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A bizarre, humped Carcharodontosauria (Theropoda) from the Lower Cretaceous of Spain

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.

New Crocodyliforms from Southwestern Europe and Definition of a Diverse Clade of European Late Cretaceous Basal Eusuchians

The late Campanian-early Maastrichtian site of Lo Hueco (Cuenca, Spain) has provided a set of well-preserved crocodyliform skull and lower jaw remains, which are described here and assigned to a new basal eusuchian taxon, Lohuecosuchus megadontos gen. et sp. nov. The reevaluation of a complete skull from the synchronous site of Fox-Amphoux (Department of Var, France) allows us to define a second species of this new genus. Phylogenetic analysis places Lohuecosuchus in a clade exclusively composed by European Late Cretaceous taxa. This new clade, defined here as Allodaposuchidae, is recognized as the sister group of Hylaeochampsidae, also comprised of European Cretaceous forms. Allodaposuchidae and Hylaeochampsidae are grouped in a clade identified as the sister group of Crocodylia, the only crocodyliform lineage that reaches our days. Allodaposuchidae shows a vicariant distribution pattern in the European Late Cretaceous archipelago, with several Ibero-Armorican forms more closely related to each other than with to Romanian Allodaposuchus precedens.

Vertebrate fauna at the Allosaurus fossil-site of Andrés (Upper Jurassic), Pombal, Portugal

An overview of the faunistic diversity of the Andres fossil-site from the Portuguese Upper Jurassic is presented. This work provides a preliminary approach on the vertebrate fauna known at present. Although this quarry is known since the 1990’s, due to the description on the first robust evidence of a member of the neotetanuran genus Allosaurus outside North America, the results presented here are mainly derived from the analysis of the elements found during the second and third field seasons in 2005. At the moment, among the material collected from Andres it was identified remains that represent a diverse vertebrate fauna, including fishes, sphenodonts, crocodrylomorphs, pterosaurs, and at least, seven distinct dinosaur forms. The recovery of this diverse and abundant osteological collection from one unique fossil-site is noteworthy for the Upper Jurassic Portuguese record, and only comparable with those from the Guimarota coalmine. Due to these two features plus the good preservation of the fossils, the Andres quarry may be a site of reference for the analysis of vertebrate ecosystems from the Portuguese Upper Jurassic. Dinosaur elements are the most abundant fossils, and among them it is particulary common the presence of remains identified as Allosaurus. These new evidences allow testing the previus phylogenetical hypothesys ascribing the firsts theropod remains from Andres to A. fragilis, a species described in synchronic levels of the North American Morrison Formation. The similarity between the Allosaurus remains collected in Andres and some specimens from the Morrison Formation seems to point the existence of a genetic flow between some continental vertebrates on both sides of the proto-north Atlantic during the Upper Jurassic. Favourable tectonic conditions for the occurrence of punctual contacts between the two continents is, at present, the best scenario for explain this situation.

A New Sail-Backed Styracosternan (Dinosauria: Ornithopoda) from the Early Cretaceous of Morella, Spain.

A new styracosternan ornithopod genus and species is here described based on a partial postcranial skeleton and an associated dentary tooth of a single specimen from the Arcillas de Morella Formation (Early Cretaceous, late Barremian) at the Morella locality, (Castellón, Spain). Morelladon beltrani gen. et sp. nov. is diagnosed by eight autapomorphic features. The set of autapomorphies includes: very elongated and vertical neural spines of the dorsal vertebrae, midline keel on ventral surface of the second to fourth sacral vertebrae restricted to the anterior half of the centrum, a posterodorsally inclined medial ridge on the postacetabular process of the ilium that meets its dorsal margin and distal end of the straight ischial shaft laterally expanded, among others. Phylogenetic analyses reveal that the new Iberian form is more closely related to its synchronic and sympatric contemporary European taxa Iguanodon bernissartensis and Mantellisaurus atherfieldensis, known from Western Europe, than to other Early Cretaceous Iberian styracosternans (Delapparentia turolensis and Proa valdearinnoensis). The recognition of Morelladon beltrani gen. et sp. nov. indicates that the Iberian Peninsula was home to a highly diverse medium to large bodied styracosternan assemblage during the Early Cretaceous.

New evidence of Ceratosaurus (Dinosauria: Theropoda) from the Late Jurassic of the Lusitanian Basin, Portugal

A theropod assigned to Ceratosaurus was previously reported from the Portuguese Lusitanian Basin based on a limited number of elements of a single individual. Here, we describe newly discovered elements that likely pertain to same, earlier described, specimen. The new elements provide additional evidence that the range of Ceratosaurus spanned from what is now North America into Europe. Previously, some differences were noted between the Portuguese specimens and the North American Ceratosaurus. We consider these differences to be trivial and attribute them to individual variation and/or ontogeny. The following set of features (lesser trochanter positioned low on the femur; crista tibiofibularis obliquely oriented with respect to the axis of the femoral shaft; infrapopliteal ridge present posteriorly on the femur; large cnemial crest; and medial condyle of the tibia continuous with proximal end) indicate that the Portuguese specimen is assignable to Ceratosaurus. This record constitutes one of the scarce evidence of basal ceratosaurian theropods in the Late Jurassic of Europe. Despite the abundance, diversity and wide geographical distribution of ceratosaurs during the Late Cretaceous, its early evolutionary history remains poorly understood. The Portuguese specimens constitute an important evidence for the knowledge of the paleobiogeographic evolution of the clade during the Late Jurassic.

A new dryosaurid ornithopod (Dinosauria, Ornithischia) from the Late Jurassic of Portugal

ABSTRACT A new dryosaurid ornithopod, Eousdryosaurus nanohallucis, gen. et sp. nov., is described here based on a single specimen from the Late Jurassic Alcobaça Formation of Portugal. Eousdryosaurus nanohallucis is distinguished from all other dryosaurids by eight autapomorphic features and an unique combination of characters, some of which are also shared by other dryosaurids. Eousdryosaurus is linked with Dryosauridae, because the fourth trochanter is proximally placed and widely separated from the scar for the insertion of the M. caudifemoralis longus, which is restricted to the medial surface of the femoral shaft. Phylogenetic analysis nests Eousdryosaurus in an unresolved polytomy at the base of Dryosauridae together with Callovosaurus, Dryosaurus, and Kangnasaurus. The complete pes of Eousdryosaurus, which has a phalangeal formula of 1-3-4-5-0, supports the putative autapomorphic reduction of the dryosaurid pes that also occurs in parallel in more derived ornithopods.

Turiasauria-like teeth from the Upper Jurassic of the Lusitanian Basin, Portugal

Turiasauria is a clade of eusauropods with a wide stratigraphic range that could extend from the Bathonian to the lower Aptian including Turiasaurus, Losillasaurus, Zby and putatively, Galveosaurus, Atlasaurus and isolated remains from Middle Jurassic-to-Lower Cretaceous. Some are characterised by the presence of heart-shaped teeth. Several tooth occurrences from the Portuguese Upper Jurassic with this type of morphology (SI: 1.1–1.8) are reported and discussed. If this morphology is regarded as synapomorphic of Turiasauria, the teeth will be tentatively related to this clade. From a sample of 43 teeth, three main morphotypes are described. Three hypotheses might explain the morphological variation: (1) the range of tooth morphologies indicates variation in the jaw, (2) the range of tooth morphologies indicates taxonomic variation or (3) a combination of both. The general wear pattern in morphotypes I and II starts with a distal facet, then the appearance of mesial/apical facet and finally a ‘V’-shaped facet. In morphotype III, the wear begins with a mesial facet. The variability observed for Portuguese Upper Jurassic specimens is congruent with the morphological variability along the tooth row shown by other sauropods with spatulate/spoon-shaped teeth and it is considered the most parsimonious hypothesis to explain it.

New data on the anatomy of Torvosaurus and other remains of megalosauroid (Dinosauria, Theropoda) from the Upper Jurassic of Portugal

A set of cranial and postcranial specimens, including two partial maxillae, several isolated teeth, vertebrae and appendicular elements of theropod dinosaurs is described. These specimens were collected in different Upper Jurassic sites from the Lusitanian Basin (Portugal) and show several characters that allow its identification as belonging to megalosauroid tetanurans. Some of these elements have a combination of features exclusively shared with other megalosaurids known in the Portuguese record, in particular with the recently described species Torvosaurus gurneyi from synchronic sedimentary levels. The geographic and stratigraphic distribution of the specimens of megalosauroids currently known in the Portuguese record indicates that members of this clade were relatively abundant from the upper Kimmeridgian to the lowermost Tithonian of the Lusitanian Basin, especially in the Consolação Sub-basin. The analysis of the different specimens described allows testing hypotheses about the distribution and variability of some characters among the Portuguese forms related to Torvosaurus.ResumenSe describen varios elementos craneales y postcraneales, incluyendo dos fragmentos maxilares, varios dientes aislados, vértebras y elementos apendiculares de dinosaurios terópodos provenientes de diferentes localidades del Jurásico Superior de la cuenca lusitánica. Este conjunto de evidencias osteológicas presenta una combinación de caracteres que permite identificarlos como pertenecientes a tetanuros megalosauroideos. Algunos de estos elementos presentan características compartidas con Torvosaurus gurneyi, especie recientemente descrita en niveles sedimentarios sincrónicos. La distribución geográfica y estratigráfica de los ejemplares de megalosauroideos conocidos en la actualidad en el registro portugués sugiere que este clado era relativamente abundante en el Kimmeridgiense superior y Tithoniense inferior de la cuenca lusitánica, sobre todo en la subcuenca de Consolação. El análisis de los diferentes ejemplares descritos ha permitido comprobar algunas hipótesis sobre la distribución y variabilidad de algunos caracteres en las formas portuguesas afines a Torvosaurus.

A juvenile allosauroid theropod (Dinosauria, Saurischia) from the Upper Jurassic of Portugal

Abstract A new specimen of a theropod dinosaur found in Upper Jurassic sedimentary levels of the Lusitanian Basin (Portugal) is described. The specimen includes axial (cervical, dorsal, and caudal vertebrae and ribs) and pelvic elements, corresponding to a small-sized and juvenile individual. This specimen is one of the most complete theropod dinosaur from the Upper Jurassic of Portugal, and the only evidence of a post-hatchling juvenile theropod individual currently recognized in this record. The phylogenetic analysis recovered the new specimen as a basal Allosauroidea. It presents a combination of characters shared with other allosauroids already known in the Upper Jurassic of the Lusitanian Basin, Allosaurus and Lourinhanosaurus, but also some differences relative to both taxa. Some of these differences may be related to the juvenile condition of the specimen, but other unusual features cannot be properly explained by ontogeny, and are interpreted as having taxonomic significance. This combination of features might justify the description of a new theropod taxon for the Portuguese Upper Jurassic. Nevertheless, the presence of three sympatric and almost synchronic, closely related basal allosauroids requires further exploration of their intra- or interspecific variability.

New data on Late Jurassic sauropods of central and northern sectors of the Bombarral Sub-basin (Lusitanian Basin, Portugal)

Abstract The Upper Jurassic’s central and northern sectors of the Bombarral Sub-basin are relatively poor in sauropod material, highlighting the specimens (mainly teeth) found in the Guimarota mine (Leiria) and the Andrés (Pombal) fossil site. The study of published and the unpublished sauropod material allows for a revision of the present state of sauropod diversity of the Bombarral Sub-basin. These new specimens come from Pombal, Leiria, Batalha, Porto de Mós, Alcobaça and Caldas da Rainha, and include an almost complete posterior or middle dorsal neural spine and a partial caudal series. The systematic re-evaluation of the sauropod record of this sector indicates the presence of turiasaurs, diplodocines, titanosauriforms and an indeterminate eusauropod form. During the last part of the twentieth century, the discovery of fossil vertebrates has increased significantly in the sediments cropping out in the central and northern sectors of the Bombarral Sub-basin (Alcobaça and Bombarral Formations), improving our understanding of the Late Jurassic faunas of the Lusitanian Basin.