The genus Kepplerites Neumary et Uhlig (Kosmoceratidae,Ammonoidea) in the Bathonian-Callovian beds (Middle Jurassic) of the Russian Platform

The succession of early species of the genus Kepplerites is established in the Upper Bathonian-Lower Callovian beds of Central Russia and compared with the ammonoid succession of East Greenland and Western Europe. Late Bathonian members of the genus Kepplerites from the Middle Volga Region are generally similar, though not identical to those from Greenland, whereas the Early Callovian Kepplerites species and their immediate Bathonian ancestors are represented by species common to all three regions. The analysis of the ammonoid distribution suggests a connection between the East Greenland and Central Russian marine basins in the Early and Middle Bathonian and in the Early Callovian, and their short-term isolation in the Late Bathonian. A new species, Kepplerites (Kepplerites) aigii sp. nov., is described from the Upper Bathonian (keuppi Zone) of the Alatyr River basin (Middle Volga Region).     

Neocrassinid bivalves (Heterodonta) from the Middle Bathonian (Jurassic) of Kachchh,Western India

Six bivalve taxa belonging to the genusNeocrassina Fischer have been described from Middle Bathonian (Middle Jurassic) rocks of Kachchh, Western India. Of these,Neocrassina (N.) ovata (Smith), TV.(N.) robusta (Etallon) andN. (N.) paphia (d?Orbigny) have been recorded previously from various parts of Europe, whileNeocrassina (N.) pandeyi Maithani is an endemic faunal element as areNeocrassina (N.) sp. A andNeocrassina (N.) sp. B. The generic and sub-generic characters ofNeocrassina are reviewed as are affinities of the taxa with closely related forms from India and other parts of the world.     

Zur stratigraphie und ammonitenfauna der varians-schichten (mittel- und unteres ober-bathonium) von talheim am lupfen (südwestl. schwäbische alb)

A section of the “Varians-Schichten” (Brauner Jura e) near Talheim am Lupfen (southwestern Swabian Alb) is described. The ammonites collected in these layers document the ?progracilis,subcontractus andmorrisi zones (Middle Bathonian, Dogger) and moreover theretrocostatum zone (lowest part of the Upper Bathonian, Dogger). Some of the described ammonites are new for SW-Germany.     

First occurrence of the Ichnogenus Selenichnites from the Middle Jurassic Strata of the Skoura Syncline (Middle Atlas,Morocco); Palaeoecological and palaeoenvironmental context

Mesozoic strata of North Africa yield the first occurrence of the ichnogenus Selenichnites. The trace fossils occur on the top surface of a sandy carbonate deposit in the axis of a Middle Atlas syncline (Skoura Syncline, NE Morocco). The ichnofossil-bearing horizon belongs to the Late Bajocian–Early Bathonian Ich Timellaline/Bou Akrabene Formation. The trace fossils are crescent-shaped and the best preserved exhibits a posterior central axial impression (possible telson tail impression). They are interpreted as feeding burrows (fodinichnia) or hiding depressions of Xiphosurids or Limulids (horseshoe crabs) on a sandy carbonate substrate beneath a veneer of muddy deposits. The sedimentological character suggests a relatively protected shallow water subtidal palaeoenvironment preceding the Bathonian regression of the Atlas domain. This discovery provides the first evidence of xiphosurans or xiphosuran-like organisms inhabiting the southern shores of the Tethys in the Middle Jurassic.     

Taxonomy and palaeobiology of the Bathonian (Middle Jurassic) tulitid ammonite Morrisiceras

Taxonomic revision of a number of species belonging to the Middle Bathonian tulitid genus Morrisiceras (Morrisiceras Buckman - macroconchs and Holzbergia Torrens - microconchs) from the Polish Jura (south-central Poland) and England, shows that the genus is in fact represented by one, albeit morphologically very plastic (especially macroconchs), species Morrisiceras morrisi (Oppel). In the Polish Jura area, all of the previously described morphotypes of the macroconch, along with its microconch Holzbergia, are characterized by their identical stratigraphic ranges, both being confined to the Middle Bathonian Morrisi Zone. Much smaller microconchs (males) may have attained maturity earlier than their macroconchs (females). Morphologically very plastic macroconchs seem to have attained full maturity at various shell diameters. Such phenomenon is known in recent coleoids and similarly may be the result of changing environmental conditions. Palaeobiogeographically, the main area occupied by the species was confined to the epicratonic seas, which spread across what is now present-day central and North-West Europe, with some occurrences in western Asia (Turkmenistan/Uzbekistan) and sporadic occurrence in a deep-water facies of Apulia (Italy). Taphonomical observations suggest that Morrisiceras shells have not undergone significant post-mortem drifting or transport after deposition. The preservation of some of the Morrisiceras morphotypes, occurring as dorso-ventrally flattened specimens in the host clays, may indicate that they were quickly buried in life position after they have landed on the sea-floor.     

Bone histology of the Middle Jurassic turtle shell remains from Kirtlington, Oxfordshire, England

The Middle Jurassic (Bathonian) turtle material from the Mammal Bed at Kirtlington, Oxfordshire, England, has recently been tentatively referred to the Pleurosternidae, although the known synapomorphies of this clade were absent from the specimens. Here we present new evidence from shell bone histology that corroborates reports of pleurosternids at Kirtlington and further reveal that two different histomorphs (= two different taxa) are present in this locality. The first histomorph presents the distinctive histological structure of pleurosternids, which is described herein for the first time: the external cortical bone layers are differentiated into an inner zone of coarse, irregularly interwoven structural fibre bundles and an outer fine-fibred zone. The second histomorph has a more plesiomorphic structure and can only be assigned to Cryptodira indet. A morphological reassessment of the Kirtlington material fails to recognize two different taxa and shows that only sparse evidence supports the presence of pleurosternids in this locality. Shell bone histology thus appears as a powerful tool to study poorly preserved specimens and may in some case (like with pleurosternids) help resolve phylogenetic relationships. According to our results, the stratigraphic appearance of the Pleurosternidae is adjusted from the Kimmeridgian (Late Jurassic) to the Bathonian (Middle Jurassic), which significantly reduces the ghost lineage of Paracryptodira.     Bone histology, turtles, Paracryptodira, Pleurosternidae, Middle Jurassic, Kirtlington.     

Evolution of pelagic swells from hardground analysis (Bathonian–Oxfordian, Eastern External Subbetic, southern Spain)

The Middle Bathonian to Middle Oxfordian interval in the Eastern External Subbetic (Betic Cordillera, SE Spain) is characterized by Ammonitico Rosso facies including various stratigraphic breaks. Five hardground-bounded units are recognized in relation to hiatuses in the ammonite record at the following stratigraphic boundaries: Hg1 (Lower–Middle Bathonian), Hg2 (Middle–Upper Bathonian), Hg3 (Lower–Middle Callovian), Hg4 (Middle–Upper Callovian), and Hg5 (Callovian–Oxfordian). Interesting features of these hardgrounds include their microfacies, ferruginous crusts and macro-oncoids, taphonomy of macroinvertebrates, trace fossils, neptunian dykes, and the hiatuses associated with each of them. The main hardgrounds (Hg1, Hg2, and Hg5) contain trace fossils of the Cruziana and Trypanites ichnofacies as well as abundant fossil macroinvertebrates with taphonomic features evidencing corrasion, early diagenesis, and reworking, indicating substrate evolution from softground to hardground. Neptunian dykes affected the trace fossils and ammonoid moulds, and their walls and the hardground surfaces were colonized by ferruginous microbial crusts. These features are characteristic of the External Subbetic pelagic swells, where the absence of sedimentation, sediment bypassing and erosion, and early diagenesis during relative sea-level falls produced hardgrounds. The neptunian dykes are indicative of tectonic activity in the areas of pelagic swells. Ferruginous crusts and macro-oncoids developed only on hardground surfaces and neptunian dykes walls prior to deposition of condensed bioclastic beds, which are interpreted as the first deposits after hardground development and are related to the onset of transgression. The varying ranges of the gaps as well as lateral facies changes are related to different local paleobathymetry controlled by the activity of listric faults.     

New species of stenolaemate bryozoans from the Jurassic of the Moscow and Saratov Regions (Russia)

Three new species of the Middle Jurassic stenolaemate bryozoans of the genera Reptomultisparsa d’Orbigny and Microeciella Taylor et Sequeiros are described: R. saratovensis sp. nov. and M. seltseri sp. nov. from the Lower Bathonian and the Upper Callovian of the Saratov Region, respectively, and R. stupachenkoi sp. nov. from the Middle Callovian of the Moscow Region. Some specific features of their astogeny and colonial morphology are discussed.     

Middle Jurassic Porifera from Kachchh, western India

From the Late Bathonian sponge biofacies at Jumara Dome, Kachchh (western India) 11 species of ‘lithistid’, hexactinellinid and calcarean sponges are described. New taxa are the order Sigmatospirida, the genusJumarella, and the speciesJumarella astrorhiza, Mastosia rhytidodes, Radicispongia kraspedophora, andHexactinella prisca. The diverse sponge assemblage is associated with a rich fauna of epibenthic bivalves and brachiopods and formed meadows on fine-grained carbonate substrates. The sponge meadows grew on a carbonate ramp at the lower end of the photic zone, in quiet waters below storm wave base. The rate of sedimentation exceeded that of sponge production. This prevented the development of reef-like bodies. In contrast to Mesozoic sponge reefs, growth of the sponge meadows appears to have been confined to the regressive phases of small transgressive-regressive cycles.     

Les Rhynchonelles du Bathonien du domaineprovencal: Liaison entre l'installation des peuplements et les modalités de la transgression bathonienne dans les Alpes-Maritimes

In the Maritime Alps, the Middle and Upper Bathoniancorresponds to a transgressive episode on the Provençal platform. The advancement of the marine invasion is very noticeable between Grasse and Antibes. The sediment shows the existence of a shallow marine environment in which benthic organisms were predominant.The deposits are at first varied: marly layers withbivalves (burrowers for the most part) and calcareous layers with monospecific populations of brachiopods (Burmirhynchia mediterranea nov. sp. in a calm environment, and B. turgidaBuckman in a more turbulent environment).The deposits then become uniform and show theexistence of very shallows environments: B. decorata kiliani nov. subsp. is the only representative of macrofauna in the micritic limestones that can be attributed to the Upper Bathonian.The Rhynchonellids, as on the other Bathonian carbonateplatforms of Western Europe, seem to be the only organisms likely to stay alive and proliferate in the specific environments in which entirely carbonate sediments are deposited in shallow water. Due to their relationships to those existing in other platforms, the species described in this article permit the clarification of biostratigraphic correlations.     

Middle to Late Jurassic radiolarians from Sicily (Italy)

Middle and Upper Jurassic radiolarian faunas from two sections of Sicily are compared with the previously proposed zonations. The ages of the faunas are estimated by correlation with these zonations and by concurrent range zone. The faunas could be assigned to the Bathonian or earlier late Tithonian or early Berriasian. Two new spumellarian species (Bernoullius furcospinus andBernoullius rectispinus) from Middle Jurassic are described.     

Middle Jurassic radiolarians from Jinlang,Zedong, southern Xizang (Tibet), China

Moderately to well-preserved radiolarians have been extracted from nine greyish green and purplish-red bedded cherts in the mud-matrix mélange of the eastern Yarlung-Zangbo Suture Zone (YZSZ) at Jinlang Section, Zedong, southern Xizang (Tibet). Forty-two species belonging to 27 genera, including Middle Jurassic characteristic species such as Laxtorum (?) jurassicum Isozaki and Matsuda, Laxtorum (?) hichisoense Isozaki and Matsuda, Stichocapsa japonica Yao, Stichocapsa robusta Matsuoka, Parahsuum (?) magnum Takemura, Sella chrafatensis (El Kadiri), and Unuma typicus Ichikawa and Yao are recognized and three assemblages, Laxtorum (?) jurassicum Assemblage (Aalenian), Quarticella ovalis Assemblage (late Bajocian), and Stichocapsa robusta Assemblage (middle Bathonian) are established in ascending order. These assemblages can be well correlated to the Middle Jurassic Unitary Association (UA) Zones (Baumgartner et al., 1995) in west Tethys and coeval biozones in Japan and provide reliable age information for the Middle Jurassic stratigraphic correlation of the pelagic sediments along the YZSZ.     

Middle Jurassic Spore- pollen Assemblages from Turpan- Shanshan Area,Xinjiang

The Middle Jurassic palynoflora from the two wells of PUl and CN1 of Turpan-Shanshan area in Xinjiang consists of 97 species of fossil spores and pollen grains referred to 45 genera, of which 2 species are newly described. Three palynological assemblages including: 1) Cyathidites-Cycadopites-Quadraeculina (CCQ), 2) Cyathidites-Classopollis-Picites (CCP) and 3 ) Granu-latisporites-Classopollis-Podocarpidites (GCP) assemblages are established in the Xishanyao, Sanjianfang and Qiketai Formations, respectively. Comparisons have been made between these assemblages with those of the adjacent regions in Xinjiang and other domestic areas and at abroad. The geological age of the CCQ assemblage is suggested to be at early Middle Jurassic (corresponding to Aalenian to Bajocian age); while the CCP and GCP assemblages are considered to be at late Middle Jurassic (corresponding to early to late Bathonian age, respectively).     

新疆吐鲁番—鄯善地区中侏罗世孢粉组合

研究新疆吐鲁番鄯善地区葡１井和草南１井中侏罗世孢子花粉化石４５属９７种,包括２个新种。建立西山窑组、三间房组和七克台组共３个孢粉组合,其地质时代相当于中侏罗世早期和晚期。     

The earliest known Salamanders (Amphibia,Caudata):A record from the Middle Jurassic of England

Marmorerpeton gen. nov. represented by M. kermackisp. nov. and M. freemani sp. nov., is the earliest known genus of fossil salamander from the Upper Bathonian, Middle Jurassic of Kirtlington, Oxfordshire, England. Marmorerpeton is more primitive than any other known salamander in the absence of intravertebral spinal nerve foramina in the atlantal centrum, but in other features it resembles members of the family Scapherpetontidae, neotenous salamanders otherwise known from the Upper Cretaceous and Palaeocene. The Kirtlington herpetofauna is a unique freshwater assemblage of Middle Jurassic small amphibians and reptiles, several of which represent the earliest known occurrences of their respective groups.     

Ostracods of the genus Palaeocytheridea Mandelstam in the Middle and Upper Jurassic of Europe: 3. Stratigraphy and paleobiogeography

The analysis of distribution of endemic and cosmopolitan ostracods of the genus Palaeocytheridea shows that, in the Bajocian and Bathonian, the Tethyan and Boreal-Atlantic regions of Western and Eastern Europe developed in partial isolation, while beginning from the middle of the Lower Callovian, these parts of the European paleobasin were connected. For the Middle Jurassic of Western and Eastern Europe and, in particular, for Ukraine, the ostracod zones are recognized based on stratigraphic distribution of species of the genus Palaeocytheridea.     

Signs of predation in the Middle Jurassic of south-central Poland: evidence from echinoderm taphonomy

Distinct faunal aggregates are described from the Middle Jurassic (uppermost Bajocian/lowermost Bathonian and Middle Bathonian) clay deposits of Częstochowa area, south-central Poland. These aggregates are composed of molluscs (scaphopods, gastropods, bivalves, ammonites and belemnites), articulate brachiopods and echinoderms (asteroids, crinoids and echinoids). A large percentage of the fossils, especially bivalves, are fragmented, but some fossils are complete. Although most of the fossils are crushed and fragmented, they are still identifiable to at least the genus level. Thorough statistical analysis of taphonomic features indicates that the preservation of asteroid marginal plates is distinct from the ossicles derived from the host clays. The high frequency of bite marks and the good state of preservation suggest that the accumulations are the products of predation activities and most probably are the effect of regurgitation. Taking into account the rich and diverse fauna, the predator was a bottom-feeding generalist. Possible predators include palaeospinacid sharks, a tooth of which was collected from the same bedding surface, but not associated with regurgitated remains. Although the bite marks on the asteroid ossicles point to sharks as potential producers of regurgitates, other vertebrates, like durophagous pycnodontiform fish, cannot be excluded.     

塔里木盆地库车坳陷中侏罗统的一些双壳类

系统描述库车坳陷中侏罗统的双壳类3 属4 种。根据双壳类Kija铰合构造变异范围的研究,认为Acyrena、Pseudocardinia、Jiangxiella、Apseudocardinia、Hunanella、Yananoconcha、Hamiconcha和Fengjiachonia都是Kija 的同物异名。库车坳陷中侏罗统的双壳类化石属于Lamprotula (Eolamprotula) cremeri Kija (=Pseudocardinia) kweichouensis动物群,分为Kija ovalis K. kweichouensis和Lamprotula (Eolamprotula) guan gyuanensis Margaritifera? cf. isfarensis两个化石组合。Kija ovalis K. kweichouensis组合产于克孜勒努尔组和恰克马克组下部,时代为中侏罗世早期,可能主要为阿林期至巴柔期;Lamprotula (Eolamprotula) guangyuanen sis Margaritifera? cf. isfarensis组合主要分布于恰克马克组中上部,时代为中侏罗世晚期,可能主要为巴通期至卡洛夫期。