Articles | Volume 12, issue 2
01 Dec 1993
 | 01 Dec 1993

An early representative of the genus Frambocythere Colin, 1980: Frambocythere pustulosa (Grékoff, 1957) from the Albian of Zaire

Jean Paul Colin

Abstract. In 1957, Grékoff described Metacypris pustulosa trom the Loia Formation originally assigned to the “Wealden” but subsequently dated of Albian age (Maheshwari et al. 1977) of Central Zaire. This species is characterized by its small size (about 0.6 mm long), the surface of the carapace covered by numerous small hemisphaerical pustulae and the presence of two two subvertical sulci.

In the original description, Grékoff compared this species with Metacyrpis consobrina Jones, 1893 from the Bear River Formation also of Albian age of Wyoming (U.S.A.). Later, in 1961 and 1962, Pinto & Sanguinetti considered Metacypris pustulosa as a junior synonym of Metacypris consobrina . The type-material of Metacypris consobrina was restudied and illustrated by Colin & Danielopol (1981: Pl. 14, figs. 1–4). This species shows striking similarities with Metacypris pustulosa: small size, similar shape and same micro-pustulose ornamentation. It nevertheless differs from the African species by the presence of a single and weak subvertical sulcus. Recent examination of material from the Albian of Central Zaire (Colin, in press) allowed to clearly demonstrate the presence of the two sulci which were mentioned by Grékoff in the original diagnosis but are not visible on the illustrations. The general morphology, size, omamentation and the presence of the two sulci lead us to transfer this species to the genus Frambocythere Colin, 1980 (in Colin & Danielopol, 1980) and therefore to the “Kovalevskiella lineage” (Colin & Danielopol 1980). It is worth mentioning that in 1965, Danielopol already suggested affinities beteween these forms and the genus Kovalevskiella . . .