Sauropod diversity in the Late Cretaceous of southwestern Europe: The lessons of odontology

Recent discoveries in southern France and northern Spain suggest that the morphology of titanosaurian teeth shows much greater variations that previously thought. It is suggested that the different morphotypes are informative at specific or generic level and that titanosaurian genera may indeed be recognized by their isolated teeth. It is also confirmed that juvenile titanosaurian teeth have a rather uniform, cylindrical morphology. Four different morphotypes are described for the Ibero-Armorican Island in the Late Cretaceous.     

Maastrichtian Sauropod footprints from the Fumanya site,Berguedà, Spain

A sauropod tracksite near Fumanya (Berguedà, Catalunya, Spain) was mapped in detail in 1996. Discovered by Viladrich (1986), this is the only known Maastrichtian sauropod tracksite in Europe. The tracks have been strongly affected by strain and erosion. The wide‐gauged, four‐clawed pes trackways are attributed to titanosaurs. Although most trackways indicate single individuals, a few trackways involved multiple individuals, suggesting social behavior.     

Extramorphological Features of Sauropod Dinosaur Tracks in the Uhangri Formation (Cretaceous), Korea

Sauropod footprints in the Uhangri Formation (Cretaceous) of Korea exhibit an unusual pattern of morphology, with the interior of each print partitioned into a series of pockets by conspicuous radial crests. The crests are evidently extramorphological features and have been interpreted as upwellings of sediment extruded through the floor of the footprint following its fracture by impact of the trackmaker's foot. That explanation entails some inconsistencies, and an alternative explanation is proposed here. The alternative explanation envisages delamination of a superficial sheet of sediment that was lifted into a canopy, which subsequently collapsed in radiating folds. The superficial sheet of sediment might have been lifted by either or both of two mechanisms—by adhering to the underside of the trackmaker's foot or by being forced upward into a blister-like dome by the backflow of water previously displaced by impact of the trackmaker's foot. These alternative explanations draw attention to minor morphological features that were previously unexplained.     

Basal titanosauriform (Dinosauria, Sauropoda) teeth from the Lower Cretaceous Yixian Formation of Liaoning Province, China

The Yixian Formation of Liaoning Province, People's Republic of China has yielded a diverse fauna of non-avian dinosaurs, but is dominated by small-bodied taxa. Here, we describe a series of isolated teeth from the Lujiatun Beds of the formation that are referable to a basal titanosauriform sauropod. Some of the teeth possess a distinctive circular boss on the lingual surface, which suggests that they are referable to cf. Euhelopus sp. This identification provides some additional support for biostratigraphical correlations between the Jehol Group and the Mengyin Formation of Shandong Province that suggest an Early Cretaceous age for the latter unit. Moreover, the titanosauriform affinities of the teeth provide further evidence for the dominance of this sauropod clade in eastern Asia during the Cretaceous.     

An associated partial skeleton of Jainosaurus cf. septentrionalis (Dinosauria: Sauropoda) from the Late Cretaceous of Chhota Simla,Central India

Abstract: The Cretaceous dinosaur fauna of Indo‐Pakistan has remained poorly understood because of a lack of associated and articulated remains, proliferation of named species, and an incomplete understanding of the dinosaur clades present (e.g. abelisaurid theropods; titanosaur sauropods). Continued work on existing collections, and new discoveries of dinosaur material from India, Pakistan and elsewhere in Gondwana, has begun to resolve the composition and affinities of Indo‐Pakistani dinosaurs. Here, we provide archival evidence that documents associations between postcranial remains of a sauropod collected from Chhota Simla, India by C. A. Matley in the 1930s and later described as ‘Titanosaurus sp.’ This partial skeleton, which represents only the fifth such documented association from Indo‐Pakistan, is referable to Jainosaurus cf. septentrionalis and provides a fuller understanding of its anatomy and phylogenetic affinities.     

A new basal hadrosauroid dinosaur from the Late Cretaceous of Uzbekistan and the early radiation of duck-billed dinosaurs

Levnesovia transoxiana gen. et sp. nov., from the Late Cretaceous (Middle–Late Turonian) of Uzbekistan, is the oldest well-documented taxon referable to Hadrosauroidea sensu Godefroit et al. It differs from a somewhat younger and closely related Bactrosaurus from Inner Mongolia (China) by a tall sagittal crest on the parietals and the absence of club-shaped dorsal neural spines in adult specimens. Levnesovia, Bactrosaurus and possibly Gilmoreosaurus represent the earliest radiation of Hadrosauroidea, which took place during the Cenomanian–Turonian and possibly in North America. The second, Santonian-age radiation of Hadrosauroidea included Aralosaurus, Hadrosauridae and lineages leading to Tanius (Campanian) and Telmatosaurus (Maastrichtian). Hadrosauridae appears to be monophyletic, but Hadrosaurinae and Lambeosaurinae originated in North America and Asia, respectively.     

Reassessing the endemic European Upper Cretaceous dinosaur egg Cairanoolithus

The fossil record of dinosaur eggs and eggshells from the uppermost Cretaceous strata of south-western Europe is composed of both worldwide-distributed and endemic egg types. In this study, we are reviewing the enigmatic European oogenus Cairanoolithus, which after analysing abundant material from classic and new localities it is reassigned to a new oofamily (Cairanoolithidae oofam. nov.) in the light of the unique combination of structural characters. The new oofamily includes one oogenus and two oospecies. Cairanoolithid eggs share several features with other ornithopod egg types indeed. Furthermore, our phylogenetic analysis places Cairanoolithus as the sister ootaxon of the ornithopod ootaxa, being considered the most basal ornithischian egg type known so far. Although neither embryonic nor bones remains are known in association with cairanoolithid eggs so far, several taxonomic attributions have been proposed for this egg type over time. On the basis of microstructural features, phylogenetic results and anatomical constrains, we discuss in this paper previous taxonomic attributions and provide new evidence for suggesting a plausible nodosaurid affinity.     

The first diplodocid from Asia and its implications for the evolutionary history of sauropod dinosaurs

Abstract: An isolated anterior caudal vertebra from the Qingshan (= Ch'ing shan) Formation (Early Cretaceous) of Shandong Province, China, is redescribed and shown to be an advanced diplodocid sauropod. This specimen possesses several derived character states that are typically observed in advanced diplodocoids or diplodocids, including the following: a mildly procoelous centrum; a deep pit‐like pneumatic fossa immediately below the caudal rib; wing‐ or fan‐shaped caudal ribs; and complex lamination of the neural spine. The neural spine is apomorphically short and the centrum is short relative to its height compared to those of other diplodocids, which, when coupled with the specimen’s unique geographical location and stratigraphical age, suggests that it probably represents a new taxon. This caudal vertebra provides the first convincing evidence that diplodocids were present in Asia, perhaps as a result of the dispersal of neosauropod lineages from Europe and/or North America during the Early Cretaceous. The discovery of a member of the Diplodocidae in the Early Cretaceous also indicates that this clade did not become extinct at the Jurassic/Cretaceous boundary as previously supposed.     

An articulated titanosaur from Patagonia (Argentina): New evidence of neosauropod pedal evolution

Most titanosaur dinosaurs are represented by incomplete skeletal elements lacking articulated pes. An exceptionally preserved specimen from the Late Campanian–Early Maastrichtian strata of Patagonia (Argentina) provides new data on pedal morphology and the evolutionary trends of these huge dinosaurs. This finding is one of the few articulated titanosaur pes known in the world, and shows a phalangeal formula of 2-2-2-2-0. The first three digits possess sickle-shaped claws and the articular facets of ungual phalanges, suggesting mobility in horizontal and vertical planes. A comparative analysis of available record suggests that titanosaurs had a progressive reduction of size and number of pedal phalanges in digits III and IV during the Late Cretaceous.     

Redescription of Bonatitan reigi (Sauropoda: Titanosauria), from the Campanian–Maastrichtian of the Río Negro Province (Argentina)

The titanosaur sauropod Bonatitan reigi is redescribed. The material collected, originally interpreted as pertaining to two different individuals, is reorganised in five individuals, and the original type specimen is separated into three different individuals. One of the braincases is designated as a new type specimen. Some materials are described by the first time (sacral ribs, distal caudal, chevrons, metacarpals, astragalus and metatarsals), others reinterpreted as different bones (‘ulna’ and ‘radius’). The diagnosis of B. reigi is emended, removing some of the original characters (longitudinal groove located on the suture between the parietals that continues posteriorly over the supraoccipital to the foramen magnum) and adding some new (small paired pits on the frontals and posterior ridge of the metacarpal IV). The phylogenetic analysis does not support B. reigi as a member of the Saltasaurinae, but rather as a basal member of a broad clade of sauropods that in turn is recovered as the sister group of the Saltasauridae.     

The northernmost sauropod record in the Northern Hemisphere

Isolated sauropod teeth from the Early Cretaceous Teete locality in Yakutia (Eastern Siberia, Russia) are the only evidence that sauropods lived in high latitudes (palaeolatitude estimate of N 62°) in the Northern Hemisphere. The spatulate broad tooth crowns of adult individuals lack marginal denticles while these are present in a juvenile tooth. The teeth have overlapping facets and likely belong to a basal macronarian. The juvenile tooth indicates that sauropods reproduced in high latitudes and possibly stayed there around the year. The Teete vertebrate assemblage comprises both endothermic, or presumably endothermic tetrapods (theropod dinosaurs, tritylodontids and mammals), and ectothermic tetrapods (salamanders, turtles, choristoderes and lizards), but no crocodyliforms. This suggests a temperate climate, with an annual mean temperature well above freezing level but below 14°C.     

A new sauropod dinosaur from the Lower Cretaceous Ilek Formation,Western Siberia,Russia

Sibirotitan astrosacralis nov. gen., nov. sp., is described based on isolated but possibly associated cervical and dorsal vertebrae, sacrum, and previously published pedal elements from the Lower Cretaceous (Barremian?) Ilek Formation at Shestakovo 1 locality (Kemerovo Province, Western Siberia, Russia). Some isolated sauropod teeth from the Shestakovo 1 locality are referred to the same taxon. The phylogenetic parsimony analyses place Sibirotitan astrosacralis nov. gen., nov. sp., as a non-titanosaurian somphospondyl titanosauriform. The new taxon exhibits four titanosauriform and one somphospondylan synapomorphies, and one autapomorphy – a hyposphene ridge that extends between the neural canal and the postzygapophyses. It differs from all other Somphospondyli by having only five sacral vertebrae. The new taxon shares with Euhelopus and Epachtosaurus sacral ribs that converge towards the middle of the sacrum in dorsal view. Sibirotitan astrosacralis nov. gen., nov. sp., is only the second sauropod taxon from Russia and one of the oldest titanosauriform described so far in Asia.     

The tiny horned dinosaur Gobiceratops minutus gen. et sp. nov. (Bagaceratopidae, Neoceratopsia) from the Upper Cretaceous of Mongolia

A new horned dinosaur, Gobiceratops minutus gen. et sp. nov. (Bagaceratopidae, Neoceratopsia), from the Upper Cretaceous Baruungoyot Formation of the Khermin Tsav locality (southern Mongolia) is described based on a 3.5-cm-long skull. The nasal included in the orbital border suggests relationship between the new taxon and Bagaceratops rozdestvenskyi. It is proposed that, unlike other neoceratopsian families, the family Bagaceratopidae is of Paleoasiatic origin.     

江西晚白垩世大型兽脚类恐龙牙齿（英文）

描述了江西晚白垩世南雄组产出的两颗大型兽脚类恐龙牙齿。这两颗牙齿的齿冠高度分别为91和76 mm左右。较小牙齿近似圆锥形,齿冠基部比率为0.72,与典型的暴龙类牙齿相似。较大牙齿横向侧扁,齿冠基部比率约为0.47,舌侧和唇侧表面近乎平坦,前后缘冠面基部发育明显的纵向褶皱,区别于已发现的暴龙科、鲨齿龙科和棘龙科成员的牙齿。江西大型兽脚类恐龙牙齿的发现对于全面了解华南地区南雄组多样化的脊椎动物群组成具有一定的意义。     

Spinosaurid teeth from the Lower Cretaceous of Ko Kut,eastern Thailand

Isolated theropod dinosaur teeth from Ko Kut (Kut Island) in eastern Thailand are referred to an indeterminate spinosaurid on the basis of their morphology and ornamentation. On the basis of other spinosaurid occurrences in Thailand and other parts of Asia, they support the attribution of the fossil-bearing beds on Ko Kut to the Lower Cretaceous rather than the Jurassic. The lack of ornithischian remains in the Ko Kut faunal assemblage suggests that it is coeval with the Sao Khua Formation (Barremian) of NE Thailand.     

Theropod dinosaur teeth from the lowermost Cretaceous Rabekke Formation on Bornholm, Denmark

The dinosaur fauna of the palynologically dated lower Berriasian Skyttegård Member of the Rabekke Formation on the Baltic island of Bornholm, Denmark, is represented by isolated tooth crowns. The assemblage is restricted to small maniraptoran theropods, assigned to the Dromaeosauridae incertae sedis and Maniraptora incertae sedis. The dromaeosaurid teeth are characterized by their labiolingually compressed and distally curved crowns that are each equipped with a lingually flexed mesial carina and a distinctly denticulated distal cutting edge. A morphologically aberrant tooth crown (referred to as Maniraptora incertae sedis) has triangular denticles of uneven width, a feature occasionally found in Upper Cretaceous hesperornithiform toothed diving birds, but also in premaxillary teeth of the velociraptorine Nuthetes from the Lower Cretaceous of England.     

Modelling equid/ruminant competition in the fossil record

It has been argued that the Late Cretaceous dinosaurs from Transylvania were affected by dwarfism as a consequence of their evolution in an insular habit. However, several bones from Nopcsa's collections housed in London and Budapest shows that some Transylvanian saltasaurids reached lengths of 10–15 m. These multi-ton animals can hardly be considered as dwarfs, even by dinosaurian standards. It is suggested here that taphonomical biases, possibly linked to the existence of age-classed communities among sauropod populations, explain why the vast majority of recovered bones are of young individuals.     

Entobia exogyrarum (Frič, 1883) from the Upper Cretaceous of the Bohemian Cretaceous Basin

The validity of the little-known ichnospecies Entobia exogyrarum (Fri?) is verified. Shells of an oyster, Rhynchostreon suborbiculatum (Lam.), represent the substrate for the sponge borings. The borings occur in many Upper Cenomanian to Middle Turonian localities of the Bohemian Cretaceous Basin. This study revealed that the sponges attacked shells of living oysters. Entobia exogyrarum (Fri?) also represents one of the shallowest occurrences of Entobia borings in the Upper Cretaceous rocks.