A new subgenus of Upper Barremian rhyncholites Hadrocheilus (Lozovskia) has been described. It differs from subgenus Hadrocheilus (Microbeccus) Shimansky et Nerodenko by much smaller size of the hood, as well as by the top of the handle, which is significantly raised over the hood, and by the flat dorsal side of the arm. Morphological features of the new taxon allow us to consider it to be an ancestral to Aptian genus Erlangericheilus, the most important feature of which is the transformation of the hood in a small tusk-shaped appendage.

Rhyncholites of the Arcuatobeccus subgenus represent a big group, counting about 25 species and known from the Western Europe, Mountain Crimea and also San-Salvador Island. A stratigraphic distribution of the Arcuatobeccus covers an interval from the Middle Jurassic up to the Middle Cenomanian, inclusively. In the Mesozoic deposits of the Mountain Crimea, Arcuatobeccus are not popular and distributed in the section unevenly. To the last moment four Cenomanian species of Arcuatobeccus were known there. A Lower Cenomanian complex included H. (A.) alekseevi Komarov, H. (A.) ratus Shimansky и H. (A.) selbuchrensis Komarov. In the Middle Cenomanian complex, a one species of Arcuatobeccus was found - tiny H. (A.) prima Komarov. It is important to note, that the Middle Cenomanian Arcuatobeccus have not been known anywhere else in the world yet. The paper illustrates a new Lower Cenomanian species of Arcuatobeccus, found in 2017 during the Crimean training geological practice of MGRI-RSGPU. It differs from the closest species Hadrocheilus (Arcuatobeccus) selbuchrensis by a bigger size, shorter and narrower handle (in relation to the hood) and sharper, knee-like transition of the hood to the handle. The results of the detailed study of the bearlng-rock have been shown.

Background. In this article, we investigate an outcrop of the Lower Jurassic limestones of the Eskiorda suite located on the northern slope of the Bodrak River basin in the south-western Crimea.Aim. The outcrop under study is mentioned in the majority of monographs devoted to the geology of the Crimean Mountains. Although the palaeontology of this assemblage has been sufficiently studied, its lithological aspects require elucidation. We carried out a series of lithological studies to identify the composition, structure and formation conditions of this limestone assemblage.Materials and methods. A macroscopic study of the outcrop was conducted followed by a detailed lithological study of collected limestone samples using a polarising microscope.Results. The conducted microscopic analysis revealed three structural types: organogenic-detrital, detrital and oolitic-organogenic-detrital limestones. The dominant component in the composition was fragments of echinoderms, mainly crinoids. Among other components were — in descending order — brachiopods, gastropods, foraminifera, remains of green algae, sponges, ostracods, ammonites and radiolarians, whose total content did not exceed 10%. Cinoid fragments were round to a various degree. The limestone fragments (intraclasts) were characterised by organogenic-clastic and pelitomorphic structures with an organogenic sludge, occasionally containing fine-sandy and silty quartz admixtures. Oolitic-organogenic-detrital limestones were almost entirely composed of crinoid fragments, some of which represented oolith cores. A specific feature of the limestones under study is their significant hardness resulting from the cementation of the structural components predominantly with crustification cement of several generations.Conclusions. The obtained results allowed us to draw conclusions about the formation conditions of the studied rocks. The limestones were formed in shallow water under the action of waves on the sediment in zones of constant currents. The hydrodynamic action on the sediment led to the formation of intraclasts. The early lithification of the sediment contributed to the formation of a hard seabed, on which subsequent generations of echinoderms settled, lived and died, forming an accumulative carbonate body.

The textbook under review considers the fundamentals of the genetic analysis of terrigenous and associated sediments. A classification scheme of the genetic types, subgroups, groups, and supergroups of these deposits is provided. According to the proposed scheme, continental, transitional, marine, and mixed genetic types are sequentially described. A set of sedimentation features that allow for identification of the genetic type, its lateral and vertical transitions to other genetic types, is introduced. The form and size of modern accumulative bodies formed by genetic types of deposits and their fossil analogues are indicated.

Приведены данные о первых находках мшанок и табулятоморфных кораллов на раковинах атрипид Закавказья в интервале от эмсского до франского яруса включительно. Большинство мшанок, представленных родами Atactotoechus ( ), Fistulipora ( ) и Leioclema ( ), обнаружено на спинных створках брахиопод в непосредственной близости от комиссуры. Кораллы рода Aulopora примерно в равных пропорциях развиты либо только на спинной створке, либо на обеих. В последнем случае колонии покрывают значительную часть спинной створки, переходят через комиссуру и занимают небольшую примакушечную часть брюшной створки. Находки эпибионтов в непосредственной близости от комиссуры (некоторые колонии ею строго ограничены) и частая ориентировка отверстий кораллитов в ее сторону свидетельствуют о прижизненном поселении обрастателей. Обнаружение колоний, переходящих через край раковины брахиопод, говорит о посмертном поселении и указывает на глубину, которую могли достигать поверхностное волнение или донные течения, приводя раковины погибших брахиопод в движение. Отсутствие нарастания колоний мшанок и кораллов друг на друга может свидетельствовать о наличии на морском дне необходимого для их жизнедеятельности твердого субстрата в достаточном количестве.