Diversity of Middle Jurassic Turtles from the Berezovsk Quarry Locality,Krasnoyarsk Region,Russia: Morphology and Histological Study

Abstract—Morphology and histology of several fragmentary turtle specimens from the Middle Jurassic locality in the Berezovsk quarry (Krasnoyarsk Region, Russia) are described, including Testudines indet. 1 (costal VIII), Testudines indet. 2 (two ornamented shell fragments), and Testudines indet. 3 (distal part of a humerus), and also skeletal elements of Annemys sp. (Xinjiangchelyidae) represented by mass material in the same locality. It is shown that Testudines indet. 1 and 3 probably belong to one or two taxa of basal aquatic turtles, while Testudines indet. 2 is most likely an abnormal Annemys sp. The presumable presence of basal turtles in the Berezovsk Quarry Assemblage agrees with the fact that they are present in other Middle Jurassic turtle assemblages of Asia.     

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.     

The skull of Cteniogenys, a choristodere (Reptilia: Archosauromorpha) from the Middle Jurassic of Oxfordshire

The genus Ctemogenys was originally described as a lizard on the basis of isolated jaw fragments from the Upper Jurassic deposits of Como Bluff, Wyoming. The discovery of new material from a Middle Jurassic locality at Kirtlington, Oxfordshire, showed that Cteniogenys was not a lizard, but an early choristodere. The skull is represented by a collection of isolated bones, associated on the basis of fit and dermal sculpture pattern. The bones are here described and compared with those of the Late Cretaceous and Palaeocene choristoderes Champsosaurus and Simoedosaurus. Allowing for the much smaller size of the Middle Jurassic form, there is a close correspondence between the isolated bones of the three genera. Comparison with known choristoderes, based on an analysis of 53 derived character states, suggests that Ctemogenys is the most primitive of known genera. In general, the character states shared by all choristoderes support recent analyses which conclude that choristoderes arc derived from archosauromorph diapsids, not lepidosauromorphs as once thought. At Kirtlington, Cteniogenys forms part of a diverse microvertebrate assemblage including amiids, sharks, frogs, salamanders, lizards, mammals, crocodiles, pterosaurs, turtles and small dinosaurs.     

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.     

Histological study of karaurids,the oldest known (stem) urodeles

Little is known about the initial phases of lissamphibian history (before the Cretaceous), because their fossil record is quite scanty. Only the morphology of the earliest members has been investigated, although other sets of data, from bone microanatomy and histology, are known to yield valuable paleobiological information. In the present study, we provide the first histological and microanatomical data on the oldest known stem-urodeles, the karaurids, from the Middle Jurassic. Three humeri from the Upper Bathonian, Oxfordshire, referred to juvenile or subadult individuals of Marmorerpeton and to an unnamed caudate of undetermined (but obviously non-larval) ontogenetic stage, were sampled in order to shed new light on the habitat and ontogeny of these basal caudates. The great compactness of the three humeri suggests that these salamanders were aquatic. The presence of extensive amounts of calcified cartilage in the humeri greatly strengthens the case for the presence of neoteny in these taxa, a suggestion that had initially been made on the basis of a few morphological characters. This constitutes the oldest known occurrence of neoteny in lissamphibians. Finally, bone histology reveals that the growth of Marmorerpeton and the related unnamed caudate was fairly slow and cyclic, a characteristic of extant lissamphibians.     

Pterosaur and dinosaur remains from the Middle Jurassic Balabansai Svita in the northern Fergana Depression, Kyrgyzstan (Central Asia)

Abstract: Isolated pterosaur and dinosaur teeth and a sauropod metatarsal I and manual phalanx V-1 from the Middle Jurassic (Callovian) Balabansai Svita in the northern Fergana Valley, Kyrgyzstan, are described and attributed to the pterosaur taxon Rhamphorhynchinae indet., a theropod Tetanurae indet., a sauropod Neosauropoda indet., and a new pachycephalosaurid Ferganocephale adenticulatum gen. et sp. nov. The Balabansai theropod is possibly a stem-lineage representative of Dromaeosauridae. The new pachycephalosaurid is the oldest representative of the group and extends its known history by 10–20 myr. The Balabansai vertebrate assemblage is most similar to the Callovian assemblages from the Qigu and Upper Shaximiao formations in China, and intermediate in the evolutionary level of the taxa present between the Bathonian assemblages from Wucaiwan and the Lower Shaximiao formations (China) and the Late Jurassic Shar Teg fauna from Mongolia.     

A Late Jurassic salamander (Amphibia: Caudata) from the Morrison Formation of North America

Despite some remarkable recent discoveries, the Mesozoic fossil record of salamanders remains limited, particularly for the Jurassic. Here we describe the first articulated salamander skeleton from the Jurassic of Euramerica, recovered from Upper Jurassic deposits of the Morrison Formation, Dinosaur National Monument, USA. The specimen was studied using both conventional methods and high-resolution computed tomography. It shows a combination of primitive and derived character states that distinguish it from all known Mesozoic salamanders and which permit the erection of a new genus and species, Iridotriton hechti . The derived states (including the presence of spinal nerve foramina in the tail) suggest a position on the stem of the Salamandroidea. Together with microvertebrate material from Britain, Portugal, and North America, this specimen confirms the presence of both stem- and crown-group salamanders in Euramerica from the Middle Jurassic (Bathonian) onwards, paralleling their evolution in Central and eastern Asia. This, in turn, provides qualified support for the current vicariance model of salamander evolution whereby basal caudates on an undivided Laurasian plate became separated into two populations by the incursion of the Turgai Sea in the Middle Jurassic, yielding Cryptobranchoidea in Asia and Salamandroidea in Euramerica.  © 2005 The Linnean Society of London , Zoological Journal of the Linnean Society , 2005, 143 , 599−616.     

A Middle Jurassic dinosaur trackway site from Oxfordshire, UK

The Middle Jurassic (Bathonian) Ardley trackway site in Oxfordshire, UK is described in detail. The track site is extensive, containing over 40 more-or-less continuous theropod and sauropod trackways preserved together on a single bedding plane with some trackways up to 180 m in length. The trackways display reasonable preservation, with claw marks discernible. Sauropod trackways are by far the most abundant and are representative of taxa that exhibit both narrow and wide-gauge styles of locomotion. Theropod trackways are represented by large tridactyl prints and claw impressions that display exceptionally low pace angulation values during their walking phase. One theropod trackway is unique in that it reveals a gait transition associated with a temporary increase of speed. These dinosaurs were walking over a lime-mud firmground to hardground that was emergent, or locally very shallowly submerged. GPS (Global Positioning Satellite) data reveal that the tracks, preserved during a short time interval, trend in a north-easterly direction. Multi-herding behaviour is suggested for the sauropods of differing size. The discovery of this site adds significantly to our knowledge of the taxonomic composition of Middle Jurassic ecosystems. Evidence concerning locomotor styles employed by saurischian dinosaurs, footprint identification, potential trackmaker, social interactions and observations concerning estimates of Middle Jurassic faunal diversity, as well as aspects of dinosaur locomotor evolution are discussed.     

A revision of the sauropod dinosaur genus ‘Bothriospondylus’ with a redescription of the type material of the Middle Jurassic form ‘B. madagascariensis’

Abstract: The sauropod dinosaur ‘Bothriospondylus’, originally named on the basis of Late Jurassic remains from England, is demonstrated to be invalid, and the characters used to diagnose it are shown to be obsolescent features which are widespread throughout Sauropoda. Material referred to this genus spans a temporal range from the Middle Jurassic until the early Late Cretaceous and has been described from five different countries, across three continents. These remains represent a wide array of sauropod groups, comprising non‐neosauropod eusauropods, a macronarian, titanosauriforms (including at least one definite brachiosaurid) and a rebbachisaurid. The type material of the Middle Jurassic ‘B. madagascariensis’ represents a derived non‐neosauropod eusauropod and possesses two potential autapomorphies. However, as a result of the fragmentary nature of the material and the uncertainty surrounding its association, a new taxon is not erected. Of the numerous specimens referred to ‘Bothriospondylus’, however, several remains are considered diagnostic: Ornithopsis hulkei (Early Cretaceous, UK), Lapparentosaurus madagascariensis (Middle Jurassic, Madagascar) and Nopcsaspondylus alarconensis (early Late Cretaceous, Argentina). At least three types of sauropod were present in the Bathonian (Middle Jurassic) of north‐west Madagascar, with a basal eusauropod (Archaeodontosaurus), a more derived eusauropod (‘B. madagascariensis’) and a titanosauriform (Lapparentosaurus) all approximately contemporaneous. Palaeocontinental reconstructions suggest that Middle Jurassic Madagascan sauropods would still have been capable of global biotic interchange, and this is perhaps reflected in their diverse assemblage. Re‐evaluation of these Malagasy forms has shed new light on this important time period in sauropod evolution.     

A NEW SEMIONOTIFORM (ACTINOPTERYGII, NEOPTERYGII) FROM UPPER JURASSIC – LOWER CRETACEOUS DEPOSITS OF NORTH-EAST THAILAND, WITH COMMENTS ON THE RELATIONSHIPS OF SEMIONOTIFORMS

Abstract:  A new semionotiform fish, Isanichthys palustris gen. et sp. nov., is described from the Late Jurassic – Early Cretaceous Phu Kradung Formation, north-east Thailand. I. palustris is known from a single, nearly complete specimen found alongside abundant Lepidotes specimens at the Phu Nam Jun locality. I. palustris shows a mixture of semionotid-like characters, such as the pattern of cheek ossifications, and lepisosteid-like characters, such as the body shape and a dorsal fin opposed by an anal fin. I. palustris possesses only some of the characters currently used to define the Semionotidae. Cladistic analyses including various semionotid and gar taxa, together with Amia calva and Leptolepis coryphaenoides , suggest that the Semionotiformes (Lepisosteidae and 'Semionotidae') form a monophyletic clade, but the 'Semionotidae' taxa form an unresolved polytomy. The relationships between Semionotiformes, Halecomorphi and Teleostei are unresolved. When restricted to the best-known taxa, however, the analysis shows the monophyly of the Semionotidae sensu stricto ( Semionotus + Lepidotes ) and a sister-group relationship between halecomorphs and teleosts. These last two results are regarded as the preferred hypothesis for further studies. I. palustris is the only known example of a predaceous, probably piscivorous, 'semionotid'. It illustrates the great diversity and ecological adaptation of the semionotiforms during the Late Jurassic – Early Cretaceous. We question the phylogenetic relationships of 'ancient fishes' founded on molecular-based trees because we suspect that the use of very few Recent taxa as representatives of previously diverse lineages is an inevitable, but important, bias in the construction of such trees.     

On the earliest known occurrence of the Middle Jurassic ammonite genusReineckeia in the Upper Bathonian of Jumara,Kachchh, western India

Two specimens of the Middle Jurassic ammonite genusReineckeia (sensu lato) have been found in the lowest beds of the Pachchham (Patcham) Limestones exposed in the core of the Jumara Dome, Kachchh (Kutch), Gujarat, western India. The stratigraphy is described in detail and the age bracketed to lie between latest Late Bathonian and Middle Bathonian, older than any previously described examples of this genus, either in India or in Europe (middle Early Callovian). The new finds are compared with other known pre-Callovian Reineckeiidae, notably those of the eastern borders of the Pacific, but the relationships are not close. The phylogenetic consequences are briefly discussed. The roots of the Reineckeiidae continue to lie hidden.     

A new lizard-like reptile (Diapsida: Lepidosauromorpha) from the Middle Jurassic of England

The Middle Jurassic (Late Bathonian) Mammal Bed at Kirtlington, Oxfordshire, has yielded a rich assemblage of small vertebrates including mammals, frogs, salamanders and small reptiles. This paper describes the skull of a new diapsid reptile, Marmorelta oxoniensis, which was common within the fauna. The skull is gracile with large orbits and relatively long external nares. The frontals and parietals are single in the adult and almost separated on the roof of the skull by the postfrontals. The temporal region shows a mosaic of primitive and derived character states. The quadrate was firmly held to the skull by a large squamosal and a small, free, quadratojugal was retained. However, reduction of the anterior process of the quadratojugal and of the posterior process of the jugal left the lower temporal fenestra broadly open. Comparison with other diapsids leads to the conclusion that Marmoretta was a lepidosauromorph, most probably the sister taxon of Lepidosauria.     

内蒙古道虎沟中侏罗世原褶蚊科化石记述(昆虫纲,双翅目,原褶蚊科)

描述原褶蚊科Eoptychopteridae Handlirsch,1906化石3新种,华美刻痕原褶蚊Crenoptychoptera decorosa sp.nov.,普通刻痕原褶蚊Crenoptychoptera vulgaris sp.nov.,近刻痕原褶蚊Crenoptychoptera vicina sp.nov..所有标本均采自内蒙古宁城道虎沟中侏罗世九龙山组,模式标本保存在首都师范大学生命科学学院.     

Rapid transformation in the braincase of sauropod dinosaurs: integrated evolution of the braincase and neck in early sauropods?

Sauropod dinosaurs were quadrupedal herbivores with a highly specialized body plan that attained the largest masses of any terrestrial vertebrates. Recent discoveries have shown that key traits associated with sauropod gigantism appeared stepwise during the Late Triassic and Early Jurassic in evolutionary ‘cascades’ of associated changes, in which a ‘head and neck’ cascade has been suggested as an important module. Here, we investigate the evolutionary transformation of the sauropodomorph braincase, using discrete anatomical characters, prompted by the reanalysis of a Middle Jurassic (Bathonian) sauropodiform braincase from England. Our analysis shows that sauropod braincases are highly distinct, and occupy a different region of morphospace than their evolutionary relatives. This resulted from anatomical transformations including a set of changes in the surface attachments of craniocervical musculature, which may indicate integrated evolution between neck elongation and transformation in braincase anatomy. Neck elongation in Late Triassic and Early or Middle Jurassic taxa is potentially associated with episodes of skull reduction, indicating that the ‘head and neck’ cascade was activated more than once in the evolutionary history of Sauropodomorpha. The re‐activation of this cascade in the Jurassic may have impacted on the differential survival of sauropodomorph lineages through the Early and Middle Jurassic.     

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.     

Middle Jurassic vegetation dynamics based on quantitative analysis of spore/pollen assemblages from the Ravenscar Group,North Yorkshire,UK

Quantitative analysis of the distribution of dispersed spores and pollen (sporomorphs) has been used to assess temporal floral variation through the Middle Jurassic Ravenscar Group (Aalenian–Bathonian), North Yorkshire, UK. Aalenian, Bajocian and Bathonian strata possess relatively distinct sporomorph and palynofacies assemblages, which potentially reflect a dynamic history regarding the nature of parent vegetation. Specifically, Aalenian palynofloras are composed of a heterogeneous mixture of conifers, ferns, simple monosulcate pollen producers, sphenophytes and Caytoniales; Bajocian palynofloras are codominated by conifers and ferns; and Bathonian palynofloras are highly rich and contain assemblages of abundant ferns, conifers, lycophytes, pteridosperms/conifers and Caytoniales. Individual‐ and sample‐based rarefaction demonstrates that Bathonian samples are richer than Aalenian and Bajocian samples. Temporal variations in assemblages are a result of long‐term depositional and possible climatic fluctuations through the Middle Jurassic. Ordinations of sporomorph data using non‐metric multidimensional scaling (NMDS) demonstrate that short‐term variations between samples are largely governed by taphonomic biases as a result of slight changes in depositional processes, which give rise to highly variable catchment areas that supply deposits with sporomorphs. Long‐term compositional changes are apparent in sporomorph assemblages regardless of lithology/local depositional environments, suggesting that long‐term variations are more substantial than short‐term variations and potentially include genuine regional temporal changes in parent vegetation. Relating sporomorph assemblages with their respective depositional environments and relative catchment area sizes using lithological and palynofacies information suggests that the basin interior was occupied by mostly low‐standing species and extrabasinal vegetation was dominated by coniferous taxa. Comparisons of the dispersed sporomorph and plant megafossil records indicate that both fossil assemblages reflect different aspects of the palaeoflora due to a multitude of taphonomic and ecological biases. Such biases include variation in sporomorph production levels, depositional environment and differential sporomorph and parent plant durability.     

First evidence of the Jurassic thalattosuchian (both teleosaurid and metriorhynchid) crocodylomorphs from Slovakia (Western Carpathians)

Abstract

We report here finds of thalattosuchians from Western Carpathians. The material consists of two isolated teeth from two different localities of the Pieniny Klippen Belt. The material represents the first evidence of the occurrence of both clades Teleosauridae and Metriorhynchidae in Slovakia. The first, a small tooth comes from the locality Beňatina and is dated early Middle Jurassic (Aalenian). Identification of the specimen shows it belongs to a longirostrine teleosaurid, possibly to Steneosaurus. Teleosaurids were largely restricted to lagoonal/near-shore environments. Their limbs allow them to support and walk on land. Regarding that fact, the presence of this taxon in Beňatina might be an indication of terrestrial land in the nearby area and shows a location of epicontinental seaways. A second larger tooth was found in the Upper Jurassic (Tithonian) sediments of the locality Kyjov, and is tentatively allocated in the genus Plesiosuchus. The members of Plesiosuchina are known in England, France, Portugal and Sicily. Our findings indicate a much wider spatial distribution of this clade in Europe and it fits well with the previous interpretation of sediments of the locality Kyjov as deep-water pelagic deposits.     

First multi-proxy record of Jurassic wildfires from Gondwana: Evidence from the Middle Jurassic of the Neuquén Basin,Argentina

Wildfires play a crucial role in recent and ancient ecosystem modeling but their detailed history on the Earth is still not well recorded or understood. The co-occurrence of charcoal and pyrolytic polycyclic aromatic hydrocarbons (PAHs) is used for the recognition of wildfires in geological record that may have implications for the analysis of the terrestrial environment, ecosystems, climate and the level of atmospheric oxygen. Here we present the first multi-proxy evidence of wildfires on the Gondwana continent during the Jurassic, based on the occurrence of charcoal and pyrolytic PAHs in the Middle Jurassic of the Neuquén Basin, Argentina. This is the first evidence of wildfire in the Aalenian, the lowest stage of the Middle Jurassic, and one of the few records of wildfires in the Bathonian. Temperature interpretations, derived from charcoal reflectance data, show that charcoals formed in low temperature surface fires that only sporadically reached the higher temperatures, possibly related to crown fires. The occurrence of charcoals in the Middle Jurassic deposits confirms recent results that the atmospheric oxygen level reached at least 15% during the Middle Jurassic times.     

Type localities of the Gibbon,Hylobates pileatus gray, 1861, and the leaf monkey,Presbytis crepuscula wroughtoni Elliot, 1909, collected by A. H. Mouhot

The type specimens of two nominal primate taxa were collected by A. H Mouhot during his historic expedition to Indochina from 1858 to 1861. His death from fever in Laos led to the material being accompanied by unreliable locality data. Combining information from his published itinerary with evidence from more recently collected specimens, I attempt to determine the type localities more accurately.