The Echinoid Directory

• Test ovate with weak anterior sulcus; posterior face truncate. Test inflated and somewhat wedge-shaped in profile.
• Apical disc ethmophract with four gonopores; central.
• Anterior ambulacrum sunken adapically, with differentiated pore-pairs uniserially arranged.
• Paired ambulacra subpetaloid aborally; petals narrow. Anterior petals around twice the length of posterior petals.
• Ambulacral zones not drastically pinched immediately beneath petals.
• Peristome D-shaped and surrounded by a distinct lip.
• Plastron plating not reported in detail.
• Periproct high on posterior truncate face; small.
• Peripetalous fasciole present; indented by one plate immediately behind anterior petals.
• Aboral tuberculation fine and dense.

Upper Cretaceous, France.

Leucaster remensis Gauthier, 1887, p. 243, by original designation. Figured syntype: Museum National d'Histoire Naturelle, Paris, R62350.

Only the type species.

Spatangoida, Hemiasterina, Hemiasteridae.

Monotypic; probably a subjective junior synonym of Hemaster.

Originally differentiated from Hemiaster because the more adapical pores in the anterior column of its anterior petals were markedly reduced. However, a similar pattern is seen in many Hemiaster species, including H. bufo, the type species. Unfortunately nothing is currently known about its plastron structure and so it can only tentatively be synonymized with Hemiaster.

Gauthier, A. 1887. Description des especes de la Craie de Reims et de quelques especes nouvelles de l'Aube et de l'Yonne. Bulletin de la Societe des Sciences de l'Yonne 41, 367-399, pls 4-8.