V. Ja. Vuks, Yu. S. Repin, A. Yu. Vovshina

A new species of ammonoids from the Upper Jurassic of the Pechora River basin

Abstract. The authors studied the Upper Jurassic — Lower Cretaceous deposits of the Paromes Formation in the Pechora River basin found in the Izhma and Kedva rivers outcrops (Komi Republic). These works contributed to clarifying the Mesozoic block of the Mezen series sheets legend of the State Geological Map (scale of 1 : 1,000,000). Field work aided in collecting a diverse collection of macrofauna, with bivalves dominating, as well as fewer ammonoids and belemnites included. Exploring the gathered macrofauna led to find and describe a new species of ammonoids Epivirgatites mesezhnikovi sp. nov., which is characteristic of the Epivirgatites nikitini zone in the Volgian Regional Stage. The new species of ammonoids accompanied rich assemblages of bivalves Buchia fischeriana (d’Orbigny), B. russiensis (Pavlow), B. mosquensis (Buch), B. spp., Pinna sp. indet., Liostrea sp. indet., and belemnites Cylindroteuthis (Cylindroteuthis) ex gr. lepida Sachs et Nalnjaeva, Lagonibelus (Holcobeloides) volgensis (d’Orbigny), Lagonibelus sp. The work resulted in collecting an extensive collection of macrofauna, which updated the complex paleontological characteristics of the Paromes Formation and especially the Epivirgatites nikitini zone of the Volgian Regional Stage.

Keywords: paleontology, stratigraphy, Upper Jurassic, ammonoids, genus Epivirgatites, bivalves, belemnites, Izhma, Pechora