Vol 52, No 13 (2018)

Anetshella golowkinskyi (Netchaev, 1894) and Oxyprora tschernyschewi (Licharew, 1931) are shown to be directly related despite their definitive shells being morphologically different. As there are no other known rostroconch species in the semi-isolated Kazanian basin, O. tschernyschewi is the only contender for an ancestral taxon. The material described in this paper shows that the morphologies of the juvenile specimens of O. tschernyschewi and the definitive shell of A. golowkinskyi are largely homologous. The aromorphic transition from the bivalvian shell of O. tschernyschewi, typical of rostroconchs, to the cap-like shell of A. golowkinskyi was on one hand fixation and subsequent development of juvenile characters, typical of the initial phase of the juvenile stage of the O. tschernyschewi shell, and on the other hand by positive allometry of the rostrum. The considerable restructuring of the body plan of Anetshella was accompanied by the appearance of morphological novelties uncharacteristic of other rostroconchs, pegma and two transverse septa, and evolutionary losses such as loss of a series of plesiomorphic characters.

Analysis of the variability of the angular length of the body chamber in the subfamilies Arctocephalitinae and Cadoceratinae (family Cardioceratidae) has shown that this feature is extremely variable both at the species level and within the genus. For most taxa the length of the body chamber (either fixed values, or mean statistical values) has no identification significance. Estimates of high variability of the body chamber length allow some classification systems of early cardioceratids to be critically evaluated and some concepts of the theoretical shell morphology and paleobiology of ammonites to be reassessed. This is primarily based on models, in which the length of the body chamber coincides with the length of the soft body, and so indirectly influences shell hydrodynamics and hydrostatics, as well as ammonite locomotion and life style. High variability of the body chamber length suggests that this effect was not as significant as previously thought.

A new species of Adelophthalmus Jordan in Jordan et von Meyer, 1854, A. khakassicus sp. nov., from the Givetian (Middle Devonian) of the Republic of Khakassia (Russia) is described. This is one of the oldest species of the genus. It is also interesting in the unusually large for Adelophthalmus.

Nine new stonefly species of the suborder Perlina from the Middle Permian Kostovaty locality, Udmurtia are described. Two species, Boreoperlidium callopterus Sinitshenkova sp. nov. and B. certus Sinitshenkova sp. nov., belong to the family Eustheniidae and six species, Properla incrassata Sinitshenkova, sp. nov., P. umbrosa Sinitshenkova, sp. nov., Kargaloperla fibrosa Sinitshenkova, sp. nov., K. queata Sinitshenkova, sp. nov., K. gratum Sinitshenkova, sp. nov., and K. postica Sinitshenkova, sp. nov., belong to the family Palaeoperlidae. Unusually great abundance and diversity of representatives of the suborder Perlina is discussed.

A taphocoenosis including remains of insects and small mammals from the Quaternary deposits in the vicinity of the village of Kalistratikha (Altai Region, Russia) on the Ob River is revealed. The ¹⁴C dating of the deposits has shown 24.438 ± 0.350 ka. Insects are mostly represented by Coleoptera (59 species of 13 families) and dominated by species of Curculionidae, especially Otiorhynchus, and Carabidae. Otiorhynchus ursus, O. altaicus, and O. unctuosus are most abundant. The following 13 species are recorded in the Pleistocene deposits of Western Siberia for the first time: Bembidion tibiale, B. gebleri, Pterostichus drescheri (Carabidae), Centorus rufipes (Tenebrionidae), Stephanocleonus ?grigorievi, Aulacobaris violaceomicans, Tychius albolineatus, Zaslavskypera conmaculata, Hypera misella, Limobius borealis, Chlorophanus tuvensis, Otiorhynchus unctuosus, and Mesagroicus piliferus (Curculionidae). Small mammals are represented by a few fragments referred to as Sorex sp., Allactaga sp., Spermophilus cf. erythrogenys, Sicista cf. subtilus, Eolagurus sp., Lagurus cf. lagurus, and Microtus gregalis. Small mammals and insects are typical of open landscapes, such as steppes and meadows; riparian insects also occur in the taphocoenosis. The modern geographical range of the majority of species of the steppe assemblage covers central Kazakhstan and adjacent areas; three species of the taphocoenosis are endemic to the mountain depressions of the Altai, Tuva, and northern Mongolia. The majority of meadow and riparian species are boreal–mountain. Judging from the composition of the taphocoenosis, the climate was drier and colder compared to the modern one, but warmer and more humid than during the succeeding Sartanian stadial. Prevailing landscapes were probably dry steppes with meadow and shrubby (osiers) vegetation in the lowered areas. Forests were absent or played a minor role (sparse trees might have been present).

Three species of ornithischian dinosaurs (Daurosaurus olovus, Kulindapteryx ukureica, and Kulindadromeus zabaikalicus) from the Jurassic Kulinda locality (Transbaikalia, Russia) have been described. Kulindadromeus zabaikalicus was established on erroneous assumption that the locality contains only one dinosaurian taxon. The characters used in the diagnosis of this species, which were registered by the holotype (imprint of bones of an incomplete distorted skull on the rock surface), cannot be treated unequivocally from the morphological point of view.

We report the discovery of frustules of pennate diatoms embedded in a freshly fractured interior surface of the Orgueil CI1 carbonaceous meteorite. Images and element composition by Energy Dispersive X-ray Spectroscopy were obtained with the TESCAN VEGA 3 Scanning Electron Microscope (SEM) in the Astrobiology Sector of the Laboratory of Radiation Biology of the Joint Institute for Nuclear Research in Dubna, Russia. The distribution of chemical elements as shown by Energy Dispersive X-Ray Spectroscopy (EDS) and 2-D element maps show no detectable nitrogen. Hence the diatoms are interpreted as indigenous to the Orgueil meteorite and therefore have direct implications to the existence of extraterrestrial life; and the hypothesis of Panspermia.