Review of taxonomy,geographic distribution,and paleoenvironments of Azhdarchidae (Pterosauria)

The taxonomy, geographic distribution, and paleoenvironmental context of azhdarchid pterosaurs are reviewed. All purported pteranodontid, tapejarid, and azhdarchid specimens from the Cenomanian Kem Kem beds of Morocco are referred to a single azhdarchid taxon, Alanqa saharica. The four proposed autapomorphies of Eurazhdarcho langendorfensis from the lower Maastrichtian Sebeş Formation of Romania are based on misinterpretations of material and this taxon is likely a subjective junior synonym of Hatzegopteryx thambema. Among 54 currently reported azhdarchid occurrences (51 skeletal remains and 3 tracks) 13% are from lacustrine deposits, 17% from fluvial plain deposits, 17% from coastal plain deposits, 18% from estuarine and lagoonal deposits, and 35% from costal marine deposits. Azhdarchids likely inhabited a variety of environments, but were abundant near large lakes and rivers and most common in nearshore marine paleoenvironments.     

New remains of <Emphasis Type="Italic">Hungarosaurus tormai</Emphasis> (Ankylosauria,Dinosauria) from the Upper Cretaceous of Hungary: skeletal reconstruction and body mass estimation

Hungarosaurus tormai is a medium-sized nodosaurid ankylosaur that was described on the basis of four partial skeletons from the Santonian (Upper Cretaceous) of Hungary. In this paper, a new fifth skeleton and several isolated remains are described which greatly improve our knowledge of this primitive nodosaurid ankylosaur. Isolated cranial remains referred to juvenile individuals provide new information on the development of cranial ornamentation in nodosaurid ankylosaurs. Apart from both preserved mandibles with in situ dentition, the fifth partial skeleton contains several previously unknown limb elements (humerus, ulnae, radius) that indicate unusual limb proportions for Hungarosaurus compared with other ankylosaurs. On the basis of the five partial skeletons and the isolated remains, a skeletal and dermal armor reconstruction is attempted. Body mass calculations using three different methods yield an estimate of 650 kg for H. tormai.      

Ammoniten des Cenomans vom Südrand der westfälischen Kreide zwischen Unna und Möhnesee

Systematically collected ammonites from the different levels of the transgressive Cenomanian of the Haarstrang Mountains between Unna and Möhnesee (southern border of the westfalian Cretaceous, NW Germany) have been investigated. Twenty-one taxa (genera and species), partly previously unknown from this region, have been found and described. The fauna from the immediate transgression level is preserved as phosphoritic internal moulds (steinkerns). Fragmentary preservation and fossil condensation levels indicate reworking processes in these basal Cretaceous deposits. The age of the Cretaceous transgression in the area investigated can be precisely established as Lower Cenomanian (=carcitanensis subzone). The Cenomanian sequence, which is lithofacially very variable, can be, on the basis of the ammonite fauna, subdivided according to the modern Cretaceous stratigraphy for the boreal realm.     

Découverte d’une nouvelle faune d’âge cénomanien dans la région de Forthassa (Atlas saharien occidental,Algérie) : Implications biostratigraphiques et paléoenvironnementales

The upper Cretaceous of the eastern part of the Ksour Mountains (Western Saharan Atlas, Algeria) is classically subdivided into three fossiliferous lithostratigraphic formations: El Rhelida (lower Cenomanian), Mdaouer (lower-middle Cenomanian) and Rhoundjaïa (upper Cenomanian-lower Turonian). The western part of the Ksour Mountains, which is less documented and poorly known, is here the subject of a detailed sedimentological and palaeontological study. Near Hassi Djeifa locality (Forthassa) the upper Cretaceous is represented by the upper part of Mdaouer Formation and by the lowermost part of Rhoundjaïa Formation. The deposits attributed to the Mdaouer Formation are composed of reddish or green marlstone intercalated by biolaminated limestone, bioclastic limestone with gastropods and bivalves, and sandstone. The selachians (Mafdetia tibniensis, Baharipristis bastetiae), pycnodontiform fishes, and ostracod fauna (Damonella spp., Ilyocypris? sp., Cypridea sp., Paracypria? sp.) coming from marly beds are studied in detail. The two selachian species (Order of Rajiformes) were so far restricted to the Early Cenomanian of Egypt. Our sedimentological and palaeontological data support a probable Early Cenomanian age of the studied deposits and indicate a coastal plain palaeoenvironment continually influenced by the action of tide.     

记新疆准噶尔盆地中侏罗世—新甲龙

一小的甲龙,作为甲龙科(Ankylosauridae)中一新属新种,明星天池龙(Tianchisaurus nedegoapeferima gen. et sp. nov.)被记述。化石是1974年,新疆大学地质地理系的师生在新疆阜康县三工河地区作野外实习时采得,其产地的地层层位经新疆石油管理局东疆石油指挥部彭希龄核对为中侏罗世头顿河组。化石包括破的头骨碎片,五个颈椎,六个背椎,一个完整荐部(由七个椎体组成),三个尾椎,和许多膜质的甲胄,甲板,以及一些四肢骨。标本编号:V.10614,新属新种的特征是:一个小的,原始的,体长约三米的甲龙;头骨较高,有小的膜质的甲片复盖;下颚高,外侧无甲片复盖,有纵的饰纹,环椎与枢椎不愈合;颈椎椎体短,双凹型;背椎椎体较长,双平型,横突与背肋不愈合;荐部由七个愈合脊椎组成:前两个是背椎,形成一个荐前棒(presacral rod),最后的一个是尾椎,四个荐椎的椎体是整个椎柱中最大的,荐椎的神经棘愈合,形成一个纵的板状脊,远端的尾椎愈合形成小的,扁的尾锤。股骨直,骨干上有饰纹,第四转子呈嵴状。蹠骨和趾骨为甲龙型,与晚期甲龙的蹠骨和趾骨比较显得瘦小。在肩部有一个由四对大的膜质的甲板愈合形成肩甲带,甲板厚有发育的中嵴。在身体覆盖着许多大小不同,形状各异的甲片。Tianchisaurus nedegoapeferima的种名是应著名科幻电影导演Steven Splelberg之约请赠送给大型科幻电影片-侏罗纪公园之明星们:Sam Naill, Laura Dern, Jeff Goldblum, Richard Attenborough, Bob Peck和Martin Ferrsro.我们称之明星天池龙(Tianchisaurus nedegoapeferima gen. et sp. nov.)。Tianchisaurus nedegoapeferima是目前甲龙亚目在亚洲的最早纪录。它的发现将甲龙的化石记录推到中侏罗世。     

The Basal Nodosaurid Ankylosaur Europelta carbonensis n. gen., n. sp. from the Lower Cretaceous (Lower Albian) Escucha Formation of Northeastern Spain

Nodosaurids are poorly known from the Lower Cretaceous of Europe. Two associated ankylosaur skeletons excavated from the lower Albian carbonaceous member of the Escucha Formation near Ariño in northeastern Teruel, Spain reveal nearly all the diagnostic recognized character that define nodosaurid ankylosaurs. These new specimens comprise a new genus and species of nodosaurid ankylosaur and represent the single most complete taxon of ankylosaur from the Cretaceous of Europe. These two specimens were examined and compared to all other known ankylosaurs. Comparisons of these specimens document that Europelta carbonensis n. gen., n. sp. is a nodosaur and is the sister taxon to the Late Cretaceous nodosaurids Anoplosaurus, Hungarosaurus, and Struthiosaurus, defining a monophyletic clade of European nodosaurids– the Struthiosaurinae.     

Partial skeleton of Dracopelta zbyszewskii N. Gen. And N. SP., an ankylosaurian dinosaur from the Upper Jurassic of Portugal

The holotype of the nodosaurid ankylosaur Dracopelta zbyszewskii n. gen. and n. sp. is described from the Kimmeridgian(Upper Jurassic) of Ribomar on the west coast of Portugal. This is the first Upper Jurassic ankylosaur to be described that is represented by articulated bones. The specimen consists of a partial rib cage with thirteen dorsal vertebrae and five different types of dermal armor, two of wich show a partial overlap between adjacent plates.     

Carbonate facies evolution from the late albian to Middle Cenomanian in Southern Istria (Croatia): influence of synsedimentary tectonics and extensive organic carbonate production

Summary During the Late Albian, Early and Middle Cenomanian in the NW part of the Adriatic Carbonate Platform (presentday Istria) specific depositional systems characterised by frequent lateral and vertical facies variations were established within a formerly homogeneous area, ranging from peritidal and barrier bars to the offshore-transition zone. In southern Istria this period is represented by the following succession: thin-bedded peritidal peloidal and stromatolitic limestones (Upper Albian); well-bedded foreshore to shoreface packstones/grainstones with synsedimentary dliding and slumping (Vraconian-lowermost Cenomanian); shoreface to off-shore storm-generated limestones (Lower Cenomanian); massive off-shore to shoreface carbonate sand bodies (Lower Cenomanian); prograding rudist bioclastic subaqueous dunes (Lower to Middle Cenomanian); rudist biostromes (Lower to Middle Cenomanian), and high-energy rudist and ostreid coquina beds within skeletal wackestones/packstones (Middle Cenomanian). Rapid changes of depositional systems near the Albian/Cenomanian transition in Istria are mainly the result of synsedimentary tectonics and the establishment of extensive rudist colonies producing enormous quantities of bioclastic material rather than the influence of eustatic changes. Tectonism is evidenced by the occurrence of sliding scars, slumps, small-scale synsedimentary faults and conspicuous bathymetric changes in formerly corresponding environments. Consequently, during the Early Cenomanian in the region of southern Istria, a deepening of the sedimentary environments occurred towards the SE, resulting in the establishment of a carbonate ramp system. Deeper parts of the ramp were below fair-weather wave base (FWWB), while the shallower parts were characterised by high-energy environments with extensive rudist colonies, and high organic production leading to the progradation of bioclastic subaqueous dunes. This resulted in numerous shallowing- and coarsening-upwards clinostratified sequences completely infilling formerly deeper environments, and the final re-establishment of the shallow-water environments over the entire area during the Middle Cenomanian.     

Developmental reorganization of the skeletal framework and its surface lamina in fusing muscle cells

The skeletal framework of cells, composed of internal structural fibers, microtrabeculae, and the surface lamina, is revealed with great clarity after extraction with detergent. When muscle cells fuse to form a multinucleated myotube, their skeletal framework reorganizes extensively. When myoblasts prepare to fuse, the previously continuous surface lamina develops numerous lacunae unique to this stage. The retention of iodinated surface proteins suggests that the lacunae are not formed by the extraction of lamina proteins. The lacunae appear to correspond to extensive patches that do not bind concanavalin A and are probably regions of lipid bilayer devoid of glycoproteins. The lacunae appear to be related to fusion and disappear rapidly after the multinucleated myotube is formed. When muscle cells fuse, their internal structural networks must interconnect to form the framework of the myotube. Transmission electron microscopy of skeletal framework whole mounts shows that proliferating myoblasts have well developed and highly interconnected internal networks. Immediately before fusion, these networks are extensively reorganized and destabilized. After fusion, a stable, extensively cross-linked internal structure is reformed, but with a morphology characteristic of the myotube. Muscle cells therefore undergo extensive reorganization both on the surface and internally at the time of fusion.     

Cenomanian belemnites from the teutoburger Wald,NW Germany

A small fauna of belemnites collected recently from the Cenomanian deposits of the Teutoburger Wald, NW Germany, is described. It includes the belemnopseidNeohibolites ultimus (d’Orbigny) and the belemnitellidsBelemnocamax boweri Crick,Actinocamax primus Arkhangelsky, andA. plenus (Blainville). The Teutoburger Wald is thus one of the few regions in NW Europe, where these four species occur. The Cenomanian belemnite events, theultimus eustato-event, theprimus eco-event, andme plenus eustato-event, are discussed.     

Platform configuration, microfacies and cyclicities of the upper Albian to Turonian of west-central Jordan

We present a comprehensive facies scheme for west-central Jordan platform deposits of upper Albian to Turonian age, discuss Cenomanian and Turonian carbonate cycles, and reconstruct the paleogeographic evolution of the platform. Comparisons with adjacent shelf areas (Israel, Sinai) emphasize local characteristics as well as the regional platform development. Platform deposits are subdivided into fifteen microfacies types that define eight environments of deposition of three facies belts. Main facies differences between Cenomanian and Turonian platforms are: rudist-bearing packstones that characterise the higher-energy shallow subtidal (transition zone) during the Cenomanian, and fossiliferous (commonly with diverse foraminifer assemblages) wackestones and packstones of an open shallow subtidal environment. On Turonian platforms high-energy environments are predominantly characterised by oolithic or bioclastic grainstones and packstones, whereas peritidal facies are indicated by dolomitic wackestones with thin, wavy (cryptmicrobial) lamination. Rhythmic facies changes define peritidal or subtidal shallowing-up carbonate cycles in several Cenomanian and Turonian platform intervals. Cyclicities are also analysed on the base of accommodation plots (Fischer Plots). High-frequency accommodation changes within lower Cenomanian cyclic bedded limestones of the central and southern area exhibit two major cyclic sets (set I and II) each containing regionally comparable peaks. Accommodation patterns within cyclic set II coincide with the sequence boundary zone of CeJo1. The lateral and vertical facies distributions on the inner shelf allow the reconstruction of paleogeographic conditions during five time intervals (Interval A to E). An increased subsidence is assumed for the central study area, locally (area of Wadi Al Karak) persisting from middle Cenomanian to middle Turonian times. In contrast, inversion and the development of a paleo-high have been postulated for an adjacent area (Wadi Mujib) during late Cenomanian to early Turonian times, while small-scale sub-basins with an occasionally dysoxic facies developed northwards and further south during this time interval. A connection between these structural elements in Jordan with basins and uplift areas in Egypt and Israel during equivalent time intervals is assumed. This emphasises the mostly concordant development of that Levant Platform segment.     

Dinocyst biostratigraphy of the Upper Cretaceous of northern Siberia

A stratigraphic chart is developed of the Upper Cretaceous deposits of northern Siberia based on dinocysts. It covers the period from the Upper Cenomanian to the Maastrichtian, including 15 biostratigraphic units (beds with characteristic assemblages or local zones), and is correlated with the inoceram zonation.     

Dinosaur Tracks from the Cedar Mountain Formation (Lower Cretaceous), Arches National Park,Utah

The seventh and largest known dinosaur tracksite from the Cedar Mountain Formation is reported from two important stratigraphic levels in the Ruby Ranch Member within the boundaries of Arches National Park. Previous reports of sites with a few isolated tracks are of limited utility in indicating the fauna represented by track makers. The Arches site reveals evidence of several theropod morphotypes, including a possible match for the coelurosaur Nedcolbertia and an apparently didactyl Utahraptor-like dromeosaurid. Sauropod tracks indicate a wide-gauge morphotype (cf. Brontopodus). Ornithischian tracks suggest the presence of an iguandontid-like ornithopod and a large ankylosaur. Dinosaur track diversity is high in comparison with other early Cretaceous vertebrate ichnofaunas, and it correlates well with faunal lists derived from skeletal remains, thus providing a convincing census of the known fauna.     

Hyaluronan is essential for the expansion of the cranial base growth plates

Exquisite control of chondrocyte function in the zone of hypertrophy results in expansive growth of cartilaginous growth plates, and is a prerequisite for normal skeletal lengthening. We hypothesize that hyaluronan-mediated hydrostatic pressure causes lacunae expansion in the zone of hypertrophy; an important mechanism in cartilaginous growth plate and associated skeletal expansion. The role of hyaluronan and CD44 in this mechanism was studied using organ culture of the bipolar cranial base synchondroses. Hyaluronan was present in the hypertrophic zones, pericellular to the hypertrophic chondrocytes, while no hyaluronan was detected in the resting, proliferating and maturing zones. This localization of hyaluronan was associated with increased lacunae size, suggesting that chondrocytes deposit and retain pericellular hyaluronan as they mature. In comparison, Toluidine Blue staining was associated with the territorial matrix. Hyaluronidase, the hyaluronan-degrading enzyme, and CD44, the receptor for hyaluronan which also participates in the uptake and degradation of hyaluronan, were co-localized within the zone of ossification. This pattern of expression suggests that cells in the early zone of ossification internalize and degrade hyaluronan through a CD44-mediated mechanism. Treatment of the cultured segments with either Streptomyces hyaluronidase or hyaluronan hexasaccharides inhibited lacunae expansion. These observations demonstrate that hyaluronan-mediated mechanisms play an important role in controlling normal skeletal lengthening.     

A new pachyostotic squamate reptile from the Cenomanian of France

Cenomanian beds from western France have yielded a new pythonomorph squamate (Reptilia) that is described here as Carentonosaurus mineaui gen. et sp. nov. This fossil is referred to non-mosasaurid mosasauroid lizards, i.e. to 'aigialosaurs'. It has been found in sediments of marine origin and its anatomy confirms that it was an aquatic lizard. It is characterized by a combination of characters that has not been reported, thus far, for squamates. Moreover, its vertebral column includes non-pachyostotic cervical vertebrae and highly pachyostotic dorsal vertebrae as in several other 'aigialosaurs'. This new taxon is perhaps restricted to the upper Cenomanian. It lived in shallow and rather warm water of the inner shelf. It is worth mentioning that nearly all pachyostotic squamates are concentrated in the Cenomanian and/or lower Turonian deposits of the present European-North African-Middle East portion of the Tethys. A parallel is drawn between the high percentage of pachyostotic squamates and the fact that this period corresponds to both the largest transgression of the Phanerozoic and the warmest period in the whole of the Mesozoic and Caenozoic.     

A new species of Lapparentophis from the mid-Cretaceous Kem Kem beds,Morocco, with remarks on the distribution of lapparentophiid snakes

Two isolated trunk vertebrae from the ?uppermost Albian–lower Cenomanian Kem Kem beds of Morocco are described and assigned to Lapparentophis, an early snake genus known from coeval deposits in Algeria. The Moroccan specimens represent a new species, Lapparentophis ragei, which can be distinguished from the type and only known species, Lapparentophis defrennei, by its smaller size, its more elongate vertebrae, the presence of parazygosphenal foramina, and paradiapophyses extending anteroventrally closer to the cotyle. The discovery of Lapparentophis in the Kem Kem beds adds to the relatively diverse snake assemblage previously reported from this formation and extends the geographical range of the genus. The distribution of Lapparentophis and lapparentophiid-grade (?lapparentophiid) snakes is discussed. This poorly known family of terrestrial snakes seems to be restricted to the latest Albian–early Cenomanian of North Africa, with the exception of Pouitella from the early–middle Cenomanian of France. As for many other vertebrate taxa of this period, this distribution is consistent with a dispersal event from Africa to the western part of the European archipelago.     

Late Cretaceous sedimentary evolution of a northern sector of the Adriatic Carbonate Platform (Matarsko Podolje,SW Slovenia)

Cretaceous shallow-marine carbonate rocks of SW Slovenia were deposited in the northern part of the Adriatic Carbonate Platform. A 560-m-thick continuous Upper Cenomanian to Santonian carbonate succession has been studied near Hru?ica Village in Matarsko Podolje. With regard to lithological, sedimentological, and stratigraphical characteristics, the succession has been divided into nine lithostratigraphic units, mainly reflecting regressive and transgressive intervals of larger scale. During the latest Cenomanian and Early Turonian, hemipelagic limestones were deposited on top of shallow-marine lagoon and peritidal Upper Cenomanian deposits indicating relative sea-level rise. Subsequently, the deeper marine depositional setting was gradually filled by clinoform bioclastic sand bodies overlain by peritidal and shallow-marine low-energy mainly lagoonal lithofacies. Similar lithofacies of predominately inner ramp/shelf depositional settings prevail over the upper part (i.e., Coniacian to Santonian) of the succession. In the area, the Upper Cetaceous carbonate rocks are separated from the overlying Lower Eocene (Upper Paleocene?) carbonate sequence by regional unconformity denoted by distinct paleokarstic features. On the Adriatic Carbonate Platform the deeper marine carbonate setting, developed at the Cenomanian/Turonian boundary, is usually correlated with OAE2 and related eustatic sea-level rise. Similarly, subsequent reestablished shallow-marine conditions are related to Late Turonian long- and short-term sea-level fall. However, we are suggesting that deeper marine deposits were deposited in a tectonically induced intraplatform basin formed simultaneously with the uplift of the northern and northeastern marginal parts of the Adriatic Carbonate Platform.     

A scanning electron-microscopic study of femoral bone surfaces from castrate rats treated with dichloromethylene biphosphonate

This study compared SEM appearances of endosteal and periosteal surfaces of anorganic femoral diaphyses from three groups of adult male rats: (1) control; (2) castrate (osteoporotic), and (3) castrate + injections of dichloromethylene biphosphonate (Cl2 entrances; (2) area of vascular canal entrances; (3) number of osteoblast lacunae, and (4) percent area of bone surface types. Endosteal surfaces from untreated osteoporotic rats had significantly more osteoblast lacunae, larger vascular canal entrances, and less resting surface than those of the other groups. There were no differences in endosteal surfaces between controls and Cl2MBP-treated castrates. Periosteal surfaces demonstrated no significant differences in percent area of bone surface types between groups, untreated castrates had more osteoblast lacunae than other groups, and vascular canal entrances were smaller in castrate groups than in controls. Castrates treated with Cl2MBP had significantly fewer periosteal vascular canal entrances, and many canal entrances and osteoblast lacunae appeared to be plugged with mineral deposits when compared with the other groups. The results indicate that Cl2MBP treatment prevented endosteal bone surface changes that occurred with castration osteoporosis, and may have disrupted normal vascularization on periosteal surfaces.     

Ankylosaur Remains from the Early Cretaceous (Valanginian) of Northwestern Germany

A fragmentary cervico-pectoral lateral spine and partial humerus of an ankylosaur from the Early Cretaceous (early Valanginian) of Gronau in Westfalen, northwestern Germany, are described. The spine shows closest morphological similarities to the characteristic cervical and pectoral spines of Hylaeosaurus armatus from the late Valanginian of England. An extensive comparison of distal humeri among thyreophoran dinosaurs supports systematic differences in the morphology of the distal condyli between Ankylosauria and Stegosauria and a referral of the Gronau specimen to the former. The humerus fragment indicates a rather small individual, probably in the size range of H. armatus, and both specimens are determined herein as ?Hylaeosaurus sp.. A short overview of other purported ankylosaur material from the Berriasian-Valanginian of northwest Germany shows that, aside from the material described herein, only tracks can be attributed to this clade with confidence at present.