frontal sulcus. Smith, A. B. & Wright, C. W. 2003. British Cretaceous echinoids. Part 7, Atelostomata, 1. Holasteroida. Palaeontographical Society Monographs, London. Pp. 440-568, pls 139-182.