The Echinoid Directory

• Test ovate and flattened, with narrow, relatively shallow, anterior sulcus.
• Apical disc anterior of centre; no plating details known.
• Anterior ambulacrum relatively narrow and sunken; pore-pair arrangement not known.
• Paired ambulacra narrow and sunken, the anterior pair straight and extending most of the way to the ambitus.
• Posterior petals subparallel and near confluent adapically but strongly diverging in their outer part.
• Periproct large, on short vertical truncate face.
• Peristome wider than long; kidney-shaped.
• Labral plate short and wide and in broad contact with both sternal plates.
• Apparently no enlarged tubercles within peripetalous fasciole.
• Plastron plating unknown.
• Subanal fasciole and peripetalous facioles present. Peripetalous fasciole deeply indented in anterior and lateral interambulacra and narrow.

Oligo-Miocene of the Caribbean.

Fernandezaster mortenseni Sanchez Roig, 1952, p. 18, by original designation.

• F. mortenseni Sanchez Roig, 1952; Oligo-Miocene of Cuba.
• F. durhami Fischer, 1985; Middle Miocene, Costa Rica.

Spatangoida, Micrasterina, ?Brissopsidae.

Probable subjective junior synonym of Brissopsis Agassiz, 1840.

There is only a single specimen of this monotypic genus, and that is poorly preserved, leaving much unknown. In having confluent posterior petals it resembles certain species of Brissopsis and Metalia. The most important difference between these two species is that the plastron of Metalia has episternals only slightly smaller than the sternals and separated by a U-shaped suture (convex anteriorly) whereas in Brissopsis the episternals are less than half the size of the sternals and are separated by a V-shaped suture (pointing posteriorly). The only known specimen has been redescribed by Kier (1984) and does not show plastron features clearly.

Fischer (1985) described a second species from the Miocene of Costa Rica, which Durham (1961) had earlier assigned to Brissopsis sp. nov. The plastron plating of Durham's specimen, though poorly preserved, is more suggestive of Brissopsis than Metalia.

Tentatively, therefore, Fernandezaster is treated as a synonym of Brissopsis.

Kier, P.M. 1984. Fossil spatangoid echinoids of Cuba. Smithsonian Contributions to Paleobiology 55, 1-336.

Fischer, R. 1985. La fauna de la Formacion Turrucares (Mioceno, Valle Central, Costa Rica). Geologica et Palaeontologica 19, 191-225.