Updated: July 2, 2010
Additions/Comments:

For a species to appear here its description must have been formally published in a recognized scientific publication.

Abstract: Aardonyx celestae gen. et sp. nov. is described from the upper Elliot Formation (Early Jurassic) of South Africa. It can be diagnosed by autapomorphies of the skull, particularly the jaws, cervical column, forearm and pes. It is found to be the sister group of a clade of obligatory quadrupedal sauropodomorphs (Melanorosaurus + Sauropoda) and thus lies at the heart of the basal sauropodomorph–sauropod transition. The narrow jaws of A. celestae retain a pointed symphysis but appear to have lacked fleshy cheeks. Broad, U-shaped jaws were previously thought to have evolved prior to the loss of gape-restricting cheeks. However, the narrow jaws of A. celestae retain a pointed symphysis but appear to have lacked fleshy cheeks, demonstrating unappreciated homoplasy in the evolution of the sauropod bulk-browsing apparatus. The limbs of A. celestae indicate that it retained a habitual bipedal gait although incipient characters associated with the pronation of the manus and the adoption of a quadrupedal gait are evident through geometric morphometric analysis (using thin-plate splines) of the ulna and femur. Cursorial ability appears to have been reduced and the weight bearing axis of the pes shifted to a medial, entaxonic position, falsifying the hypothesis that entaxony evolved in sauropods only after an obligate quadrupedal gait had been adopted.

Abstract: Sauropod dinosaur bones are common in Mesozoic terrestrial sediments, but sauropod skulls are exceedingly rare—cranial materials are known for less than one third of sauropod genera and even fewer are known from complete skulls. Here we describe the first complete sauropod skull from the Cretaceous of the Americas, Abydosaurus mcintoshi, n. gen., n. sp., known from 104.46±0.95 Ma (megannum) sediments from Dinosaur National Monument, USA. Abydosaurus shares close ancestry with Brachiosaurus, which appeared in the fossil record ca. 45 million years earlier and had substantially broader teeth. A survey of tooth shape in sauropodomorphs demonstrates that sauropods evolved broad crowns during the Early Jurassic but did not evolve narrow crowns until the Late Jurassic, when they occupied their greatest range of crown breadths. During the Cretaceous, brachiosaurids
and other lineages independently underwent a marked diminution in tooth breadth, and before the latest Cretaceous broad-crowned sauropods were extinct on all continental landmasses. Differential survival and diversification of narrow-crowned sauropods in the Late Cretaceous appears to be a directed trend that was not correlated with changes in plant diversity or abundance, but may signal a shift towards elevated tooth replacement rates and highwear dentition. Sauropods lacked many of the complex herbivorous adaptations present within contemporaneous ornithischian herbivores, such as beaks, cheeks, kinesis, and heterodonty. The spartan design of sauropod skulls may be related to their remarkably small size—sauropod skulls account for only 1/200th of total body volume compared to 1/30th body volume in ornithopod dinosaurs.

Abstract: Ceratopsians (horned dinosaurs) represent a highly diverse and abundant radiation of non-avian dinosaurs known primarily from the Cretaceous period (65–145 million years ago). This radiation has been considered to be geographically limited to Asia and western North America with only controversial remains reported from other continents. Here we describe new ceratopsian cranial material from the Late Cretaceous of Iharkút, Hungary, from a coronosaurian ceratopsian, Ajkaceratops kozmai. Ajkaceratops is most similar to ‘bagaceratopsids’ such as Bagaceratops and Magnirostris, previously known only from Late Cretaceous east Asia. The new material unambiguously demonstrates that ceratopsians occupied Late Cretaceous Europe and, when considered with the recent discovery of possible leptoceratopsid teeth from Sweden, indicates that the clade may have reached Europe on at least two independent occasions. European Late Cretaceous dinosaur faunas have been characterized as consisting of a mix of endemic ‘relictual’ taxa and ‘Gondwanan’ taxa, with typical Asian and North American groups largely absent. Ajkaceratops demonstrates that this prevailing biogeographical hypothesis is overly simplified and requires reassessment. Iharkút was part of the western Tethyan archipelago, a tectonically complex series of island chains between Africa and Europe, and the occurrence of a coronosaurian ceratopsian in this locality may represent an early Late Cretaceous ‘island-hopping’ dispersal across the Tethys Ocean.

Abstract: A new sauropod dinosaur, Arkharavia heterocoelica gen. et sp. nov., from the Maastrichtian (Udurchukan Formation) of the Amur Region, Russia, is described based on a tooth and several isolated anterior caudal vertebrae. It is distinguished by the saddle-shaped centrum and high neural spine of the anterior caudal vertebrae. Certain structural characters of the new genus are in common with Chubutisaurus insignis (Titanosauriformes) from the Upper Cretaceous of Argentina.

Abstract: We describe the new basal abelisauroid dinosaur Austrocheirus isasii gen. et sp. nov. from the Late Cretaceous Pari Aike Formation of southwestern Patagonia, Argentina. The preserved remains include manual bones, a distal tibia, and some pedal and axial elements. Austrocheirus is differentiated from other basal theropods by the presence of metacarpal III with a dorsoventrally compressed shaft and posteriorly displaced collateral tendon fossae located at the same level of the proximal end of distal condyles, and pedal phalanges with a conspicuous longitudinal crest delimitating the dorsal margin of the distal collateral tendon fossae. A cladistic analysis recovered the new species as more derived than Ceratosaurus and Berberosaurus, but within a polytomy at the base of Abelisauroidea, an assignment supported by two abelisauroid synapomorphies: distal end of tibia with a planar vertical scar for the reception of the ascending process of the astragalus that occupies most of its anterior surface and is medially bounded by the longitudinally oriented facet; and scar for the reception of the ascending process with a median vertical ridge, which imbeds into a crescentic vertical groove on the posterior surface of the ascending process of the astragalus forming an interlocking tibiotarsal articulation. Furthermore, Austrocheirus represents the first known medium-sized Late Cretaceous abelisauroid bearing nonatrophied hands. The evidence provided here suggests that the strong reduction of the forelimb recorded in derived abelisaurids is not directly correlated with their increased body-size, but it seems to be an evolutionary event exclusive to this lineage within Ceratosauria.

Abstract: We describe the new basal abelisauroid dinosaur Austrocheirus isasii gen. et sp. nov. from the Late Cretaceous Pari Aike Formation of southwestern Patagonia, Argentina. The preserved remains include manual bones, a distal tibia, and some pedal and axial elements. Austrocheirus is differentiated from other basal theropods by the presence of metacarpal III with a dorsoventrally compressed shaft and posteriorly displaced collateral tendon fossae located at the same level of the proximal end of distal condyles, and pedal phalanges with a conspicuous longitudinal crest delimitating the dorsal margin of the distal collateral tendon fossae. A cladistic analysis recovered the new species as more derived than Ceratosaurus and Berberosaurus, but within a polytomy at the base of Abelisauroidea, an assignment supported by two abelisauroid synapomorphies: distal end of tibia with a planar vertical scar for the reception of the ascending process of the astragalus that occupies most of its anterior surface and is medially bounded by the longitudinally oriented facet; and scar for the reception of the ascending process with a median vertical ridge, which imbeds into a crescentic vertical groove on the posterior surface of the ascending process of the astragalus forming an interlocking tibiotarsal articulation. Furthermore, Austrocheirus represents the first known medium-sized Late Cretaceous abelisauroid bearing nonatrophied hands. The evidence provided here suggests that the strong reduction of the forelimb recorded in derived abelisaurids is not directly correlated with their increased body-size, but it seems to be an evolutionary event exclusive to this lineage within Ceratosauria.

Abstract: Here we report a new oviraptorid taxon based on a specimen possibly collected from the Upper Cretaceous Nanxiong Formation of Ganzhou, Jiangxi, China. This new taxon is distinguishable from other species based on the following features: a crest formed by the premaxillae and nasals having a step wise posterior end and bearing two longitudinal grooves and numerous oblique striations on each of its lateral surfaces, an extremely elongate external naris that is posteriorly situated and close to the or bit, a deep fossa on the dorsal surface of the palatal ramus of the pterygoid, several longitudinal grooves along the posterior part of the dorsal margin of the dentary, and several tubercles along the lateral shelf at the dorsal margin of the surangular. This new taxon possesses some palatal and mandibular features not seen in other oviraptorids but similar to those in more basal oviraptorosaurs, suggesting a relatively basal position for this taxon within the Oviraptoridae. This systematic hypothesis is supported by a numerical cladistic analysis. This discovery not only adds to the known diversity of Late Cretaceous.
Holotype: IVPP V 16896, a nearly complete skull and mandible

Type locality and horizon: The specimen was acquired from an amateur collector who is not willing to reveal his indentity. The only information concerning the provenance of the specimen provided by this collector is that the specimen was collected in the Hongcheng Basin near Ganzhou City, Jiangxi Province. The red beds exposed in the Hongcheng Basin are normally correlated with the Upper Cretaceous Nanxiong Formation (Sato, et al., 2005)
Etymology: Genus name from "ban", speckle, but sometimes referring to stripes in Chinese, and "ji", crest; refers to the animal's bearing a crest with distinctive striations over the snout. The species name "long" is a tranliteration of the Chinese word for dragon.
Diagnosis: An oviraptorid distinguishable from other species based on the following features: a crest formed by the premaxillae and nasals having a step-wise posterior end and bearing two longitudinal grooves ans numerous oblique striations on each of its lateral surfaces, an extremely enlongate naris that is posteriorly situated and close to the orbit, a deep fossa on the dorsal surface of the palatal ramus of the pterygoid, several longitudinal grooves alang the posterior part of the dorsal margin of the dentary, and several turbercles along the lateral shelf at the dorsal margin of the surangular.

Abstract: This short review discusses current understanding of the history, anatomy and taxonomy of the lower Wealden Group-aged (Valanginian ~141–137Ma) iguanodontian dinosaurs from southern England.
English Wealden iguanodontian taxonomy has been the subject of comment and scrutiny since the latter half of the 19th century. As proposed over two decades ago, iguanodontians recovered from quarries across this geographic region can be subdivided into anatomically and chronologically distinct assemblages. A review of the lower Wealden Group (Valanginian) assemblage (formerly understood to comprise the relatively poorly known and understood taxa Iguanodon dawsoni, Iguanodon fittoni and Iguanodon hollingtoniensis) establishes the presence of two diagnosable taxa: Barilium dawsoni (Lydekker, 1888) comb. nov. and Hypselospinus fittoni (Lydekker, 1889) comb. nov. The upper Wealden Group (Hauterivian–Lower Aptian) assemblage comprises Iguanodon bernissartensis and Mantellisaurus atherfieldensis.
Recent suggestions concerning the creation of additional new Wealden Group taxa reflect systemic misunderstandings of the actual skeletal material. A detailed taxonomic review of all Wealden Group iguanodontians is in preparation.

Nobu Tamura

Abstract: Skeletal remains of Late Cretaceous (Campanian and Maastrichtian) tyrannosauroids are rare in southwestern North America (Carr and Williamson, 2000). Historically, the identity and diversity of southwestern tyrannosauroids was unclear because most of the fossils were isolated teeth and bones that are not diagnostic of known genera or species (Carr and Williamson, 2000). One partial skull and skeleton (OMNH 10131) from the upper Campanian of New Mexico was referred to the problematic tooth taxon Aublysodon cf. A. mirandus, a referral that was later falsified (Lehman and Carpenter, 1990; Carr and Williamson, 2004). Recently, two fairly complete skulls and skeletons were collected that enabled a review of tyrannosauroid fossils from the Campanian of New Mexico. These specimens provide the opportunity to accurately characterize Campanian tyrannosauroids of the southwest, and recover their phylogenetic relationships with well-known species (Carr and Williamson, 2000). We report the presence of a new genus and species of deep-snouted tyrannosauroid from the upper Campanian of New Mexico, represented by several specimens including the partial skeleton of an adult and a juvenile. This new taxon is part of the diversification of deep-snouted tyrannosauroids and emphasizes the high species richness of this widespread clade in the upper Campanian of western North America.

Informaworld: Bistahieversor sealeyi, a new tyrannosauroid from New Mexico and the origin of deep snouts in Tyrannosauroidea

Lukas Panzarin

A new species of horned dinosaur unearthed in Mexico has larger horns that any other species – up to 4 feet long – and has given scientists fresh insights into the ancient history of western North America, according to a research team led by paleontologists from the Utah Museum of Natural History at the University of Utah.

"We know very little about the dinosaurs of Mexico, and this find increases immeasurably our knowledge of the dinosaurs living in Mexico during the Late Cretaceous," said Mark Loewen, a paleontologist with the Utah Museum of Natural History and lead author of the study.

Elliot Merton

Abstract: Previously undocumented postcranial material from the Chipping Norton Limestone Formation (Middle Jurassic: Lower Bathonian) of Cross Hands Quarry, near Little Compton, Warwickshire represents a new large−bodied theropod dinosaur, distinct from the contemporaneous Megalosaurus bucklandi. Cruxicheiros newmanorum gen. et sp. nov. is diagnosed by a single autapomorphy, the presence of a proximomedially inclined ridge within the groove that marks the lateral extent of the posterior flange of the femoral caput (trochanteric fossa). C. newmanorum shows three tetanuran features: widely separated cervical zygapophyses, a swollen ridge on the lateral surface of the iliac blade and an anterior spur of the caudal neural spines. However, due to fragmentary preservation its affinities within Tetanurae remain uncertain: phylogenetic analysis places it as the most basal tetanuran, the most basal megalosauroid (= spinosauroid) or the most basal neotetanuran.

Abstract: A new basal centrosaurine ceratopsid, Diabloceratops eatoni, is described from the Wahweap Formation (lower to middle Campanian, Upper Cretaceous) of Grand Staircase-Escalante National Monument, southern Utah. The isolated, nearly complete skull is one of the oldest and is the first diagnosable centrosaurine recovered south of Montana. It shares with more derived centrosaurines a stepped squamosal and a nasalpremaxillary process along the caudal border of the naris. The species may be diagnosed by numerous autapomorphies relative to other centrosaurines: 1) the preorbital skull is deeper and shorter than other known ceratopsids, 2) rostral to a low, subconical nasal horn is a smaller "epinasal", 3) a large accessory antorbital fenestra is present, 4) fused frontals form a steep vault between large postorbital horns at level of palpebrals, 5) elongate jugals expose the caudal end of maxillae in lateral view, 6) large, triangular, vertically oriented, blade-like epijugal extends laterally from the jugal bone, 7) the erect frill is widest at the laterally directed squamosals, tapering to half its width at the base of a pair of elongate caudal parietal spines separated by a medial notch, 8) epoccipitals on the lateral margin of parietal decrease in size caudally to base of parietal spines, and 9) the parietal fenestrae are caudorostrally elongate. The long postorbital horns and small narial horn are primitive character states for ceratopsids as indicated by the ceratopsid sister taxon Zuniceratops. The basal position of Diabloceratops among centrosaurines is supported by the ascending process of the premaxilla not contacting the lacrimal as in 3 other centrosaurines; rather it terminates rostrally to this element as in Zuniceratops and all chasmosaurines.

A second, larger partial centrosaurine skull recovered from the Wahweap Formation is not represented by enough critical elements to be confidently diagnosed. We tentatively placed it in the genus Diabloceratops based on the presence of long postorbital horns, and a dorsoventrally oriented attachment scar on the jugal bone, indicating the presence of a possibly similar blade-like epijugal. It can be distinguished from Diabloceratops eatoni in bearing epoccipitals closely appressed to either side of the squamosal-parietal suture.

The presence of a well-developed accessory antorbital fenestra in Diabloceratops is shared with its sister taxon Zuniceratops. Among more basal neoceratopsians, only Magnirostris and Bagaceratops share this distinct character. The presence of distinct, albeit tiny, postorbital horns, indicates that Magnirostris is the Asian sister taxon to North America’s larger ceratopsids.

Abstract: The extremes of dinosaur body size have long fascinated scientists. The smallest (1m length) known dinosaurs are carnivorous saurischian theropods, and similarly diminutive herbivorous or omnivorous ornithischians (the other major group of dinosaurs) are unknown. We report a new ornithischian dinosaur, Fruitadens haagarorum, from the Late Jurassic of western North America that rivals the smallest theropods in size. The largest specimens of Fruitadens represent young adults in their fifth year of development and are estimated at just 65–75 cm in total body length and 0.5–0.75 kg body mass. They are thus the smallest known ornithischians. Fruitadens is a late-surviving member of the basal dinosaur clade Heterodontosauridae, and is the first member of this clade to be described from North America. The craniodental anatomy and diminutive body size of Fruitadens suggest that this taxon was an ecological generalist with an omnivorous diet, thus providing new insights into morphological and palaeoecological diversity within Dinosauria. Late-surviving (Late Jurassic and Early Cretaceous) heterodontosaurids are smaller and less ecologically specialized than Early (Late Triassic and Early Jurassic) heterodontosaurids, and this ecological generalization may account in part for the remarkable 100-million-year-long longevity of the clade.

Abstract: A titanosauriform dinosaur: Fukuititan nipponensis gen. et sp. nov. is erected based on the incomplete skeleton. It is characterized by elongated asymmetric tooth crown with a weak or absent labial groove and without lingual concavity; stalk-like epipophysis of cervical vertebra; the transverse width of the proximal end of the humerus approximately 32% of the humerus length; metacarpal longer, approximately 48% of the radius and the distal end of the ischia slightly expanded. It represents the first relatively complete titanosauriform skeleton found from Japan. The discovery of Fukuititan indicates that the diversity and geographical distribution of Titanosauriformes are much higher than the previous thought.

Abstract: A new genus and species of hadrosauroid dinosaur, Glishades ericksoni, is described based on paired partial premaxillae collected from the Upper Cretaceous Two Medicine Formation of Montana, in the Western Interior of the United States of America. This taxon is diagnosed on the basis of a unique combination of characters: absence of everted oral margin, arcuate oral margin with wide and straight, obliquely oriented, and undeflected anterolateral corner, grooved transversal thickening on ventral surface of premaxilla posterior to denticulate oral margin, and foramina on anteromedial surface above oral edge and adjacent to proximal end of narial bar. Maximum parsimony analysis positioned G. ericksoni as a derived hadrosauroid. Exclusion of G. ericksoni from Hadrosauridae was unambiguously supported by the lack in AMNH 27414 of a dorsomedially reflected premaxillary oral margin. Furthermore, the maximum agreement subtree positioned G. ericksoni as the sister taxon to Bactrosaurus johnsoni. This position was unambiguously supported by posteroventral thickening on the ventral surface of the premaxilla (independently derived in saurolophid hadrosaurids and Ouranosaurus nigeriensis) and having foramina on each premaxilla on the anterior surface, adjacent to the parasagittal plane of the rostrum (reconstructed as independently derived in Brachylophosaurus canadensis, Maiasaura peeblesorum, and Edmontosaurus annectens).

Abstract: The fossil record of Jurassic theropod dinosaurs closely related to birds remains poor. A new theropod from the earliest Late Jurassic of western China represents the earliest diverging member of the enigmatic theropod group Alvarezsauroidea and confirms that this group is a basal member of Maniraptora, the clade containing birds and their closest theropod relatives. It extends the fossil record of Alvarezsauroidea by 63 million years and provides evidence for maniraptorans earlier in the fossil record than Archaeopteryx. The new taxon confirms extreme morphological convergence between birds and derived alvarezsauroids and illuminates incipient stages of the highly modified alvarezsaurid forelimb.

Abstract: This short review discusses current understanding of the history, anatomy and taxonomy of the lower Wealden Group-aged (Valanginian ~141–137Ma) iguanodontian dinosaurs from southern England.
English Wealden iguanodontian taxonomy has been the subject of comment and scrutiny since the latter half of the 19th century. As proposed over two decades ago, iguanodontians recovered from quarries across this geographic region can be subdivided into anatomically and chronologically distinct assemblages. A review of the lower Wealden Group (Valanginian) assemblage (formerly understood to comprise the relatively poorly known and understood taxa Iguanodon dawsoni, Iguanodon fittoni and Iguanodon hollingtoniensis) establishes the presence of two diagnosable taxa: Barilium dawsoni (Lydekker, 1888) comb. nov. and Hypselospinus fittoni (Lydekker, 1889) comb. nov. The upper Wealden Group (Hauterivian–Lower Aptian) assemblage comprises Iguanodon bernissartensis and Mantellisaurus atherfieldensis.
Recent suggestions concerning the creation of additional new Wealden Group taxa reflect systemic misunderstandings of the actual skeletal material. A detailed taxonomic review of all Wealden Group iguanodontians is in preparation.

Abstract: A well-preserved, articulated dinosaur skeleton from southern Africa is described. The specimen comes from the upper Elliot Formation (?Hettangian) of Ha Ralekoala (Lesotho) and represents a new species: Ignavusaurus rachelis genus et species nova. A cladistic analysis suggests that Ignavusaurus is more derived than Thecodontosaurus–Pantydraco, but more primitive than Efraasia. Ignavusaurus indeed shares a number of unambiguous synapomorphies with the taxa more derived than Thecodontosaurus–Pantydraco, such as a fully open acetabulum, but it is more plesiomorphic than Efraasia and more derived sauropodomorphs as shown by the evidence of, for instance, the distal extremity of its tibia that is is longer (cranio-caudally) than wide (latero-medially). The discovery of Ignavusaurus increases the known diversity of the early sauropodomorph fauna of the upper Elliot Formation, which stands as one of the richest horizons in the world in this respect.

Abstract:

Robert Gay

Abstract: Kileskus aristotocus gen. sp. nov. from the Middle Jurasic (Bathonian) Itat Formation at Berezovsk Quarry Krasnoyarsk Territory (West Siberia, Russia), is based on an associated maxilla and premaxilla, a mandible fragment, and some possible associated postcranial ellements. Kileskus gen nov. is referred together with the Middle Jurassic Proceratosaurus from England and the Late Jurassic Guanlong from China to Proceratosauridae fam. nov. (Tyrannosauroidae, Coelurosauria) which is characterized by sigittal nasal crest (unknown for Kileskus gen. nov.), enlarged external nares, short ventral margin of premaxilla, and depth of the antorbital fossa ventral to the antorbital fenestra that is much greater than the depth of the maxilla below the ventral margin of the antorbital fossa. Kileskus gen. nov. is more simular to Proceratosaurus than to Guanlong in having anterodorsal process of the premaxilla inclined slightly anterodorsally and nares inclined posterodorsally, but differs from these two genera by having ascending process of the maxilla confluent with anterior rim of maxillary, body and gently sloping posterodorsally. Kileskus gen. nov. has a basal position whitin the Proceratosauridae. Dilong from the Early Cretaceous of China with a parasagittal nasal crests is the sister taxon for the Proceratosauridae. The new taxon is one of the oldest members of Coelurosauria and Tyrannosauroidae in the fossil record.

Matt van Rooijen

Abstract: We describe a new dromaeosaurid theropod from the Upper Cretaceous Wulansuhai Formation of Bayan Mandahu, Inner Mongolia. The new taxon, Linheraptor exquisitus gen. et sp. nov., is based on an exceptionally well-preserved, nearly complete skeleton. This specimen represents the fifth dromaeosaurid taxon recovered from the Upper Cretaceous Djadokhta Formation and its laterally equivalent strata, which include the Wulansuhai Formation, and adds to the known diversity of Late Cretaceous dromaeosaurids. Linheraptor exquisitus closely resembles the recently reported Tsaagan mangas. Uniquely among dromaeosaurids, the two taxa share a large, anteriorly located maxillary fenestra and a contact between the jugal and the squamosal that excludes the postorbital from the infratemporal fenestra. These features suggest a sister-taxon relationship between L. exquisitus and T. mangas, which indicates the presence of a unique dromaeosaurid lineage in the Late Cretaceous of Asia. A number of cranial and dental features seen in L. exquisitus and T. mangas, and particularly some postcranial features of L. exquisitus, suggest that these two taxa are probably intermediate in systematic position between known basal and derived dromaeosaurids. The discovery of Linheraptor exquisitus is thus important for understanding the evolution of some salient features seen in the derived dromaeosaurids.

Abstract:
A new chasmosaurine ceratopsid is described based on cranial material collected from a bonebed in the Judith River Formation (Campanian) near Havre, Montana. Originally, all ceratopsid material from the bonebed was referred to the basal centrosaurine Albertaceratops Ryan 2007, the holotype of which was collected from roughly equivalent-aged beds of the Oldman Formation of Alberta, Canada. Reevaluation of key cranial characters from the Montanan bonebed, including the number and shape of the preserved epiparietals, necessitate referral of at least some material from this site to a new chasmosaurine taxon. Although the bonebed does include centrosaurine cranial (and probably postcranial) elements that may eventually be referable to Albertaceratops, the site appears to be dominated by elements of chasmosaurine affinity. In addition to being the first unequivocal occurrence of a Campanian-aged chasmosaurine ceratopsid in Montana, the new chasmosaur is also the oldest known Chasmosaurine ceratopsid (approximately 77.5 Ma). Assessment of all known chasmosaurines gives support to the origin of this group in the Late Cretaceous northern paleobiogeographic zone.

New Perspectives on Horned Dinosaurs: The Royal Tyrrell Museum Ceratopsian Symposium, Bloomington, Indiana University Press: A New Chasmosaurine (Ceratopsidae, Dinosauria) from the Upper Cretaceous Ojo Alamo Formation (Naashoibito Member), San Juan Basin, New Mexico

Abstract:
Quantitative and qualitative analyses of isolated teeth and postcranial elements of non-avian theropod dinosaurs from the Upper Cretaceous (Santonian) Csehbánya Formation, Iharkút (western Hungary) indicate that these remains represent multiple dinosaur groups. Based on comparative and statistical analyses, 58 teeth and tooth fragments are identified as belonging to medium-sized basal tetanuran theropods that may have represented the top-predator of the terrestrial Iharkút ecosystem. These teeth are almost identical with the two ‘Megalosaurus pannoniensis’ teeth from the lower Campanian of Muthmannsdorf (Austria) and show a notable similarity to teeth of the Middle Jurassic M. bucklandii and the Lower Cretaceous ‘M. dunkeri’ from England. A single pedal ungual phalanx is interpreted as the oldest European occurrence of Late Cretaceous abelisaurids, as suggested by a ventral groove and bifurcated grooves laterally bordering a convex, triangular area. Small-bodied paravian theropods are found to be the best represented group in Iharkút, including teeth, caudal vertebrae, a metacarpal III, manual phalanges, and a fragmentary left tibia. A particularly notable paravian remain is a complete left scapulocoracoid possessing a unique pneumatic foramen ventral to the coracoid foramen. This specimen is assigned to Pneumatoraptor fodori n. g. et sp. Finally, numerous postcranial elements of Theropoda indet. were recovered, including a fragmentary sacrum that offers new insights into the sacral pneumaticity of theropods. The presence of these theropods in the Santonian Iharkút ecosystem provides the first evidence that during the early Late Cretaceous the Mediterranean archipelago was inhabited by both Gondwanan and Euramerican members of theropod dinosaurs. Consistent with data available for other archosaurian taxa, the close relationship of the basal tetanuran teeth with much older forms suggests that the Iharkút area may have functioned as a refugium in the early Late Cretaceous Mediterranean archipelago.

Abstract:

Abstract:
Background
Basal sauropodomorphs, or ‘prosauropods,’ are a globally widespread paraphyletic assemblage of terrestrial herbivorous dinosaurs from the Late Triassic and Early Jurassic. In contrast to several other landmasses, the North American record of sauropodomorphs during this time interval remains sparse, limited to Early Jurassic occurrences of a single well-known taxon from eastern North America and several fragmentary specimens from western North America.
Methodology/Principal Findings
On the basis of a partial skeleton, we describe here a new basal sauropodomorph dinosaur from the Lower Jurassic Navajo Sandstone of southern Utah, Seitaad ruessi gen. et sp. nov. The partially articulated skeleton of Seitaad was likely buried post-mortem in the base of a collapsed dune foreset. The new taxon is characterized by a plate-like medial process of the scapula, a prominent proximal expansion of the deltopectoral crest of the humerus, a strongly inclined distal articular surface of the radius, and a proximally and laterally hypertrophied proximal metacarpal I.
Conclusions/Significance
Phylogenetic analysis recovers Seitaad as a derived basal sauropodomorph closely related to plateosaurid or massospondylid ‘prosauropods’ and its presence in western North America is not unexpected for a member of this highly cosmopolitan clade. This occurrence represents one of the most complete vertebrate body fossil specimens yet recovered from the Navajo Sandstone and one of the few basal sauropodomorph taxa currently known from North America.

Abstract: Ceratopsid dinosaurs represent one of the best known dinosaur groups in the Late Cretaceous, and their unquestionable fossil re-cords are exclusively restricted to western North America. Here we report a new ceratopsid dinosaur, Sinoceratops zhuchengensis gen. et sp. nov., from the Upper Cretaceous Wangshi Group of Zhucheng, Shandong Province, China. Cladistic analysis placesthis new taxon as the only known ceratopsid from outside North America, in a basal position within the Centrosaurinae. It is con-siderably larger than most other centrosaurines but similar in size to basal chasmosaurines. Furthermore, it is more similar tochasmosaurines than to other centrosaurines in several features, thus blurring the distinction of the two ceratopsid subgroups. Thisnew find not only provides significant information on the morphological transition from non-ceratopsid to ceratopsid dinosaurs,but also complicates the biogeography of the Ceratopsidae, and further demonstrates that fossil sampling has profound effects onreconstructing dinosaurian biogeography.

Abstract: Recent work in the Campanian Aguja Formation of Big Bend, Texas, has resulted in the recovery of two frontoparietal domes from a new genus of pachycephalosaur. Texacephale langstoni gen. et sp. nov. is diagnosed by a tall, arched nasal boss, flange-like processes articulating the dome with the peripheral elements, and a low pedicel separating the cerebral fossa from the skull roof. The skull dome is composed largely of the fused frontals and parietals, with limited participation of the peripheral elements, and the supratemporal fenestrae remain open. Phylogenetic analysis indicates that Texacephale langstoni is a basal member of the Pachycephalosauria. The discovery of Texacephale supports previous suggestions that the dinosaur fauna of Texas was distinct from that of contemporary assemblages to the north. The phylogenetic analysis presented here indicates that the Asian pachycephalosaurs form a monophyletic group, deeply nested within the Pachycephalosauridae, and that the basal members of the group are all North American. This finding indicates that pachycephalosaurids originated in North America, rather than Asia, as previously believed. The high diversity of North American pachycephalosaurs and the late appearance of pachycephalosaurs in Asia are consistent with this hypothesis. The biology of Texacephale and other Pachycephalosauridae are also discussed. The morphology of the dome in Texacephale and other pachycephalosaurs supports the hypothesis that pachycephalosaurids engaged in intraspecific combat, while the occurrence of Texacephale and other pachycephalosaurs in nearshore deposits argues that the pachycephalosaurs were not restricted to inland habitats.

A new alvarezsaurid theropod, Xixianykus zhangi gen. et sp. nov., is described based on a partial postcranial skeleton collected from the Upper Cretaceous Majiacun Formation of Xixia County, Henan Province. The new taxon can be diagnosed by the following autapomorphies: sacral rib-transverse process complexes and zygapophyses fused to form separate anterior and posterior laminae; distinct fossa dorsal to antitrochanter on lateral surface of ilium; short ridge along posterior surface of pubic shaft near proximal end; distinct depression on lateral surface of ischium near proximal end; sharp groove along posterior surface of ischium; distal end of femur with transversely narrow ectocondylar tuber that extends considerable distance proximally as sharp ridge; transversely narrow tibial cnemial crest with sharp, ridgelike distal half; lateral margin of tibiotarsus forms step near distal end; fibula with substantial extension of proximal articular surface onto posterior face of posteriorly curving shaft; distal tarsals and metatarsals co-ossified to form tarsometatarsus; and sharp flange along anteromedial margin of metatarsal IV near proximal end. Cladistic analysis places this taxon as a basal parvicursorine within the Alvarezsauridae, a position consistent with the presence of several incipiently developed parvicursorine features in this taxon and also with its relatively early geological age. A brief analysis of vertebral functional morphology, together with data from the hindlimb, suggests that parvicursorines represent extreme cursors among non-avian dinosaurs.

Zootaxa: A basal parvicursorine (Theropoda: Alvarezsauridae) from the Upper Cretaceous of China

A new troodontid dinosaur, Xixiasaurus henanensis gen. et sp. nov., from the Upper Cretaceous Majiacun Formation of Xixia Basin, Henan Province, is erected, based on a partial skull. It is characterized by bearing 22 maxillary teeth, a distinct opening on the lateral surface of the base of nasal process of the premaxilla, the rostral end of the upper jaw forming a tapered U-shape, and the mandibular symphyseal region slightly inflected medially. Xixiasaurus is most closely related to the Mongolian Byronosaurus among troodontids. Byronosaurus, Urbacodon and Xixiasaurus may form a new clade, suggesting an endemic radiation of troodontids across Asia, including multiple taxa without dental serrations. The discovery of Xixiasaurus in the Xixia Basin may imply that the Xixiasaurus-bearing Majiacun Formation is Campanian in age.

Acta Palaeontologica Polonica: A new troodontid (Theropoda: Troodontidae) from the Late Cretaceous of central China, and the radiation of Asian troodontids