Review of “Clupea humilis” from the Sarmatian of Moldova and description of Moldavichthys switshenskae gen. et sp. nov.

Abstract

Moldavichthys switshenskae is established as a new fossil genus and species of the family Clupeidae, subfamily Alosinae, to encompass the specimens from the Sarmatian of Moldova, which hitherto have been recorded as Clupeonella humilis (v.Meyer, 1851). Specimens from the type area and strata (Ottnangian of the Western Paratethys) differ from the Moldovan ones in a greater number of vertebrae, the more posterior position of dorsal fin and a greater number of postventral scutes. Their generic allocation requires review. Moldavichthys resembles the recent genus Alosa, known from the northern Atlantic, NE Pacific, the Mediterranean and the Ponto-Caspian Sea. Moldavichthys differs from Alosa in the shape of the jaw and the opercular bones and the otolith morphology and is thought to represent an extinct Paratethyan endemic lineage. Otolith in situ was found in three skeletons of Moldavichthys switshenskae. They are unusually compact and compressed when compared to Recent Alosa otoliths, with the caveat however, that very little is known of otoliths from the extant Ponto-Caspian Alosa species. There are no isolated fossil otoliths known, which would correspond to M. switshenskae, although recently Alosa paulicrenata Bratishko, Schwarzhans & Reichenbacher 2015 has been described from the Konkian of Kazakhstan. A review of Sarmatian otoliths from Bulgaria has revealed a species, which we tentatively assign as Moldavichthys? gomotartziensis (Strashimirov, 1985).