A brief review of the fossil vertebrates of the Komi Republic

General information on the distribution of vertebrate remains in the Phanerozoic successions of the Komi republic is presented. A short description is given for some localities which are the most important and interesting for the evolution of the group and for biostratigraphy. The most productive sites of fossil vertebrates are confined to the Devonian, Permian, Triassic and Quaternary deposits. The oldest vertebrate remains represented by thelodont scales come from the Upper Ordovician. The Silurian - Middle Devonian marine deposits yield microremains only, among which acanthodian scales are dominant. A rich series of Upper Givetian - Frasnian sites are known in Timan. The following vertebrate taxa were originally described from these localities: Tartuosteus ? ornatus , Asterolepis radiata , Janiosteus timanicus . Of particular note is the Lower Famennian section of Sosnovsky Geological Monument. Numerous remains of the earliest reconstructable tetrapod Parmastega aelidae as well as semiarticulated fish skeletons are known there. Vertebrates are quite rare in the Carboniferous deposits and are mainly represented by elasmobranch teeth. An unusual find from the Lower Tournaisian of the Podcherem River, named Proamphibia problematica , was described by A. P. Karpinsky as an amphibian shed skin turned inside out. The Permian deposits yield quite diverse tetrapod and fish remains, among which many taxa were originally described from the territory of the Komi Republic: Clamorosaurus borealis , C. nocturnus , Intasuchus silvicola , Syndyodosuchus tetricus , Parabradysaurus silantjevi , Timanosaurus ivachnenkoi , Koinia silantjevi , Koinichthys ivachnenkoi , etc. Complete skulls of Angusaurus tsylmensis and Vladlenosaurus alexeyevi are known from the Lower Triassic of the Tsilma and Luza rivers, respectively. In the Jurassic deposits, the most important finds are the tooth plates of chimeroid fishes from the Kargort locality and an incomplete skeleton of the ichthyosaur Arthropterygius lundi from the Izhma River. Single finds of mosasaurid remains were recorded from the Upper Cretaceous of the Lemva River. The Quaternary deposits generally contain single finds of bones of large mammals of the so-called «mammoth fauna»: mammoth, woolly rhinoceros, steppe bison, musk ox, wild horse, reindeer, cave bear, etc. About 20 localities are known in alluvial deposits yielding bone remains of the cold-adapted lemming fauna of voles. Among all the localities of the Quaternary vertebrates, the following two stand out: the Medvezhya Cave with the most diverse mammal fauna of the Late Pleistocene, and the Byzovaya Paleolithic site yielding numerous remains of mammoth.