Updated: February 10, 2011
Additions/Comments:

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.

Proceedings of The Royal Society: A new transitional sauropodomorph dinosaur from the Early Jurassic of South Africa and the evolution of sauropod feeding and quadrupedalism

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 species of basal neoceratopsian dinosaur Archaeoceratops yujingziensis, is described. The specimen was collected from the Lower Cretaceous Xinminpu Group of the Yujingzi Basin in the Mazongshan area of northwestern China, and is represented by a partial skull, right mandible, and partial postcranial skeleton. A. yujingziensis differs from the type species, A. oshimai, in having a laterally deflected rostral end of the maxilla; striations on the enamaled premaxillary teeth; absence of a primary ridge on the maxillary teeth; and a horizontal shelf on the dentary teeth. The discovery of A. yujingziensis extends the geographic distribution of the genus 100km southeast, and is compatible with the Early Cretaceous age designation for the dinosaur-bearing beds of the Yujingzi Basin in the Mazongshan area.

New Perspectives on Horned Dinosaurs: The Royal Tyrrell Museum Ceratopsian Symposium. Bloomington and Indianapolis: Indiana University Press. pp. 59–67.

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: A new titanosaur, Atsinganosaurus velauciensis, gen. and sp. nov. is described from well-preserved remains from the new Upper Cretaceous locality of Velaux-La Bastide Neuve (Aix-en-Provence Basin, France). This taxon is mainly diagnosed by a combination of characters, which differentiates it without ambiguity from other European Late Cretaceous taxa (Lirainosaurus, Ampelosaurus and Magyarosaurus). Atsinganosaurus confirms the presence in western Europe during the latest Cretaceous of a third titanosaurian species, slender and less derived which allows us to better understand the evolutionary and paleobiogeographical history of this group during the Cretaceous.

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.

Emily Willoughby

Abstract: Islands are noted for the occurrence of aberrant, endemic, and dwarfed taxa (the “island effect”). Late Cretaceous vertebrate assemblages of Romania and elsewhere in Europe are classic examples of island faunas in the fossil record, and are characterized by dwarfed herbivorous dinosaurs and other endemic taxa that are noticeably primitive relative to their mainland contemporaries. Fossils of the predators inhabiting the European paleoislands, however, are exceptionally rare and fragmentary. We describe a new dromaeosaurid theropod, based on an articulated skeleton from the Maastrichtian of Romania, which represents the most complete predatory dinosaur from the middle to Late Cretaceous of Europe. This taxon is characterized by a peculiar body plan, most notably extensive fusion in the hand and distal hindlimb, a highly retroverted pelvis with enlarged femoral muscle attachments, and a pair of hyperextensive pedal claws. However, unlike the island-dwelling herbivorous dinosaurs, its closest relatives are contemporary similar-sized Laurasian taxa, indicating faunal connections between Asia and the European islands late into the Cretaceous. This theropod provides support for the aberrant nature of the Late Cretaceous European island-dwelling dinosaurs, but indicates that predators on these islands were not necessarily small, geographically endemic, or primitive.

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.

Abstract: Ornithomimosaurs (ostrich-mimic dinosaurs) are a common element of some Cretaceous dinosaur assemblages of Asia and North America. Here, we describe a new species of ornithomimosaur, Beishanlong grandis, from an associated, partial postcranial skeleton from the Aptian-Albian Xinminpu Group of northern Gansu, China. Beishanlong is similar to another Aptian-Albian ornithomimosaur, Harpymimus, with which it shares a phylogenetic position as more derived than the Barremian Shenzhousaurus and as sister to a Late Cretaceous clade composed of Garudimimus and the Ornithomimidae. Beishanlong is one of the largest definitive ornithomimosaurs yet described, though histological analysis shows that the holotype individual was still growing at its death. Together with the co-eval and sympatric therizinosaur Suzhousaurus and the oviraptorosaur Gigantraptor, Beishanlong provides evidence for the parallel evolution of gigantism in separate lineages of beaked and possibly herbivorous coelurosaurs within a short time span in Central Asia.

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

Arturo de Miguel

Abstract: Blasisaurus canudoi gen. et sp. nov. is described on the basis of disarticulated skull and lower jaw remains found in the Blasi 1 locality of Arén (Huesca, south-central Pyrenees of Spain), located in the upper part of the Arén Formation, late Maastrichtian in age. This new lambeosaurine hadrosaurid is characterized by a jugal combining a hook-like dorsal edge of the posterior process and a narrow, D-shaped infratemporal fenestra. Blasisaurus differs from Arenysaurus from the Blasi 3 site of Arén mainly by the absence of secondary ridges in the dentary teeth, and from Koutalisaurus (probably a junior synonym of Pararhabdodon) from the Isona region of Lleida by the anteriormost portion of the dentary that is modestly deflected ventrally. A phylogenetic analysis places Blasisaurus as closely related to Arenysaurus in a clade of basal lambeosaurines more derived than Tsintaosaurus and Jaxartosaurus; this clade forms part of a polytomy with Amurosaurus and with more derived lambeosaurines. Palaeobiogeographically, the presence of Blasisaurus and other hadrosaurids in the Maastrichtian European archipelago suggests one or, more probably, a series of dispersal events from Asia across intermittent land bridges during the second half of the Late Cretaceous.

Informaworld: Blasisaurus canudoi gen. et sp. nov., a new lambeosaurine dinosaur (Hadrosauridae) from the Latest Cretaceous of Arén (Huesca, Spain)

Abstract: The sub-complete skeleton of a new basal Iguanodon, Bolong yixianensis gene.et sp. November., was discovered in the Yixian Formation of Western Liaoning Province, China. This new taxon is characterized by several cranial and dental autapomorphies: a depressed area at between the maxilla and lachrymal junction, the caudal ramus of prefrontal rostrocaudally forming a depressed area above-the orbital margin, caudally the ventral process running parallel to the ventral margin of the predentary, the articular surface for the rostrodorsal predentary occupying less Than two-Thirds of the height of the dentary and the rostral tip of dentary therefore situated above-the ventral third of the bone, and distally deflected the primary ridge on maxillary crowns. It differs from Jinzhousaurus, also from the Yixian Fm of Western Liaoning by at least 14 cranial and dental characters, Including the not-down-turner in sti tip rostral maxilla, ventral process in predentary bifurcate, with Several secondary ridges on maxillary teeth, etc. Bolong is one of the most basal iguanodontoids ever discovered in Asia.

Abstract: It was traditionally thought that the oldest known dinosaur assemblages were not diverse, and that their early diversification and numerical dominance over other tetrapods occurred during the latest Triassic. However, new evidence gathered from the lower levels of the Ischigualasto Fm. of Argentina challenges this view. New dinosaur remains are described from this stratigraphical unit, including the new species Chromogisaurus novasi. This taxon is distinguished from other basal dinosauriforms by the presence of proximal caudals without median notch separating the postzygapophyses, femoral lateral surface with deep and large fossa immediately below the trochanteric shelf, and metatarsal II with strongly dorsoventrally asymmetric distal condyles. A phylogenetic analysis found Chromogisaurus to lie at the base of Sauropodomorpha, as a member of Guaibasauridae, an early branch of basal sauropodomorphs composed of Guaibasaurus, Agnosphitys, Panphagia, Saturnalia and Chromogisaurus. Such an affinity is for the first time suggested for Guaibasaurus, whereas Panphagia is not recovered as the most basal sauropodomorph. Furthermore, Chromogisaurus is consistently located as more closely related to Saturnalia than to any other dinosaur. Thus, the Saturnalia + Chromogisaurus clade is named here as the new subfamily Saturnaliinae. In addition, Eoraptor is found to be the sister-taxon of Neotheropoda, and herrerasaurids to be non-eusaurischian saurischians. The new evidence presented here demonstrates that dinosaurs first appeared in the fossil record as a diverse group, although they were a numerically minor component of faunas in which they occur. Accordingly, the early increase of dinosaur diversity and their numerical dominance over other terrestrial tetrapods were diachronous processes, with the latter preceded by a period of low abundance but high diversity.

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.

Abstract: Carcharodontosaurs were the largest predatory dinosaurs, and their early evolutionary history seems to be more intricate than was previously thought. Until recently, carcharodontosaurs were restricted to a group of large theropods inhabiting the Late Cretaceous Gondwanan land masses but in the last few years Laurasian evidence has been causing a reevaluation of their initial diversification. Here we describe an almost complete and exquisitely preserved skeleton of a medium-sized (roughly six metres long) theropod from the Lower Cretaceous series (Barremian stage) Konservat-Lagerstätte of Las Hoyas in Cuenca, Spain. Cladistic analysis supports the idea that the new taxon Concavenator corcovatus is a primitive member of Carcharodontosauria, exhibiting two unusual features: elongation of the neurapophyses of two presacral vertebrae forming a pointed, hump-like structure and a series of small bumps on the ulna. We think that these bumps are homologous to quill knobs present on some modern birds; the knobs are related to the insertion area of follicular ligaments that anchor the roots of the flight feathers (remiges) to the arm. We propose that Concavenator has integumentary follicular structures inserted on the ulna, as in modern birds. Because scales do not have follicles, we consider the structures anchored to the Concavenator arms to be non-scale skin appendages homologous to the feathers of modern birds. If this is true, then the phylogenetic bracket for the presence of non-scale skin structures homologous to feathers in theropod dinosaurs would be extended to the Neotetanurae, enlarging the scope for explaining the origin of feathers in theropods.

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: 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: 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.

Fukui Prefectural Dinosaur Museum

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

Background
The theropod dinosaur family Troodontidae is known from the Upper Jurassic, Lower Cretaceous, and Upper Cretaceous of Asia and from the Upper Jurassic and Upper Cretaceous of North America. Before now no undisputed troodontids from North America have been reported from the Early Cretaceous.
Methodology/Principal Findings
Herein we describe a theropod maxilla from the Lower Cretaceous Cedar Mountain Formation of Utah and perform a phylogenetic analysis to determine its phylogenetic position. The specimen is distinctive enough to assign to a new genus and species, Geminiraptor suarezarum. Phylogenetic analysis places G. suarezarum within Troodontidae in an unresolved polytomy with Mei, Byronosaurus, Sinornithoides, Sinusonasus, and Troodon + (Saurornithoides + Zanabazar). Geminiraptor suarezarum uniquely exhibits extreme pneumatic inflation of the maxilla internal to the antorbital fossa such that the anterior maxilla has a triangular cross-section. Unlike troodontids more closely related to Troodon, G. suarezarum exhibits bony septa between the dental alveoli and a promaxillary foramen that is visible in lateral view.
Conclusions/Significance
This is the first report of a North American troodontid from the Lower Cretaceous. It therefore contributes to a fuller understanding of troodontid biogeography through time. It also adds to the known dinosaurian fauna of the Cedar Mountain Formation.

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

Background
Basal iguanodontian dinosaurs were extremely successful animals, found in great abundance and diversity almost worldwide during the Early Cretaceous. In contrast to Europe and Asia, the North American record of Early Cretaceous basal iguanodonts has until recently been limited largely to skulls and skeletons of Tenontosaurus tilletti.
Methodology/Principal Findings
Herein we describe two new basal iguanodonts from the Yellow Cat Member of the Cedar Mountain Formation of eastern Utah, each known from a partial skull and skeleton. Iguanacolossus fortis gen. et sp. nov. and Hippodraco scutodens gen. et sp. nov. are each diagnosed by a single autapomorphy and a unique combination of characters.
Conclusions/Significance
Iguanacolossus and Hippodraco add greatly to our knowledge of North American basal iguanodonts and prompt a new comprehensive phylogenetic analysis of basal iguanodont relationships. This analysis indicates that North American Early Cretaceous basal iguanodonts are more basal than their contemporaries in Europe and Asia.

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

Background
Basal iguanodontian dinosaurs were extremely successful animals, found in great abundance and diversity almost worldwide during the Early Cretaceous. In contrast to Europe and Asia, the North American record of Early Cretaceous basal iguanodonts has until recently been limited largely to skulls and skeletons of Tenontosaurus tilletti.
Methodology/Principal Findings
Herein we describe two new basal iguanodonts from the Yellow Cat Member of the Cedar Mountain Formation of eastern Utah, each known from a partial skull and skeleton. Iguanacolossus fortis gen. et sp. nov. and Hippodraco scutodens gen. et sp. nov. are each diagnosed by a single autapomorphy and a unique combination of characters.
Conclusions/Significance
Iguanacolossus and Hippodraco add greatly to our knowledge of North American basal iguanodonts and prompt a new comprehensive phylogenetic analysis of basal iguanodont relationships. This analysis indicates that North American Early Cretaceous basal iguanodonts are more basal than their contemporaries in Europe and Asia.

Lukas Panzarin

Abstract:

Robert Gay

Self-published through Lulu Press: Kayentavenator elysiae", a new tetanuran from the early Jurassic of Arizona" In: Notes on Early Mesozoic Theropods

Sergey Krasovskiy

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.

Abstract: The Seonso Conglomerate (?Santonian – Campanian, Late Cretacous) of Boseong site 5 (southern coast of Korean Peninsula) has yielded well-preserved postcranial material belonging to a new taxon of ornithischian dinosaur, Koreanosaurus boseongensis nov. gen., nov. sp. This dinosaur is characterized by elongated neck vertebrae, very long and massive scapulocoracoid and humerus, proportionally short hindlimbs with a low hindlimb ratio for tibia/femur, and anteroposteriorly-elongated femoral head forming an obtuse 135° angle with the femoral shaft. Koreanosaurus displays a series of neornithischian synapomorphies. Amongst Neornithischia, most features of the postcranial skeleton suggest affinities with basal ornithopods and, amongst them, particularly with a small clade formed by three genera from the Cretaceous of Montana: Zephyrosaurus schaffi, Orodromeus makelai, and Oryctodromeus cubicularis. According to the morphological, phylogenetic, sedimentological, and taphonomic data at hand, it is tentatively postulated that Koreanosaurus was a burrowing dinosaur, like Oryctodromeus.

Lukas Panzarin

ABSTRACT
Background
During much of the Late Cretaceous, a shallow, epeiric sea divided North America into eastern and western landmasses. The western landmass, known as Laramidia, although diminutive in size, witnessed a major evolutionary radiation of dinosaurs. Other than hadrosaurs (duck-billed dinosaurs), the most common dinosaurs were ceratopsids (large-bodied horned dinosaurs), currently known only from Laramidia and Asia. Remarkably, previous studies have postulated the occurrence of latitudinally arrayed dinosaur “provinces,” or “biomes,” on Laramidia. Yet this hypothesis has been challenged on multiple fronts and has remained poorly tested.

Methodology/Principal Findings
Here we describe two new, co-occurring ceratopsids from the Upper Cretaceous Kaiparowits Formation of Utah that provide the strongest support to date for the dinosaur provincialism hypothesis. Both pertain to the clade of ceratopsids known as Chasmosaurinae, dramatically increasing representation of this group from the southern portion of the Western Interior Basin of North America. Utahceratops gettyi gen. et sp. nov.—characterized by short, rounded, laterally projecting supraorbital horncores and an elongate frill with a deep median embayment—is recovered as the sister taxon to Pentaceratops sternbergii from the late Campanian of New Mexico. Kosmoceratops richardsoni gen. et sp. nov.—characterized by elongate, laterally projecting supraorbital horncores and a short, broad frill adorned with ten well developed hooks—has the most ornate skull of any known dinosaur and is closely allied to Chasmosaurus irvinensis from the late Campanian of Alberta.

Conclusions/Significance
Considered in unison, the phylogenetic, stratigraphic, and biogeographic evidence documents distinct, co-occurring chasmosaurine taxa north and south on the diminutive landmass of Laramidia. The famous Triceratops and all other, more nested chasmosaurines are postulated as descendants of forms previously restricted to the southern portion of Laramidia. Results further suggest the presence of latitudinally arrayed evolutionary centers of endemism within chasmosaurine ceratopsids during the late Campanian, the first documented occurrence of intracontinental endemism within dinosaurs.

Abstract: A nearly complete right dentary originally noted by Mantell in 1848 is redescribed. The specimen, NHMUK 28660, was discovered in a quarry near Cuckfield, West Sussex, from the same formation as the original teeth of Iguanodon anglicus. Fresh examination reveals that NHMUK 28660 exhibits a single autapomorphy (a row of foramina extending from the ventral surface of the symphysis onto the lateral surface of the dentary) and a unique combination of characters that distinguish it from all other iguanodontian dentaries. In light of this and because I. anglicus is regarded as a nomen dubium to which additional material cannot be unambiguously referred, NHMUK 28660 is made the holotype of the new genus and species Kukufeldia tilgatensis.

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 sauropod dinosaur, Liubangosaurus hei gen. et sp. nov., is erected based on a specimen represented by five articulated middle-caudal dorsal vertebrae, which was discovered in the Lower Cretaceous Napai Formation of Guangxi Province, southern China. This new taxon is diagnosed by a unique combination of derived features: prezygapophysis closely contacts with parapophysis, with the prdl and prpl absent; presence of cavity on the dorsal surface of the diapophysis; neural spine very low, with its distal end level with that of diapophysis; distal end of the neural spine strongly expanded laterally to form a platform; marked fossa formed between the infradiapophyseal lamina and the parapophysis; broad, flat area of featureless bone on lateral surface of neural arch; vertically directed infradiapophyseal lamina expands or bifurcates ventrally to form a inverted “Y”; highly positioned parapophyses large and tear-drop in shape. The discovery of this new taxon increases the diversity of sauropods in China during the Early Cretaceous.

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.

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.

Abstract:
A new genus of long-horned chasmosaurine ceratopsid is described from the Dinosaur Park Formation (upper Campanian) of Western Canada. Mojoceratops perifania is represented by a skull and a parietal from the Dinosaur Park Formation of Alberta and an isolated parietal from the Dinosaur Park Formation of Saskatchewan. Several other specimens are provisionally referred to this taxon. While Mojoceratops shares many plesiomorphies with Chasmosaurus, the animal lacks the forward-curving parietal epoccipitals and reduced postorbital horns that diagnose the genus Chasmosaurus, and it differs from all other chasmosaurines in exhibiting a prominent sulcus on the anterior margin of the parietal, swellings on the anterodorsal surface of the parietal rami, and a small accessory process on the first parietal epoccipital. Other unusual features include anteriorly extended parietal fenestrae, a broad, heart-shaped frill, and transverse expansion of the postfrontal fontanelle. The type material of “Eoceratops canadensis” and “Chasmosaurus kaiseni” are nondiagnostic and these names are therefore considered nomina dubia, but their morphology is consistent with Mojoceratops and they probably belong to this genus. The frill of Mojoceratops shows marked variation. Some of this variation probably results from intraspecific variation or ontogenetic changes, but because the Dinosaur Park Formation encompasses more than a million years of time, evolution may explain some of these differences. Phylogenetic analysis shows that Mojoceratops forms a clade with Agujaceratops mariscalensis; Chasmosaurus is the most basal member of Chasmosaurinae.

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:
Remains of titanosaurian sauropods are common in the Upper Cretaceous (Maastrichtian) of the Haţeg Basin, Romania, but their usual occurrence as either isolated elements or dispersed bones in multitaxon bonebeds has hampered the understanding of their detailed anatomy or systematic position. The discovery of a partial articulated skeleton in floodplain deposits at Nǎlaţ-Vad, preserving parts of the vertebral column and pelvic girdle, allows for the first time a more detailed understanding of the axial anatomy of the Romanian titanosaurs. The specimen is described as a new taxon, Paludititan nalatzensis gen. et sp. nov., based on several autapomorphies: presence of an accessory anterior centrodiapophyseal lamina in the posterior dorsals; dorsal segments of the anterior and posterior centrodiapophyseal laminae parallel in posterior dorsals; presence of amphiplatyan mid-caudal vertebrae within the procoelous series; anterior caudal vertebrae with narrow neural spines showing anteriorly projecting anterodorsal corner, and presence of a posterolateral buttress on the iliac peduncle of the ischium. The description of Paludititan supports a higher titanosaurian diversity in the Haţeg assemblage than previously recognized, and will contribute to the clarification of the taxonomic status of Magyarosaurus, the only titanosaur previously described from the area, and its included species. Phylogenetic analyses of Paludititan show it is a relatively derived titanosaur, but yields equivocal results as to its more precise systematic position and relationships, depending on the dataset used. These preliminary results suggest that development of a standard dataset for cladistic analyses should represent one of the major tasks of sauropod systematics.

Abstract:
We describe a new sauropod Titanosauridae schroederi Panamericansaurus Allen Formation, Neuquén Province. The holotype was found in rocks from the lower Campanian-Maastrichtian of NW Patagonia. This new taxon is strongly located within the South American titanosaurids Aeolosaurini. Within this Aeolosaurinos synapomorphic characters shared all except the anterior margin in previous flow is not directed anterodorsal half, this morphology is present also in A. colhuehuapensis . P. schroederi is unique in presenting middle caudal-directed anterodorsal prezygapophysis subsequent equal to or shorter than the length of the base of the vertebral body, postzigapofisis located in medial position with respect to the vertebral body, expanded dorsoventrally espinoprezigapofiseal sheet in middle caudal and humerus with a robustness index of less than 0.40 different from all other Aeolosaurinos. Is the first record of a dinosaur for the Allen Formation in the province of Neuquen, Argentina.

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

Abstract

Abstract
Herrerasauridae comprises a basal clade of dinosaurs best known from the Upper Triassic of Argentina and Brazil, which have yielded remains of Herrerasaurus ischigualastensis and Staurikosaurus pricei, respectively. Systematic opinion regarding the position of Herrerasauridae at the base of Dinosauria has varied. Here we describe a new herrerasaurid, Sanjuansaurus gordilloi gen. n. sp. n., based on a partial skeleton from Carnian-age strata of the the Upper Triassic Ischigualasto Formation of northwestern Argentina. The new taxon is diagnosed by numerous features, including long, band-shaped and posterolaterally oriented transverse process on the posterior cervical vertebrae; neural spines of the sixth to eighth dorsal vertebrae, at least, bearing acute anterior and posterior processes; scapula and coracoid with everted lateral margins of the glenoid; and short pubis (63% of the femoral length). Phylogenetic analysis placed Sanjuansaurus within a monophyletic Herrerasauridae, at the base of Theropoda and including Herrerasaurus and Staurikosaurus. The presence of Sanjuansaurus at the base of the Ischigualasto Formation, along with other dinosaurs such as Herrerasaurus, Eoraptor, Panphagia, and Chromogisaurus suggests that saurischian dinosaurs in southwestern Pangea were already widely diversified by the late Carnian rather than increasing in diversity across the Carnian-Norian boundary.

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

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.

Nobu Tamura

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.

N. Tamura

Abstract
Recent discoveries of basal dromaeosaurids from the Early Cretaceous Jiufotang and Yixian formations of Liaoning, China, add significant new information about the transition from non-avian dinosaurs to avians. Here we report on a new dromaeosaurid, Tianyuraptor ostromi gen. et sp. nov., from the Early Cretaceous Yixian Formation of western Liaoning, China, based on a nearly complete skeleton. Tianyuraptor possesses several features only seen in other Liaoning dromaeosaurids, although to a less developed degree, and it also exhibits features unknown in Laurasian dromaeosaurids but present in the Gondwanan dromaeosaurids and basal avialans, thus reducing the morphological gap between these groups. Tianyuraptor possesses a comparatively small furcula and proportionally short forelimbs. This lies in stark contrast to the possible capacity for flight in the microraptorines, which have proportionally long and robust forelimbs and large furculae. The presence of such striking differences between the Early Cretaceous Jehol dromaeosaurids reveals a great diversity in morphology, locomotion and ecology early in dromaeosaurid evolution.

Abstract
A new sauropod, Tonganosaurus hei gen. et sp. nov. from the Yimen Formation (Lower Jurassic) of southern Sichuan, China, is described on the basis of a collection of bones. These fossils include about 20 vertebrae, a complete right pectoral girdle and right forelimb, the distal end of a left scapula, a pair of complete ischia, a complete right hindlimb, the proximal and distal ends of a left femur, right metatarsals (mt. I,II,III and V),a right pedal ungual,and ten neural spine and rib fragments. The third cervical and anterior caudals are most similar in shape to those of the mamenchisaurid Omeisaurus (from the Middle Jurassic,Sichuan Basin), and quite different from those of other sauropods. The material was therefore assigned to the Family Mamenchisauridae Young & Chao, 1972 and a new genus and species were established. This represents the first discovery of a sauropod in the Lower Jurassic of China since Gongxianosaurus was found in Sichuan Basin. The Tonganosaurus material is of great importance for understanding the phylogenetics of the early Sauropoda.

Abstract
Background
During much of the Late Cretaceous, a shallow, epeiric sea divided North America into eastern and western landmasses. The western landmass, known as Laramidia, although diminutive in size, witnessed a major evolutionary radiation of dinosaurs. Other than hadrosaurs (duck-billed dinosaurs), the most common dinosaurs were ceratopsids (large-bodied horned dinosaurs), currently known only from Laramidia and Asia. Remarkably, previous studies have postulated the occurrence of latitudinally arrayed dinosaur “provinces,” or “biomes,” on Laramidia. Yet this hypothesis has been challenged on multiple fronts and has remained poorly tested.

Methodology/Principal Findings
Here we describe two new, co-occurring ceratopsids from the Upper Cretaceous Kaiparowits Formation of Utah that provide the strongest support to date for the dinosaur provincialism hypothesis. Both pertain to the clade of ceratopsids known as Chasmosaurinae, dramatically increasing representation of this group from the southern portion of the Western Interior Basin of North America. Utahceratops gettyi gen. et sp. nov.—characterized by short, rounded, laterally projecting supraorbital horncores and an elongate frill with a deep median embayment—is recovered as the sister taxon to Pentaceratops sternbergii from the late Campanian of New Mexico. Kosmoceratops richardsoni gen. et sp. nov.—characterized by elongate, laterally projecting supraorbital horncores and a short, broad frill adorned with ten well developed hooks—has the most ornate skull of any known dinosaur and is closely allied to Chasmosaurus irvinensis from the late Campanian of Alberta.

Conclusions/Significance
Considered in unison, the phylogenetic, stratigraphic, and biogeographic evidence documents distinct, co-occurring chasmosaurine taxa north and south on the diminutive landmass of Laramidia. The famous Triceratops and all other, more nested chasmosaurines are postulated as descendants of forms previously restricted to the southern portion of Laramidia. Results further suggest the presence of latitudinally arrayed evolutionary centers of endemism within chasmosaurine ceratopsids during the late Campanian, the first documented occurrence of intracontinental endemism within dinosaurs.

Abstract
Background
During much of the Late Cretaceous, a shallow, epeiric sea divided North America into eastern and western landmasses. The western landmass, known as Laramidia, although diminutive in size, witnessed a major evolutionary radiation of dinosaurs. Other than hadrosaurs (duck-billed dinosaurs), the most common dinosaurs were ceratopsids (large-bodied horned dinosaurs), currently known only from Laramidia and Asia. Remarkably, previous studies have postulated the occurrence of latitudinally arrayed dinosaur “provinces,” or “biomes,” on Laramidia. Yet this hypothesis has been challenged on multiple fronts and has remained poorly tested.

Methodology/Principal Findings
Here we describe two new, co-occurring ceratopsids from the Upper Cretaceous Kaiparowits Formation of Utah that provide the strongest support to date for the dinosaur provincialism hypothesis. Both pertain to the clade of ceratopsids known as Chasmosaurinae, dramatically increasing representation of this group from the southern portion of the Western Interior Basin of North America. Utahceratops gettyi gen. et sp. nov.—characterized by short, rounded, laterally projecting supraorbital horncores and an elongate frill with a deep median embayment—is recovered as the sister taxon to Pentaceratops sternbergii from the late Campanian of New Mexico. Kosmoceratops richardsoni gen. et sp. nov.—characterized by elongate, laterally projecting supraorbital horncores and a short, broad frill adorned with ten well developed hooks—has the most ornate skull of any known dinosaur and is closely allied to Chasmosaurus irvinensis from the late Campanian of Alberta.

Conclusions/Significance
Considered in unison, the phylogenetic, stratigraphic, and biogeographic evidence documents distinct, co-occurring chasmosaurine taxa north and south on the diminutive landmass of Laramidia. The famous Triceratops and all other, more nested chasmosaurines are postulated as descendants of forms previously restricted to the southern portion of Laramidia. Results further suggest the presence of latitudinally arrayed evolutionary centers of endemism within chasmosaurine ceratopsids during the late Campanian, the first documented occurrence of intracontinental endemism within dinosaurs.

Abstract
The fossil record of tyrannosauroid theropods is marked by a substantial temporal and morphological gap between small-bodied, Barremian taxa, and extremely large-bodied taxa from the latest Cretaceous. Here we describe a new tyrannosauroid, Xiongguanlong baimoensis n. gen. et sp., from the Aptian–Albian Xinminpu Group of western China that represents a phylogenetic, morphological, and temporal link between these disjunct portions of tyrannosauroid evolutionary history. Xiongguanlong is recovered in our phylogenetic analysis as the sister taxon to Tyrannosauridae plus Appalachiosaurus, and marks the appearance of several tyrannosaurid hallmark features, including a sharp parietal sagittal crest, a boxy basicranium, a quadratojugal with a flaring dorsal process and a flexed caudal edge, premaxillary teeth bearing a median lingual ridge, and an expanded axial neural spine surmounted by distinct processes at its corners. Xiongguanlong is characterized by a narrow and elongate muzzle resembling that of Alioramus. The slender, unornamented nasals of Xiongguanlong are inconsistent with recent hypotheses of correlated progression in tyrannosauroid feeding mechanics, and suggest more complex patterns of character evolution in the integration of feeding adaptations in tyrannosaurids. Body mass estimates for the full-grown holotype specimen of Xiongguanlong fall between those of Late Cretaceous tyrannosaurids and Barremian tyrannosauroids, suggesting that the trend of increasing body size observed in North American Late Cretaceous Tyrannosauridae may extend through the Cretaceous history of Tyrannosauroidea though further phylogenetic work is required to corroborate this.

Proceedings of the Royal Society B: A longirostrine tyrannosauroid from the Early Cretaceous of China

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.

A new prosauropod dinosaur Xixiposaurus suni gen. et sp. nov. from the lower Lufeng Formation of lower Jurassic in Lufeng of Yunnan, China is reported. The diagnostic characters are as follows: steep slant of the skull roof in lateral view; the maximum height of the mandible larger than twice of minimum height of the dentary; the 4th cervical centrum being longest in cervicals; minimum width of the pubic apron wider of the pubic peduncle; the fourth trochanter having a V-shape notch in lateral view. The phylogenetic analysis shows that it is one of the most derived forms among Chinese prosauropods.

NobuTamura

ABSTRACT
Background
The ceratopsians represent one of the last dinosaurian radiations. Traditionally the only universally accepted speciose clade within the group was the Ceratopsidae. However, recent discoveries and phylogenetic analyses have led to the recognition of a new speciose clade, the Leptoceratopsidae, which is predominantly known from the Upper Cretaceous of North America.
Methodology/Principal Findings
Here we report a new leptoceratopsid taxon, Zhuchengceratops inexpectus gen. et sp. nov., based on a partial, articulated skeleton recovered from the Upper Cretaceous Wangshi Group of Zhucheng, Shandong Province, China. Although Zhuchengceratops is significantly different from other known leptoceratopsids, it is recovered as a derived member of the group by our phylogenetic analysis. Furthermore, Zhuchengceratops exhibits several features previously unknown in leptoceratopsids but seen in ceratopsids and their close relatives, suggesting that the distribution of morphological features within ceratopsians is more complex than previously realized.
Conclusion/Significance
The discovery of Zhuchengceratops increases both the taxonomic diversity and the morphological disparity of the Leptoceratopsidae, providing further support for the hypothesis that this clade represents a successful radiation of horned dinosaurs in parallel with the Ceratopsidae in the Late Cretaceous. This documents a surprising case of the coexistence and radiation of two closely-related lineages with contrasting suites of jaw and dental features that probably reflect adaptation to different food resources.

We describe a new coelurosaurian theropod, Zuolong salleei, gen. et sp. nov., from exposures of the upper part of the Shishugou Formation at the Wucaiwan locality, Xinjiang Autonomous Region, People's Republic of China. Zuolong has a large, inclined quadrate foramen that extends onto the medial surface of the quadratojugal, an unusually large fovea capitis on the femoral head, and an apomorphically large distal condyle of metatarsal III with a medially projecting flange on the extensor surface. Radiometric dating of the Shishugou Formation constrains the age of the specimen to the beginning of the Late Jurassic (Oxfordian). A cladistic analysis of Zuolong salleei in a broadly sampled theropod data matrix recovers it as a basal coelurosaur. These data make Zuolong one of the oldest coelurosaur fossils yet known that preserves both cranial and postcranial bones.