The Echinoid Directory

• Test inflated, ovate with faint anterior sulcus on oral surface; posterior face obliquely truncate. Test thick-shelled.
• Apical disc ethmophract with four gonopores.
• Frontal ambulacrum flush adapically and in a vague groove adorally. Pore-pairs small and oblique; not differentiated adapically.
• Paired ambulacra more or less apetaloid; flush; parallel-sided and open distally. Pore-pairs circular.
• Peristome small and circular; more or less downward-facing.
• Labral plate longitudinally elongate; extending to midway down ambulacral plate 2. Sternal plates not much longer; median suture vertical; subsequent plating biserial.
• Periproct small and towards top of posterior obliquely truncate face.
• Peripetalous fasciole present; passing high up on the test behind the apical disc and dropping to become inframarginal around the anterior. Passoing a few plates below the ends of the petals.
• Aboral tuberculation consisting of small scattered tubercles set in a groundmass of granules.

Upper Cretaceous (Campanian-Maastrichtian) to Palaeocene. (Danian); Europe, former SSU, North Africa, Greenland, Japan.

Ornithaster evaristei Cotteau, 1886, p. 72, by original designation.

• H. evaristei (Cotteau, 1886); ?Campanian, Maastrichtian-Danian, Europe, former Soviet Union, North Africa, Greenland, Mozambique.
• H. sulcatus Nisiyama, 1968; Maastrichtian, Japan.
• H. petaloides Lambert, 1924; Maastrichtian, Algeria.

Spatangoida, Hemiasterina, Aeropsidae.

Subjective synonym of Homoeaster.

Differs from Homoeaster only by having round rather than slightly elongate pores adapically in the paired ambulacra. This is insufficient to merit generic separation.

Cotteau, G. H. 1887 (January). Bulletin de la Societe zoologique de France 11, p. 710.

Smith, A. B. & Jeffery, C. H. 2000. Maastrichtian and Palaeocene echinoids: A key to world faunas. Special Papers in Palaeontology 63, 1-406.