Description of Karaganops n. gen. perratus (Daniltshenko 1970) with otoliths in situ, an endemic Karaganian (Middle Miocene) herring (Clupeidae) in the Eastern Paratethys

Abstract

Karaganops is established as a new fossil genus of the family Clupeidae, subfamily Clupeinae, to encompass the nominal species Sardinella perrata Daniltshenko 1970 from the Karaganian of southern Russia. Karaganops belongs to the group of genera characterized by the presence of two elongated rays at the end of the anal fin, which further includes Sardinella, Clupeonella, Sardina, Sardinops, and Harengula. It differs from Sardinella amongst others in the absence of tooth plates on the palatines and pterygoids, the presence of seven branchiostegal rays (vs. six), the presence of two epurals (vs. three) and the presence of nine pelvic fin rays (vs. 7–8). Otoliths found in situ further support the separation of Karaganops from Sardinella and related genera and add evidence for a second, otolith-based species—Karaganops komochtitziensis (Strashimirov 1985)—from the Middle Sarmatian of Bulgaria. Karaganops is thought to represent an endemic clupeid genus of the Eastern Paratethys that evolved during the mid-Miocene Karaganian ecological crisis in the basin. An otolith found in situ in a skeleton of Sarmatella doljeana (Kramberger 1883) from the Early Sarmatian of Belgrade, Serbia and an otolith interpreted to be associated with another fossil clupeid genus and species—Sarmatella tsurevica (Baykina 2012)—from the Early Sarmatian of the Caucasus facilitates correlation with previously described otolith-based species. It demonstrates that Sarmatella may not represent a primary endemic of the Paratethys and that its fossil record reaches back in time to Early Miocene and possibly Late Oligocene in the North Sea Basin.