Paleontologičeskij žurnal

The ammonoid fauna from the stratotype section of the Beleutian Regional Substage in the Beleuty River basin in the Ulytau Region of Central Kazakhstan is studied. For the first time, the locality details and precise level of the ammonoid occurrence marking the base of the Beleutian Regional Substage in the stratotype section of terrigenous-carbonate Beleuty Formation are documented. The composition of the assemblage indicates the lower Serpukhovian Uralopronorites–Cravenoceras Genozone, but probably not its base. A new species of the genus Cravenoceras is described.

The results of the study of ostracods from sediments of the Chargat Formation (Lower Silurian, Llandovery) and the middle part of the Tsagaanbulag Formation (Upper Silurian, Ludlow) are presented for the first time for Mongolia. Brief characteristics of the localities where ostracod remains of this age have been found are given, as well as descriptions and images of shell crustaceans belonging to the genera Khandianella Melnikova, gen. nov., Chargatanella Melnikova, gen. nov., Hemsiella Martinsson, 1962, Simplicibeyrichia Martinsson, 1962, Invisibila Polenova, 1960, Calcaribeyrichia Martinsson, 1962, Thrallella Stewart et Hendrix, 1945, Spinobolbina Abushik, 1968.

Permian ray-finned fishes from Nizhny Novgorod Region (Russia) are represented by teeth and scales of Toyemia blumentalis, Isadia aristoviensis, I. suchonensis, I. arefievi, Isadia sp., Mutovinia stella, Geryonichthys longus, Varialepis vitalii, Strelnia sp., Elonichthyidae gen. indet., Discordichthyidae gen. indet. Most species are distributed throughout the Vyatkian Stage and occur in other regions of the European Russia. The occurrence of Isadia arefievi in Sartakovo and Lagerny Ovrag-1, -3 indicates the Upper Vyatkian (Nefedovian and/or Zhukovian) age of these localities. The fauna of ray-finned fishes from the Vyatkian deposits of the Nizhny Novgorod Region is most similar to synchronous but better known fauna of the Vladimir Region.

The morphological description and taxonomic identification of pareiasaur postcranial osteoderms from eight Upper Severodvinian localities in Eastern Europe are carried out. The localities are confined to three stratigraphic levels in the Upper Putyatinian Regional Substage of the Upper Severodvinian: Vanyushonkian, Syominian, and Kichugian beds. The Vanyushonkian Beds are characterized by Deltavjatia rossica (Hartmann-Weinberg). The Syominian Beds contain Proelginia permiana Hartmann-Weinberg, Scutosaurus sp., Pareiasauria gen. indet. The Kichugian Beds contain Scutosaurus cf. itilensis Lebedev et Ivachnenko, Scutosaurus sp., Senectosaurus cf. karamzini Boyarinova et Golubev, Pareiasauridae gen. indet. For the first time, the presence of the genera Scutosaurus and Senectosaurus was established in the Upper Severodvinian, in layers with the Ilyinskoe Subassemblage of the Sokolki Assemblage of Permian tetrapods of Eastern Europe.

First data on the leaf anatomy of bennettitalean Ptilophyllum riparium Gordenko emend. nov. from the Middle Jurassic of Central Russia were obtained. It was found that P. riparium ememd. nov. exhibits general anatomical features, characteristic of bennettitalean leaves, but differs from other representatives of the genus Ptilophyllum Morris (P. sahnii Gupta et Sharma, P. amarjolense Bose, and P. nipanica Vishnu-Mittre, Lower Cretaceous of India) with known anatomical structure by significantly less degree of rachis vascular tissue dissection, continuous layer of mechanical tissue, accompanying a phloem in the abaxial part of vascular bundles ring of rachis, and by the presence of two layers of hypodermal cells underlying the upper epidermis in pinnae. It is shown that in P. riparium emend. nov., two vascular bundles depart from the vascular system of rachis to the pinna.