A Tetrapod Ichnoassociation from the Middle Triassic (Anisian,Pelsonian) of Northern Italy

A new Middle Triassic ichnofauna recovered nearby the town of Tisens (Bozen) in the Adige Valley (Trentino, Northern Italy) is described. A relatively large ichnoassociation, in which various ichnogenera can be recognized, comes from the basal inter-supratidal layers of a mixed carbonate siliciclastic unit of Pelsonian (Middle Anisian) age. Most of the isolated footprints and trackways pertain to lizard-like reptiles referable to Rhyncosauroides and, subordinately, to archosaurian reptiles. In particular, the ichnogenera Rotodactylus, Synaptichnium and Chirotherium have been recognized. Many tracks are at present unidentified; among them a lizard-like morphotype (morphotype A). The site also yelded numerous fossil plant horizons and some scattered vertebrate remains referable to Placodontidae (cf. Placodus gigas). The site shows the continuity in the Pelsonian of the “chirothere ichnofauna” and the dominance of Rhynchosauroides in carbonate, tidal flat environments.     

Bats (Chiroptera,Vespertillionidae) from the Cis-Urals and South Urals (Republic of Bashkortostan)

New and previously published data on the distribution of 12 bat species in the Cis-Urals and South Urals (Republic of Bashkortostan) are summarized. Data on their subspecies status are given. There is a need to clarify the taxonomic status of the pipistrelle bats Pipistrellus pipistrellus/pygmaeus. In terms of composition, the bat fauna of the Republic of Bashkortostan is a variant of the Central European fauna. It was revealed that the territory in question marks the eastern limits of distribution of Nyctalus leisleri and P. pipistrellus/pygmaeus. An important feature of the territory of Bashkortostan is the presence of places of mass wintering of bats of natural origin: more than 980 karst caves used by bats not only in winter, but also during the period of activity. According to the results of captures in 14 caves, data on the frequency and relative abundance of sedentary bat species in the Republic of Bashkortostan are given.     

A new dasycladalean alga from the Middle Triassic carbonates of Northern Calabria (Southern Italy)

Summary A new dasyclad alga—Acicularia boniae n.sp.—is discribed from Middle Triassic (?Ladinian) of the Piano del Minatore Formation, outcropping in the Cozzo del Pellegrino area (Calabria, southern Italy). The systematic position of this species, with respect to the genusAcicularia and morphogeneraAciculella andTerquemella, is discussed.

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Riassunto Viene descritta una nuova specie di dasicladale—Acicularia boniae—proveniente dal Triassico Medio della formazione del Piano del Minatore affiorante nel massiccio del Cozzo del Pellegrino (Calabria, Italia meridionale). Viene discussa la posizione sistematica rispetto al genereAcicularia ed ai morfogeneriTerquemella edAciculella.

     

The Permian/Triassic mass extinction among brachiopods in the Northern Caucasus (northern Palaeo-Tethys): A tentative assessment

A palaeontological record of the Northern Caucasus provides new data to evaluate the influence of the Permian/Triassic mass extinction on brachiopod communities. The study region is currently located in the southwest of Russia; it laid on the northern margin of the Palaeo-Tethys Ocean during the late Paleozoic-early Mesozoic. A total of 168 genera and 36 superfamilies are known from the Changhsingian-Bajocian deposits of this region. The total diversity of brachiopods was very high in the Changhsingian (57 genera and 19 superfamilies), but these organisms disappeared entirely at the Permian/Triassic boundary. Three genera and three superfamilies existed in the Induan, but brachiopods perished again in the Olenekian. A recovery began in the Anisian, but the Changhsingian diversity was never reached again. No genera crossed the Permian/Triassic boundary, whereas 4 superfamilies became able to do this. Ambocoelioidea was a “dead clade walking” and went extinct in the Induan, whereas three other superfamilies (Dialasmatoidea, Rhynchonelloidea, and Wellerelloidea) were more successful. Survivors included no less than 20% of genera during the entire Induan-Bajocian time interval. The Changhsingian-Anisian interval is dominated by just one type of facies in the studied region, which may explain differences in the post-extinction diversity patterns between the Northern Caucasus, South China, and other parts of the World. Use of the alternative Triassic time scale does not change the absolute duration of the post-extinction stress (5.1 myr), whereas it highlights higher rates for the Anisian recovery (appearance of 0.9 superfamilies and 2.8 genera per myr).     

Evolutionary rates of the Triassic marine macrofauna and sea-level changes: Evidences from the Northwestern Caucasus,Northern Neotethys (Russia)

A diverse Triassic marine macrofauna from the Northwestern Caucasus sheds new light on the biotic evolution after the end-Permian mass extinction. In the early Mesozoic, the study area was located on the northern margin of the Neotethys Ocean. Data on stratigraphic ranges of 130 genera of brachiopods, bivalves, ammonoids, corals, and sponges have been used to calculate the changes in two evolutionary rates, namely faunal transformation rate (FTR) and rate of transformation of the taxonomic diversity structure (TTDSR). The FTR demonstrates the changes in the generic composition of assemblages through geologic time, whereas the TTDSR indicates changes in the generic control of the species diversity. The Triassic marine macrofauna of the Northwestern Caucasus was characterized by very high FTR and TTDSR during the Early Triassic through early Late Triassic. The FTR slowed in the Middle Triassic, and accelerated again in the Carnian–Norian. In contrast, the FTR was abnormally slow in the Norian–Rhaetian. A remarkable turnover among macrofauna occurred at the Carnian–Norian transition. Regional sea-level changes were similar to the global eustatic fluctuations. It is difficult to establish their direct connections with changes in the evolutionary rates, although the turnover at the Carnian–Norian boundary coincided with a prominent regressive episode. In general, high evolutionary rates reported for the Triassic marine macrofauna of the Northwestern Caucasus may be explained as a consequence of the devastating end-Permian mass extinction.     

Ninety years of the Paleontological Society

The establishment in 1916 and the subsequent 90-year history of the Russian (later All-Union and All-Russia) Paleontological Society are discussed. The society’s works and endeavors over ninety years were closely connected with the needs of practical geology, and primarily with paleontological research, the development of a stratigraphic basis, and their use in paleogeography, paleoecology, and biosphere studies.     

The structure and seasonal dynamics of myriapods (Chilopoda and Diplopoda) in the southern taiga of the Perm Cis-Urals Region

The spatial and temporal dynamics of myriapod assemblages in the Preduralye protected area (Kishertskii District, Perm Territory) is studied. There are 10 species found, which have been assigned to three landscape groups (floodplain, terrace, and forest species) and four phenological groups (spring-summer, summer, latesummerautumn, and autumn species). Seasonally stable differences are found between myriapod assemblages of riverine biotopes (floodplain and fluvial terraces) and those of drainage divides (hillsides and uplands). The structure of the myriapod assemblage changes thrice in the course of the growing season. The spring-early-summer pattern develops without drastic transformations into the summer one, which is characterized by maximum diversity. The establishment of the autumn pattern is marked ubiquitously by stronger dominance of two eurybiont species, a lithobiomorph centipede Lithobius curtipes (C.L. Koch, 1847) and a millipede Altajosoma golovatchi (Shear, 1990), which is accompanied by the simplification of the species structure and the reduction of diversity of taxocenes. The horizons of the application of the landscape-phenological classification of species are briefly discussed, as well as the consideration of phenological patterns during invertebrate surveys.     

The Asteroidea (Echinodermata) of the Muschelkalk (Middle Triassic of Germany)

Trichasteropsis Eck, from the Muschelkalk of Germany is the only Triassic asteroid known from more than fragmentary material. Most spécimens representT. weissmanni (Münster) whereasT. senfti ECK,T. bielertorum n. sp., andBerckhemeraster charistikos n. gen. et n. sp., are each known from few individuals.Parsimony analysis hère treats the füll Ordovician to Récent history of the Asteroidea using a somasteroid (a pre-asteroid stelleroid) outgroup. Ambulacral évolution is critical in echinoderm history; the ambulacral arrangement of crown-group asteroids first appears in Paleozoic sister groups, and the subclass Ambuloasteroidea n. subcl. is proposed for Paleozoic and younger taxa with critical ambulacral apomorphies. Muschelkalk asteroids are assigned to the family Trichasteropsiidae n. fam., superorder Forcipulatacea. The recently described Triassic genusNoriaster belongs to the extant family Poraniidae, superorder Valvatacea.Trichasteropsis andNoriaster represent separate major phylogenetic branches of the post-Paleozoic infraclass Neoasteroidea, and together they indicate that diversification of modern-type asteroids was under-way during the Triassic, although the Mesozoic marine révolution largely was a Jurassic and later event. Post-Paleozoic asteroids appear to hâve returned to Paleozoic life modes in spite of new morphological expressions. Trichasteropsis is skeletally robust, suggesting protection from wave impact or predators. It is found in sédiments associated with shell banks but not from within the banks.Trichasteropsis senfti commonly occurs with brachiopods whereasT. weissmanni does not, although brachiopods are found in associated strata. Aspects of morphology of both species are similar to those of récent predatory Asteriidae suggesting similar behavior, but feeding habits ofTrichasteropsis are unverified.     

Heterobranchia (Gastropoda) from the Jurassic Deposits of Russia

Small gastropods from the Jurassic deposits of the European Russia, united into the lower Heterobranchia or Allogastropoda, are described. The families of Ampezzanildidae, Cimidae, Cornirostridae, Ebalidae, and Stuoraxidae are distinguished, and a set of taxa is given without reference to a definite family. The family Ampezzanildidae from the Jurassic deposits is described for the first time on the basis of the mass material, ascribed to the new genus Zizipupa gen. nov. with the sole species of Z. costata sp. nov. The family Cimidae includes the genera of Cristalloella, Rotfanella, Urlocella, and Unzhispira gen. nov. with species C. spiralocostata (Gründel, 1998), R. gerasimovi sp. nov., R. reticulata sp. nov., Urlocella undulata sp. nov., and Unzhispira minuta sp. nov. The genus Heteronatica gen. nov. is included into the family Cornirostridae. This genus is the first siphonostomatous representative of the given family including the sole long-living species H. globosa sp. nov., which is subdivided into subspecies H. globosa globosa and H. globosapromota subsp. nov. The family Ebalidae is represented by the genus Ebala, shells of which are distributed from the Middle Oxfordian to the Middle Volgian. The family Stuoraxidae is described based on two genera Stuoraxis and Aneudaronia gen. nov., including species of S. crassa sp. nov. and A. elegans sp. nov. The genus Doggerostra, which fits into different families of Heterobranchia in terms of shell morphology is represented by the species D. riedeli Gründel, 1998, which was previously known from the Bathonian and Callowian deposits in Poland and Germany, as well as form the Upper Jurassic interval in the Russian Plate. The Middle Volgian subspecies D. riedeli affinis subsp. nov. is distinguished in the composition of this species. In addition, the genus Masaevia gen. nov. with the sole species of M. sinistra sp. nov. is described. Due to so specific shell morphology of this genus, its position in the Heterobranchia system is unclear. It is not improbable that we deal with small planktonic gastropods of protoconchs of unknown group of planktonic or benthic gastropods.     

Fossil vertebrate faunas of the British Rhaetian (latest Triassic)

Rhaetian fossil vertebrate faunas of Britain represent rich but biased samples of taxonomic diversity during uppermost Triassic time. Review of the Westbury Formation, Penarth Group, in particular, reveals a combination of marine, littoral, and terrestrial elements. Minimally, six species of shark are preserved along with a myriacanthid holocephalan, at least four actinopterygian taxa, a characteristic lungfish, ichthyosaurs, plesiosaurs, dinosaurs, and potentially the earliest representative of the Choristodera. Rare mammalian occurrences in the Westbury beds are also possible. Severnichthys gen. nov. is a large osteichthyan, probably a palaeonisciform chondrostean, which historically has been mistaken for a labyrinthodont amphibian. At least two additional actinopterygian species and a holocephalan are known from die Lilstock Formation, and a mammal or mammallike reptile is recorded from the uppermost Blue Anchor Formation. Analysis of element abundance in the disarticulated Westbury Formation assemblage indicates that many parts of some taxa are never preserved while other elements of the same form are common. Such preservational bias suggests that many species may be missing entirely from this long-studied but poorly understood taphocoenosis. Possibly contemporaneous cave faunas from nearby upland areas give a similarly biased picture of the terrestrial fauna during this time of widespread marine transgression.     

Sea-level changes as controlling factor of early diagenesis: the reefal limestones of Adnet (Late Triassic,Northern Calcareous Alps,Austria)

The uppermost Rhaetian Adnet reef is part of the Dachstein carbonate platform and is situated at the transition to the intrashelf Kössen Basin. Its diagenetic evolution is investigated focusing on dissolution cavities in the Tropfbruch quarry of Adnet (near Salzburg) stratigraphically situated immediately below the Triassic–Jurassic boundary. Sea-level changes due to global eustatic trends and regional tectonics are assumed to be the controlling factors in the development of a manifold diagenetic sequence characterized by phases of meteoric dissolution, marine and burial cementation, and internal sedimentation. Despite small-scale variations of the sequence, a superordinate pattern of diagenetic phases could be elaborated. Small-scale eustatic sea-level falls subordinate to a global regression trend caused subaerial exposures of the Adnet reef in the latest Rhaetian to earliest Hettangian. The result was karstification and meteoric dissolution of aragonitic coral skeletons (Retiophyllia) leading to the formation of biomoldic porosity. Coral septa which escaped dissolution were transformed into neomorphic calcite spar under meteoric–phreatic conditions. A first generation of dog-tooth cements precipitated sporadically on the altered coral skeletons. Eustatic sea-level rise in Early to Mid-Hettangian times caused a renewed flooding of the pore space of the Adnet reef by marine water and the influx of a first generation of internal sediments (IS I), derived from the karstified host rock of the Upper Rhaetian reef limestone. These internal sediments are overgrown by radiaxial-fibrous calcites (RFCs) whose oxygen-isotopic signature (δ¹⁸O = ?1.3 (±0.7)‰) indicates precipitation in deeper (colder) water (18–21°C) due to a first phase of drowning. An intermediate phase of eustatic sea-level lowstand in the Late Hettangian is expressed by dissolution and corrosion of RFCs. Rapid drowning of the Dachstein carbonate platform due to eustatic sea-level rise and tectonic movements took place in the Early Sinemurian and a second generation of internal sediments (IS II) derived from the Lower Sinemurian Adnet Formation is washed into the dissolution cavities. Where IS II is absent, RFCs are overgrown by a second generation of dog-tooth cements with a bright-luminescent outer rim indicating the transition to negative redox conditions in the pore water during shallow burial. Burial diagenesis is represented by blocky calcite cements which occlude the remaining pore space. Depleted oxygen-isotope values and significant Fe contents indicate precipitation under reducing redox conditions and elevated temperatures of 30–50°C at burial depths of 420–870 m. Locally, replacive saddle dolomite is the latest diagenetic phase in the Adnet reef indicating crystallization under hydrothermal influences related to compressional subduction regimes of the Penninic Ocean.     

Population structure of common juniper in the Cis-Urals and Southern Urals

The population structure of common juniper (Juniperus communis L.) growing in the Cis-Urals and Southern Urals has been studied using 17 morphological traits of generative and vegetative organs. A multivariate analysis of ten coenopopulations has recognized three phenotypically different local populations: Cis-Ural, forest Cis-Ural forest-steppe, and Southern Ural mountain populations. The Cis-Ural forest population is strictly associated with lowland pine forests of the northwestern part of the Bashkir Cis-Urals. The Cis-Ural forest-steppe population is located in the northwestern part of the Bashkir Cis-Urals and the southeastern part of the Udmurt Cis-Urals. The Southern Ural mountain population is located in the central part of the Southern Urals and is associated mainly with mountain pine and dark coniferous forests. The last population is divided into forest and forest-edge subpopulations; the first one is represented by typical undergrowth locations, whereas the second is associated with open steppelike slopes and forest edges. In general, based on morphological traits of generative organs, the revealed local subpopulations hold an intermediate position between the Eastern European and Siberian populations of common juniper. Based on the morphological traits of vegetative organs, Cis-Ural populations are considered related to the populations of the European part of Russia, whereas the mountain Southern Ural population resemble Siberian populations. Concerning morphological traits of generative organs, the intrapopulation phenotypic diversity of common juniper is higher for mountain habitats; in the case of vegetative organs, the maximum diversity is observed for lowland habitats. The character of phenotypic differentiation determines the need to conserve the gene pool of common juniper of the Cis-Urals and southern Urals on a population basis.     

Mycological Characterization of the Occupation Deposits in Excavated Medieval Russian Settlements

Microbiological analysis showed that the cultural layers of soils in excavated medieval Russian settlements differ from the surrounding soils in that the cultural layers have more fungal spores, their morphology is more diverse, the species diversity of microscopic fungi is higher, and the Penicilliumspecies that are able to grow at an elevated temperature (37°C) are more frequent.