Betaneospirifer Gatinaud 1949

Genus Betaneospirifer Gatinaud, 1949 Type species Spirifera moosakhailensis Davidson, 1862: 28; original designation. Diagnosis Shells relatively thick-walled, medium to large in size; with transverse outlines; cardinal extremities from weakly rounded to mucronate or alate; ventral area triangular or trapezoidal with subparallel lower and upper edges, usually apsacline; hinge line denticulate; lateral slopes moderately or sharply folded, covered with numerous fasciculated almost uniform in width ribs, microornament regularly imbricate. Ventral valve has short deltirial plate, composed of short, rapidly diverging adminicula and dental flanges. Remarks The remark in the description of Betaneospirifer (Carter et al. 2006: 1790) “The validity of this genus is contingent on confirmation and completion of the diagnosis of Neospirifer ” was related to the error in the choice of the lectotype of Spirifer fasciger Keyserling, 1846 as the type species of Neospirifer Frederiks, 1924. The revision of Keyserling’s (1846) collection published by Poletaev (1997) showed that the specimen SPGGI 129/46, chosen by Archbold & Thomas (1984) as the lectotype of Spirifer fasciger, most probably does not belong to the real syntypes of this species, because its image is missing among the primary good quality drawings of Keyserling’s specimens. In addition, this specimen does not show any characters of the species and has to be rejected as lectotype. Specimen SPGGI 128/46 has been proposed (Poletaev 1997) as neolectotype of Spirifer fasciger (not paralectotype as decided by Carter et al. 2006: fig. 1185, 1b–c). It is the “ragged” ventral valve, which has an ovate overline, a few weak radial plicae on the flanks, and obviously belongs to Neospiriferinae. This ventral valve was first shown in dorsal view by Poletaev (1997) and has a very unusual type of short triangular ventral area and a trace of a delthyrial plate. The difference between the confirmed type species of Neospirifer and Spirifera moosakhailensis, the type species of Betaneospirifer, is obvious. The genus Neospirifer includes only the type species and some closely related species from the Productus Limestone (Late Permian) of Salt Range (Pakistan), described by Reed (1944: 678) and Waterhouse (2004: 1–265). Most of the thick-walled species of Neospiriferinae with long, trapezoidal ventral area belong to Betaneospirifer and other neospiriferid genera. Distribution Carboniferous (late Moscovian) to Early Permian of Russia and Pakistan.