Polcyn, M. J., Bardet N., Amaghzaz M., Gon{\c c}alves O. A., Jourani E., Kaddumi H. F., Lindgren J., Mateus O., Meslouhf S., Morais M. L., Pereda-Suberbiola X., Schulp A. S., Vincent P., & Jacobs L. L.
(2016).
An extremely derived plioplatecarpine mosasaur from the Maastrichtian of Africa and the Middle East.
5th Triennial Mosasaur Meeting- a global perspective on Mesozoic marine amniotes. 16-20, May 16-20, 2016., Uppsala, Sweden: Museum of Evolutiom, Uppsala University.
Abstract
Polcyn, M. J., Bardet N., Amaghzaz M., Gon\{\c c\}alves O. A., Jourani E., Kaddumi H. F., Lindgren J., Mateus O., Meslouhf S., Morais M. L., Pereda-Suberbiola X., Schulp A. S., Vincent P., & Jacobs L. L.
(2016).
An extremely derived plioplatecarpine mosasaur from the Maastrichtian of Africa and the Middle East.
5th Triennial Mosasaur Meeting- a global perspective on Mesozoic marine amniotes. 16-20, May 16-20, 2016., Uppsala, Sweden
Abstractn/a
Mateus, O.
(2016).
Late Jurassic of Morrison Formation and Portugal tetrapods compared: a model to explain faunal exchange and similarity.
Annual Meeting of the Society of Vertebrate Paleontology. 185., Salt Late City: Journal of Vertebrate Paleontology, Program and Abstracts, 2016
AbstractThe 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.
Polcyn, M. J., Bardet N., Amaghzaz M., Gonçalves O. A., Jourani E., Kaddumi H. F., Lindgren J., Mateus O., Meslouhf S., Morais M. L., Pereda-Suberbiola X., Schulp A. S., Vincent P., & Jacobs L. L.
(2016).
An extremely derived plioplatecarpine mosasaur from the Maastrichtian of Africa and the Middle East.
5th Triennial Mosasaur Meeting- a global perspective on Mesozoic marine amniotes. 16-20(May 16-20, 2016), May 16-20, 2016., Uppsala, Sweden: Museum of Evolutiom, Uppsala University.
Abstract
Mateus, O.
(2016).
Late Jurassic of Morrison Formation and Portugal tetrapods compared: a model to explain faunal exchange and similarity.
Annual Meeting of the Society of Vertebrate Paleontology. 185., Salt Late City: Journal of Vertebrate Paleontology, Program and Abstracts, 2016
AbstractThe 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.
Myers, T. S., Mateus O., Polcyn M. J., Vineyard D., & Jacobs L. L.
(2016).
A new chelonioid turtle from the Paleocene of Cabinda, Angola.
Annual Meeting of the Society of Vertebrate Paleontology. 194.: Journal of Vertebrate Paleontology, Program and Abstracts, 2016
AbstractWe report a new chelonioid turtle on the basis of a nearly complete skull collected in lower Paleocene, shallow marine deposits, equivalent to the offshore Landana Formation, near the town of Landana in Cabinda Province, Angola. Chelonioid material previously reported from this locality is likely referable to this new taxon. The well-preserved skull is missing the left quadrate, squamosal, and prootic, both opisthotics, and the mandible. The skull possesses a rod-like basisphenoid rostrum, which is a synapomorphy of Chelonioidea, but it differs from other chelonioid skulls in that the contact between the parietal and squamosal is absent, and the posterior palatine foramen is present. Phylogenetic analysis recovers the new taxon as a basal chelonioid. The Paleocene– Eocene strata near Landana have produced a wealth of turtle fossils, including the holotype of the pleurodire Taphrosphys congolensis. A turtle humerus collected from the Landana locality differs morphologically from the humeri of chelonioids and Taphrosphys, indicating the presence of a third taxon. Chelonioid fossil material in the Landana assemblage is rare compared to the abundant fragmentary remains of Taphrosphys that are found throughout the stratigraphic section. This disparity in abundance suggests the new chelonioid taxon preferred open marine habitats, whereas Taphrosphys frequented nearshore environments.
Muchagata, J., & Mateus O.
(2016).
Sexual display and rostral variation in extinct beaked whale, Globicetus hiberus.
XIV EAVP Meeting. 136., Haarlem, The Netherlands: XIV EAVP Meeting, Programme and Abstract Book
AbstractIberian 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.
Hendrickx, C., Mateus O., & Buffetaut E.
(2016).
Morphofunctional Analysis of the Quadrate of Spinosauridae (Dinosauria: Theropoda) and the Presence of Spinosaurus and a Second Spinosaurine Taxon in the Cenomanian of North Africa..
PLoS ONE. 11, e0144695., 01, Number 1: Public Library of Science
AbstractSix 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.
Hendrickx, C., Mateus O., & Buffetaut E.
(2016).
Morphofunctional Analysis of the Quadrate of Spinosauridae (Dinosauria: Theropoda) and the Presence of Spinosaurus and a Second Spinosaurine Taxon in the Cenomanian of North Africa..
PLoS ONE. 11, e0144695., 01, Number 1: Public Library of Science
AbstractSix 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.
Silva, T., Costa F., Fernandes J., Calvo R., & Mateus O.
(2016).
The use of a portable X-ray fluorescence analyzer in the reconstitution of dinosaur fossils.
, 7: European Conference on X-Ray Spectrometry (EXRS)
AbstractPortable X-ray fluorescence spectrometers (p-XRF) have been used in many fields of application/studies like art, archaeology, heavy metals in soil, rocks and ores characterization, and have been a powerful tool for a rapid non-destructive in-situ analysis, without any sample preparation required. This approach was applied in the present case, to distinguish the origin of the fossil bones of two dinosaur specimens from different localities that were accidentally put together in the museum a few years ago. Fossil bones with sedimentary matrix associated were stored together until today in the collection of Geological Museum (Lisbon) and regarded as one single specimen. One set of bones is part of the holotype MG 5787 of the ankylosaur Dracopelta zbyszweskii, which was discovered at Praia do Sul, and described in 1980, while the other, is an undescribed half skeleton of dacentrurine stegosaur, unearthed in the 1960’s at Atouguia da Baleia, near Peniche (both in the coast of central Portugal, distanced about 100 km from each other). Since both specimens are highly valuable for paleontology, a study was developed with the aim of separating and reconstituting the two specimens. The handheld p-XRF (Genius 9000+7000 from Skyray Instrument) was directly used in the sedimentary matrix when it was separated from the bone, and the measure of the chemical content was performed in the intermediate layer between the surface and the bone, to avoid contaminations. Although the light elements could not be attained, because the analyzer is not equipped with the option of gas charging system, the spectra obtained showed differences mainly in the ratio K/Ca, allowing distinguishing the provenance of the bones (Atouguia or Praia do Sul). These results were compared with chemical analysis obtained with XRF laboratorial equipment and complemented by the mineralogical study through X-ray diffraction (XRD) of the sediments where the bones fossilized. The difference observed in the mineralogical constitution of the sedimentary matrix from the two localities (mainly quartz, calcite, feldspars and micas with variable content) explains the variation in the values found for the ratio K/Ca (<0.5 for Atouguia and >>1 for Praia do Sul). The data obtained will be presented and discussed focusing on the importance of using a portable X-ray fluorescence analyzer applied to the reconstitution of dinosaur fossils that proved to be very useful in the present case.