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Three new additional skull specimens of Talarurus plicatospineus have been recovered from the Upper Cretaceous (Cenomanian–Santonian) Bayanshiree Formation, of Bayan Shiree cliffs, eastern Gobi Desert, Mongolia. The skulls feature unique characters such as an anteriorly protruded single internarial caputegulum, around 20 flat or concave nasal-area caputegulae surrounded by a wide sulcus, a vertically oriented elongate loreal caputegulum with a pitted surface, an elongate lacrimal caputegulum positioned above the posterodorsal border of the maxilla, two longitudinally arranged large frontoparietal caputegulae surrounded by smaller rhomboid caputegulae, small but elongate medial supraorbital caputegulae, a posterior supraorbital caputegulum that is four times larger than the anterior one, up to three transverse parallel grooves on the dorsal surface of the posterior supraorbital caputegulum, postocular caputegulae along the ventral to posterior rim of the orbit that extend almost to the anteroventral margin of the squamosal horn, a longitudinal furrow tapering towards the apex of the squamosal horn, a lateral nuchal caputegulum four to five times larger than other nuchal caputegulae, and a pterygovomerine keel with a ventral margin that is dorsally positioned to the alveolar ridge. The phylogenetic analysis result showed that Talarurus is sister to the clade that includes the derived Asian ankylosaurines (Saichania chulsanensis, Tarchia kielanae, and Zaraapelta nomadis). It also shows that there was dispersal of ankylosaurines from Asia into western North America before the Cenomanian. Moreover, the rostral differences between Talarurus and Tsagantegia, another ankylosaur from the same formation, suggest possible niche partitioning between these taxa.

Allosaurus is one of the most famous theropod dinosaurs, but the validity and relationships between the different species have been confusing and often questioned. Portugal is relevant to the understanding of the genus in light of the discovery of A. europaeus ML415 from the Early Tithonian of Lourinhã and Allosaurus MNHNUL/AND.001 from Andrés. However, the exact classification and validity of these two specimens has always been controversial. The presence of Allosaurus in Portugal is strong evidence for a North America–Europe Late Jurassic dispersal, later supported by other taxa. A detailed cranial description and specimen-based phylogeny were performed and resolved many of the open questions: (1) The diversity of Allosaurus is limited to three named species: A. fragilis, A. europaeus, and A. jimmadseni. (2) Nine autapomorphies were found in A. europaeus, confirming the validity of the species. (3) Phylogenetic analyses place both Portuguese specimens in the genus Allosaurus, based on the following synapomorphies: jugal bone lateral view, relative heights of quadratojugal prongs, the dorsal prong is equal in height, the jugal bone in lateral view shows shallow accessory pneumatization of the antorbital fossa, the palatine pneumatic recess shape is small, and lacrimal horn morphology has a triangular horn. (4) The Andrés specimen is placed with the A. europaeus and they are considered here to be the same species, which is paleo-geographically and biochronologically congruent. (5) A. europaeus and A. jimmadseni are sister taxa and closer to each other than to A. fragilis. The genus is distributed in occurrences from the United States, Germany, and Portugal, and from the Late Kimmeridgian to the Late Tithonian, while the Cenomanian report from Japan is reidentified as Segnosaurus.

Forty partial fossil skulls belonging to beaked whales (Cetacea, Odontoceti, Ziphiidae) were collected by trawling and long-line fishing on Neogene (probably Late Early to Middle Miocene) layers of the Atlantic floor off the coasts of Portugal and Spain (Asturias and Galicia). e systematic study of the most diagnostic Iberian specimens, those preserving the rostrum and the dorsal part of the cranium, led to the recognition of two new genera (Globicetus n. gen. and Imocetus n. gen.) and four new species (Choneziphius leidyi n. sp., G. hiberus n. gen., n. sp., I. piscatus n. gen., n. sp., and Tusciziphius atlanticus n. sp.).
Based on the matrix of a previous work, the phylogenetic analysis places all the new taxa in the subfamily Ziphiinae Gray, 1850. More fragmentary specimens are tentatively referred to the genera Caviziphius Bianucci & Post, 2005 and Ziphirostrum du Bus, 1868. Among these new ziphiids, extremely bizarre skull morphologies are observed. In G. hiberus n. gen., n. sp. the proximal portion of the rostrum bears a voluminous premaxillary spheroid. In T. atlanticus n. sp. a medial premaxillary bulge is present on the rostrum; together with asymmetric
rostral maxillary eminences at the rostrum base, this bulge displays various degrees of elevation in different specimens, which may be interpreted as sexual dimorphism. Specimens of I. piscatus n. gen., n. sp. bear two sets of even crests: spur-like rostral maxillary crests and longitudinal maxillary crests laterally bordering a wide and long facial basin. A preliminary macroscopic observation of these elements indicates very dense bones, with a compactness comparable with that of cetacean ear bones. Questioning their function, the high medial rostral elements (the premaxillary spheroid of G. hiberus n. gen., n. sp. and the medial bulge of T. atlanticus n. sp.) remind the huge rostral maxillary crests of adult males of the extant Hyperoodon ampullatus (Forster, 1770). In the latter, the crests are very likely related to head-butting. However, they are made of much more spongy bone than in the fossil taxa studied here, and therefore possibly better mechanically suited for facing impacts. Other interpretations of these unusual bone specializations, related to deep-diving (ballast) and echolocation (sound reflection), fail to explain the diversity of shapes and the hypothetical sexual dimorphism observed in at least part of the taxa. e spur-like rostral maxillary crests and long maxillary crests limiting the large facial basin in I. piscatus n. gen., n. sp. and the excrescences on the maxilla at the rostrum base in Choneziphius spp. are instead interpreted as areas of origin for rostral and facial muscles, acting on the nasal passages, blowhole, and melon. From a palaeobiogeographic point of view, the newly described taxa further emphasize the differences in the North Atlantic (including Iberian Peninsula) and South African Neogene ziphiid faunal lists. Even if the stratigraphic context is poorly understood, leaving open the question of the geological age for most of the dredged specimens, these differences in the composition of cold to temperate northern and southern hemisphere fossil ziphiid faunas may be explained by a warm-water equatorial barrier.

The Spheroolithidae oospecies Guegoolithus turolensis, putatively attributed to non-hadrosauroid styracosterns was first described in the Barremian of the Iberian Basin, and later reported in the Valanginian–Hauterivian of the Cameros Basin, with both occurrences separated by a few hundred kilometres but by over 10 million years.

We here present fossil Crocodylomorpha eggshells from the Upper Jurassic Lourinhã Formation of Portugal, recovered from five sites: one nest from Cambelas with 13 eggs, and three partial eggs and various fragments from, Paimogo N (I), Paimogo S (II), Casal da Rola, and Peralta. All specimens but the nest were found in association with dinosaur egg material. Our research reveals that on a micro- and ultrastructural analysis, all samples present the typical characters consistent with crocodiloid eggshell morphotype, such as the shell unit shape, the organization of the eggshell layers, and the triangular blocky extinction observed with crossed nicols. We assign the material from the Lourinhã Formation to the oofamily Krokolithidae, making it the oldest crocodylomorph eggs known so far, as well as the best record for eggs of non- crocodylian crocodylomorphs. Furthermore, our study indicates that the basic structure of crocodiloid eggshells has remained stable since at least the Upper Jurassic.

We here present fossil Crocodylomorpha eggshells from the Upper Jurassic Lourinhã Formation of Portugal, recovered from five sites: one nest from Cambelas with 13 eggs, and three partial eggs and various fragments from, Paimogo N (I), Paimogo S (II), Casal da Rola, and Peralta. All specimens but the nest were found in association with dinosaur egg material. Our research reveals that on a micro- and ultrastructural analysis, all samples present the typical characters consistent with crocodiloid eggshell morphotype, such as the shell unit shape, the organization of the eggshell layers, and the triangular blocky extinction observed with crossed nicols. We assign the material from the Lourinhã Formation to the oofamily Krokolithidae, making it the oldest crocodylomorph eggs known so far, as well as the best record for eggs of non- crocodylian crocodylomorphs. Furthermore, our study indicates that the basic structure of crocodiloid eggshells has remained stable since at least the Upper Jurassic.

Thyreophoran dinosaurs have spike- and club-shaped osteoderms probably used for defensive weapons. The structural and histological variations have been little known. Here, we provide the comparisons of the internal structures in defensive weapons of ankylosaurs and stegosaurs, using spikes of a polacanthid (Gastonia) and a nodosaurid (Edmontonia), clubs of ankylosaurids (Saichania and Ankylosauridae indet. from Canada), and spikes of stegosaurids (Stegosaurus and Dacentrurus), which sheds light on understandings of evolutionary history and functional implications of defensive weapons in thyreophorans. In ankylosaurs, the structural and histological features of spikes and clubs are similar with those of small osteoderms in having thin compact bones, thick cancellous bones with large vascular canals, and abundant collagen fibers. A previous study demonstrated that each of three groups of ankylosaurs (polacanthid, nodosaurid, and ankylosaurid) has distinct characteristic arrangements of collagen fibers in small osteoderms. This study shows that spikes and clubs of ankylosaurs maintain the same characteristic features for each group despite of the differences in shapes and sizes. Conversely, the spike-shaped osteoderms in primitive (Dacentrurus) and derived (Stegosaurus) stegosaurids have similar structure to each other and are significantly different from the other types of stegosaur osteoderms (throat bony ossicles and plates) in having thick compact bones with a medullary cavity. These lack abundant collagen fibers unlike ankylosaur osteoderms. The spikes of ankylosaurs and stegosaurs are similar in shape, but their structural and histological features are different in having unique structures of collagen fibers for ankylosaurs and thick compact bones for stegosaurs, providing enough strength to have large spikes and to use them as defensive weapons. Although the shapes of ankylosaur clubs are different from spikes, the internal structures are similar, suggesting that ankylosaurs maintain similar structures despite of different shapes in osteoderms. These results indicate that ankylosaurs and stegosaurs used different strategies independently to evolve defensive weapons.

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The non-avian saurischians that have associated eggshells and embryos are represented only by the sauropodomorph Massospondylus and Coelurosauria (derived theropods), thus missing the basal theropod representatives. We report a dinosaur clutch containing several crushed eggs and embryonic material ascribed to the megalosaurid theropod Torvosaurus. It represents the first associated eggshells and embryos of megalosauroids, thus filling an important phylogenetic gap between two distantly related groups of saurischians. These fossils represent the only unequivocal basal theropod embryos found to date. The assemblage was found in early Tithonian fluvial overbank deposits of the Lourinhã Formation in West Portugal. The morphological, microstructural and chemical characterization results of the eggshell fragments indicate very mild diagenesis. Furthermore, these fossils allow unambiguous association of basal theropod osteology with a specific and unique new eggshell morphology.

ABSTRACTVirtual palaeontology is a growing field, leading palaeontologists to better understand the microanatomy of many extinct species. The application of techniques such as CT and μCT-scanning allows the researchers to study micro-anatomical features in a non-invasive way and make inferences on the palaeobiology of animals. Dinosaurs have been extensively studied using these techniques, with particular focus on the microanatomy of the cranium, whereas relatively little is known of other cranial elements, such as the lower jaw. Here, we aim to fill this gap, describing the microanatomy of the specimen ML 768, an isolated dentary belonging to a dryosaurid iguanodontian dinosaur from the Upper Jurassic of Lourinhã Fm. The dentary ML 768 was subjected to μCT-scanning, and subsequently the data were segmented in Avizo and rendered in Blender. We identified functional and replacement teeth, recognising remnants of old replacement cycles. Furthermore, we mapped a rich neurovascular network present in the dentary and compared it with reference literature. We found that the high vascularisation is shared with other cerapodan dinosaurs with high tooth replacement rates, although homoeostasis may have also played a role in the development of this condition. Further evidence is needed to appreciate the macroevolutionary significance of these findings.

The Late Triassic (Norian) outcrops of the Malmros Klint Formation, Jameson Land (Greenland) have yielded numerous specimens of non-sauropod sauropodomorphs. Relevant fossils were briefly reported in 1994 and were assigned to Plateosaurus trossingensis. However, continuous new findings of early non-sauropod sauropodomorphs around the globe facilitate comparisons and allow us to now revise this material. Here, the non-sauropod sauropodomorph Issi saaneq gen. et sp. nov. is described based on two almost complete and articulated skulls. The two skulls represent a middle-stage juvenile and a late-stage juvenile or subadult. Issi saaneq differs from all other sauropodomorphs by several unique traits: (1) a small foramen at the medial surface of the premaxilla; (2) an anteroposteriorly elongated dorsoposterior process of the squamosal; (3) a relatively high quadrate relative to rostrum height; (4) a well-developed posterodorsal process of the articular. These features cannot be explained by taphonomy, ontogeny, or intraspecific variation. Issi saaneq shows affinities to Brazilian plateosaurids and the European Plateosaurus, being recovered as the sister clade of the latter in our phylogenetic analysis. It is the northernmost record of a Late Triassic sauropodomorph, and a new dinosaur species erected for Greenland. Issi saaneq broadens our knowledge about the evolution of plateosaurid sauropodomorphs.

Late Jurassic theropod tracks are very common both in North Africa and Europe. Two recently described ichnotaxa Megalosauripus transjuranicus and Jurabrontes curtedulensis from the Kimmeridgian of Switzerland show the coexistence of two apex predators in the same palaeoenvironment. Similar tracks can be found in tracksites from the Iberian Peninsula and from Morocco. Here, we further explore the similarities among the Swiss ichnotaxa and the other tracks from Germany (Kimmeridgian), Spain (Tithonian-Berriasian), Portugal (Oxfordian-Tithonian) and Morocco (Kimmeridgian) through novel three-dimensional data comparisons. Specimens were grouped in two morphotypes: 1) large and gracile (30 < Foot Length<50 cm) and 2) giant and robust (FL > 50 cm). The analyses show a great morphological overlap among these two morphotypes and the Swiss ichnotaxa (Megalosauripus transjuranicus and Jurabrontes curtedulensis, respectively), even despite the differences in sedimentary environment and age. This suggests a widespread occurrence of similar ichnotaxa along the western margin of Tethys during the Late Jurassic. The new data support the hypothesis of a Gondwana-Laurasia faunal exchange during the Middle or early Late Jurassic, and the presence of migratory routes around the Tethys.

This study focuses on the assessment of the degradation processes occurring in three sandstone infills of fossilized Late Jurassic ornithopod tridactyl footprints, found in 2001 in a coastline cliff in Porto das Barcas (Lourinhã, Portugal) and exhibited in a museum display since 2004. These dinosaur footprints present nowadays severe decay phenomena compromising their physical integrity and are leading gradually to their loss of value. The deterioration patterns were recorded, a map of their distribution was prepared and several samples were collected both in the dinosaur footprints and in the coastline cliff. Different analytical procedures were applied such as XRD, FTIR, FESEM and Ion Chromatography. A microclimatic survey was also performed and air temperature and relative humidity was measured during eight months both indoor and also outdoor. The decay patterns observed are a combination intrinsic and extrinsic factors the stone material, namely swelling of clay minerals in the rock matrix (smectite and chlorite-smectite mixed-layer), presence of salts (mainly chlorides), application of past conservation treatments (poly(vinyl) acetate and epoxy resins) and with the museum's indoor thermohygrometric conditions (mainly non-stable hygrometric conditions). This scientific knowledge is therefore essential to the sustainable preservation of this paleontological heritage.

This study focuses on the assessment of the degradation processes occurring in three sandstone infills of fossilized Late Jurassic ornithopod tridactyl footprints, found in 2001 in a coastline cliff in Porto das Barcas (Lourinhã, Portugal) and exhibited in a museum display since 2004. These dinosaur footprints present nowadays severe decay phenomena compromising their physical integrity and are leading gradually to their loss of value. The deterioration patterns were recorded, a map of their distribution was prepared and several samples were collected both in the dinosaur footprints and in the coastline cliff. Different analytical procedures were applied such as XRD, FTIR, FESEM and Ion Chromatography. A microclimatic survey was also performed and air temperature and relative humidity was measured during eight months both indoor and also outdoor. The decay patterns observed are a combination intrinsic and extrinsic factors the stone material, namely swelling of clay minerals in the rock matrix (smectite and chlorite-smectite mixed-layer), presence of salts (mainly chlorides), application of past conservation treatments (poly(vinyl) acetate and epoxy resins) and with the museum’s indoor thermohygrometric conditions (mainly non-stable hygrometric conditions). This scientific knowledge is therefore essential to the sustainable preservation of this paleontological heritage.

Abstract Several analyses of diversity through geological time use global, synoptic databases, and this practice often makes it difficult to distinguish true signals in changing diversity from regional-scale sampling and/or geological artefacts. Here we investigate how echinoid diversity changed through the Mesozoic of the Lusitanian basin in Portugal based on a comprehensive, revised database, and seek to distinguish biological signal from geological or environmental constraints. The observed diversity pattern is far from having a defined trend, showing many fluctuations that appear to be linked with gaps in the geological record. This study revealed that, independently of the method used, whether correlation tests or model fitting, the diversity signal is not completely explained by the studied sampling proxies. Among the different proxies, marine facies variation in combination with outcrop area best explains the palaeodiversity curve.

Six quadrate bones, of which two almost certainly come from the Kem Kem beds (Cenomanian, Upper Cretaceous) of south-eastern Morocco, are determined to be from juvenile and adult individuals of Spinosaurinae based on phylogenetic, geometric morphometric, and phylogenetic morphometric analyses. Their morphology indicates two morphotypes evidencing the presence of two spinosaurine taxa ascribed to Spinosaurus aegyptiacus and? Sigilmassasaurus brevicollis in the Cenomanian of North Africa, casting doubt on the accuracy of some recent skeletal reconstructions which may be based on elements from several distinct species. Morphofunctional analysis of the mandibular articulation of the quadrate has shown that the jaw mechanics was peculiar in Spinosauridae. In mature spinosaurids, the posterior parts of the two mandibular rami displaced laterally when the jaw was depressed due to a lateromedially oriented intercondylar sulcus of the quadrate. Such lateral movement of the mandibular ramus was possible due to a movable mandibular symphysis in spinosaurids, allowing the pharynx to be widened. Similar jaw mechanics also occur in some pterosaurs and living pelecanids which are both adapted to capture and swallow large prey items. Spinosauridae, which were engaged, at least partially, in a piscivorous lifestyle, were able to consume large fish and may have occasionally fed on other prey such as pterosaurs and juvenile dinosaurs.

Six quadrate bones, of which two almost certainly come from the Kem Kem beds (Cenomanian, Upper Cretaceous) of south-eastern Morocco, are determined to be from juvenile and adult individuals of Spinosaurinae based on phylogenetic, geometric morphometric, and phylogenetic morphometric analyses. Their morphology indicates two morphotypes evidencing the presence of two spinosaurine taxa ascribed to Spinosaurus aegyptiacus and? Sigilmassasaurus brevicollis in the Cenomanian of North Africa, casting doubt on the accuracy of some recent skeletal reconstructions which may be based on elements from several distinct species. Morphofunctional analysis of the mandibular articulation of the quadrate has shown that the jaw mechanics was peculiar in Spinosauridae. In mature spinosaurids, the posterior parts of the two mandibular rami displaced laterally when the jaw was depressed due to a lateromedially oriented intercondylar sulcus of the quadrate. Such lateral movement of the mandibular ramus was possible due to a movable mandibular symphysis in spinosaurids, allowing the pharynx to be widened. Similar jaw mechanics also occur in some pterosaurs and living pelecanids which are both adapted to capture and swallow large prey items. Spinosauridae, which were engaged, at least partially, in a piscivorous lifestyle, were able to consume large fish and may have occasionally fed on other prey such as pterosaurs and juvenile dinosaurs.

ABSTRACT Modern birds are typified by the presence of feathers, complex evolutionary innovations that were already widespread in the group of theropod dinosaurs (Maniraptoriformes) that include crown Aves. Squamous or scaly reptilian-like skin is, however, considered the plesiomorphic condition for theropods and dinosaurs more broadly. Here, we review the morphology and distribution of non-feathered integumentary structures in non-avialan theropods, covering squamous skin and naked skin as well as dermal ossifications. The integumentary record of non-averostran theropods is limited to tracks, which ubiquitously show a covering of tiny reticulate scales on the plantar surface of the pes. This is consistent also with younger averostran body fossils, which confirm an arthral arrangement of the digital pads. Among averostrans, squamous skin is confirmed in Ceratosauria (Carnotaurus), Allosauroidea (Allosaurus, Concavenator, Lourinhanosaurus), Compsognathidae (Juravenator), and Tyrannosauroidea (Santanaraptor, Albertosaurus, Daspletosaurus, Gorgosaurus, Tarbosaurus, Tyrannosaurus), whereas dermal ossifications consisting of sagittate and mosaic osteoderms are restricted to Ceratosaurus. Naked, non-scale bearing skin is found in the contentious tetanuran Sciurumimus, ornithomimosaurians (Ornithomimus) and possibly tyrannosauroids (Santanaraptor), and also on the patagia of scansoriopterygids (Ambopteryx, Yi). Scales are surprisingly conservative among non-avialan theropods compared to some dinosaurian groups (e.g. hadrosaurids); however, the limited preservation of tegument on most specimens hinders further interrogation. Scale patterns vary among and/or within body regions in Carnotaurus, Concavenator and Juravenator, and include polarised, snake-like ventral scales on the tail of the latter two genera. Unusual but more uniformly distributed patterning also occurs in Tyrannosaurus, whereas feature scales are present only in Albertosaurus and Carnotaurus. Few theropods currently show compelling evidence for the co-occurrence of scales and feathers (e.g. Juravenator, Sinornithosaurus), although reticulate scales were probably retained on the mani and pedes of many theropods with a heavy plumage. Feathers and filamentous structures appear to have replaced widespread scaly integuments in maniraptorans. Theropod skin, and that of dinosaurs more broadly, remains a virtually untapped area of study and the appropriation of commonly used techniques in other palaeontological fields to the study of skin holds great promise for future insights into the biology, taphonomy and relationships of these extinct animals.

ABSTRACTCrocodylomorph eggs and eggshells are known as old as the Late Jurassic and are frequent components of most multiootaxic eggshell assemblages. Classified within the oofamily Krokolithidae, thei histo- and ultrastructures are conservative throughout geological time, characterised by inverted-trapezoid-shaped shell units that grow from highly spaced basal knobs and present a diagnostic tabular ultrastructure. Here, we report 327 eggshell fragments from a new fossil site from the Maastrichtian of the Southern Pyrenees, Veracruz 1, and erect a new oogenus and oospecies, Pachykrokolithus excavatum oogen. et oosp. nov. characterised by crocodyloid morphotype and a prominent rugosocavate ornamentation. Eggshells from the slightly older locality of Blasi 2b, previously reported as aff. Krokolithidae, are also assigned to this new ootaxon. Different crocodylomorph taxa coexisted during the Late Cretaceous of the Tremp Basin, hindering the attribution of Pachykrokolithus excavatum oogen. et oosp. nov. to a single clade. Nevertheless, allodaposuchid eusuchians were dominant in this ecosystem, and are the most probable producers of Pachykrokolithus excavatum oogen. et oosp. nov. eggs.

Presacral vertebrae of a new Diplodocidae from the Late Jurassic Amoreira-Porto Novo Formation of Lourinhã, Portugal are described and figured. Dinheirosaurus lourinhanensis gen. et sp. is diagnosed by well developed accessory articulations derived from the hyposphene, exposed in lateral view; and by the smaller dorsoventral length of the lower section of the neural arch. It is considered that the organization of the dorsal neural arch of Dinheirosaurus is more derived than in Diplodocus, except in the dorsoventral development of the lower portion of it, which is higher (more derived) in the latter. Possibly the isolated geography of Portugal in the Late Jurassic gave rise to the distinct characters of this new genus.

An incomplete, yet remarkably-sized dentated rostrum and associated partial cervical vertebrae of a pterosaur (ML 2554) were recently discovered from the Late Jurassic (Late Kimmeridgian-Early Tithonian) Lourinhã Formation of Praia do Caniçal, of central west Portugal. This specimen exhibits features such as a spatulated anterior expansion of the rostrum, robust comb-like dentition, and pronounced rims of the tooth alveoli, indicating gnathosaurine affinities. Based on its further unique tooth and dentary morphology, a new genus and species, \textit{Lusognathus almadrava} gen. et spec. nov., is proposed, making this the first named pterosaur species found within Portugal. The presence of this taxon adds yet another element to the fluvio-deltaic lagoonal environment that has been suggested as representative of the Lourinhã Formation in the Late Jurassic, further contributing to the diversity and distribution of gnathosaurines worldwide.

Although diplodocoid sauropods from Africa and the Americas are well known, their European record remains largely neglected. Here we redescribe Dinheirosaurus lourinhanensis from the Late Jurassic of Portugal. The holotype comprises two posterior cervical vertebrae, the dorsal series and a caudal centrum. Redescription demonstrates its validity on the basis of three autapomorphies: (1) posteriorly restricted ventral keel on posterior cervical vertebrae; (2) three small subcircular fossae posterior to the lateral coel on posterior cervical neural spines; (3) accessory lamina linking the hyposphene with base of the posterior centrodiapophyseal lamina in middle-posterior dorsal vertebrae. Phylogenetic analysis places Dinheirosaurus as the sister taxon to Supersaurus, and this clade forms the sister taxon to other diplodocines. However, this position should be treated with caution as Dinheirosaurus displays several plesiomorphic features absent in other diplodocids (including unbifurcated presacral neural spines, and dorsolaterally projecting diapophyses on dorsal vertebrae) and only four additional steps are required to place Dinheirosaurus outside of Flagellicaudata. We identify Amazonsaurus as the basal-most rebbachisaurid and recover Zapalasaurus outside of the South American Limaysaurinae, suggesting the biogeographic history of rebbachisaurids is more complex than previously proposed. Review of the European diplodocoid record reveals evidence for the earliest known diplodocid, as well as additional diplodocid remains from the Late Jurassic of Spain. A Portuguese specimen, previously referred to Dinheirosaurus, displays strong similarities to Apatosaurus from the contemporaneous Morrison Formation of North America, indicating the presence of a second Late Jurassic Portuguese diplodocid taxon. Along with Dinheirosaurus, these Portuguese remains provide further evidence for a Late Jurassic palaeobiogeographic connection between Europe and North America. No dicraeosaurids are currently known from Europe, but rebbachisaurids are present in the Early Cretaceous, with weak evidence for the earliest known representative from the Late Jurassic of Spain; however, more complete material is required to recognize early members of this clade.