A ‘Problematic fossil’ revealed:Pycnoporidium ? eomesozoicum Flügel, 1972 (Late Triassic,Tethys)—not an enigmatic alga but a strophomenid brachiopod (Gosaukammerella n.g.)

Summary The microproblematicumPycnoporidium ? eomesozoicum Flügel, 1972, from Upper Triassic reefs of the Alpine-Mediterranean region, Turkey Oman and Iran (originally interpreted as possible alga) represents the type species of a new strophomenid brachiopod genus (Gosaukammerella n.g.). The genus is characterized by a very small, millimeter-sized plano-convex shell, whose ventral valve is attached to the substratum (mainly sponges) by symmetrically arranged outgrowths developing from a pseudopunctate, lamellose foliated shell wall and composed of densely spaced subparallel ‘tubes’ comparable with productide spines secreted by papillose extensions of the mantle.Gosaukammerella seems to be the only reliable candidate for the existence of post-Paleozoic strophomenid (productid ?) brachiopods. Gosaukammerella eomesozoica is restricted to possibly cryptic, shaded reef environments inhabited predominantly by sponges serving as substrates for micromorphic brachiopods.     

Les ammonites boréales des formationsnéocomiennes du Sud-Est français (province subméditerranéenne)

The boreal Ammonites (and the more or lessphylogenetically related ones) of the southeast France (Tethyan Realm) are described and figured. 24 forms are refered to, or compared with, previously identified species. 3 are left under open nomenclature, and 7 are new ones. Two new subgenus: Julianites (Paquiericeras) and Lemurostephanus (Olcostephanus) are also introduced.Their biostratigraphic position in the Frenchzonal scheme is detailed. Their contribution to the establishment of correlation between the Boreal and Tethyan provinces is stressed.The most interesting feature is the identification of a Prodichotomites horizon just below the Verrucosum zone, allowing comparison of the definition of the Lower-Upper Valanginian boundary in these two paleobiogeographic realms.     

Les Radiolaires d'âge jurassique supérieurà crétacé supérieur dans les Radiolarites du Pinde-Olonos (Presqu'île de Koroni; Péloponnèse méridional,Grèce)

Radiolarians of several radiolarites sections of the Pindos-Olonos zone, southern Peloponnesus, lead to propose direct datations of mesozoic sediments. The acuity of such datations allow to distinguish two periods for depositionof radiolarites s.s. in the tethyan region. The first period would be Upper Jurassic and general in tethyan realm, radiolarites depositing under various latitudes (0–35°N). This would be the result of a strong ocean surface current. The second period would be Upper Cretaceous (Vraconian—Coniacian) and be geographically much more restricted (0–15°N). This could result from a weaker current. The absence of radiolaritic sedimentation is possibly the result of the destruction or insulation of the accurate basins during the obduction of ophiolites on the apulo-african realm. The inventory of Late Cretaceous radiolarian fauna, rarely done on alpine series so far, shows similar result to those obtained in Central American and California.     

Une nouvelle sous-famille,les Poulpinae, et quatre nouvelles espèces de Saitoum radiolaires mésozoiques téthysiens

Studies of skeleton elements of several jurassic species of Saitoum allow to compare them with Poulpus from Trias. The sub-family Poulpinae is introduced, caracterised by three cephalic arcs and the collar position of the cephalic structure. Among the jurassic forms, 4 species are newly described: S. corniculum, S. elegans, S. levium and S. trichylum.     

Lower Jurassic corals from the Pamir Mountains,Central Asia

The paper describes new Lower Jurassic corals from the South-Eastern Pamir Mountains (Tajikistan) and interprets their relationships with contemporaneous West Tethyan corals. Taxonomic similarities with Pliensbachian European and North African faunas indicate a Pliensbachian age for this fauna, which was previously considered to be of Hettangian/Sinemurian age. Together with the taxa earlier described from the Pamirs, this fauna consists of 30 species of 25 genera, including Triassic holdover genera such as Stylophyllopsis, Phacelostylophyllum and Eocomoseris. The bulk of the fauna represents new Jurassic genera: Alichurastrea, Eomicrophyllia, Guembelastreomorpha, Gurumdynia, Pinacomorpha, Protostephanastrea, Psenophyllia, Sedekastrea and Stylimorpha. Earlier coral studies of the region concerned the genera: Archaeosmilia Melnikova, 1975, Archaeosmiliopsis Melnikova, 1975, Cylismilia Roniewicz, 1988, Pachysmilia Melnikova, 1989, and Prodonacosmilia Melnikova in Melnikova and Roniewicz, 1976. Two species that were considered to belong to the genus Cylismilia, are redescribed and reclassified in the genera Psenophyllia, and Archaeosmilia Melnikova, respectively.     

First record of the Late Cretaceous starfish Metopaster parkinsoni (Forbes, 1848) in Iran

A body fossil of the starfish Metopaster parkinsoni was collected from chalky rocks of the Coniacian – Santonian transition in the Abderaz Formation at the Padeha section, east of Mashhad (Kopet-Dagh, Iran). The species is common in the English Chalk and is well known from the Cenomanian to the Maastrichtian of Europe. The new Iranian occurrence of M. parkinsoni extends its geographical range of 700 km to the South and 2500 km to the East. The species proliferated in upper offshore environments of the North Tethyan continental shelves. The outstanding occurrence of many well-preserved specimens during the Coniacian – Santonian transition in Europe and Iran may be related to favorable taphonomic conditions driven by the Ocean Anoxic Event (OAE III).     

Plankton populations of Lake Leake and Tooms Lake—Oligotrophic Tasmanian Lakes

The characteristic feature of Lake Leake and Tooms Lake is their great similarity in physical and chemical limnology. This similarity extends to the plankton populations in general terms, both lakes being dominated by Cyclotella stelligera Cleve et Grun. and having few other species. Floristic differences are minimal. Despite this floristic similarity distinct differences exist in plankton periodicity, principally in that of Cyclotella stelligera. The extreme oligotrophy of the lakes, already suspected from their low nutrient levels, is confirmed by the extremely meagre standing crops.     

Pliensbachian gastropods from Venetian Southern Alps (Italy) and their palaeobiogeographical significance

Abstract: The Pliensbachian gastropods described by De Toni in 1912, coming from an isolated boulder at the foot of Mt Vedana (eastern margin of Trento Platform, Venetian Southern Alps, Italy) are revised. The fauna consists of 13 species representing nine families and eight superfamilies. Despite the low number of species, the assemblage represents the most diverse Early Jurassic gastropod fauna known for the Venetian Southern Alps. The boulder yielding the material was thought to derive from the upper part of the Early Jurassic Calcari Grigi Group, a carbonate platform unit extensively cropping out in the Mt Vedana area. The sedimentological analysis indicates a prevalently bioclastic wackstone‐floatstone, reflecting a lime‐muddy deposit undergone to an early consolidation. This and the high content of ammonoids, which is unusual for the Calcari Grigi Group, are typical aspects of a condensed pelagic sediment, presumably a fissure filling at the top of the carbonate platform succession. Palaeobiogeographical comparisons show that the fauna is composed of species occurring exclusively in pelagic limestones of the western Tethys. By contrast, it shows no relationships with the coeval faunas of the adjacent Trento platform and of the other western Tethyan carbonate platforms. These lines of evidence and the facies analysis would testify to the Pliensbachian drowning of the eastern margin of the Trento platform. In the wider context of the palaeobiogeographical history of Early Jurassic western Tethyan gastropods, the species from Vedana belong to a faunal stock which is typical for pelagic, mainly postdrowning sediments. Thus, appearance and diffusion in space and time of this stock were probably regulated by the direction, rate and pattern of the Neotethyan rifting. A new subgenus, Proarcirsa (Schafbergia) subgen. nov., and three new species, namely Ataphrus (Ataphrus) cordevolensis sp. nov., Guidonia pseudorotula sp. nov. and Proarcirsa (Schafbergia) zirettoensis sp. nov. are erected.     

Thanetian–Ilerdian coralline algae and benthic foraminifera from northeast India: microfacies analysis and new insights into the Tethyan perspective

Thanetian–Ilerdian carbonate deposits from the Lakadong Limestone in Assam Shelf, Meghalaya, northeast India, are studied with respect to microfacies distributions and controlling ecological factors on dominant biogenic components. Palaeoenvironmental implications are inferred following the detailed analysis of microfacies characterized by rich assemblages of coralline red algae and benthic foraminifera. The carbonate sediments have been interpreted as lagoonal to outer shelf facies. It is envisaged that the analysed benthic communities thrived in a meso‐oligotrophic regime above the fair‐weather wave base. The Lakadong Limestone constitutes a well‐preserved record of Late Palaeocene–earliest Eocene shallow marine carbonate ecosystem and has high potential to decipher its response to an interval of distinct changes in climate and tectonic settings. The abundance of oligotrophic larger benthic foraminifera in the Lakadong Limestone is comparable to the foraminiferal assemblages of west Tethys. The phylogenetic changes (‘Larger Foraminiferal Turnover’, LFT) and subsequent rapid radiation of typical Eocene larger benthic foraminifera (Alveolina, Nummulites) usually observed in the west Tethys have also been observed in the upper part of the Lakadong Limestone. The eastward migration of Eocene foraminifera from the west coincided with the India‐Asia collision and global warming events at the Palaeocene–Eocene boundary that may have produced a wide array of modifications in biogeography, seasonal run‐offs and ocean circulation pathways. The data indicate that rapid rate of migration from west before the onset of geographic barriers and/or timely restoration of pan‐Tethyan environmental conditions ensured the incidence of these forms in the earliest Eocene sediments.