Vol 53, No 3 (2019)

The 50th anniversary of the Joint Russian-Mongolian Paleontological Expedition will be celebrated in 2019. Participants of the expedition made a fundamental contribution to the knowledge on fossil organisms and biostratigraphy of the upper Proterozoic and Phanerozoic of Mongolia. The main achievements of the expedition are described and the most important results and scientists who have made significant contributions to the study of fossil fauna and flora of Mongolia are presented. The organization of international research in the form of a permanent bilateral expedition has demonstrated high efficiency evident from the high publication activity, a fruitful exchange of scientific experience, and the successful training of new qualified research personnel.

The change in marine bivalve communities at the Carboniferous–Permian transition of Northeast Asia has been analyzed for the first time. A significant increase in the taxonomic diversity of the group occurs near the Carboniferous–Permian boundary, most likely, due to the invasion of a number of thermophilic elements from the more southerly basins into the Omolon Basin, associated with a short-term global warming episode. The position of the Carboniferous–Permian boundary in Northeast Asia is considered. A conclusion is made that this boundary in the Kolyma–Omolon–Chukchi region is most likely located within the Verchojania mirandus–Prothyris elongatus complex Zone.

Carboniferous ammonoids from the Taimyr Peninsula (Russian Arctic) are described for the first time. Despite its rare occurrence, the ammonoid fauna is of great importance for the regional stratigraphy. Scientific names of ammonoids are given according to the modern systematic scheme, three biostratigraphic assemblages that specify the age of cephalopod-bearing strata are established. New species such as Glaphyrites taimyricus Konovalova et Borissenkov, sp. nov. from the upper part of the Makarovskaya Formation of the Western Taimyr and Kayutoceras pogrebitskyi Borissenkov et Kutygin, sp. nov. from the Olen’ynskaya Formation of the Central Taimyr are described.

The organophosphate-shelled brachiopods are for the first time described from the Lower Devonian (Lochkovian) of the Timan–Pechora Basin. Several shells preserved both protegulum and brephic shell. The shell microstructure of the Early Devonian Orbiculoidea cf. magnifica Mergl, 2001, is described for the first time, including its changes at different developmental stages.

New gryllones insects (Insecta; Gryllones) Mesoidelia bakhilka sp. nov. (Eoblattida: Mesorthopteridae) and Kostovata catagrapha gen. et sp. nov. (Reculida: Chaulioditidae) are described from the Middle Permian Kostovaty and Tshepanikha localities (Urzhumian Stage of Russia). Paraliomopterum rectum Aristov, 2004 (Reculida: Liomopteridae) from Tshepanikha locality is redescribed.

A new genus and species of soldier beetles of the subfamily Cantharinae, Cnathrion sakhalinense gen. et sp. nov., from the Middle Eocene Sakhalinian amber is described. This is the first beetle species represented by an imago found in Sakhalinian amber. Hypothetic predation of the species on aphids is discussed.

Brain morphology and topography of cranial nerves of the armored dinosaur Bissektipelta archibaldi from the late Cretaceous of Uzbekistan are studied using an artificial endocranial cast. We reconstruct for the Bissektian ankylosaur well-developed olfaction, poor hearing and eyesight, good taste sensitivity, omnivorous diet as well as the ability to filter-feed. The brain structure of Bissektipelta archibaldi is archaic compared with other ankylosaurian species.