2022/12/01 by V. V. Bulanov, Alla V. Minikh, В. К. Голубев · 1 citation
Earth and Planetary Sciences · Environmental Science · #Paleontology and Evolutionary Biology #Ichthyology and Marine Biology #Fish biology, ecology, and behavior
paper · doi:10.1134/s0031030122110041
openalex publication_date 2022/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/13
Abstract A new member of the order Eurynotoidiformes (Actinopterygii), Minicholepis primus gen. et sp. nov., is described based on individual teeth from the Ivantsevka locality, Kirov Region, European Russia. All teeth collected combine the tricuspid pattern of crown and widened, scraper-like central cusp bearing distinct wear area along its entire labial side, which indicates the scraping type of feeding. A similar pattern of marginal teeth was previously recorded among eurynotoidiform fishes in the most specialized species of the genus Isadia, I. arefievi, in which the widened axial blade of the crowns of the jaw teeth were presumably formed by conjoining several central cusps. The jaw teeth of M. primus evolved from the more primitive, tricuspid, modification via enlargement of the central cusp, which indicates the convergent adaptation to scraping periphyton in different phylogenetic branches of Eurynotoidiformes. This feeding mode in this fish group firstly occurred as early as in the late Urzhumian–early Severodvinian time as a result of expansion in the niche of primary consumers. Isadia opokiensis is currently regarded as a type species of new genus, Vologdinia gen. nov., on the basis of the differences in the morphology of the teeth and scales.