No 1 (2024)

Among the early archosaurs, various ecological types are represented – from predators to herbivores, from terrestrial to semi-aquatic forms. A special place among them is occupied by the family Ornithosuchidae, which are traditionally considered as active predators. The unique structure of the jaw apparatus and the morphology of the postcranial skeleton of Ornithosuchidae indicate the formation in them the only special ecological type among archosaurs – a hyperanisodont macrophagous predator. At the same time, some analogies can be noted between ornithosuchids and saber-toothed therapsids and mammals.

Data on the distribution of early Olenekian ammonoids of the genus Churkites (family Arctoceratidae Arthaber, 1911) from a new locality in South Primorye (Artyomovka River basin, Shtykovskiye Prudy) are given. The new species of Churkites (Ch. ungunensis sp. nov. and Ch. subungunensis sp. nov.) are described on the basis of material from the lower Olenekian zones of the Khabarovsk region (T.M. Okuneva’s collection) and South Primorye. The type species of the genus Churkites (Ch. egregius Zharnikova et Okuneva, 1990) is described in a different volume than previously proposed. It is proposed to distinguish three phylogenetic lineages within the genera Arctoceras (A. tuberculatum) and Churkites (six species): (I) Arctoceras tuberculatum – Churkites noblei – Ch. egregius, (II) Ch. egregius – Ch. syaskoi и (III) Ch. syaskoi – Ch. subungunensis – Ch. ungunensis.

The core samples derive from the XC-1 borehole (1012-1013 m), Shumnine Formation, Botomian-Toyonian stages, Lower Cambrian, Siberian platform. The samples are represented by thin laminated bituminous mudstone. The imprints of phosphate brachiopod (lingulids and acrotretids) valves and casts of the valves occur on the bedding surface of the samples. One sample bare a cluster of small fossils (60-220 µm) probably belonging to embryos or brephic valves of these brachiopods. Chemical analysis has revealed that the originally organic material of the valves was replaced by pyrite most likely after their death. At the same time, the fragments of the valves of the adult lingulate are composed of calcium phosphate.

In bradoriids Sinskolutella ordinata (Melnikova, 1983) from the unique Sinsk locality (Lower Cambrian of the Siberian Platform), a large round spot was found in the anterior half of the shell, identified as the adductor muscle scar. Additional characteristics of the pores on the valves of this species are described. Similarities in the outline, shell size, and development of a large muscle scar suggest that sinskolutellas are related to ostracods of the order Leperditicopida, known from the Ordovician and widely diversified during the Silurian and Devonian.

Permian ray-finned fishes from freshwater deposits of the Leninsk (Tatarian Series, Severodvinian Stage) and the Tailugan Formations (Tatarian Series, Vyatkian Stage) of Kuznetsk Basin are revised. The taxa considered in the work were not previously formally published and remained nomina nuda. Two new genera (Gregarialepis and Planalepis) and two new species (G. binaria and P. diserta) are described. Scales of Heterolepis undata (reidentified cf. Eurynotoides sp.), Mitinolepis surickovensis (reidentified Strelnia sp.), are too poorly preserved, the available features are not sufficient to distinguish new taxa, and they can only be identified to genus-level.

From the Early Pleistocene of the Taurida Cave (Crimea), the remains of Lyrurus partium Kretzoi, 1962 and “Lagopus” atavus Jánossy, 1974 (tribe Tetraonini of the family Phasianidae; order Galliformes) are described – these are the oldest finds of the grouse group in Eurasia outside the region of Central and Eastern Europe (Bulgaria, Hungary and Poland). The discovery of the primitive Black Grouse L. partium indicates that in the Early Pleistocene these birds were part of the savanna-like faunal associations of the Northern Black Sea region along with Otididae and Struthionidae. The origin and evolutionary history of the modern Caucasian Black Grouse T. mlokosiewiczi Taczanowski, 1875 is discussed. The complete tarsometatarsus of “Lagopus” atavus from the Taurida Cave indicates a separate generic status of this poorly studied Plio-Pleistocene form, which in this work is allocated to the genus Paralyra gen. nov. Thus, the presence of ptarmigans (genus Lagopus) in the pre-glacial Plio-Pleistocene faunas of Eastern Europe is not confirmed.