Shell structure of <Emphasis Type="Italic">Kutorgina</Emphasis> Billings (Brachiopoda,Kutorginida)

Shell structure in members of the genus Kutorgina, Lower Cambrian brachiopods with calcareous shells and primitive articulation, is described for the first time. This type of shell structure resembles that of the Lower Cambrian mollusks and hyoliths rather than of brachiopods.     

Shell microstructure and imprints of cells of the outer mantle epithelium of <Emphasis Type="Italic">Monticlarella</Emphasis> Wisniewska (Brachiopoda: Rhynchonellida,Norelloidea)

The shell microstructure of the genus Monticlarella Wisniewska, 1932 is studied for the first time, with the species M. nova (Karakash, 1907) and M. lineolata (Phillips, 1835) from the Upper Hauterivian–Lower Barremian of Crimea being used as an example. It is shown that there is a strong similarity between the shell structure of this genus and another representative of the family Norellidae, Suiaella, thus supporting the possibility of using the shell microstructure as a diagnostic feature of the family Norellidae.     

A new genus of cardioceratids (Ammonoidea) from the Upper Callovian-Lower Oxfordian of northern Siberia

A new genus, Anabariceras, and two new species, A. meledinae and A. aspectabile, are described from the Upper Callovian-Lower Oxfordian boundary beds from the Anabar River basin. Based on analysis of the ontogenetic development of major characters (suture, shell shape, and ornamentation), the affinity of this genus to the subfamily Quenstedtoceratinae is substantiated.     

Trend of changes in species diversity of Permian radiolarians of the genus <Emphasis Type="Italic">Entactinia</Emphasis> Foreman

The trend of species diversity and spatiotemporal distribution of spherical radiolarians of the genus Entactinia Foreman, 1963 in the Permian Period is analyzed. The center of origin of Permian entactinians in the Cis-Ural Paleobasin is established in the area of the modern interfluve of the Ural River and latitudinal current of the Belaya River on the Southern Urals. It is shown that the species composition of this genus almost completely changed in certain Permian epochs. Two forefather species of each new pleiad of Early, Middle, and Late Permian are revealed: Entactinia parapycnoclada and E. tyrrelli. Two new species of the Lower Permian radiolarians from the Southern Urals and Northern Mugodzhary, E. chernykhi sp. nov. and E. subquadrata sp. nov., are described.     

Nouvelles données paléontologiques sur le genre Dissimilites Sarkar, 1954

A nearly complete specimen of a heteromorphic ammonite belonging to the genus Dissimilites Sarkar, 1954 (Ammonoidea, Ancyloceratina) has been collected in the Lower Barremian from south-east France. It is the first time that a such sample has been collected since the discovery by d'Orbigny in 1842 of the first specimens belonging of this taxon. Hypothetic until today, the existence of a spire in the first development of the shell is confirmed and a new diagnosis of the genus is given. Finally, the specific content of the genus is briefly analyzed as also its stratigraphical occurrence.     

A first report of Sphenothallus Hall, 1847 in the Cambrian of Variscan Europe

Ten specimens of two phosphatic fossils have been recently discovered in lower and middle portions of Middle Cambrian Jince Formation in the Czech Republic. They are attributed to the genus Sphenothallus Hall, 1847 and described as two separate species; comparatively small conchs are described as S. kozaki sp. nov., the much larger specimens characterized by its smooth and partly flexible organo-phosphatic walls of shell are determined as ?S. kordulei sp. nov. Sphenothallus is known to range from Cambrian to Permian and accommodates numerous species. However, its Cambrian distribution is considerably restricted. Generally rare specimens have been described from Lower to Middle Cambrian of Laurentia and from the Lower Cambrian of Gondwana and peri-Gondwana. The new record of Sphenothallus from the Jince Biota represents a notable extension of their geographic range.     

Pyramidal spiriferids (brachiopods) from the Middle and Upper Devonian of the Russian Plate: Morphology, systematics, and shell wall structure

The pyramidal spiriferids Thomasaria Stainbrook, 1945 and Pyramina Ljaschenko, 1969 from the collection of brachiopods of Ljaschenko are examined. New data on the shell microornamentation and inner structure support the validity of the genus Piramina and its type species P. oskolensis Ljaschenko. A new species of the genus Thomasaria, T. rotunda is described.     

The genus <Emphasis Type="Italic">Keppleritiana</Emphasis> gen. nov. (Stephanoceratidae,Ammonoidea) from the Upper Bajocian of the Northern Caucasus

A new ammonite genus of the subfamily Garantianinae, family Stephanoceratidae, from the Upper Bajocian Strenoceras niortense Zone in the Bolshoi Zelenchuk River basin (Karachay-Cherkessia), with two new species from two different localities, is established. The type species Keppleritiana rostovtsevi gen. et sp. nov. is homeomorphic to some species of the Upper Bathonian–Lower Callovian genus Kepplerites (Fam. Kosmoceratidae) but is distinguished by the presence of a ventral furrow in adults. An isolated valve of an aptychus possibly belonging to this species is illustrated. Keppleritiana graebensteini sp. nov. has a more archaic morphology and is apparently ancestral to the type species. The macroconchs and microconchs of both species are described.     

A revision of the Early Carnian Trachyceratidae (Ammonoidea) of Northeastern Asia

Major morphological features of the shell are studied, and new trachyceratid genera, Boreotrachyceras gen. nov. with the type species B. omkutchanicum (Bytschkov) and Okhototrachyceras gen. nov. with the type species O. seimkanense (Bytschkov), are established based on material from the Lower Carnian of the Omolon Massif and Northern Okhotsk Region. The first record of the genus Trachyceras in the Boreal Realm allows the correlation of the omkutchanicum Zone of Northeastern Asia with the standard aon Zone.     

On the miocene centracanthidae (Teleostei, Perciformes) from the eastern Paratethys

A new genus, Naslavcea, is erected for the Middle Miocene species Spicara fundata Bannikov, 1990 (Centracanthidae) from the Lower Sarmatian of northern Moldova. This genus is characterized by the relatively small number of rays in the dorsal and anal fins. At the same time, Pelates islamdagicus Prokofiev, 2001 from the Lower Miocene of the Apsheron Peninsula (Azerbaijan) is transferred from the family Terapontidae to Centracanthidae and referred to the genus Spicara.     

Trilobites of the suborder Eodiscina from the Lower Cambrian of the northeastern Siberian platform (Khorbosuonka River section)

Trilobites of the suborder Eodiscina from the Lower Cambrian section of the Khorbosuonka River (Siberian Platform, Olenek Uplift) are studied. The stratigraphic distribution of these forms in the section is shown Two new species, Hebediscus sublongus sp. nov. and Korobovia khorbosuonica sp. nov., are described. This is the first occurrence of the genus Korobovia on the Siberian Platform. The new record provides additional data on morphology and expands the paleogeographic range of the genera represented by the newly described species.     

Pearl mussels of the genus Dahurinaia (Bivalvia,Margaritiferidae): Differently sized groups of Margaritifera dahurica Middendorff, 1850

Molecular and genetic studies have revealed that all five species of pearl mussels of the genus Dahurinaia (Bivalvia, Margaritiferidae) inhabiting the upper basin of the Amur River on the territory of Transbaikalia belong to Margaritifera dahurica Middendorff, 1850. Based on the statistical analysis, it has been shown that morphometric shell ratios form continuous variation series without differentiation on discrete groups. It has been found that changes in these ratios are caused by the shell growth of pearl mussels and their morphological variations reflects the high level of polymorphism. The so-called “comparator” species of the genus Dahurinaia are differently sized groups of one polymorphic biological species M. dahurica.     

A new clupeid genus (pisces, clupeiformes, clupeidae) from the Sarmatian of the Eastern Paratethys, Krasnodar Region

Two collections of clupeid fishes, which have previously been assigned to the species Sardinella sardinites (Heckel, 1850), from the Lower and Middle Sarmatian of the Pshekha River Basin (Western Ciscaucasia, Krasnodar Region) were studied. A new genus, Illusionella gen. nov., with two species, I. tsurevica sp. nov. and I. pshekhensis sp. nov., was described based on morphological characteristics. They are the most abundant species in Sarmatian fish assemblages of the Psekups-Belaya interfluve.     

Retrograde evolution of Albaillella during the Permian-Triassic crisis

In the present paper, we discuss the evolution of an upper Permian anagenetic lineage of polycystine radiolarians belonging to the genus Albaillella. This genus is characterized by increasing curvature of the shell during the upper Permian and the trend is reversed (proteromorphic retrogradation) in the Lower Triassic with the sudden appearance of forms that are homeomorphic to the earliest Permian representative of the genus. These primitive-looking forms are derived from their immediate ancestors by retrograde evolution, a phenomenon which has been described as proteromorphosis.     

<Emphasis Type="Italic">Argutostrea</Emphasis> gen. nov.: Questions of taxonomy and ethology of Middle–Late Jurassic epibiont oysters (Bivalvia,Ostreoidea)

Morphology and ethology of the Middle–Late Jurassic oyster “Liostrea” roemeri (Quenstedt) from the Upper Callovian of the Volga Region near Saratov and Middle Volgian of the Subpolar Urals are considered. The inverted shell shape and presence of a beaked umbo on the right valves allow the assignment of these oysters to a new monotypic genus, Argutostrea Kosenko, gen. nov. Features of the internal valve structure examined in only one specimen suggest that the new genus should tentatively be included in the subfamily Pycnodonteinae Stenzel, 1959 of the family Gryphaeidae Vialov, 1936. It is shown that shell morphology of the oyster A. roemeri is connected with transition to dwelling on floating ammonites.     

Glossomyophorus costatus nov. gen. nov. sp., Rudiste (Caprotinidae) nouveau de l'Aptien du domaine méditerranéen central et oriental

A new caprotinid rudist, Glossomyophorus costatus nov. gen. nov. sp. is described and figured from the Lower Cretaceous of Saudi Arabia, Bosnia (Yugoslavia) and southern Italy. Its costulate shell has a straight, tubular (attached) right valve, with a single, central tooth, and an openly enrolled, elongate left valve, with two subequal teeth. It differs from other caprotinids in possessing an erect, tongue-shaped posterior myophore in the left valve, the muscle scar of which directly flanks the body cavity, with no intervening accessory cavity joined to the central tooth socket. This scar faces onto the posterior wall of a laminar posterior myophore in the right valve. A single accessory cavity in each valve separates the posterior myophore from the shell wall. That in the right valve is similar in size to the teeth sockets, such that sections across the valve have a distinctive array of three more or less equal sockets. Evolutionary affinities with Monopleura or with Caprotina are equally possible. At present the genus is only known from the Lower Aptian of the Central and Eastern mediterranean Subprovinces and thus might serve as a valuable biostratigraphic and palaeobiogeographic marker.     

First finding of loach (Cobitidae: <Emphasis Type="Italic">Misgurnus</Emphasis>) in the lower Miocene deposits of Western Siberia

The first finding of a fossil loach of the genus Misgurnus from the Lower Miocene deposits of Western Siberia is described. The fossil form is extremely close to the modern M. mohoity from the Amur River basin. It is the actual proof of the hypothesis of latitudinal community of the Eurasian Neogene ichthyofauna.     

The first Eocene tumbling beetle of the genus <Emphasis Type="Italic">Isotrilophus</Emphasis> (Insecta: Coleoptera: Mordellidae) from the Green River Formation (Colorado,United States)

The first fossil representative of the genus Isotrilophus Liljeblad (Mordellidae), I. rasnitsyni sp. nov., from the Lower Eocene of the Green River Formation (Colorado) is described. The new species differs from its only congener, I. erraticus (Smith, 1883), in the shape of eye, metepisternum, configuration of temporal angle, lateral edge of the prothorax, and in the length ratio of the prothorax and elytra. The first I. erraticus south of Nicaragua (e.g., in Costa Rica and Peru) are recorded.     

New data on the morphology of ancient gastropods of the genus Aldanella Vostokova, 1962 (Archaeobranchia, Pelagielliformes)

The position of attachment of the shell muscle is discovered in the columellar area of the shell of the Early Cambrian univalved genus Aldanella (family Aldanellidae, order Pelagielliformes, subclass Archaeobranchia), the structure of its protoconch is described, and the presence of series of septa in the embryonic part of their shell is confirmed. These new features confidently support the position of the family Aldanellidae within the gastropod class and allow them to be considered ancestral to younger gastropod lineages with a turbospiral shell.     

New sepulcids (Hymenoptera: Sepulcidae) from the Lower Cretaceous of Asia. I. Parapamphiliinae and Xyelulinae

Three new species of sepulcids (Hymenoptera: Sepulcidae) are described from the Lower Cretaceous of Khasurty, Transbaikalia: Pamparaphilius khasurtensis sp. nov., Micramphilius mirabilipennis sp. nov., and Onokhoius venustus sp. nov. The new species reveal the previously unknown structure of the hindwings in the subfamily Xyelulinae and the genus Micramphilius. A new method of preparation for stone fossils is also described.