The biostratigraphic and palaeoenvironmental significance of Lower Cambrian (Botomian) trilobites from the Ak-Kaya section of the Altai Mountains (southern Siberia,Russia)

The presence of one of the oldest records of polycystine Radiolaria in the Lower Cambrian sedimentary sequence of the Ak-Kaya section (Gorny Altai) requires a biostratigraphic dating. The trilobites found recently a few tens of meters below the radiolarian-bearing level belong to Calodiscus resimus Repina, Serrodiscus fossuliferus Repina and Alacephalus aff. contortus Repina; they suggest that this part of the Shashkunar Formation can be correlated with the lower part of the Botomian stage. The absence of eyes in the two former species suggests a mode of life buried in the fine pelagic sediments. Indications of the presence of a strongly developed musculature on the third species point to a palaeoenvironment characterized by a relatively high hydrodynamic regime.     

Biostratigraphy of Lower Cretaceous microfossils from the Araripe basin, northeastern Brazil

A biostratigraphic study was carried out in the Lower Cretaceous Araripe basin, northeastern Brazil, allowing the recognition of several chronostratigraphic units: the Dom João (Jurassic?-Lower Cretaceous?), the Rio da Serra (Neocomian) and the Alagoas (Aptian/Albian) local stages. For the first time a large hiatus between the Rio da Serra and Alagoas local stages is carefully documented. The palynomorphs and the ostracode associations throughout the Jurassic?-Aptian/Albian sequence allow the interpretation of the paleoenvironmental evolution of the Araripe basin which otherwise confirms that a polycyclical sedimentation occurred in the basin, being one of the controlling factors on the distribution of ostracodes and palynomorphes.     

Lower Cambrian (Botomian) polycystine Radiolaria from the Altai Mountains (southern Siberia, Russia)

Relatively well-preserved polycystine Radiolaria are here described from Lower Cambrian (Botomian) strata of the Shashkunar Formation, Altai Mountains in southern Siberia (Russia). These radiolarians display a test formed of a disorderly and three-dimensionally interwoven meshwork of numerous straight and curved bars branching from a five-rayed point-centered spicule located within the inner shell surface. The shell structure allows their assignment to the family Archeoentactiniidae, thus extending the known age range of the family down to the Lower Cambrian. The Botomian age is based essentially on trilobites (Parapagetia-Serrodiscus zone), but also on archaeocyathids identified in earlier publications. The study of the radiolarian-bearing sedimentary sequence confirms the presence of polycystine radiolaria in the external platform environments of Lower Cambrian ecosystems.     

Biostratigraphy and Paleogeography of the Bazhenovo Formation (Upper Jurassic and Lower Cretaceous) Based on Radiolarians,Nannoplankton and Calcareous Dinocysts

Paleontological Journal - New data on the taxonomic diversity of radiolarians, calcareous dinocysts and nannoplankton associations in the Late Jurassic and Early Cretaceous of the Bazhenovo...     

The genus Kephyrion Pascher in the basin of the Sabun River (Western Siberia,Russia)

Species diversity of the genus Kephyrion Pascher in the basin of the Sabun River (subzone of northern taiga in western Siberia) is discussed. Its territory holds the Sibirskie Uvaly Nature Park. The genus Kephyrion is represented by 16 specimens in the basin of the Sabun River and by 14 specimens in the bodies of water of the park. Their temperature, visibility, and active reaction of water stimulating vegetation have been identified. Five species and one variety of the genus have been for the first time registered in the flora of western Siberia.     

New dinocyst species (family Ceratiaceae Willey et Hickson) from the Lower Cretaceous of Southwestern Western Siberia

New species of Aptian dinoflagellate cyst of the family Ceratiaceae, Endoceratium immarinum sp. nov. and Nyktericysta (Hastodinium) sibirica sp. nov., are described. These taxa interpreted as nonmarine expand the palynological characteristics of the Vikulovo Formation of Western Siberia.     

Estimation of periphytic microalgae gross primary production with DCMU-fluorescence method in Yenisei River (Siberia, Russia)

Periphyton (epilithon) gross primary production (GPP) was estimated using the DCMU-fluorescence method in the Yenisei River. In the unshaded littoral zone, chlorophyll a concentration (Chl a) and GPP value varied from 0.83 to 973.74 mg m⁻²and 2–304,425 O₂ m⁻² day⁻¹ (0.64–95 133 mg C m⁻² day⁻¹), respectively. Positive significant correlation (r = 0.8) between daily GPP and periphyton Chl a was found. Average ratio GPP:Chl a for periphyton was 36.36 mg C mg Chl a m⁻² day⁻¹. The obtained GPP values for the Yenisei River have a high significant correlation with values predicted by a conventional empirical model for stream periphyton. We concluded that the DCMU-fluorescence method can be successfully used for measuring of gross primary production of stream phytoperiphyton at least as another useful tool for such studies.     

Detection of Babesia spp. DNA in small mammals and ixodic ticks on the territory of north Ural, west Siberia and far east of Russia

Totally, 932 small mammals and 458 questing adult Ixodes persulcatus from Sverdlovsk and Novosibirsk regions and Khabarovsk Territory, as well as 128 Haemaphysalis japonica, 34 H. concinna and 29 Dermacentor silvarum from Khabarovsk Territory were examined for the presence of Babesia by nested PCR based on the 18S rRNA gene. Babesia microti DNA was found in samples of small mammals from all the studied regions--in 36.2% of samples from Sverdlovsk region, 5.3% of samples from Novosibirsk region, and 6.7% of samples from Khabarovsk Territory. The determined B. microti 18S rRNA gene sequences from Novosibirsk region (6 sequences) and from Khabarovsk Territory (10 sequences) were identical to each other and to the sequences of pathogenic for human B. microti US-type, while the determined B. microti 18S rRNA gene sequences from Sverdlovsk region (12 sequences) were identical to those of B. microti strain Munich. B. microti were found most frequently in samples of Myodes spp., they were found also in Microtus spp., Apodemus spp., Sorer spp., and Sicista betulinav. It was shown that one of 347 analyzed I. persulcatus from Novosibirsk region and one of 77 I. persulcatus from Khabarovsk Territory contained B. microti US-type DNA. One I. persulcatus from Novosibirsk region contained B. divergens DNA. In this work B. divergens was for the first time determined in I. persulcatus and B. microti in I. persulcatus in Asian part of Russia. Three different genetic variants of Babesia sensu stricto were found in three H. japonica from Khabarovsk Territory. The first genetic variant was closely related to Babesia sp. revealed in a feral raccoon in Japan (99.9% similarity on the basis of 18S rRNA gene sequences). Two others Babesia genetic variants were most similar to the ovine pathogen Babesia crassa (97.1-97.6% similarity on the basis of 18S rRNA gene sequences).     

New enantiornithine bird (Aves, Ornithothoraces) from the Late Cretaceous of NW Argentina

A new enantiornithine bird, Intiornis inexpectatus gen. et sp. nov, is described here. It is based on a partial hind limb found in beds of the Upper Cretaceous Las Curtiembres Formation (Campanian), North-West Argentina. The new taxon is referred to the family Avisauridae on the basis of its cranially convex third metatarsal. Several features suggest close relationships between Intiornis and the avisaurid Soroavisaurus, from the Lecho Formation (Maastrichtian; North-West Argentina). Intiornis was the size of a sparrow, thus representing the smallest Enantiornithes known from South America. The new species shows adaptations for a perching mode of life. Moreover, the hypothesis suggesting that the flying pterosaur reptiles decrease in taxonomic diversity due to competitive interaction with birds is discussed. The new species shows adaptations for a perching mode of life. Moreover, the hypothesis suggesting that the flying pterosaur reptiles decrease in taxonomic diversity due to competitive interaction with birds is discussed.     

Two new genera of Lasiosynidae (Insecta,Coleoptera) from the Lower Cretaceous of Russia and Mongolia,and principal trends of the morphological evolution of the family

Two new monotypic genera of the family Lasiosynidae, Microsyne gen. nov. and Crassisyne gen. nov., are described from two Early Cretaceous localities: Baisa (Eastern Siberia, Zaza Formation) and Sharyn-Gol (Mongolia, Sharyn-Gol Formation): Peculiar morphological features of different lasiosynid genera and general trends of their morphological evolution are discussed.     

Integrated Silurian Chitinozoan and Graptolite Biostratigraphy of the Banwy River Section, Wales

The succession of 38 upper Llandovery–lower Wenlock chitinozoan taxa from graptolitic horizons in the Banwy River section (Powys, Wales) is described. Five new species are named: Bursachitina nestorae Conochitina leviscapulae Conochitina mathrafalensis Belonechitina cavei Belonechitina meifodensis . A further ten taxa are described under open nomenclature. Seven chitinozoan biozones are recognized in the Banwy River section, three of which ( Cingulochitina bouniensis Conochitina acuminata Salopochitina bella ) are new. The base of each biozone is correlated with the graptolite biostratigraphical scheme as follows: Angochitina longicollis Biozone — upper spiralis Biozone; Conochitina acuminata Biozone — lowermost lapworthi Biozone; Margachitina banwyensis Biozone — upper lapworthi Biozone; Margachitina margaritana Biozone — lowermost insectus Biozone; Cingulochitina bouniensis Biozone — upper murchisoni Biozone; Salopochitina bella Biozone — upper firmus Biozone. The succession of chitinozoan biozones in the Banwy River section is compared with that in other sections which have graptolite biostratigraphical control. This has highlighted the following: (1) the correlation of the base of the dolioliformis Biozone with the graptolite biozonation is imprecise; (2) E. dolioliformis is recorded only from levels after the first A. longicollis in Sweden (although this may reflect previously unrecognized synonymies); (3) the longicollis Biozone may be diachronous, its base correlating with levels low in the Telychian in Sweden, Norway and Estonia and with the upper Telychian spiralis Biozone in Wales and the Prague Basin; (4) data herein and from the Prague Basin indicate that the base of the margaritana Biozone correlates with a level low in the insectus Biozone.     

Discovery of the Jehol Biota from the Celaomiao region and discussion of the Lower Cretaceous of the Bayingebi Basin,northwestern China

Some typical components of the Jehol Biota, including conchostracans Eosestheria sp., the mayfly Ephemeropsis trisetalis Eichwald, 1864, the aquatic beetle Coptoclava longipoda Ping, 1928, and a fragmentary dragonfly, are reported for the first time from the Bayingebi Formation in the Celaomiao region, western Inner Mongolia, China. This discovery indicates that the middle Upper Member of Bayingebi Formation can be correlated with the upper Yixian and the lower Jiufotang formations in western Liaoning Province. Combining it with the radio-isotopic dating result, we further believed that the Upper Member of Bayingebi Formation could be roughly correlated with the Yixian, Jiufotang, and Shahai formations, and the overlying Suhongtu Formation with the Fuxin Formation in western Liaoning Province.In the major Bayingebi Basin, palaeontological and radio-isotopic dating evidence shows that the Bayingebi Formation has a long depositional history of over 30 Ma: its Upper Member bearing the Jehol Biota and the early Fuxin Biota is probably coeval to the Yixian, Jiufotang and Shahai formations and has a Barremian–early Albian age; its Lower Member may be Berriasian–Hauterivian in age and could be correlated with the upper Tuchengzi, Zhangjiakou, and Dabeigou formations in northern Hebei Province. This suggests that the Bayingebi Formation should be promoted to the stratigraphic rank of group and subdivided into several secondary units (formations). Unlike the previous result, the Yingen Formation is considered across the Lower Cretaceous–Upper Cretaceous boundary and being late Albian–early Turonian in age.     

New jewel beetles (Coleoptera: Buprestidae) from the Cretaceous of Russia,Kazakhstan, and Mongolia

A new jewel beetle genus, with one species (Cretofrontolina kzyldzharica gen. et sp. nov.) from the Upper Cretaceous of Kazakhstan is described based on a body; and three new species of the formal genus Metabuprestium are described based on isolated elytra: Metabuprestium sibiricum sp. nov. and M. arkagalense sp. nov. come from the Arkagala locality (Upper Cretaceous of Russia) and M. ichbogdense sp. nov. is from the Shar Tologoi locality (Lower Cretaceous of Mongolia).     

AFLP analysis of the genetic diversity of closely related rhododendron species of the section rhodorastra (Ericaceae) from Siberia and the Far East of Russia

Using AFLP analysis, the genetic variation in four population samples of Rhododendron ledebourii, three such samples of Rh. dauricum, two samples of Rh. sichotense, and one sample of Rh. mucronulatum was examined. Application of three selective primer pairs provided genotyping of 87 accessions from the four species at 213 loci. An analysis of molecular variance revealed a high level of differences between all four species (F _ST = 0.172). Populations within the species were also differentiated: for Rh. dauricum F _ST = 0.245; Rh. ledebourii F _ST = 0.264; Rh. sichotense F _ST = 0.034. The highest Nei distance was observed for Rh. mucronulatum with Rh. dauricum and Rh. ledebourii (D = 0.057 and 0.069, respectively). Similarity was observed between the species pairs of Rh. ledebourii-Rh. dauricum (0.032) and Rh. sichotense-Rh. mucronulatum (0.034). The Far Eastern species Rh. sichotense and Rh. mucronulatum were characterized by an elevated level of intrapopulation variation. The data from the AFLP-based analysis of differentiation and variation that were thus obtained were compared with the literature data on the morphological criteria that differentiate the species of interest and those regarding the history of the formation of their ranges. The independence of all the species we examined was confirmed.     

Palaeohistology and preservation of tetrapods from Las Hoyas (Lower Cretaceous,Spain)

The Upper Barremian (Lower Cretaceous) site of Las Hoyas (Spain) is an important Konservat Lagerstätte that has a yielded well-preserved biota. Both the palaeohistology and the preservation of six tetrapods were investigated in this study. Chemical analysis (Ca/P ratio, fluorine, strontium, barium and REE amounts) reveals an alteration of the original apatite of the bone in fluoroapatite by postmortem substitutions, a late Sr incorporation during fossilization, and a rather moderate postmortem REE incorporation in the freshwater environment of Las Hoyas. However, the conditions of fossilization have limited the dissolution-recrystallisation processes and preserved the microstructure of the bones. Bone growth rate estimations have been made according to Amprino's rule. The Discoglossidae indet, the Centrocryptodira indet. and Scandensia ciervensis are characterized by low growth rates and an ectothermic metabolism. Concornis lacustris, Pelecanimimus polyodon and the Archosauria indet. are characterized by a faster growth and probably higher resting metabolic rate. All of the specimens are adults of small-sized species. This leads to the hypothesis of an ecological filter favoring small-sized species in this ecosystem, strengthening the taphonomical results. The combination of geochemical and histological studies seems to offer a more precise overlook of life history traits and preservation of these fossils from Las Hoyas.     

Faunistic complexes of the Cladocera (Crustacea,Branchiopoda) of Eastern Siberia and the Far East of Russia

Faunistic complexes of 155 species of the Cladocera found in Eastern Siberia and the Far East of Russian Federation are described. The eight complexes are specified: unrevised widely spread species (51), the widespread Eurasian faunistic complex (34 species), the circumpolar complex (4 species), the East Asian and American (Beringian) complex (8 species), the endemic East Asian complex (19 species), the southern thermophilic complex (12 species), the mountainous endemic complex (3 species), and the Baikal endemic complex (8 species). Directions for further studies are suggested. Faunistic investigations of the modern level in the East Palearctic represent an independent task, which should be accomplished by taxonomists in close cooperation with specialists on local faunas.     

New species of Praeichneumonidae (Hymenoptera,Ichneumonoidea) from the Lower Cretaceous of Transbaikalia

Three new species of the fossil Lower Cretaceous family Praeichneumonidae are described from the Lower Cretaceous of Transbaikalia (Russia, Buryatia, Khasurty locality): Praeichneumon dzhidensis sp. nov., P. khamardabanicus sp. nov., and P. zakhaaminicus sp. nov. One poorly preserved specimen, Praeichneumon sp., is described. Rudiments of the second anal vein A2 and internal vein a₁–a₂ and bullae in crossveins of the fore- and hindwing are described in Praeichneumonidae for the first time.     

Densities and distribution of flagellates and ciliates in the chemocline of saline,meromictic Lake Shunet (Siberia,Russia)

The vertical and seasonal distributions of the phytoflagellate Cryptomonas spp., and its most common, the planktonic ciliate predators (Oligotrichida, Scuticociliatida, Hypotrichida and Prostomatida) were investigated in chemocline region of small saline, meromictic lake Shunet (Siberia, Russia) during 2003 and 2005. The lake has a pronounced chemocline, with abundance of purple and green sulphur bacteria. Vertical distribution of the Cryptomonas populations near the oxic/anoxic boundary layer was studied at close intervals in water sampled using a hydraulically operated thin-layer sampler. In both summer and winter, Cryptomonas peaked in water stratum 5–10 cm above anoxic zone or in the anoxic zone water column in the chemocline (about 5 m). Ciliate densities and biomass were also much higher in chemocline than in mixolimnion. The range of diurnal migration of Cryptomonas population was not very wide, and it was restricted to layers with high light intensity. The ciliates were sometimes detected above the upper border of the anoxic zone but also several centimetres below this zone.     

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.