n/a

n/a

Although occurrences of marine reptiles have been previously reported from Angola, with the exception of two Turonian taxa, these reports were based largely on isolated teeth. Fieldwork in 2005 and 2006 yielded well-preserved remains of marine reptiles including plesiosaurs, turtles, and mosasaurs. The mosasaurs discussed here were recovered from two field areas: Turonian sediments at Iembe along the north coast and Maastrichtian sediments at Bentiaba on the south coast. The Turonian section near Iembe produced at least two new specimens of Angolasaurus bocagei and one fragmentary specimen of Tylosaurus iembeensis. One of the Angolasaurus specimens is represented by a well preserved, complete and articulated skull and partial postcrania, including portions of the forelimbs and pectoral girdle. The preservation of material from the Bentiaba locality is remarkable due to the grain support of the entombing sandstone, which preserves fine anatomical details with little apparent crushing, and in the number of articulated, semi-articulated, and associated skeletons. Identifications from the field and preliminary preparation show the Bentiaba mosasaur fauna is represented by at least five genera including Mosasaurus, Prognathodon, Globidens, Plioplatecarpus and Halisaurus. Collectively, these new specimens greatly expand our knowledge of the anatomy and systematics of Angolan mosasaurs.

Portugal is rich on dinosaur remains (bones, eggs, and tracks) from Early Jurassic to Late
Cretaceous ages, but mainly from the Late Jurassic, in which dozen of tracksites have been reported.
Here are reported new or poorly known track localities:
1) Five tracksites share the preservation substrate (marine carbonated limestone), age (late Jurassic), geographic area (Leiria district of Portugal), kind of preservation (true tracks), and completeness (trackways of multiple individuals):
i) Praia dos Salgados includes eight trackways, mostly ornithopods and theropods, and one wide gauge sauropod, made in very soft sediment; some preserve the hallux impression.
ii) Serra de Mangues is mostly covered with vegetation but seems to include dozens of tracks comprising theropods, thyreophorans, ornithopods and sauropods.
iii) Sobral da Lagoa (Pedreira do Rio Real) include six trackways but poorly preserved;
and
iv) Serra de Bouro that preserves four sauropod trackways in one single layer.
v) Pedrógão, preserved, at least, one theropod trackway and several isolated tracks of
theropods and ornithopods were found in different layers in the Early Oxfordian.
2) The locality in Praia de Porto das Barcas yielded natural casts of stegosaur tracks
(including pes print with skin impression) and a very large sauropod pes print with about
1.2 m long pes.
3) A new pterosaur tracksite was found in the Late Jurassic of Peralta, Lourinhã (Sobral Member, Lourinhã Fm.; Late Kimmeridgian/Early Tithonian). More than 220 manus and pes tracks have been collected in about five square meters, all ascribed to pterosaurs. The tracks were produced in a thin mud layer that has been covered by sand which preserved them as sandstone mould infill (natural casts). The manus of the largest specimens is 13 cm wide and 5.5 cm long and the pes measures 14.5 cm in length and 9 cm in width. This shows the occurrence of very large pterosaurs in the Late Jurassic. Other pterosaur tracksites in the Late Jurassic of Portugal are: Porto das Barcas (Lourinhã Municipality), South of Consolação (Peniche Municipality), and Zambujal de Baixo (Sesimbra Municipality).

n/a

n/a

Here we describe a new species of the mosasaurine genus Prognathodon from the Maastrichtian of Namibe, Angola, on the basis of five specimens which represent most of the cranial skeleton including the diagnostic quadrate. Phylogenetic analysis shows this new taxon, P. kianda nov. sp., to be the sister taxon to all other species of Prognathodon. It is unique amongst Prognathodon in possessing a high marginal tooth count and relatively small pterygoid teeth. The tooth morphology in the new taxon is reminiscent of some species of the genus Liodon, allowing association of Liodon-like dentition with otherwise Prognathodon-like crania, and thus resolves the long-standing question of the phylogenetic affinities of Liodon.

n/a

n/a

The quadrate in nonavian theropods is incredibly diverse morphologically; however this morphological disparity has been underestimated for taxonomic purposes. The quadrate topological homologies and anatomy, as well as the terminology, among nonavian theropod clades are reviewed. In order to evaluate the phylogenetic potential and investigate the evolutionary transformations of the quadrate, we conducted a Catalano-Goloboff phylogenetic morphometric analysis using 3 morphometric characters, a total of 28 landmarks coded for 23 taxa, as well as a cladistic analysis using 115 discrete quadrate-related characters coded for 43 taxa. The cladistic analysis provides a fully resolved tree mirroring the current classification of nonavian theropods. The quadrate morphology by its own provides a wealth of data with strong phylogenetic signal. Several unambiguous synapomorphies support nonavian theropod relationships and the resulting consensus tree allows inference of major trends in the evolution of this bone. Important synapomorphies include: for Abelisauridae, a lateral ramus extending to the ectocondyle; for Tetanurae, the absence of the lateral process; for Spinosauridae, a medial curvature of the ventral part of the pterygoid ramus occurring just above the mandibular articulation; for Neotetanurae, an anterior margin of the pterygoid flange formed by a roughly parabolic margin; and for Tyrannosauroidea, a semi-oval pterygoid flange shape in medial view. The Catalano-Goloboff phylogenetic morphometric analysis reveals two main morphotypes of the mandibular articulation of the quadrate linked to function. The first morphotype, characterized by an anteroposteriorly broad mandibular articulation with two ovoid/subcircular condyles roughly subequal in size, is found in Ceratosauria, Tyrannosauroidea and Oviraptorosauria. This morphotype allows a very weak displacement of the mandible laterally. The second morphotype is characterized by an elongate and anteroposteriorly narrow mandibular articulation and a long and parabolic/sigmoid ectocondyle. Present in Megalosauroidea, Allosauroidea and Dromaeosauridae, this morphotype permits the lower jaw rami to be displaced laterally when the mouth opened.

The record of ornithischian dinosaurs from Portugal is substantial but incomplete in terms of our understanding of taxonomic composition and details of the anatomy of many forms. New data and reinterpretation of these forms are provided. The basal thyreophoran from the Lower Jurassic (the nomen dubium “Lusitanosaurus liasicus”) is the most primitive dinosaur from Iberia. Concerning the Late Jurassic, new material from the Lourinhã Formation (Kimmeridgian/Tithonian) referable to the stegosaur Dacentrurus provides additional information on the systematic position and osteology.
The new material shows two rows of paired triangular plates, with a notch in the anterior rim. A maxillary of an ankylosaur from the Vale Frades (Lourinhã Fm.) is here reported, but cannot be referable to Dracopelta, the only ankylosaur genus currently known from Portugal. The ornithopod Alocodon kuehnei reported as Middle Jurassic (Callovian) is probably Oxfordian in age. A right dentary (ML768 from Zimbral) from the Lourinhã Formation, Kimmeridgian/Tithonian, and shares affinities with Dryosaurus but possesses more denticulation and no secondary ridges, suggesting the occurrence of a new or unreported species for the Late Jurassic of Portugal, which is here tentatively ascribed to aff. Dryosaurus sp. In summary, the Late Jurassic ornithischians species/genera from Portugal include Dacentrurus armatus, Stegosaurus cf. ungulatus, Dracopelta zbyszewskii, Phyllodon henkeli, Hypsilophodon sp., Alocodon kuehnei, Trimucrodon cuneatus, aff. Dryosaurus and Draconyx loureiroi. The Lower Cretaceous (Hauterivian / Barremian) of Praia das Aguncheiras, in Cabo Espichel, provided a partial left maxillary (CPGP.1.99.7) of a basal iguanodontian that shows affinities with Camptosaurus, and is tentatively assigned to this genus. The maxillary teeth denticles differ from Iguanodon or other Iguanodontoidea because not show mammillations. More material is necessary to validate but, to be true, that would confirm the presence of this genus in the lower Cretaceous. The Iguanodon has been well reported in the Lower Cretaceous of Cabo Espichel.

n/a

Although nonavian theropod have received considerable interest in the last years, their ontogeny still remains poorly understood, especially the ontogenetical changes affecting their skull (Rauhutand Fechner, 2005). The quadrate, for instance, is preserved in several embryos and juvenile specimens belonging to many clades of theropods such as the Tyrannosauridae (Carr, 1999), Compsognathidae (Dal Sasso and Maganuco, 2011), Therizinosauroidea (Kúndrat et al., 2007), Oviraptoridae (Norell et al., 1994; Norell et al., 2001; Weishampel et al., 2008) and Troodontidae (Varrichio et al., 2002) but very little is usually said about the anatomy of this bone and no one has ever investigated ontogenetical variation in the nonavian theropod quadrate. The discovery of two quadrates belonging to embryos of the sinraptorid Lourinhanosaurus antunesi from Portugal and five isolated quadrates pertaining to juvenile, subadult and adult specimens of Spinosauridae from Morocco fills this gap and allows some ontogenetic information to be drawn for this bone in these two specific clades of Theropoda.

n/a