Autecology of the upper jurassic oysternanogyra virgula (defrance)

The late Jurassic exogyrine oysterNanogyra virgula occurs in fine-grained low-energy sediments of the European epicontinental sea. It is interpreted as having lived cemented to hard substrates during early juvenile stages, but commonly reclining on soft, muddy substrates in the adult stage. This is supported by several morphological adaptations to such a mode of life.     

Growth and environmental hazards of the upper jurassic colonial coralactinastrea matheyi (koby) from Portugal

Development and growth of Upper Jurassic colonial corals(Actinastrea matheyi) from Portugal was ruled by abiotic factors (water energy, sedimentation rate) and biotic factors (predation and parasitism). Phases of growth were interrupted by high energy events which caused tilting of the corals. In addition, intensified parasitism and predation occurred.     

Palaeoecology of coralline sponge-coral meadows from the upper jurassic of Portugal

TheComophyllia polymorpha-Crispispongia cf.expansa association of the Kimmeridgian Alcobaça Formation occurs in a 5–10 m thick unit that can be followed for at least 10 km in the vicinity of Alcobaça (Estremadura). Corals, coralline sponges (mainly Calcarea), cryptalgal crusts and, to a lesser extent, crinoids are the dominant constituents of the autochthonous community relic which can be grouped in framebuilders, framework encrusters, frame binders, reef-dwellers, and reef destroyers. These organisms formed low meadows in a shallow, fully marine environment subject to low rates of sedimentation and moderate to low energy levels punctuated by rare high energy events. The abundance of coralline sponges in reefs and reef-like communities is uncommon in the Jurassic and appears to be restricted to very shallow water environments.     

Middle jurassic Haploceratidae (Ammonitina)from the Subbetic Zone (South Spain)

Upper Aalenian to Upper Bathonian Haploceratidaefrom the Subbetic Zone are studied taxonomically, biostratigraphically and paleogeographically. The genera Lissoceras, Bradfordia, Toxamblyites and Poecilomorphus include nine species. Toxamblyites paviai is new. Stratigraphic and geographic distributions are discussed. Phylogenetic interpretations are proposed; Bradfordia, the first haploceratid, comes from the graphoceratids and two clades may be possible: (1) the Bradfordia with slightly developed ribbing evolved to Lissoceras and (2) the Bradfordia strongly ribbed evolved to Poecilomorphus via Toxamblyites.     

New Obrieniidae from the jurassic of Kazakhstan (Coleoptera,Obrienioidea)

A new subfamily, Pseudobrieniinae, including the new genus Pseudobrienia and the new species Pseudobrienia rasnitsyni, Kararhynchus jurassicus, and K. gratshevi, are described from the Middle-Late Jurassic of Karatau. K. occiduus Zherikhin et Gratshev, 1993 is redescribed.     

The life and death of torquirhynchia inconstans (brachiopoda,upper jurassic) in England

Torquirhynchia inconstans, a rhynchonellid brachiopod, shows a curious asymmetric commissure. This is interpreted as an adaptation to life in tidal environments. Type of preservation, growth line, and size frequency analysis indicate that the population analyzed consist of dominantly mature individuals, which by analogy with recent brachiopod populations is a primary feature of the original population, and not due to selective destruction, selective transport, or selective predation of smaller individuals. The possible functions of the asymmetry of Torquirhynchia inconstans are considered, and it is concluded that the brachiopod was adapted to life in tidal environments, a conclusion supported by sedimentological evidence. Asymmetric brachiopods are considered to have developed from colonies of partly asymmetric, variable brachiopods by selection of extreme variants.     

Elaphrosaurus,an ornithomimid dinosaur from the upper jurassic of north America and Africa

A humerus from the Morrison Formation (Upper Jurassic) of western North America is referred toElaphrosaurus which is represented by a skeleton from the Tendaguru Beds of Tanzania, East Africa. The referral ofCoelurus agilis Marsh (Morrison Formation, western U.S.A.) andTeinurosaurus sauvagei (Huene) (Kimmeridgian, France) toElaphrosaurus is incorrect. The recognition ofElaphrosaurus from North America provides additional evidence for a Morrison-Tendaguru land connection sometime during the Late Jurassic.Elaphrosaurus is referred to the family Ornithomimidae because the form of the humerus, slender and straight with a low deltopectoral crest, is diagnostic of this family.Deinocheirus from the Upper Cretaceous of Mongolia is a giant ornithomimid.     

Early jurassic (Upper Pliensbachian) gastropods from the Herforder Liasmulde (Bielefeld, Northwest Germany)

An Early Jurassic (Upper Pliensbachian) gastropod fauna from the Herforder Liasmulde (Herford Lias Syncline) near Bielefeld, Northwest Germany is described. This is one of the first detailed and illustrated reports of Pliensbachian gastropods from this area. Sixteen species are reported. Surface collecting yielded relatively large vetigastropods (pleurotomarioids amd trochomorphs). Bulk samples yielded abundant small caenogastropods (especiallyLevipleura blainvillei andKalchreuthia frankei) and cylindrobullinid opisthobranchs (e.g.Cylindrobullina dornend). These small species are also abundant in the Pliensbachian of South Germany (N Bavaria, Franconia). Therefore, this characteristic Pliensbachian microgastropod assemblage was widespread in Germany and probably also in other comparable marine deposits of Central Europe (e.g. the Paris Basin).      

Some hematological data from marsh harriers (Circus aeruginosus) in central spain

• 1.1. Hematocrit, total protein and glucose values were determined in blood samples from 19 marsh harriers (Circus aeruginosus), 10 males and nine females.
• 2.2. The different parameters were studied on the basis of the ranges described in other birds.
• 3.3. There was a significant correlation between weight and blood glucose level.

     

Enigmatic dinosaur trackways from the lower jurassic (Pliensbachian) of the Sarca valley,Northeast Italy

Four large limestone blocks with dinosaur footprints have been discovered in a large landslide situated in the Sarca Valley (northeast Italy). The trampled sediments have been ascribed to the upper part (Pliensbachian) of the Lower Jurassic Calcari Grigi Formation, which in the Sarca Valley consists of oolitic‐bioclastic limestones. These carbonates were originally deposited on the western margin of the Trento Platform, a paleogeographic structural high that was located in the northern tropical belt at the westernmost end of Tethys. Several footprints form trackways of quadrupedal dinosaurs. The data suggest the presence, within the ichnoassociation, of possible prosauropods and basal Thyrephora. This inference is consistent with the chronological and geographical distribution of both prosauropods and Thyreophora.     

First diagnostic marine reptile remains from the aalenian (middle jurassic): a new ichthyosaur from southwestern Germany

Background

The Middle Jurassic was a critical time in the evolutionary history of ichthyosaurs. During this time interval, the diverse, well-studied faunas of the Lower Jurassic were entirely replaced by ophthalmosaurids, a new group that arose sometime prior to the Aalenian-Bajocian boundary and by the latest middle Jurassic comprised the only surviving group of ichthyosaurs. Thus, the Middle Jurassic Aalenian-Bathonian interval (176–165 million years ago) comprises the time frame during which ophthalmosaurids not only originated but also achieved taxonomic dominance. However, diagnostic ichthyosaur remains have been described previously from only a single locality from this interval, from the Bajocian of Argentina.

Methodology/Principal Findings

In this paper, we describe a new species of ichthyosaur based on a partial articulated specimen from the Middle Jurassic of southwestern Germany. This specimen was recovered from the Opalinuston Formation (early Aalenian) and is referable to Stenopterygius aaleniensis sp. nov. reflecting features of the skull and forefin. The genus Stenopterygius is diverse and abundant in the Lower Jurassic of Europe, but its presence has not previously been confirmed in younger (Middle Jurassic) rocks from the northern hemisphere.

Conclusions/Significance

This specimen represents the only diagnostic ichthyosaur remains reported from the Aalenian. It bears numerous similarities in size and in morphology to the Lower Jurassic species of the genus Stenopterygius and provides additional evidence that the major ecological changes hypothesized to have occurred at the end of the Toarcian took place sometime after this point and most likely did not occur suddenly. There is currently no evidence for the presence of ophthalmosaurids in the northern hemisphere during the Aalenian-Bathonian interval.     

Palynological investigation in the lower jurassic of the vicentinian alps (Northeastern Italy)

The present paper emphasizes the applicability of palynological data as an aid to the solution of the problems related to the correlation of non-ammonitiferous Liassic strata in the Southern Alps with the ammonoid-based standard stages as recognized in the outer-Alpine part of Europe.In the Noriglio Grey Limestone Formation of the Vicentinian Alps, northeastern Italy, rich and well-preserved Liassic palynological assemblages can be abundantly found in the marly intercalations of its upper part; in the lower part palynological assemblages have appeared to be very rare. A qualitative and quantitative analysis of the assemblages has indicated the presence of a single palynological assemblage zone. Minor compositional differences do not warrant a zonal subdivision.The overall composition of the assemblages is characterized by the general dominance of Circulina and smooth trilete spores in combination with a large amount of relatively rarely occurring forms of spores, pollen grains and other acid-resistant microfossils.Because of the presence of rich and well-preserved material, it has been possible to detect a relatively wide range of variability within species of Tigrisporites, Foveosporites, Porcellispora and Crassosphaera.Among the forms which could not be matched with previously described taxa the new formgenus Skarbysporites is formally erected together with the new species Skarbysporites elsendoornii, Skarbysporites puntii, Foveosporites visscheri and Tigrisporites jonkeri. Moreover, an emended diagnosis of Circulina is proposed, implicating the assignment to this formgenus of most forms generally included in Classo pollis. Also the generic diagnosis of Tigrisporites is emended.An evaluation of the Liassic palynological assemblages from the outer-Alpine part of Europe with special reference to their potential in characterizing the ammonoid-based chronostratigraphical subdivisions may indicate that two temporal subdivisions of the Liassic Series on the basis of palynological characteristics are now slowly becoming discernable: an assemblage zone characterizing the Hettangian, Sinemurian and Lower Pliensbachian, and an assemblage zone characterizing the Upper Pliensbachian and Toarcian.Because of the possibility of a correlation with the latter zone, the assemblages from the Noriglio Grey Limestone Formation can be reasonably regarded to be indicative of a Late Pliensbachian—Toarchian age of the source-strata.When considering the ammonoid evidence from the overlying “Cape San Vigilio Oolite” it may be concluded that the upper part of the lower subdivision of the Noriglio Grey Limestone Formation and the Rotzo Member represent the Upper Pliensbachian—Lower Toarcian.Because of its potential in correlating non-ammonitiferous strata from the Southern Alps with the successions in northwestern Europe, it is believed that palynology may earn a prominent place in regional Liassic chronostratigraphy.     

Proposed validation of the specific namescrenatus Bruguière, 1789, andrenggeri Oppel, 1863 (Class Cephalopoda,Order Ammonoidea) from the Oxfordian stage of the upper jurassic

Ammonites crenata Bruguière (1789) is one of the oldest species names used in modern ammonite taxonomy. This is a nomen dubium that is probably a synonym of what modern authors callCreniceras renggeri (Oppel 1863), a common species of the early Oxfordian.Ammonites crenatus Bruguière in Oppel (1863) is a stratigraphically junior taxon of the middle Oxfordian. Nevertheless, there is a possibility, however improbable it may be, thatAmmonites crenata Bruguière andAmmonites crenatus Oppel are synonyms. Therefore it is proposed here to retain the current usage of the namescrenatus Bruguière emend. d’Orbigny (1847) andrenggeri Oppel.     

HLA gene and haplotype frequencies in Galicia (NW spain)

The purpose of this paper is to present the genetic distribution at the HLA-A, B and C loci in the Galician population (Spain). A random sample of 264 unrelated individuals from the autochtonous population were tested. The gene frequencies observed at the three loci are within the respective variability ranges found in European populations. The linkage disequilibrium value, D, was calculated using the phenotype frequencies at the A-B, A-C and B-C loci; the most frequent haplotype combinations were A1-B8 and A2-B44, A2-Cw7 and A1-Cw7, and B7-Cw7 and B35-Cw4, respectively.     

Orthogonikleithrus leichi n. gen., n. sp. (pisces: teleostei) from the late jurassic of Germany

Orthogonikleithrus leichi n. gen and n. sp. from the Late Jurassic of Zandt, W-Germany resemblesLeptolepides in the supra- and infraorbital sensory canals and in the length of the anterior process of the maxilla, andAscalabos in the massive aspect of the premaxilla. The caudal skeleton has some similarities with that ofLeptolepides (e. g. the broadening of the neural and haemal spines of the last caudal vertebrae, length of uroneurals 1 and 2), but also with that ofAnaethalion (in the neural arches above preural centrum 1 and ural centra). According to this combination of features, the fish remains as Elopocephala incertae sedis.     

A dinosaur ichnocoenosis from the middle jurassic of Yorkshire,UK

An assemblage of dinosaur tracks from the undersurface of a sandstone bed in the Saltwick Formation (Middle Jurassic) of Yorkshire shows a range of morphological types, preservational variants and behavioral styles. The tracks are combinations of transmitted prints and underprints and include three distinct trackways. One trackway was made by an animal walking on exposed damp sand, another was left by an animal swimming diagonally across a current and being swept down current, while the third may have been made by an animal either running or pushing off with its feet as it drifted down current. Environmental conditions that existed during the formation of the trackways varied between crevasse splay floods and exposed damp sand. The morphology of the swimming tracks is sufficiently distinctive to warrant the erection of a new ichnogenus and ichnospecies—Characichnos tridactylus. Previously described material from Kansas, Wyoming and New Mexico can be attributed to this new ichnogenus, while specimens from Germany and Utah are only provisionally referred to it. This indicates a known range from Triassic to Cretaceous.     

Bryozoan (Stenolaemata) records from the upper Callovian (Middle Jurassic) of the Moscow region

Encrusting bryozoans (Stenolaemata, Tubuliporida) discovered from upper Callovian deposits (Middle Jurassic) near the town of Kolomna in the Moscow region are described. They belong to two new species: Microeciella kolomnensis sp. nov. and Diplosolen akatjevense sp. nov. These bryozoans encrust a fragment of the large shell of cephalopod mollusk (ammonite), which is an unusual substrate not only for bryozoans but also for the other encrusting organisms.