№ 4 (2024)

The microfossils and problematica from the Upper Ediacaran deposits of the Zuun-Arts Formation of the Zavkhan terrane of Western Mongolia are considered. For the first time, various organic remains preserved in mineralized and organic-clay taphocenoses have been described from these deposits. Numerous tubular microfossils are interpreted as remains of the sheaths of the giant sulfide-oxidizing Thioploca bacteria Candidatus Marithioploca araucae. Autochthonous and allochthonous components of microbiota were identified, and the putative facies-ecological structure of the paleobasin was analyzed.

Numerous representatives of the genus Foremanina Empson-Morin, 1981, emend. nov. were studied from the Upper Cretaceous (Maastrichtian) deposits of the Lefkara Formation (Cyprus). Diagnosis of the genus Foremanina is emended. New species F. macropora sp. nov., F. coronata sp. nov. и F. ornata sp. nov. are described. Species F. macropora sp. nov. is for the first time recorded in the Campanian of Sakhalin. Thus, the paleogeographic occurrence of genus Foremanina is expanded and covers Tehyan Realm and Hokkaido-Sakhalin paleobasin. The latest representatives of Foremanina were for the first time found in the upper Maastrichtian of Cyprus. The stratigraphic ranges of genus Foremanina are expanded.

This paper discusses the origin of the superfamily Popanoceratoidea Hyatt, and substantiates the hypothesis that the suborder Cyclolobina (order Goniatitida) evolved from the family Glaphyritidae Ruzhencev et Bogoslovskaya. The genus Tabantalites Ruzhencev is proposed as an intermediate form between Vidrioceratidae Plummer et Scott and Popanoceratidae Hyatt. The early phylogeny of popanoceratids in the Early Permian is considered in detail (Protopopanoceras → Propopanoceras → Popanoceras, Pamiropopanoceras). Information on the biogeography of Popanoceratoidea is provided.

The sample of individual bones coming from five East European localities provides new data on the morphology and stratigraphic range of kotlassiid Kotlassia prima Amal. (Seymouriamorpha). New finds allow to suppose the complete reduction of the seismosensory system in K. prima at the late ontogenetic stages that indicates more terrestrial ecology of the above species at adult state in comparison with other upper Permian kotlassiids (Microphon spp.), for which the paedomorphic features of cranial and postcranial anatomy are common. The homodont dentition and monocuspid shape of teeth of K. prima allow identification this form as a carnivore, the diet of which was predominated by conditions of inhabited biotopes and included vast kinds of trophic objects such as invertebrates and small-sized vertebrates. New finds prove the wide spread of K. prima in tetrapod communities of the north-east of Eastern Europe, and prolong the stratigraphic distribution the species up to the terminal-most Permian beds (Zhukovian Regional Stage), exhibiting the taxonomic diversity and important role of kotlassiids within the vertebrate associations in time preceding the Permo-Triassic crisis event.

The study of new finds of mosasaurids from the Izhberda locality (Southern Urals, Orenburg Region) allowed to identify for the first time for the Upper Cretaceous of the Orenburg Region the presence of mosasaurs from the subfamilies Mosasaurinae, Tylosaurinae and Plioplatecarpinae, including representatives of the genera Mosasaurus, Prognathodon and Clidastes known from the Upper Cretaceous of North America and Western Europe. Of interest is the discovery of the tylosaurine Taniwhasaurus, previously known from New Zealand, Antarctica, South Africa and Japan. Thus, the Campanian mosasaurid fauna of the Southern Urals is intermediate, including North American–European and Asia–Pacific taxa. However, all finds of mosasaurs from the Izhberda locality can be identified only in open nomenclature, making detailed comparisons of faunas difficult. Revision of material to the article of N.N. Bogolyubov (1910), who first described the remains of mosasaurs from the Southern Urals collected by P.S. Nazarov, allowed us to conclude that the type series of the mosasaur Liodon rhipaeus Bogolubov, 1910, in addition to three mosasaurian vertebrae, includes the ischium and the posterior fragment of the mandible of a plesiosaur. Liodon rhipaeus is clearly a nomen dubium and the vertebrae of its type series cannot be identified more precisely than Tylosaurinae indet.

The presence of the large comb-antlered deer Eucladoceros orientalis (Radulesco et Samson, 1967) has been discovered in the Early Pleistocene fauna (1.8–1.5 Ma) of the Tavrida Cave in the Crimea. The proximal parts of two antlers, two incomplete upper jaws, lower jaw, dentition, and metatarsal bone are described. New data on the morphology of this species confirm its assignment to the genus Eucladoceros. E. orientalis, an autochthonous species of the Early Pleistocene fauna of the Northern Black Sea region, is characteristic of the Psekupsian faunal complex of southern Eastern Europe.