Anoptambonites Williams, 1962

F. Nikitin, Igor, E. Popov, Leonid & G. Bassett, Michael, 2003, Late Ordovician brachiopods from the Selety river basin, north Central Kazakhstan, Acta Palaeontologica Polonica 48 (1), pp. 39-54 : 46

Genus Anoptambonites Williams, 1962 Anoptambonites sp.

Fig. 3N, O.

Material.—One complete specimen and one ventral valve.

Measurements.—NMW 98.30G.17, conjoined valves, Ld: 15.8, LPl: 10.8; NMW 98.30G.18, ventral valve, Lv: 12.2, W: 16.4, T: 4.9.

Remarks.—These specimens are comparable with Anoptambonites orientalis Popov, 1980 from the Anderken Formation (Caradoc) of the Chu−Ili Range in having equally parvicostellate radial ornament, an open delthyrium and an undercut, striated cardinal process, but differ in having an only slightly carinate ventral valve and an uneven lateral profile with its highest point at about one quarter of the shell length from the anterior margin.The equally parvicostellate radial ornament, unevenly convex ventral lateral profile and open delthyrium in the Tauken Formation specimens also distinguish them from Anoptambonites kovalevskii Popov, Nikitin, and Cocks, 2000 from the Dulankara Formation (upper Caradoc) of the Chu−Ili Range in Kazakhstan.

Occurrence.—Locality 780.