Middle Triassic radiolarians from the Southeastern Pamirs (Republic of Tajikistan)

Triassic radiolarians were studied from a limestone/chert succession of the Dzhangisu and Boztere formations, Southeastern Pamirs, Republic of Tajikistan. The middle part of the Dzhangisu Formation is characterized by a Late Anisian assemblage with Eptingium nakasekoi Kozur and Mostler, Archaeospongoprunum bispinosum Kozur and Mostler, A. mesotriassicum mesotriassicum Kozur and Mostler, Paroertlispongus multispinosus Kozur and Mostler, P. rarispinosus Kozur and Mostler and Hozmadia rotunda (Nakaseko and Nishimura) that belongs either to the upper part of the Tetraspinocyrtis laevis Zone or to the Spongosilicarmiger transitus Zone (Kozur, 2003). The lowermost part of the Boztere Formation is characterized by a Late Ladinian assemblage with Muelleritortis cochleata (Nakaseko and Nishimura), M. expansa (Kozur and Mostler), Spongoserrula rarauana Dumitrica that corresponds to the M. cochleata Zone. Pamirian localities have a transitional position between the Western Tethys (Alpine–Mediterranean region) and the Eastern Tethys–Pacific junction (Southern China and Thailand). The assemblages are Tethyan in affinity.     

The oldest nautiloid recorded from the Triassic Germanic Basin and the first ammonoid from the Aegean (Middle Triassic) of Poland

During the Triassic in Europe, the Germanic Basin extended from England in the west to the eastern border of Poland in the east. Although cephalopods are common in some Middle Triassic (Muschelkalk) horizons, there still persists a gap in the palaeontological record of the eastern part of the Germanic Basin, notably in the lowermost parts of the Lower Muschelkalk, spanning the latest Olenekian-Aegean interval. The present contribution attempts to fill this gap by presenting the first ammonoid (ceratitid Beneckeia sp.) and nautiloids (Germanonautilus cf. dolomiticus and G. cf. salinarius) from the Lower Gogolin Beds (Upper Silesia, Poland). These Germanonautilus are the oldest nautiloids found in the entire Germanic Basin.     

New high latitude Capnuchosphaera species (Triassic Radiolaria) from Waipapa Terrane,New Zealand

Two new species and one new subspecies of genus Capnuchosphaera, (Capnuchosphaera tumida nov. sp., C. waihekeensis nov. sp. and C. texensis australis nov. ssp.) are described herein from phosphatic nodules included in mudstone and sandstone beds of the Waipapa Terrane, Waiheke Island, New Zealand. The phosphatic nodules yielded a rich Late Triassic (Carnian-Norian) radiolarian fauna, with a high abundance of spumellarian taxa including numerous species of the genera Capnuchosphaera, Vinassaspongus, Kahlerosphaera, Sarla and Dumitricasphaera. Waiheke Island Capnuchosphaera are characterized by a large cortical shell and a distinctively low ratio of spine length to cortical shell diameter. These features differ significantly from those of Capnuchosphaera in the Tethyan Realm and are considered to be the result of adaptation to an Austral-New Zealand peripheral ocean of Gondwanaland in the Mesozoic Southern Hemisphere.     

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).     

Microbial Community Structure and Density Under Different Tree Species in an Acid Forest Soil (Morvan, France)

Overexploitation of forests to increase wood production has led to the replacement of native forest by large areas of monospecific tree plantations. In the present study, the effects of different monospecific tree cover plantations on density and composition of the indigenous soil microbial community are described. The experimental site of “Breuil-Chenue” in the Morvan (France) was the site of a comparison of a similar mineral soil under Norway spruce (Picea abies), Douglas fir (Pseudotuga menziesii), oak (Quercus sessiflora), and native forest [mixed stand dominated by oak and beech (Fagus sylvatica)]. Sampling was performed during winter (February) at three depths (0–5, 5–10, and 10–15 cm). Abundance of microorganisms was estimated via microbial biomass measurements, using the fumigation–extraction method. The genetic structure of microbial communities was investigated using the bacterial- and fungal-automated ribosomal intergenic spacer analysis (B-ARISA and F-ARISA, respectively) DNA fingerprint. Only small differences in microbial biomass were observed between tree species, the highest values being recorded under oak forest and the lowest under Douglas fir. B- and F-ARISA community profiles of the different tree covers clustered separately, but noticeable similarities were observed for soils under Douglas fir and oak. A significant stratification was revealed under each tree species by a decrease in microbial biomass with increasing depths and by distinct microbial communities for each soil layer. Differences in density and community composition according to tree species and depth were related to soil physicochemical characteristics and organic matter composition.     

Phytosaur remains (Reptilia,Thecodontia)from the Upper Triassic of North-Eastern Thailand

The recently discovered late Triassic vertebratelocality at Chulabhorn Dam (North-Eastern Thailand) has yielded incomplete remains (jaw fragments and teeth) of phytosaurs, which are apparently indicative of a form related to Belodon and Rutiodon. They can be interpreted as showing that in the late Triassic North-Eastern Thailand was already biogeographically part of Laurasia.     

Desmids from the Auvergne (France)

An investigation has been made into the present occurrence and distribution of desmids in the French Auvergne. 27 samples from different habitats revealed the presence of 280 taxa belonging to 251 species, of which 120 had not previously been recorded from this region.The number of taxa per sample varied from 2 to 118; especially the samples from mesotrophic lakes were very rich in desmid species. An annotated list with corresponding figures of the recognized taxa is presented, and previous reports relating to desmids from the study-area are discussed.     

Teeth of enigmatic neoselachian sharks and an ornithischian dinosaur from the uppermost Triassic of Lons-le-Saunier (Jura, France)

Shark teeth and an ornithischian dinosaur tooth are described from a new palynologically dated Rhaetian locality at Lons-le-Saunier (Jura, France). The structure of the enameloid of the teeth ofSynechodus rhaeticus has been studied, but this appears quite different from the usual pattern seen in neoselachian sharks, making the precise relationships of this species difficult to determine. On the other hand,‘Hybodus’ minor, which has long be thought to be a hybodont shark, is included among the Synechodontiformes. The find of the tooth of an ornithischian dinosaur is also reported. Study of the Lonsle-Saunier site seems to indicate a change in the marine faunas during the Rhaetian transgression, preferentially affecting the neoselachian sharks, which increase in abundance, and thedurophasous bony fishes, which become dominated bySareodon tomicus.     

Geological significance of the discovery of Middle Triassic (Ladinian) radiolarians from the Hong Hoi Formation of the Lampang Group,Sukhothai Zone,northern Thailand

This paper presents a newly found fauna of Ladinian (Middle Triassic) radiolarians from the Hong Hoi Formation of the Lampang Group, Sukhothai Zone, northern Thailand. The Ladinian age determined by the radiolarian fauna concords with the age previously determined by mollusks. The study section consists of intercalated sandstone and shale in the lower part and a thick conglomerate in the upper part. The radiolarian-bearing siliceous beds are intercalated within the lower unit. The lithic sandstone of the lower unit consists mainly of volcanic rock fragments, quartz, and feldspar, whereas the thickly bedded conglomerate of the upper unit is characterized by abundant gravel-sized clasts of volcanic rock and limestone. These lithic features of the study section suggest that during deposition the Hong Hoi Formation was located near a supply of volcanic materials. A forearc basin close to the Sukhothai Arc would be the most suitable environment for the deposition. The Ladinian age determined by the radiolarian fauna supports the occurrence of intensive volcanic activity within the Sukhothai Arc during the Middle Triassic.     

Problematic calcispheres from the Upper Muschelkalk (Middle Triassic) of eastern France as producers of calcisiltite and micrite in shallow-water limestones

Problematic calcispheres formed a small part of the calcisiltite and their fragments formed a great part of the micrite in a Middle Triassic fine-grained limestone unit, which was deposited on a shallow subtidal carbonate platform in the Upper Muschelkalk of eastern France. The observations suggest that calcispheres were important producers of fine-grained carbonate on this early Mesozoic platform.     

Cyclotosaurus cf. PosthumusFraas (Capitosauridae,Stereospondyli) from the Huai Hin Lat Formation (Upper Triassic), Northeastern Thailand: With a note on capitosaurid biogeography

Part of a large capitosaurid skull, similar to that of Cyclotosaurus posthumus from the Upper Triassic of Germany, has been discovered in the upper part of the Huai Hin Lat Formation near Chulabhorn (Nam Phrom) Dam. This discovery is consistent with the presumed Norian age of this formation. Although the phylogeny of the Capitosauridae is still unclear, the group of Upper Triassic Cyclotosaurus species to which C. posthumus belongs is monophyletic and seems to be known only from Laurasia or Northwestern Gondwana (Morocco). The occurrence of C. cf. posthumus in Thailand is consistent with the hypothesis previously put forward, that this part of Southeast Asia was bound to Laurasia in Mesozoic times.     

The black layer in cephalopods from the German Muschelkalk (Triassic)

Thin, dark, probably phosphatic coatings were found on the dorsum in front of and sometimes behind the aperture of 50 specimens of Paraceratites and Ceratites (Ammonoidea) belonging to 14 species and subspecies and in three specimens of Germanonautilus , all from the Middle Triassic of Germany. The proportions, occurrences, position, outline, and preservation in fossil Nautiloidea and Ammonoidea (originally organic matter) of this structure support the hypothesis that it is homologous with the black layer in Recent Nautilus and Allonautilus . It is not yet possible to test whether these cephalopods show homologous styles of the development of these structures or whether the black layer can be identified in a common ancestor. In contrast to many ammonoids, Ceratites and Paraceratites , most Palaeozoic ammonoids, and some Mesozoic ammonoids probably did not have lower mandibles that were suitable for the closure of the aperture. They probably possessed a dorsally extending mantle (supracephalic mantle fold) and a hood, as in Recent Nautilus and Allonautilus , that was attached to the black layer. This interpretation is corroborated by a similar morphology of the black layer in an adult specimen of the nautilid Cenoceras from the South German Middle Jurassic and three specimens of Germanonautilus from the South German Middle Triassic (both Nautiloidea).     

Late Triassic (Late Norian) gastropods from the Wallowa Terrane (Idaho,USA)

A diverse Late Triassic (Late Norian) gastropod fauna is described from the Mission Creek Limestone of the Wallowa terrane (Idaho, USA). Sample standardization by rarefaction analysis indicates that the fauna is even more diverse than the Late Triassic gastropod fauna from the Pucara Formation (Peru) which represents the most diverse gastropod fauna from South America. The gastropod fauna consists of 66 species; several genera are reported for the first time from North America. A high percentage of the species are highly ornamented and several have distinct siphonal canals. This suggests that the appearance of truly Mesozoic elements among the gastropods began before the Mesozoic Marine Revolution in other clades. The fauna is dominated by high-spired strongly ornamented procerithiids, a group more characteristic for the Jurassic. Comparison of the present fauna and the Iranian Nayband Formation gastropod fauna show that the procerithiids underwent a first global radiation in the Late Triassic. The high number of new species in this fauna suggests that sampling of Late Triassic gastropod faunas is still incomplete and hinders palaeobiogeographic considerations. Previous suggesions that gastropod faunas from the Wallowa and Wrangellia terranes resemble each other and are distinct from those of Alexander, Chulitna, and Farewell terranes are basically corroborated. The gastropod fauna of the Mission Creek Limestone differs considerably from that of the western and central Tethys but shares several taxa with the Late Triassic gastropod fauna of the Pucara Formation in Peru. Thus, the Hispanic corridor was probably not present in the Norian but opened only in the Early Jurassic. The subfamily Andangulariinae is introduced and placed in the Zygopleuridae. The generaSpiniomphalus, Nodoconus, Gudrunella, Blodgettella, Idahospira, andSiphonilda and the subgenusCryptaulax (Wallowax) are introduced. 27 species are erected. A lectotype is designated forCryptaulax rhabdocolpoides Haas, 1953.      

Alpine marmot (Marmota marmota) distribution evolution under climate change: The use of species distribution models at a local scale in the western Pyrenees massif (France)

The Alpine marmot (Marmota marmota) is a social mammal living in mountainous grassland areas and has the particularity to hibernate in winter. Recent studies on a population in the French Alps found that climate change is affecting Alpine marmot population dynamics and might impact their overall distribution in the future. Using Species Distribution Models (SDMs), the effect of climate change on Alpine marmot's future distribution was investigated at a local scale, in the western part of the Pyrenean massif (New-Aquitaine region, France). This scale was chosen as an appropriate action scale for the conservation strategy for the species. Three climatic scenarios were used (RCP 2.6, RCP 4.5, and RCP 8.5) over three future 30-year periods (2021–2050, 2040–2070, 2071–2100) to predict the short- to long-term potential distribution of the target species. The results are consistent with naturalistic knowledge of the species´ ecological needs in terms of variable importance and response type. Mean maximum temperature in winter, standard-deviation of daily temperature in winter, along with the median rainfall amount in summer were the three most important climatic variables. Predictions under the two most pessimistic climate scenarios showed potential large habitat loss. In the long term, for RCP 4.5, an estimated habitat loss of 18% was predicted. In the case of RCP 8.5, a higher impact was predicted, with a 54% habitat loss. Our results show that high impact due to climate change can be expected at a long term. In addition, if winter climatic conditions are important for marmot survival through hibernation, drought in summer might be one of the drivers of future population dynamic and distribution. Our findings can be applied for other species living in grassland mountainous environments and for which access to food resources in summer is essential, facilitating the conservation of target areas.     

Inorganic nitrogen dynamics in the River Seine downstream from Paris (France)

The River Seine, below Paris, receives the effluents from a large sewage treatment plant, increasing the ammonium concentration up to 6 mgN.1⁻ in late summer. Careful measurement of ammonium, nitrate and organic nitrogen during the downriver travel of the water masses over 100 km below the outfall, along with direct determination of nitrification and benthic fluxes, allowed to establish a budget of nitrogen transport and transformations in this reach of the river. Nitrification is shown to start after a distinct period of several days required for the growth of a significant nitrifying bacterial population. Denitrification is active in the upper layer of bottom sediments but absent from the water column. Comparison of our data with those published for the period 1973–1976 shows that the nitrate load carried by the river has increased not only because of higher runoff of agricultural nitrate in the upstream part of the watershed, but also as a result of the severe reduction in the rate of denitrification processes, owing to the restoration of better oxygen conditions.     

The shark fauna from the Middle Triassic (Anisian) of North-Western Nevada

The shark fauna from the Anisian of Nevada is dominated by durophagous hybodontiforms but also shows an important neoselachian component. Two new species of hybodontiform sharks, Acrodus cuneocostatus and Polyacrodus bucheri , are described in addition to a new neoselachian taxon: Mucrovenator minimus. The enameloid of the teeth of Acrodus and Polyacrodus comprises two layers, an outer compact layer and an inner bundled layer. For the typical three-layered enameloid of neoselachian teeth, we propose to replace the terms parallel-fibred enameloid and tangled-fibred enameloid by the more appropriate parallel-bundled and tangled-bundled enameloid.     

First procolophonid (Reptilia,Parareptilia) from the Lower Triassic of Madagascar

Lasasaurus beltanae nov. gen. nov. sp., a new procolophonid (Reptilia, Parareptilia) from the Lower Triassic of Madagascar, is represented by a single partial skeleton preserved in a ferro-calcareous nodule from the Middle Sakamena Formation, in the North of the island. This new taxon is unique in possessing peculiar, fine and dendritic crests running along the posterolateral side of the squamosal, widely spaced maxillary teeth, subparallel mesiodistal ridges connecting maxillary teeth to the tooth row, and a strongly acute anterior margin of the copula (hyoid bone). This well-preserved specimen belongs to a juvenile individual. The inclusion of L. beltanae nov. gen. nov. sp. in a phylogenetic analysis suggests that it is close to Theledectinae, Procolophoninae, and Leptopleurinae, though their respective relationships are uncertain. This specimen is the first procolophonid described from Madagascar and represents a minor terrestrial component of a coastal vertebrate assemblage dominated by amphibious to fully-aquatic taxa.     

Smithian (Early Triassic) ammonoids from Tulong, South Tibet

Intensive sampling of the Tulong Formation in South Tibet has facilitated the construction of a highly-resolved middle and late Smithian ammonoid succession. The new biostratigraphical sequence comprises the middle Smithian Brayardites compressus beds, Nammalites pilatoides beds, and the Nyalamites angustecostatus beds followed by the late Smithian Wasatchites distractus beds and Glyptophiceras sinuatum beds. This faunal succession correlates very well with that of other Tethyan sequences such as the Salt Range (Pakistan), Spiti (India), Oman and South China. The Smithian faunal sequence from Tulong contains several taxa with broad geographic distribution (e.g., Owenites, Paranannites spathi, Shigetaceras, Wasatchites), thus enabling correlation with faunal successions from areas outside the Tethys (e.g., USA, British Columbia, Arctic Canada, South Primorye, Siberia). Early Smithian ammonoid faunas are almost absent in Tulong because of a preservation bias (absence of carbonate rocks). Five new ammonoid genera (Brayardites, Nammalites, Nyalamites, Shigetaceras, Tulongites) and six new species (Brayardites crassus, Brayardites compressus, Prionites involutus, ?Subflemingites compressus, Tulongites xiaoqiaoi, Urdyceras tulongensis) are described.     

Upper Triassic (Norian) hypercalcified sponges from the Musandam Peninsula (United Arab Emirates and Oman)

Supercalcified sponges, including sphinctozoans, inozoans, chaetetids, spongiomorphids, occurring in Upper Triassic (Norian-Rhaetian) shallow-marine limestones of Musandam Mountains in United Arab Emirates (UAE), are described. The following taxa were determined: sphinctozoans: Hajarispongia osmani Senowbari-Daryan and Yancey, Nevadathalamia arabica n. sp., Nevadathalamia conica n. sp., Fanthalamia milahaensis n. sp., Iranothalamia incrustans (Boiko), Cinnabaria regularis n. sp.; inozoans: Cavsonella triassica n. sp., Molengraaffia regularis Vinassa de Regny, Peronidella? sp., Circopora cf. caucasica Moiseev, Circopora? sp.; spongiomorphids: Spongiomorpha sp.; chaetetids: Lovcenipora chaetetiformis Vinassa de Regny, Lovcenipora musandamensis n. sp., Lovcenipora sp., chaetetid sponge gen. et sp. indet. The most abundant sponge in the studied material is Nevadathalamia arabica n. sp. The described sponge association of the Arabian shelf (Musandam Mountains) shows close affinity to the sponge association known from age-equivalent terranes in the Panthalassa Ocean (Sonora Mountains in Mexico; Pilot Mountains in Nevada, USA), but is remarkably different from sponge associations in carbonates bordering the Tethys. This difference goes along with the biogeography of wallowaconchid bivalves and is most likely attributed to climatic, palaeogeographic or oceanographic factors.