A New Basal Sauropod Dinosaur from the Lufeng Basin,Yunnan Province, Southwestern China

<正>A new dinosaur Chuxiongosaurus lufengensis gen.et sp.nov.is erected based on a nearly complete skull.The taxon is characterized by the lacrimal perpendicular to the ventral margin of the upper jaw,which is similar to that of Thecodontosaurus;a depression present on the dorsal profile of the snout behind the naris;the rostral profile of the maxilla slopes continuously towards the rostral tip;and the presence of 25 dentary teeth.It also displays prosauropod characters such as a relatively long skull,the slope of the maxillary rostral profile,and teeth that do not have basically constricted crowns.The new specimen is more basal than Anchisaurus and represents the first basal sauropod dinosaur from the Early Jurassic of China.     

A Baby Pterodactyloid Pterosaur from the Yixian Formation of Ningcheng,Inner Mongolia,China

A new baby pterodactyloid pterosaur with soft tissue preserved, Ningchengopterus liuae gen. et sp. nov., is erected based on a nearly complete skeleton with a skull. It was characterized by the skull, slightly longer than the combined length of the dorsal and sacral vertebrae; 50 teeth (including upper and lower jaws); short mid-cervical vertebrae; the humerus and the scapula, equal to that of the wing metacarpal in length; the ulna and the femur, equal to that of the first and third wing phalanx in length, respectively. The similar ratio of the wing phalanx 2 to wing phalanx 1 of Ningchengopterus and Eosipterus implies that Ningchengopterus may be close to the ctenochasmatid pterosaur. However, it may also imply that the isometrically growing of the first two wing phalanges exists among some pterosaurs.     

New Species of Enantiornithes (Aves: Ornithothoraces) from the Qiaotou Formation in Northern Hebei,China

<正>We report on a new species of enantiornithine bird from the Lower Cretaceous Qiaotou Formation of northern Hebei,China.The new taxon,Shenqiornis mengi gen.et sp.nov.,possesses several enantiornithine synapomorphies but is unique from other known species.The specimen has a well-preserved skull that reveals new information about enantiornithine cranial morphology.The new taxon possesses a large postorbital with a long tapering jugal process indicating that some enantiornithines may have had a fully diapsid skull,as in Confuciusornis.The tooth morphology of the specimen is unique and likely represents a previously unknown trophic specialization within Enantiornithes.     

New Study of Anshunsaurus huangnihensis Cheng, 2007 (Reptilia: Thalattosauria): Revealing its Transitional Position in Askeptosauridae

The skull of Anshunsaurus huangnihensis Cheng, 2007, especially the skull roof, is described in detail in this paper. Compared to other genera and species of Askeptosauroidea, Anshunsaurus huangnihensis has some important transitional characters from Askeptosaurus italicus to Anshunsaurus huangguoshuensis: the rostral length related to the skull length between Askeptosaurus italicus and Anshunsaurus huangguoshuensis; the postfrontal existing but distinctly reduced; the posterolateral process relatedly short and overlapping the parietal. The phylogenetic analysis weakly supports the evolutional progress from Anshunsaurus huangnihensis to Anshunsaurus huangguoshuensis. The skeletal ratios indicated that the node among the Askeptosauridae ingroup. The evolutional direction of Askeptosauridae should be from Askeptosaurus italicus to Anshunsaurus huangguoshuensis. The skeletal ratios indicated that the evolutional progress is Askeptosaurus italicus – Anshunsaurus huangnihensis – Anshunsaurus huangguoshuensis. In biogeography provinces, the Askeptosauroidea taxa from south China have a close relationship with those from western Tethys; however, Xinpusaurus from the Late Triassic is more related to those from the eastern Pacific.     

Baurusuchus salgadoensis, a New Crocodylomorpha from the Bauru Basin (Cretaceous), Brazil

Baurusuchus salgadoensis is a new baurusuchid crocodylomorph from Bauru Basin (Cretaceous), Brazil, partially preserved through a complete skull. The fossil comes from a fine sandstone sequence of Adamantina Formation, General Salgado County, São Paulo State. The sedimentary sequence where it was found, located in Fazenda Buriti, is considered Turonian-Santonian in age. The described species _Baurusuchus salgadoensis sp. nov. _ is a baurusuchid with an antorbital fenestra, double external nares with a bony septum, two well-fused supraorbitals, the supratemporal fenestrae larger than the orbits and a quadrangular-shaped laterotemporal fenestra. The position of the external nares, located on anterior and terminal portion of the rostrum together with the theropod-like lateral compression of the snout and teeth are indicators that Baurusuchus salgadoensis was a terrestrial crocodyliform. This was a carnivorous species and the lateral compression of the rostrum could be interpreted as a mechanism to increase the skull resistance forces during biting. The pointed, conical teeth, some with crenulated borders, could be used to perforate and to carve the prey. The geological context of Baurusuchus salgadoensis indicates that it probably lived in a hot and arid climate.     

A New Species of Gobiconodon (Mammalia) from Western Liaoning,China and its Implication for the Dental Formula of Gobiconodon

A new species of Gobiconodon from the Early Cretaceous in the Lujiatun locality of western Liaoning is erected based on an almost complete skull and lower jaw. It has a flatten skull roof, the lambdoidal crest is strongly curved forward, and the sagittal crest is short and low. There is a protuberance near the anterior base of the zygoma. The preservation of the upper teeth is very rare in all known Gobiconodon, and this provides important information for the study on the formula of Gobiconodon. The new species is the fifth primitive mammal unearthed from the Lujiatun locality, and is of great value for the study of the geological age of the stratigraphy at Lujiatun by primitive mammal material.     

Largest Toothed Pterosaur Skull from the Early Cretaceous Yixian Formation of Western Liaoning,China, with Comments on the Family Boreopteridae

A new pterosaur Moganopterus zhuiana gen. et sp. nov. is erected based on a complete skull with lower jaws and anterior cervical vertebrae. It is characterized by much elongated upper and lower jaws with at least 62 total, long, curved teeth with sharp tips, a well developed parietal crest extending posterodorsally, forming an angle of 15 degrees with the ventral margin of the skull, the ratio of length to width of cervical vertebrae greater than 5:1. The skull length is 750 mm, and it is the largest toothed pterosaur found so far in the world. Based on this new pterosaur, the Boreopteridae can be divided into two subgroups: Boreopterinae sub-fam. nov. and Moganopterinae sub-fam. nov., which is also confirmed by the phylogenetic analysis.     

Fossils Explained 83: Diversity of skull morphology in the Titanosauria

Titanosaurs were a globally distributed group of sauropod dinosaurs. They had diverse forms and a wide-gauge stance, with a few of their species reaching immense sizes, such as Argentinosaurus huinculensis and Patagotitan mayorum (reaching >35 m in length). There are about 100 valid titanosaur species known so far, but most of the originally described species are no longer valid, due to the incomplete nature of fossil materials. Our understanding of titanosaur skull morphology is based on very few incomplete fragmented cranial materials and findings of the complete skull are even rarer. Understanding the skull morphology of extinct animals helps palaeontologists make deductions of feeding mechanisms and also provide an idea about their appearance when they were alive. Diversity in titanosaur skull morphology is greater than that of any other sauropod clade, indicating diversity in feeding mechanism among these dinosaurs. Titanosaurs were the last surviving clade of sauropod dinosaurs, occupying nearly every ecological niche around the world during the Late Cretaceous, and resulting in a rich diversity in this group. This article highlights diversity in the basic structure of sauropods with special emphasis on titanosaur skull morphology.     

New material of Anancus kenyensis (proboscidea, mammalia) from Toros-Menalla (Late Miocene, Chad): Contribution to the systematics of African anancines

New fossil remains of the proboscidean genus Anancus are described. Among them, a complete skull allows us to revisit for the first time the entire Chadian Anancus fossil record. This genus occurred in the Old World from the late Miocene up to the early Pleistocene. The analysis of dental and cranial characters was allowed individual variations from specific characters to be distinguished. In this study we show that Anancus kenyensis and Anancus osiris are very likely synonym taxa which leads us to emend the diagnosis of A. kenyensis. In addition, this study shows that dental characters in anancines lineage are of little significance for biostratigraphical inference, by contrast to previous works. This study brings new data about the phylogenetical and palaeobiogeographical history of the African anancines.     

New remains of Eremotherium laurillardi (Lund, 1842) (Megatheriidae, Xenarthra) from the coastal region of Ecuador

New remains of Eremotherium were recovered from the Pacific coast of Ecuador’s Manabi province. The Machalilla fossiliferous locality records the northernmost presence of Eremotherium along the Pacific coast of South America. Most of the fossil remains belong to the same individual, mainly its posterior half, but other individuals are represented. Among the better-preserved specimens are skull fragments, most of the hind limb bones and a number of trunk and caudal centra. These remains were compared with samples collected during the 20th century along the southern coastal regions of Ecuador and northern Peru. Many characters of the long bones and tarsals testify to a possibly different lineage despite the closeness of other Eremotherium populations. Some metric and morphological aspects suggest a different space-temporal southern Caribbean provenance. Other Eremotherium specimens, coming from other Ecuadorian localities, were studied and compared with classic Eremotherium samples. Interesting morpho-functional aspects are pointed out with regard to the tail and its importance in the bipedal stance.     

A New Troodontid Dinosaur from the Lower Cretaceous Yixian Formation of Liaoning Province, China

A new troodontid dinosaur,Daliansaurus liaoningensis gen.et sp.nov.,is erected based on a nearly complete specimen from the Lower Cretaceous Yixian Formation of Beipiao City,Liaoning Province,China.This well preserved skeleton provides important new details of the anatomy for Liaoning troodontids,and gives new insight into their phylogenetic relationships and evolution.Daliansaurus is distinguished from other troodontids by an enlarged ungual on pedal digit IV,which is approximately the same size as the sickle-shaped second ungual,and is differentiated from other Liaoning troodontids by a number of characters of the skull,manus,pelvis,and hindlimb.A phylogenetic analysis recovers Daliansaurus within a subclade of Liaoning troodontids that also includes Sinovenator,Sinusonasus,and Mei.We erect a name for this group—Sinovenatorinae—and argue that it reflects a localized radiation of small-bodied troodontids in the Early Cretaceous of eastern Asia,similar to previously recognized radiations of Liaoning dromaeosaurids and avialans.As more Liaoning theropods are discovered,it is becoming apparent that small,feathered paravians were particularly diverse during the Early Cretaceous,and future work is needed to clarify how this diversity arose,which species coexisted,and how these numerous species partitioned niches.     

A New Boreopterid Pterodactyloid Pterosaur from the Early Cretaceous Yixian Formation of Liaoning Province, Northeastern China

<正>A new boreopterid pterosaur:Zhenyuanopterus longirostris gen.et sp.nov.from the Yixian Formation of western Liaoning is erected,based on the complete skeleton with a skull and lower jaws preserved.It is characterized by:a large boreopterid pterosaur with a high number of teeth,where the anterior teeth are much larger than posterior ones;the length of the dorsal + sacral vertebrae is nearly half the length of the skull;ratio of the length of the humerus to metacarpal IV is approximately 91%and the,humerus,femur and third wing phalanx are all equal in length and the feet are specially small.It represents the largest boroepterid pterosaur discovered from western Liaoning and its surrounding areas so far     

First record of the leptonectid ichthyosaur <Emphasis Type="Italic">Eurhinosaurus longirostris</Emphasis> from the Early Jurassic of Switzerland and its stratigraphic framework

An incomplete skull of the leptonectid ichthyosaur Eurhinosaurus longirostris found in the Rietheim Member (previously “Posidonienschiefer”; Toarcian, Early Jurassic) of Staffelegg, Canton Aargau, is the first record from Switzerland of this taxon and supports the status of Eurhinosaurus longirostris as a palaeobiogeographic very widespread ichthyosaur species in the Early Toarcian of Western Europe. Being from either the Bifrons or Variabilis zone, it is one of the youngest records of Eurhinosaurus and one of the few diagnostic ichthyosaur finds from this time interval. The partial skull is well articulated and preserved three-dimensionally in a carbonate concretion. Both the mode of preservation of the ichthyosaur and an associated ammonoid (Catacoeloceras raquinianum) provided the age of the concretion, which had been collected from scree. Taphocoenosis and taphonomy show the C. raquinianum to be one of few non re-worked fossils recorded from the Early to Late Toarcian boundary (Bifrons/Variabilis zone) of northern Switzerland in general and of this ammonite species in particular. The Toarcian section at Staffelegg differs from other localities where strata of the same age are exposed with respect to facies variations of the Rietheim Member (previously “Posidonienschiefer”, Early Toarcian) and the extraordinarily high thickness of the Gross Wolf Member (previously “Jurensis-Mergel”, Late Toarcian).     

A New Specimen of Shansisuchus shansisuchus Young, 1964 (Diapsida: Archosauriformes) from the Triassic of Shanxi, China

Shansisuchus shansisuchus Young,1964 was restudied on the basis of a new specimen.Some anatomical features that were either briefly or not described at all in the original study were detailed.The new specimen not only provides further information on the skull anatomy and the vertebral column but also expands the range of the geographical distribution of the taxon.With new information,the diagnosis of S.shansisuchus was emended and its phylogenetic relationships were further analyzed.S.shansisuchus differs from other archosauriforms primarily in the presence of a large subnarial fenestra anterior to the antorbital fenestra,tongue-in-groove articulations between the ascending process of the premaxilla and nasal and between the premaxilla and maxilla,a tall and posterodorsally directed ascending process of the maxilla,a knee-shaped process of the postorbital projecting into the orbit,a broad descending process of squamosal distally well forked and a large,deeply bow-shaped intercentrum tightly anchoring/capping the sharp ventral edges of two neighboring centra together in cervical and at least first eight dorsal vertebrae.With additional information derived from the new specimen,the phylogenetic relationships of S.shansisuchus were reanalyzed;it is closely related to Erythrosuchus-Vjushkovia clade.     

Le régime alimentaire du Cervidae (Mammalia) Eucladoceros ctenoides (Nesti 1841) reconstitué par la morphologie du crane et par l’usure dentaire

The paleodiet of Eucladoceros ctenoides (Nesti 1841), has been investigated on two sub-species from the Villafranchian fossiliferous sites of Saint-Vallier (Drôme, France), E. ctenoides vireti Heintz 1970, and Senèze (Haute-Loire, France), E. ctenoides senezensis Depéret 1910, using skull and mandible morphological features as well as the meso- and microwears methods. The validity of skull and mandible characters used to infer diet has been tested on extant cervid species: browsers (roe deer, moose and white-tailed deer) and mixed feeders at different level (Père David’s deer, fallow deer, chital, sambar, red deer and elk). The obtained results show that the Eucladoceros specimens from Saint-Vallier and Senèze shared paleodiet and ecologic niche. Cranial morphology and tooth wear are more similar to those characterising browsers than mixed feeders. Cranial morphology can be considered as a useful tool in inferring palaeodiets, in particular when tooth samples are too scanty to apply of micro- and/or mesowear analytic methods.

Manuscrit reçu le 17 septembre 2003 Révision acceptée le 16 février 16, 2005     

A new species of Tupuxuara (Thalassodromidae,Azhdarchoidea) from the Lower Cretaceous Santana Formation of Brazil,with a note on the nomenclature of Thalassodromidae

A new species of the sail-crested pterosaur Tupuxuara is described from the Santana Formation of Brazil, Tupuxuara deliradamus sp. nov. The holotype, a partial skull, and a larger, partial skull referred to the same taxon differs from Tupuxuara leonardii by having a nasoantorbital fenestra with an acutely-angled posterior border with a long, straight posterodorsal margin, a reclined cranium, and an orbit situated entirely in the ventral half of the nasoantorbitral fenestra. Unfortunately, neither specimen is comparable with the fragmentary rostrum representing Tupuxuara longicristatus. In addition, resolution of a recent nomenclatural problem over the correct name for the clade containing Tupuxuara and its sister taxon, Thalassodromeus, is provided. Both genera are used by different authors as the nomenclatural basis for the group, but “Tupuxuaridae” has never been explicitly erected as a new taxon, and therefore fails to meet ICZN criteria that new taxa are only valid if authors clearly indicate their intention to establish new names. By contrast, “Thalassodrominae” was explicitly erected as a name for the Thalassodromeus + Tupuxuara clade, thereby fulfilling all ICZN requirements for naming of a new taxon and making Thalassodromeus stand as the type genus for this group.     

Age of the fossil Dali Man in north-central China deduced from chronostratigraphy of the loess–paleosol sequence

Dali Man, an archaic type of early Homo sapiens, is of great significance to the origin of Homo sapiens. Achievements have been made during the past decades in the understanding of the fossil human skull as well as the accompanying mammalian fossils and stone artifacts. However, the absolute age of the fossil Dali Man still remains unclear. Based on the magnetic susceptibility of loess sediments and the relationship of terracing process with climatic condition, we correlated the loess sequence and the subjacent terrace alluvium at the Dali Man site with the well-studied loess–paleosol sequence at Luochuan in the central part of the Chinese Loess Plateau. The correlation indicates that the loess–paleosol sequence at the Dali Man site extends down to the paleosol S2, and the underlying fluvial deposits correspond to the loess L3. Because the Dali Man skull appears in the basal gravel layer of the terrace, and because the deposition of the terrace gravels would occur during the transition from S3 paleosol formation to L3 loess accumulation, the age of the fossil Dali Man is inferred to be ca 270 ka, which is equivalent to the age of the boundary between the loess L3 and paleosol S3 on the magnetic susceptibility time series of the Luochuan loess–paleosol sequence.     

A new ctenochasmatoid pterosaur from the Early Cretaceous Yixian Formation of western Liaoning,China

A new ctenochasmatoid pterosaur, Gladocephaloideus jingangshanensis gen. et sp. nov. from the Yixian Formation of western Laioning Province is erected based on a complete skull and partial postcranial skeleton. It is characterized by following features: about 50 total teeth with sharp tips; small nasoantorbital opening, occupying approximately 13% of the skull length; ratio of prenarial length to skull length approximately 0.63. The diagnoses of the Ctenochasmatoidea and Gallodactylidae are amended based on the new taxon. Gladocephaloideus jingangshanensis is the first gallodactylid pterosaur found in Asia. Its discovery not only provides much more osteological information about the Gallodactylidae but also indicates that the ctenochasmatoid pterosaurs were highly diverse in the Early Cretaceous. The filamentous structures preserved near the dorsal and posterior margins of the posterior portion of the skull and around the neck indicate that it had an epidermal covering and may have been a warm-blooded animal.