n/a

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).

n/a

n/a

n/a

n/a

The diversity of fossil crocodylomorphs in Portugal is high, with occurrence as old as Mystriosaurus (=Steneosaurus) bollensis from the Lower Jurassic. The Late Jurassic forms are the better documented, and include the following taxa: Machimosaurus hugii, Lisboasaurus estesi Seiffert, 1973, Lusitanisuchus mitrocostatus Seiffert, 1975; Schwarz & Fechner 2004, Theriosuchus guimarotae Schwarz and Salisbury 2005, Cf. Alligatorium, Goniopholis baryglyphaeus, and a crocodylomorph-like eggs in dinosaur nests (Mateus et al., 1998; Ricqlès et al., 2001). From the Lower Cretaceous were reported a few dinosaurs but its record is strangely scarce in crocodylomorphs (Mateus et al., 2011). The Upper Cretaceous crocodiles show a large diversity, but it is mostly based in fragmentary material that require revision, such as “Crocodylus” blavieri? Grey from the Upper Campanian - Maastrichtian of Viso, near Aveiro (initially reported by Sauvage 1897-98), Goniopholis cf. crassidens Owen 1841 and Oweniasuchus pulchelus Jonet 1981. Moreover there is a fascinating, but poorly understood, crocodylomorph diversity in the Cenomanian of Portugal, documented by fragmentary specimens that have been doubtfully assigned to Thoracosaurus Leidy 1852 of the Middle Cenomanian of Cacém, to the nomen dubium Oweniasuchus lusitanicus Sauvage 1897-98 (interpreted as a mesosuchian goniopholid) based in a fragmentary mandible from the Campanian-Maastrichtian, and also from the Middle Cenomanian of Portugal, Buffetaut and Lauverjat (1978) report an fragmentary unidentified possible dyrosaurid from Nazaré. All this specimens are too incomplete to be compared with the specimen here described. In contrast, Cenozoic crocodiles of Portugal are often known after complete skulls and several individuals. The taxa list include Iberosuchus macrodon (Lower to Middle Eocene), Tomistoma calaritanus (Early Miocene) and T. lusitanica (Burdigalian-Helvetian), and Diplocynodon sp. (Antunes, 1961, 1987, 1994).
At least, two different morphotypes of crocodylomorph eggs from the Late Jurassic of Lourinhã Formation are also known.
A new specimen here reported of crocodile based in a partial skull and mandible (ML1818) from the Uppermost Middle Cenomanian platform carbonates of Baixo Mondego, west central Portugal (Tentúgal Fm., Callapez, 2004). The taxon is phylogenetically positioned as a basal Eusuchia, due to the choanae enclosed by the pterygoid, and closely related with stem Crocodylia and Borealosuchus. This specimen represents the only well documented and valid eusuchian species in the Cenomanian of Europe and is the oldest representative of an eusuchian crocodylomorph, with the exception for the Barremian Hylaeochampsa vectiana.

n/a

n/a

n/a

Does not have ISSN or ISBN

Clavicles and interclavicles are plesiomorphically present in Reptilia. However, several groups show reduction or even loss of these elements. Crocodylimorpha, e.g., lost the clavicles, whereas dinosaurs are generally interpreted to only preserve the clavicles, the theropod furcula representing an unique case of fused clavicles. In sauropods, reports of clavicles are relatively frequent in non-titanosauriforms. These elements are elongated, curved, and rather stout bones with a spatulate and a bifurcate end. However, they were always found as single bones, and differ from the relatively short and unbifurcated clavicles found articulated with the scapulae of basal sauropodomorphs. Elements from the Howe Quarry (Late Jurassic; Wyoming, USA) shed new light on these interpretations. Besides the elongated, curved bones (herein named morphotype A), also pairs of symmetric, L-shaped bones were recovered (morphotype B), associated with diplodocid dorsal and cervical vertebrae. Elements resembling morphotype B - articulated between the scapulae - have recently been reported from a diplodocid found near Tensleep, Wyoming. Taphonomic evidence, as well as the fact that they were preserved in symmetrical pairs, therefore implies that morphotype B represents the true sauropod clavicles. Contrary to earlier reports, morphotype A elements from the Howe Quarry, as well as of previously reported specimens show a symmetry plane following the long axis of the elements. It is thus possible that the morphotype A elements were single bones from the body midline. The only such element present in the pectoral girdle of tetrapods are the interclavicle and the furcula. Comparison with crocodilian and lacertiform interclavicles indicates that the bifurcate end of the sauropod elements might represent the reduced transverse processes of the anterior end, and the spatulate end would have covered the coracoids or sternal plates ventrally. The presence of both clavicles and interclavicles in the pectoral girdle stiffens the anterior trunk, and enhances considerably its stability. Such an enforcement might have been needed in diplodocids due to the strong lateral forces induced to the fore-limbs by the posteriorly placed center of mass (due to shorter fore- than hind-limbs), as well as lateral movements of the enormously elongated necks and tails. The absence of clavicles and interclavicles in titanosauriforms coincides with the development of wide-gauge locomotion style. The presence of interclavicles in sauropods supports the recently proposed homology of the furcula with the interclavicle, instead of representing fused clavicles. Interclavicles were thus not lost, but may have remained cartilaginous or have yet to be found in basal dinosauriforms.

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.

A single, geographically and temporally restricted horizon at Bentiaba, Angola (14.3° S), preserves a concentration of skeletons and isolated elements representing sharks, rays, bony fish, at least three species of turtles, two species of plesiosaurs, at least five species of mosasaurs, and rare volant and terrestrial forms. The concentration, referred to as the Bench 19 Fauna, formed on a narrow continental shelf at paleolatitude 24°S as predicted by paleomagnetic data and confirmed by plate motion models. The shelf evolved as a transform passive margin along faults associated with the opening of the South Atlantic. Latitude 24°S falls today along the coast of northern Namibia, an area of intense upwelling and hyperarid coastal desert. The Namibe Basin in southern Angola is separated from the Walvis Basin of Namibia by the Walvis Ridge, and the continental shelf in northern Namibia is eight times the width of that at Bentiaba. However, the sediment entombing the fossils at Bentiaba is an immature feldspathic sand, shown by detrital zircon ages to be derived from nearby exposed granitic shield rocks, suggesting similar climatic and drainage conditions between the two regions. Temporal control of the Bentiaba section is provided by magnetostratigraphy and stable carbon isotope chemostratigraphy anchored by an Ar40/Ar39radiometric date on basalt. The age of Bench 19 is constrained to chron C32n.1n and thus falls between 71.4 and 71.64 Ma. Massive bedding without hummocky cross-bedding or other sedimentary structures indicates deposition in shallow water below wave base. δ18O analysis of bivalve shells indicates a water temperature of 18° C immediately below Bench 19. Nearest neighbor distance peaks at 5 m (n=19