Fossil marine vertebrates (Chondrichthyes, Actinopterygii, Reptilia) from the Upper Cretaceous of Akkermanovka (Orenburg Oblast, Southern Urals, Russia)

Author(s)
Patrick Leopold Jambura, Sergey V. Solonin, Samuel L. A. Cooper, Eduard V. Mychko, Maxim S. Arkhangelsky, Julia Türtscher, Manuel Amadori, Sebastian Stumpf, Alexey V. Vodorezov, Jürgen Kriwet
Abstract

Upper Cretaceous coastal marine deposits are widespread in the Southern Urals with a number of marine vertebrates previously reported from this region. However, previous studies on the vertebrate faunas in this region often lack detailed taxonomic descriptions and illustrations, rendering comparisons to other faunal assemblages difficult. A new diverse vertebrate assemblage comprising cartilaginous and bony fishes, as well as marine reptiles, is described here from the Orenburg region near Akkermanovka (Southern Urals, Russia). Thirty five taxa are identified, including three holocephalans (Elasmodus sp., Ischyodus yanschini, Chimaeroid indet.), two hybodontiform sharks (Meristodonoides sp., cf. Polyacrodus sp.), 17 neoselachians (Paraorthacodus cf. andersoni, Paraorthacodus sp., Synechodus sp., Cederstroemia nilsi, Acrolamna acuminata, Archaeolamna ex gr. kopingensis, Cretalamna sarcoportheta, Cretoxyrhina mantelli, Eostriatolamia segedini, E. venusta, Hispidaspis horridus, H. cf. gigas, Pseudocorax laevis, Pseudoscapanorhynchus compressidens, Scapanorhynchus rhaphiodon, Squalicorax kaupi, Ptychodus rugosus), a holostean (Lepisosteidae indet.), nine teleosts (Protosphyraena sp., Saurodontidae indet., cf. Pachyrhizodus sp., Pachyrhizodontidae indet., Enchodus petrosus, E. ferox, E. cf. gladiolus, E. spp., Alepisauroidei indet.), two plesiosaurs (Polycotylidae indet., Plesiosauria indet.), and one mosasaurid (Tylosaurinae indet.). Based on the faunal assemblage, a Santoniane?early Campanian age is proposed. Lamniform sharks are the best represented group in terms of taxic diversity and relative abundance, probably reflecting the peak in diversity this group experienced following the Cenomanian radiation in the Late Cretaceous. The faunal assemblage of Akkermanovka exhibits significant taxonomic overlaps with assemblages reported from Asia and North America, but not from Southern Hemisphere continents, indicating east-west dispersal of several marine taxa during the Late Cretaceous.

Organisation(s)
Department of Palaeontology
External organisation(s)
SMNS, Universität Hohenheim, Russian Academy of Sciences, Museum of the World Ocean, Immanuel Kant Baltic Federal University, Saratov State University, Ryazan State University named for S. A. Yesenin
Journal
Cretaceous Research
Volume
155
Pages
1-44
No. of pages
44
ISSN
0195-6671
DOI
https://doi.org/10.1016/j.cretres.2023.105779
Publication date
03-2024
Peer reviewed
Yes
Austrian Fields of Science 2012
105118 Palaeontology
Keywords
ASJC Scopus subject areas
Palaeontology
Sustainable Development Goals
SDG 14 - Life Below Water
Portal url
https://ucrisportal.univie.ac.at/en/publications/9d63c7a5-9a8d-429d-8124-8958eefae588