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The first paleontological works on Mesozoic vertebrates from Portugal, carried out from the end of the 19th and the first half of the 20th century, provided the discovery of significant collections of vertebrate fossils. These collections are particularly relevant because they include several specimens collected from different regions of the Lusitanian Basin (some of the sites are currently inaccessible), whose fossil record is poorly known. Theropod remains are relatively scarce and generally consist of fragmentary material, mostly assigned to the megalosaurid Megalosaurus from the Middle Jurassic of England, the first dinosaur to be named and a "wastebasket" taxon used by many scientists to identify theropod material. The studied fossils mostly consist of isolated teeth and vertebrae collected from Upper Jurassic levels of the coastal region, with also some material from Lower and Upper Cretaceous strata from the central and northern sectors of the Lusitanian Basin. Here specimens attributed to Megalosaurus from different Portuguese institutions are reviewed and their taxonomic affinity and stratigraphic context are updated. Most specimens actually belong to different theropod groups, including several isolated teeth from different Upper Jurassic localities here assigned to Ceratosaurus, Torvosaurus, andAllosaurus, as well as an isolated tooth from the Lower Cretaceous that is attributed to an indeterminate allosauroid. Other theropod remains consist mostly of vertebral fragments of indeterminate avetheropods and allosau-roids. Elements of other dinosaur groups are also represented, including a few vertebrae here referred to stegosaurians and iguanodontians, as well as a vertebra and some appendicular remains attributed to sauropods. Two vertebrae assigned to thalattosuchians were also identified. The study of this collection allows to better characterize the diversity of Late Jurassic dinosaur faunas from different areas of the Lusitanian Basin and provides some data on the poorly known Cretaceous fossil record of theropods from Portugal. [ABSTRACT FROM AUTHOR]

Xenoposeidon proneneukos is a sauropod dinosaur from the Early Cretaceous Hastings Group of England. It is represented by a single partial dorsal vertebra, NHMUK PV R2095, which consists of the centrum and the base of a tall neural arch. Despite its fragmentary nature, it is recognisably distinct from all other sauropods, and is here diagnosed with five unique characters. One character previously considered unique is here recognised as shared with the rebbachisaurid diplodocoid Rebbachisaurus garasbae from the mid-Cretaceous of Morocco: an 'M'-shaped arrangement of laminae on the lateral face of the neural arch. Following the more completely preserved R. garasbae, these laminae are now interpreted as ACPL and lateral CPRL, which intersect anteriorly; and PCDL and CPOL, which intersect posteriorly. Similar arrangements are also seen in some other rebbachisaurid specimens (though not all, possibly due to serial variation), but never in non-rebbachisaurid sauropods. Xenoposeidon is therefore referred to Rebbachisauridae. Due to its inferred elevated parapophysis, the holotype vertebra is considered a mid-posterior dorsal despite its elongate centrum. Since Xenoposeidon is from the Berriasian-Valanginian (earliest Cretaceous) Ashdown Formation of the Wealden Supergroup of southern England, it is the earliest known rebbachisaurid by some 10 million years. Electronic 3Dmodels were invaluable in determining Xenoposeidon's true affinities: descriptions of complex bones such as sauropod vertebrae should always provide them where possible. [ABSTRACT FROM AUTHOR]

The sauropod dinosaur ‘ Bothriospondylus’, originally named on the basis of Late Jurassic remains from England, is demonstrated to be invalid, and the characters used to diagnose it are shown to be obsolescent features which are widespread throughout Sauropoda. Material referred to this genus spans a temporal range from the Middle Jurassic until the early Late Cretaceous and has been described from five different countries, across three continents. These remains represent a wide array of sauropod groups, comprising non-neosauropod eusauropods, a macronarian, titanosauriforms (including at least one definite brachiosaurid) and a rebbachisaurid. The type material of the Middle Jurassic ‘ B. madagascariensis’ represents a derived non-neosauropod eusauropod and possesses two potential autapomorphies. However, as a result of the fragmentary nature of the material and the uncertainty surrounding its association, a new taxon is not erected. Of the numerous specimens referred to ‘ Bothriospondylus’, however, several remains are considered diagnostic: Ornithopsis hulkei (Early Cretaceous, UK), Lapparentosaurus madagascariensis (Middle Jurassic, Madagascar) and Nopcsaspondylus alarconensis (early Late Cretaceous, Argentina). At least three types of sauropod were present in the Bathonian (Middle Jurassic) of north-west Madagascar, with a basal eusauropod ( Archaeodontosaurus), a more derived eusauropod (‘ B. madagascariensis’) and a titanosauriform ( Lapparentosaurus) all approximately contemporaneous. Palaeocontinental reconstructions suggest that Middle Jurassic Madagascan sauropods would still have been capable of global biotic interchange, and this is perhaps reflected in their diverse assemblage. Re-evaluation of these Malagasy forms has shed new light on this important time period in sauropod evolution. [ABSTRACT FROM AUTHOR]

Abstract: Rebbachisauridae is one of the most enigmatic and poorly understood clades of sauropod dinosaurs. They are considered to be basal diplodocoids, are known solely from the Cretaceous (Hauterivian-Coniacian), and have only been recovered from Africa, South America, and Europe. As a result of their extreme skeletal reduction, rebbachisaurid material is highly susceptible to destructive taphonomic processes and thus most remains are highly incomplete and fragmentary. Previous remains attributed to rebbachisaurids from England are restricted to isolated teeth. Here a sauropod scapula from the Lower Cretaceous (Barremian) Wessex Formation of the Isle of Wight, England, is described. Although incomplete, this scapula possesses both the extreme dorsoventral expansion of the scapular blade and the “hook”-like acromial process that are characteristic of rebbachisaurids. This study has also enabled the recognition of a putative local synapomorphy of Rebbachisauridae, with the highest point on the dorsal margin of the scapula blade equal to or exceeding that of the dorsal margin of the proximal plate. This scapula is one of the oldest known examples of a rebbachisaurid and represents the first postcranial remains of this clade to be described from the United Kingdom. In addition, it provides further support for the presence of rebbachisaurids in the Early-mid Cretaceous of Europe. [Copyright &y& Elsevier]

Xenoposeidon proneneukos gen. et sp. nov. is a neosauropod represented by BMNH R2095, a well-preserved partial mid-to-posterior dorsal vertebra from the Berriasian–Valanginian Hastings Beds Group of Ecclesbourne Glen, East Sussex, England. It was briefly described by Lydekker in 1893, but it has subsequently been overlooked. This specimen's concave cotyle, large lateral pneumatic fossae, complex system of bony laminae and camerate internal structure show that it represents a neosauropod dinosaur. However, it differs from all other sauropods in the form of its neural arch, which is taller than the centrum, covers the entire dorsal surface of the centrum, has its posterior margin continuous with that of the cotyle, and slopes forward at 35 degrees relative to the vertical. Also unique is a broad, flat area of featureless bone on the lateral face of the arch; the accessory infraparapophyseal and postzygapophyseal laminae which meet in a V; and the asymmetric neural canal, small and round posteriorly but large and teardrop-shaped anteriorly, bounded by arched supporting laminae. The specimen cannot be referred to any known sauropod genus, and clearly represents a new genus and possibly a new ‘family’. Other sauropod remains from the Hastings Beds Group represent basal Titanosauriformes, Titanosauria and Diplodocidae; X. proneneukos may bring to four the number of sauropod ‘families’ represented in this unit. Sauropods may in general have been much less morphologically conservative than is usually assumed. Since neurocentral fusion is complete in R2095, it is probably from a mature or nearly mature animal. Nevertheless, size comparisons of R2095 with corresponding vertebrae in the Brachiosaurus brancai holotype HMN SII and Diplodocus carnegii holotype CM 84 suggest a rather small sauropod: perhaps 15 m long and 7600 kg in mass if built like a brachiosaurid, or 20 m and 2800 kg if built like a diplodocid. [ABSTRACT FROM AUTHOR]