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Iberian extinct ziphiid, Globicetus hiberus, bears a peculiar large bony sphere in the rostrum, the Mesorostral Process of the Premaxillae or MPP. The MPP varies in size and shape of growth in the six specimens studied and seems to have an allometrically growth in one subgroup, but not in the other, suggesting subgroups correspond to males and females (sexual dimorphism). Even more, some rostral structures, such as the medial pad of the premaxillae seem to be associated with the specimens with lower and leaner MPP’s and ossification of the mesorostral canal by the vomer can also be of value in differentiating sex. Beaked whales are deep-diving, echolocation-user odontocetes and able to perceive bones as distinctive echoic images with their sonar; therefore the MPP may work as a secondary sexual organ (“antlers inside” hypothesis by Gol´din, 2014), a mute display structure acting as an “acoustic flag” to be perceived through echolocation by other individuals, giving information about the shape and size of the MPP.

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The Late Triassic (ca. 237-201.5 million years ago) was a transitional interval in the evolution of terrestrial ecosystems, during which ‘modern’ clades such as archosaurs and mammals were radiating while ‘archaic’ groups such as temnospondyl amphibians and basal synapsids remained abundant. Little is known about the Triassic terrestrial (nonmarine) vertebrates of the Iberian Peninsula. The Algarve Basin of southern Portugal is an extensional rift basin formed during the breakup of Pangaea, which is filled with terrestrial, lacustrine, and marginal marine siliciclastics of the Grés de Silves Formation, interbedded with CAMP basalts that mark the end-Triassic extinction (radioisotopically dated to ~198-201.5 Ma). Since 2009, our field project in the Algarve has discovered numerous vertebrate specimens within the Grés de Silves, including a monodominant bonebed containing hundreds of specimens of metoposaurids, a peculiar group of temnospondyls that filled crocodile-like predatory niches in lacustrine and fluvial environments. These specimens appear to belong to a new species of Metoposaurus, similar to M. diagnosticus and M. krasiejowensis from central Europe but possessing several putative autapomorphies of the braincase and lower jaw. We also discovered a mandible of a phytosaur, the first specimen of these long-snouted, semi-aquatic archosauriforms from the Iberian Peninsula. These discoveries of characteristic Carnian Norian taxa indicate that the fossil-bearing portion of the Grés de Silves is Late Triassic in age, and provide further evidence that metoposaurids and phytosaurs commonly occurred together in low palaeolatitudes during this time.

Portugal is ranked within the ten countries with more dinosaur taxa and the Lourinhã Formation is known
by the Late Jurassic findings of dinosaurs and other fossils. Often, studies of the external morphological
characteristics of the fossils are not sufficient and, observations of internal structures, using non-
destructive techniques, are required. The fossils here presented belong to the Museum da Lourinhã
(Portugal) and comprise a lower jaw of a basal crocodilian (possibly a Tomistomidae), eggshells and
several vertebrae from the exceptionally well preserved in ovo remains of Late Jurassic theropod dinosaur
Lourinhanosaurus. Neutron Tomography (NT) experiments with this material has been carried out at the
Geesthacht Neutron Facility in Germany. Additionally, eggshell fragments and several vertebrae have
been studied by Synchrotron-Radiation based Micro-Computed Tomography (SRμCT) at the HARWI II and
BW2 beamlines, respectively. These beamlines are operated by the Helmholtz-Zentrum Geesthacht at the
storage ring DORIS III at the Deutsches Elektronen–Synchrotron DESY in Hamburg, Germany. In both cases
(NT and SRμCT) complete 3D recordings have been obtained using a non-destructive procedure. The high-
quality tomographic datasets can be effectively studied through interactive digital visualization. Hence,
these visualization methods provide precious information about the 3D internal micro morphology of
fossils, like the network of the eggshell pores, often invisible in more traditional techniques, and provide a
direct window into the evolutionary history of organisms.

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In this session we review the Upper Cretaceous marine amniote records from the west coasts of North America and Africa. Recent work by our group in Angola, on the west coast of Africa, has opened up new fossiliferous localities, producing well-preserved turtles, plesiosaurs, and mosasaurs, ranging in age from Late Turonian to Late Maastrichtian. These African localities were deposited in arid latitudes and highly productive upwelling zones along the passive margin of a growing South Atlantic Ocean. The fossil record of Cretaceous marine amniotes from the West Coast of North America is relatively meager when compared to the African record and the prolific fossil beds laid down in the epicontinental seas of the Western Interior Seaway and northern Europe. Nonetheless, these localities provide an important glimpse of a marine ecosystem that developed on the active margins of a deep ocean basin. Historically considered to be depauperate and endemic, the west coast fauna was characterized by unusual forms such as Plotosaurus, arguably one of the most derived mosasaurs; however, in recent years, additional taxa have been described, revealing species diversity and ecological partitioning within these communities and in some cases, faunal interchange with other regions. The large quantity of well-preserved fossils from the west coast of Africa is influenced in part by its paleogeographic position, deposited within highly productive areas of Hadley Cell controlled upwelling zones. By contrast, the North American west coast localities have been deposited in temperate and higher latitudes since the Late Cretaceous. Nonetheless, the North American and African faunas share some common characteristics in a possessing a mix of endemic and more cosmopolitan forms. Habitat partitioning reflected in tooth form and body size is comparable between the Angolan and the North American west coast, and there is remarkable convergence in taxa which appear to exploit certain like-niches.

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The Algar do Vale da Pena is a cave that was discovered during limestone mining works around 1980, at the Natural Park of Serras de Aire e Candeeiros, Portugal. The entrance to the cave, through the collapsed roof, is a 30 meter near-vertical well, inaccessible without means of vertical progression and specialized equipment. Soon after the discovery of the cave, bone material belonging to bears and hundreds of bear claw marks were located inside it. Nevertheless, the technical descent and the extraordinary difficulties of retrieving the calcite flowstones that encased the bones prevented scientists from undertaking excavations for nearly 40 years. Since 2016 a series of expeditions by a team of paleontologists from NOVA University and Museum of Lourinhã recovered more than 20 disarticulated remains from five bone accumulations, separated more than five meters apart, which given the level of erosion and breakage, are para-autochthonous in origin. These are interpreted as belonging to different individuals. Morphological characters, like a relatively elongated third phalanx, the clear separation of paracone-metacone of the first upper molar and the ventral position of the mandibular condyle; as well as numerous morphometric characters, allow to ascribe the remains to Ursus arctos. Nevertheless, the main finding from the cave is a complete skull with an articulated mandible; which denotes absence of transport, encased within a 180 kg calcite flowstone, including other skeletal remains as well, which could not be extracted from the cave until 2021. This block was removed with the help of members of several speleological groups. It promises a wealth of information about fossil brown bears, being the most complete bear fossil ever recovered in Portugal. It is currently being dated trough magnetostratigraphy and prepared. We consider this intervention as an extraordinary example of citizen science applied to paleontology

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The richness of Late Jurassic vertebrates in Portugal is known since the 19th century by Paul Choffat, Henri Sauvage and other. The Kimmeridgian Guimarota fauna assemblage is the best known, followed by the fauna of Lourinhã formation. Here is presented an attempt to provide a checklist of the reptiles and amphibians of the Late Jurassic. Amphibia: Lissamphibia (Celtedens, cf. Marmorerpeton, Discoglossidae indet.). Chelonia: Eucryptodira (Pleurosternidae indet., Platychelyidae indet., Plesiochelys cf. etalloni, Plesiochelys choffati, Anosteirinae indet.). Squamata: Scincomorpha (Becklesius hoffstetteri; Paramacellodus sp., Saurillodon proraformis, S. henkeli, S. cf. obtusus). Squamata: Anguimorpha (Dorsetisaurus pollicidens, Parviraptor estesi). Crown Lepidosauromorpha (Marmoretta sp.). Choristodera: Cteniogenidae (Ctenogenys reedi). Sauropterygia: Plesiosauria: Cryptoclidoidea: Cryptoclididae indet. Crocodylomorpha (Lisboasaurus estesi, L. mitrocostatus). Crocodyliformes: Neosuchia (Machimosaurus hugii, Goniopholis cf. simus, Goniopholis baryglyphaeus, cf. Bernissartia, Atoposauridae, Theriosuchus guimarotae, cf. Alligatorium, Metriorhynchus sp.). Pterosauria (Rhamphorhynchus sp., Pterodactylus sp.). Dinosauria: Theropoda (Ceratosaurus sp. , Torvosaurus sp., Lourinhanosaurus antunesi, Allosaurus europaeus, Cf. Compsognathus sp., cf. Richardoestesia sp., Dromaeosaurinae indeter., Velociraptorinae indeter., cf. Archaeopteryx sp., aff. Paronychodon). Dinosauria: Sauropoda: Eusauropoda (Dinheirosaurus lourinhanensis, Lourinhasaurus alenquerensis, Lusotitan atalaiensis, Apatosaurus sp.). Dinosauria: Ornithischia: Thyreophora (Dacentrurus armatus, Stegosaurus sp., Dracopelta zbyszewskii). Dinosauria: Ornithischia: Ornithopoda (Phyllodon henkeli, Dryosaurus sp., Hypsilophodon sp., Alocodon kuehnei, Trimucrodon cuneatus, Draconyx loureiroi).

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