Vol 52, No 2 (2018)

Long-term (18 month) experiments were conducted, burying soft bodied organisms (Artemia salina, Crustacea) in marine sediment. For the first time in experimental taphonomy, the mineralogical transformation of the sediment that accompanied the process of decomposition was correlated with the degree of preservation. To obtain different quantitative characteristics of preservation, we used four dilutions of marine water (marine water: to fresh water as 1: 0; 1: 1, 1: 4, 1: 9).It was shown that higher dilutions corresponded to lower degrees of preservation. The proportion of kaolinite decreased in the marine sediment and, accordingly, the amorphous phase increased; in the diluted variants, the opposite pattern was revealed: the crystalline kaolinite phase increased and the amorphous phase decreased. Since no differences in the chemical composition of the residues from different dilutions were identified, the effect of sea salt concentration on preservation was considered to be negligible. A plausible hypothesis suggested that dissolving of kaolinite slows of organic decomposition and the beginnings of mineralization. Due to the acidic hydrolysis of kaolinite, Al cations appear in the solution; subsequently proteins are converted into insoluble forms, and thus escape from bacterial degradation. These taphonomic experiments reveal some overlooked physicochemical aspects important for the mechanisms of exceptional preservation.

Anew genus, Zezinia gen. nov., and two new species, Zezinia multicostata sp. nov. and Zaigunrostrum nakhichevanense sp. nov., are described from the Upper Devonian of Transcaucasia. The first genus is one of the last Frasnian representatives of the family Uncinulidae. The Famennian Z. nakhichevanense sp. nov. belongs to punctate rhynchonellids of the family Trigonirhynchiidae.

Thairia transbaikalica Felker et Vasilenko, gen. et sp. nov. (Odonata, Hemiphlebiidae) from the Mesozoic Chernovskie Kopi locality is described. A short review of known genera of Hemiphlebiidae is provided. Relative age of enclosing rocks is discussed.

The extinct monotypic ant genus Fallomyrma was described by Dlussky and Radchenko in 2006 based on workers from Late Eocene Rovno (Ukraine), Scandinavian (Denmark), and Bitterfeld (Germany) ambers. Three new Fallomyrma species from the Rovno amber are here described based on workers: F. anodonta sp. nov., F. marginata sp. nov., and F. robusta sp. nov. A key to all known species of this genus is compiled. The quantity ratios (of the numbers of species and specimens) of Fallomyrma and other amber Myrmicinae genera are considered. The opinion of the autochthonous origin of the Rovno amber is confirmed.

The manuscript was written in the mid-1950s, providing the results of survey of an unusual tetrapod burial in the Upper Permian beds of the town of Vyazniki (Vladimir Region). The bone-bearing sand strata form here the top of the Permian beds, which are underlain by clays with conchostracans tentatively dated Early Tatarian. Abundant tetrapod remains obtained in the course of excavations are dominated by isolated bones; these are associated with scales and cranial bones of palaeoniscids, fin spines of hybodontid sharks and coprolites. The tetrapod assemblage includes the kotlassiomorph Bystrowiana permira Vjuschkov, the stegocephalian Dvinosaurus sp. (new species prevailing in number in the assemblage), the dicynodont Dicynodon sp., gorgonopians, therocephalians, and presumably cynodonts, along with procolophonoids (or other small reptiles, such as eosuchians or protorosaurians). The presence of one more stegocephalian is also probable. It is assumed that the Vyazniki assemblage represents an early developmental stage of the Severodvinian pareiasaurian fauna corresponding to the uppermost Lower Tatarian.

Abstract—Morphology and histology of several fragmentary turtle specimens from the Middle Jurassic locality in the Berezovsk quarry (Krasnoyarsk Region, Russia) are described, including Testudines indet. 1 (costal VIII), Testudines indet. 2 (two ornamented shell fragments), and Testudines indet. 3 (distal part of a humerus), and also skeletal elements of Annemys sp. (Xinjiangchelyidae) represented by mass material in the same locality. It is shown that Testudines indet. 1 and 3 probably belong to one or two taxa of basal aquatic turtles, while Testudines indet. 2 is most likely an abnormal Annemys sp. The presumable presence of basal turtles in the Berezovsk Quarry Assemblage agrees with the fact that they are present in other Middle Jurassic turtle assemblages of Asia.

A new species, Ulmus priamurica sp. nov. (Ulmaceae), from the deposits of the Sazanka Formation (upper Middle–Upper Miocene) of the Erkovetskii Brown Coal Field (Amur Region, Russia) is described based on anatomical features of fossil wood. The new species shows some wood anatomical characters of the extant elms U. japonica and U. americana. Fossil wood of Ulmus was found in the Amur Region for the first time.