The precursor of the North Atlantic existed between the North American and Iberian blocks from the earliest Jurassic Hettangian and has been ever expanding since. By the Kimmeridgian and Tithonian, when much of the Morrison Fm rocks were deposited, the proto-Atlantic was more than 300 km wide at 27° paleolatitude between North America and Iberia. Macrovertebrate paleontology reveals a unique story to the isolation of Iberia and instead suggest a paleogeographic land connection between North American and Iberia. Torvosaurus, Allosaurus, Ceratosaurus, Stegosaurus, Supersaurus and others have a distribution restricted to Morrison Formation in North America and Lourinhã Formation in Portugal. A novel paleogeographic model is here suggested: (1) around the Middle–Late Jurassic transition there is a major palaeoceanographic and palaeoclimatic reorganization, coincidental to a major eustatic sea-level drop and uplift associated with the Callovian– Oxfordian Atlantic Regressive Event; (2) creating an ephemeral land bridge presenting a temporary opportunity for terrestrial gateways likely across the Flemish Cap and Galician Bank land masses, allowing large dinosaurian taxa to cross the northern proto-Atlantic in both directions; (3) finally, a Callovian–Oxfordian faunal exchange around the 163 Ma, through latest Kimmeridgian at 152 Ma (the age of equivalent genera in both Morrison and Portugal), is was an interval that allowed speciation, but retaining generic similarity of vertebrates. This model is consistent with the chronology and taxonomy required for speciation of the Iberian and American forms, exemplified by the coeval sister-taxa pairs Torvosaurus tanneri and T. gurneyi, Allosaurus fragilis and A. europaeus, or Supersaurus vivianae and S. lourinhanensis. While some of the smaller animals in the fauna show Morrison/Portugal affinities, most from Iberia have European or even Asian affinities. The larger-bodied fauna are more closely related to Morrison than to mainland Europe (except for dacentrurine stegosaurs). The body size differences and affinities of taxa across paleogeography is comparable to what is observed today across the Wallace Line. Migration may have also occurred in both directions. The closest relative of Torvosaurus is likely the European Bathonian Megalosaurus, thus the presence of the genus in North America represents a European migration. On other hand, Allosaurus and Supersaurus origins are consistent with a North American origin, representing an westto-east migration.

Although the Late Jurassic of Portugal has provided abundant dinosaur fossils, material from the Early Cretaceous is scarce. This paper reports new cranial and postcranial material of the theropod dinosaur Baryonyx walkeri found in the Barremian (Papo Seco Formation) of Portugal. This specimen, found at Praia das Aguncheiras, Cabo Espichel, consists of a partial dentary, isolated teeth, pedal ungual, two calcanea, presacral and caudal vertebrae, fragmentary pubis, scapula, and rib fragments. It represents the most complete spinosaurid yet discovered in the Iberian Peninsula and the most complete dinosaur from the Early Cretaceous of Portugal. This specimen is confidently identified as a member of Baryonychinae due to the presence of conical teeth with flutes and denticles in a dentary rosette. The specimen ML1190 shares the following characteristics with Baryonyx walkeri: enamel surface with small (nearly vertical) wrinkles, variable denticle size along the carinae, 6–7 denticles per mm, wrinkles forming a 45 degree angle near the carinae, and tooth root longer than crown. In addition, dubious taxa based on teeth morphology such as Suchosaurus cultridens (Owen, 1840–1845), and Suchosaurus girardi (Sauvage 1897–98; Antunes & Mateus 2003) are discussed, based on comparisons with well-known material such as Baryonyx walkeri Charig & Milner, 1986. Suchosaurus cultridens and S. girardi are considered as nomina dubia due to the lack of diagnostic apomorphies, but both specimens are referred to Baryonychinae incertae sedis.

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A new Lower Cretaceous (Aptian-Albian) dinosaur tracksite at the Olhos de Água beach is described. It is the first vertebrate fossil finding ever found in the concerned unit, and yielded 128 tracks in 17 trackways within an area of ca. 80 square metres.
Three tridactyl footprint morphotypes have been recognized: - Type 1 (“Iguanodontipus-like”) - trackways D, F, K, J and P; - Type 2 (large theropod), although larger in size, typically from a Grallator-like theropod footprint, i.e. A, B, G, H and O trackways; - Type 3 (medium size theropod); M is the only track of this type. There are other, poorly preserved, unidentified trackways. The theropod, swinging trackway B was produced by an animal that was limping. The theropod track M starts eastwards but drastically changes westwards, speeding up at the same time; this dinosaur decided to turn around and run in the opposite direction.
This site shows three main trackway directions: to the South, to the East, and westwards. Except for the trackway O, large theropods A, B, G and H walked southwards. Perpendicularly to these, ornithopods, small theropods and unidentified trackmakers walked towards East (5) and West (7). The segregation of trackmakers and directions, with large theropod trackways southwards and other dinosaurs’ west or eastwards, may mean that large theropods patrolled a walkway area to an important resource, most probably water, often frequented by ornithopods and smaller theropods. There is no evidence of social behavior or gregarism: footprints’ overposition shows that the large, southwards walking theropods passed on different occasions. Three trackway sequences can be established by chronologic order.

Este capítulo apresenta uma visão geral da paleobiodiversidade alfa de Angola com base no registo fóssil disponível, o qual se limita às rochas sedimentares, a sua idade variando entre o Pré‑Câmbrico e o pre‑
sente. O período geológico com a maior paleobiodiversidade no registo fóssil angolano é o Cretácico, com mais de 80% do total dos táxones fósseis conhecidos, especialmente moluscos marinhos, sendo estes na sua maioria
amonites. Os vertebrados representam cerca de 15% da fauna conhecida e cerca de um décimo destes são espécies descritas pela primeira vez com base em espécimes de Angola.

The Upper Jurassic Lourinhã Formation (Lusitanian Basin, Portugal) contains a diverse dinosaur fauna comprising theropods, sauropods, stegosaurs, ankylosaurs and several genera of ornithopods. The sedimentology in the area favours preservation of tracksways, and tracks from most of the dinosaurs are also represented by skeletal remains. During fieldwork in the summer of 2003 a new, large, tridactyl track was found at the beach of Vale Frades, approximately 6 km north of Lourinhã (central west Portugal). The track was found together with a stegosaur track on a clay bed exposed within the intertidal zone. Due to the immediate danger of erosion, the track was collected and is now on display at Museu da Lourinhã. The track is 70 cm long and 69 cm wide, the toes are short and broad, with indications of short blunt claws, and there is a high angle of divarication between the outer digits. The shape and dimensions of the track identifies it as deriving from an ornithopod dinosaur with an estimated hip height around three metres. Although very large ornithopods are known from the Cretaceous, the largest known Jurassic ornithopod is Camptosaurus from North America, and the largest known from Portugal is the camptosaurid Draconyx loureiroi. Neither of these reached the body size suggested by the new track. So far the track described herein is the only evidence for a Jurassic ornithopod of that size.

The end-Triassic extinction event (ETE), considered one of the ‘Big Five’ mass extinctions, marks a dividing line between early Mesozoic vertebrate assemblages, typically including abundant temnospondyls, basal synapsids and basal archosaurs, and ‘typical’ Mesozoic faunas dominated by dinosaurs, pterosaurs, crocodylomorphs, turtles and mammaliaforms. Recent geochemical work has provided strong evidence that the ETE is synchronous with, and likely caused by, the emplacement of the Central Atlantic magmatic province (CAMP). However, stratigraphic sections containing both terrestrial vertebrates and CAMP basalts are scarce, complicating attempts to examine terrestrial faunal changes during this extinction event. The Triassic–Jurassic Algarve Basin, southern Portugal, is an extensional rift basin to-marginal marine red beds (the ‘Grés de Silves’ Group) interbedded with CAMP basalts.... bonebed from the interval ‘AB1’ of the Grés de Silves. Preliminary excavations yielded at least nine well-preserved temnospondyl individuals represented by partial to nearly complete skulls and disarticulated postcranial elements of juvenile to adult ages. Nearly all material appears to represent a single species of metoposaurid referable to the genus Metoposaurus, well known from the late Carnian–early Norian of Germany and Poland. A number of char- acters of the occiput and mandible suggest that the Algarve material may represent a new species. This new material provides new data on the diversity and paleogeographical distri- bution of the metoposaurids, a highly autapomorphic and peculiar group composed of large aquatic carnivores with a unique elongated but brevirostral skull. This taxon also provides [...] Horizon may be within or close to the late Carnian–early Norian. Additional bone-bearing horizons within the ‘Grés de Silves’ provide a rare opportunity to examine terrestrial faunal change in the lead-up to the ETE.

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The Upper Jurassic of Portugal has a rich vertebrate fauna well documented from both body and trace fossils. Although the occurrence of crocodyles and pterosaurs is well documented from body fossils, trace fossils from both groups were unknown until now. Here we describe an isolated crocodyle-like track from Praia da Peralta and pterosaur tracks from the Kimmeridgian of Pedreira do Avelino, Sesimbra (Azóia Fm.) and Porto das Barcas, Lourinhã (Lourinhã Fm.). An enigmatic track suggests the possible presence of a small, tail-dragging tetrapod. Possible track-makers are suggested based on the known Late Jurassic vertebrate fauna of Portugal.

THE CRETACEOUS SKELETON COAST OF ANGOLA JACOBS, Louis, SMU, Dallas, TX, USA; POLCYN, Michael, SMU, Dallas, TX, USA; MATEUS, Octávio, Museu da Lourinhã, Lourinhã, Portugal; SCHULP, Anne, Natuurhistorisch Museum Maastricht, Maastricht, Netherlands; NETO, André , Universidade Agostinho Neto, Luanda, Angola Cretaceous coastal sediments of Angola present a rich and diverse fauna of marine amniotes, including turtles, mosasaurs, and plesiosaurs. The abundance of mosasaurs in particular suggests a highly productive coastal area. Angola today lies at the northern limit of the Namibian Desert, the so-called Skeleton Coast, which results from prevailing southeasterly winds of the descending limb of the southern Hadley Cell sweeping across the African coast. The Benguela upwelling and a highly productive sea are found today off the Namibian Desert coast. However, the Benguela upwelling system, based on results of DSDP studies, is said to have originated in the late Neogene and therefore cannot explain the productivity found along the length of the West African coast. The explanation is found in the northward drift of Africa through the arid climate zone, and is demonstrated by the tracing of the paleogeographic position of fossil localities through time.

Despite more than a century of collecting, resulting in one of the best-studied vertebrate fossil records anywhere in the world, the Upper Jurassic Morrison Formation has produced surprisingly few examples of dinosaur eggs associated with embryonic remains. Even more puzzling, none of these seem to pertain to the theropod Allosaurus, one of the most common and best-understood dinosaur taxa in the formation. Here we report on a dinosaur nest site that has produced both abundant prismatoolithid eggshell and embryonic (or perinatal) bones of Allosaurus from Fox Mesa, Wyoming. This represents the first such discovery for any theropod in the Jurassic of North America. The nest is heavily weathered but contains a few ellipsoid eggshell clusters that suggest an egg size of about 8 x 6.5 cm. Study of the eggshell morphology and microstructure confirms that a single egg type is present throughout, which is indistinguishable from Prismatoolithus coloradensis. All of the identifiable embryonic materials pertain to theropods, and two premaxillae specimens show the five alveoli diagnostic for Allosaurus among Morrison theropods. This confirms the theropod origin of Prismatoolithus eggs and implicates Allosaurus as the specific Morrison parent taxon. As a result, it is now possible to assign several previous discoveries of dinosaur eggs and potential nests to Allosaurus, including the isolated egg from the Cleveland-Lloyd Quarry. This discovery also calls into question prior assignments of Prismatoolithus eggs to ornithopods, and suggests that more detailed study of such sites is warranted. Prismatoolithus eggshells are also associated with the Upper Jurassic theropod Lourinhanosaurus from Portugal, along with larger embryos that exhibit four premaxillary alveoli.

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NEW SPECIMENS OF ANGOLASAURUS BOCAGEI AND COMMENTS ON THE EARLY RADIATIONS OF PLIOPLATECARPINE MOSASAURS POLCYN, Michael, SMU, Dallas, TX, USA; JACOBS, Louis, SMU, Dallas, TX, USA; MATEUS, Octávio, Museu da Lourinhã, Lourinhã, Portugal; SCHULP, Anne, Natuurhistorisch Museum Maastricht, Maastricht, Netherlands New, well preserved material of the Turonian mosasaur Angolasaurus bocagei from the Tadi Beds of the Itombe Formation in northern Angola, allows detailed redescription of its morphology and reassessment of its phylogenetic relationships. Angolasaurus had been previously referred to the genus Platecarpus; however, phylogenetic analysis confirms the valid taxonomic status of A. bocagei, and reconstructs that taxon within a clade that also includes the genera Selmasaurus and Ectenosaurus. These forms are united by an elaborated infrastapedial process of the quadrate and a unique ridge-like descending process of the parietal forming the supraoccipital articulation, but also retain a relatively plesiomorphic configuration of the braincase. That clade is united with all other plioplatecarpines by a number of derived characters including the presence of a novel basicranial circulation pattern. In Africa, North and South America, early plioplatecarpines are known by the Middle Turonian and Angolasaurus and closely related forms appear by the Upper Turonian. Selmasaurus and Ectenosaurus are a rare faunal component of the Santonian and Campanian of North America. Platecarpus planifrons appears in the Coniacian of North America and represents the plesiomorphic condition of the clade containing the remaining species of Platecarpus and Plioplatecarpus, that appears in the Santonian and persist until the end of the Cretaceous, reaching global distribution. The temporal and geographic distribution of these radiations suggest influence of paleogeography and eustatic sea levels.

Although rich in Cretaceous vertebrate fossils, prior to 2005 the amniote fossil record of Angola was poorly known. Two horizons and localities have yielded the majority of the vertebrate fossils collected thus far; the Turonian Itombe Formation of Iembe in Bengo Province and the Maastrichtian Mocuio Formation of Bentiaba in Namibe Province. Amniotes of the Mesozoic of Angola are currently restricted to the Cretaceous and include eucryptodire turtles, plesiosaurs, mosasaurs, pterosaurs, and dinosaurs. Recent collecting efforts have greatly expanded our knowledge of the amniote fauna of Angola and most of the taxa reported here were unknown prior to 2005.