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2021
Beccari, V., Pinheiro F. L., Nunes I., Anelli L. E., Mateus O., & Costa F. R. (2021).  Osteology of an exceptionally well-preserved tapejarid skeleton from Brazil: Revealing the anatomy of a curious pterodactyloid clade. PLOS ONE. 16(8), e0254789 - ., 2021/08/25: Public Library of Science Abstractbeccari_et_al_2021.pdfWebsite

A remarkably well-preserved, almost complete and articulated new specimen (GP/2E 9266) of Tupandactylus navigans is here described for the Early Cretaceous Crato Formation of Brazil. The new specimen comprises an almost complete skeleton, preserving both the skull and post-cranium, associated with remarkable preservation of soft tissues, which makes it the most complete tapejarid known thus far. CT-Scanning was performed to allow the assessment of bones still covered by sediment. The specimen can be assigned to Tupa. navigans due to its vertical supra-premaxillary bony process and short and rounded parietal crest. It also bears the largest dentary crest among tapejarine pterosaurs and a notarium, which is absent in other representatives of the clade. The new specimen is here regarded as an adult individual. This is the first time that postcranial remains of Tupa. navigans are described, being also an unprecedented record of an articulated tapejarid skeleton from the Araripe Basin.

Mateus, O. (2021).  Overview of vertebrate fossils from Portugal, focus on Mesozoic dinosaurs. 3rd Palaeontological Virtual Congress. 15.: ISBN 978-84-09-36657-6 Abstractmateus_2021_pvc3_key_note_speaker.pdf

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2019
Mateus, O., Callapez P. M., Polcyn M. J., Schulp A. S., Gonçalves A. O., & Jacobs L. L. (2019).  O registo fóssil da biodiversidade em Angola ao longo do tempo: uma perspectiva paleontológica. (Huntley B.J., Russo V., Lages F., Ferrand N., Ed.).Biodiversidade de Angola: Ciência e Conservação - Uma Síntese Moderna. 89-116., Porto: Arte & Ciência Abstractmateus_et_al_2019_paleobiodiversidade_angola.pdf

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.

2018
2017
Tschopp, {E. D. }, Tschopp {F. A. }, & Mateus O. (2017).  Overlap Indices: Tools to quantify the amount of anatomical overlap among groups of incomplete terminal taxa in phylogenetic analyses. Acta Zoologica. 99, 169–176., 6, Number 2: Wiley-Blackwell Abstract

Phylogenetic analyses of morphological data are often characterized by missing data due to incomplete operational taxonomic units, as in fossils. This incomplete knowledge derives from various reasons, including—in the case of fossils—the numerous filters an organism has to pass through during taphonomy, fossilization, weathering and collecting. Whereas several methods have been proposed to address issues raised by the inclusion of incomplete terminal taxa, until recently no tool existed to easily quantify the amount of anatomical overlap within a particular clade. The Overlap Indices provide such values and might prove useful for comparative cladistics. We herein describe these new indices and their applications in detail and provide an example file for their calculation. A case study of diplodocid sauropod dinosaurs shows how the Overlap Indices will help to explore and quantify, which one of a number of conflicting tree topologies is supported by more anatomical traits, which skeletal regions are underrepresented in a particular phylogenetic matrix, and which taxon would improve character state score completeness.

Mateus, O., Callapez P. M., & Puértolas-Pascual E. (2017).  The oldest Crocodylia? a new eusuchian from the Late Cretaceous (Cenomanian) of Portugal. Journal of Vertebrate Paleontology, Program and Abstracts. 2017, 160. Abstractmateus_et_al_2017_oldest_crocodylia_svp_2017_abstract.pdf

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Correia, T., Barcelos L., Nunes T., Riff D., & Mateus O. (2017).  On a titanosaur scapula from the Marília Formation (Upper Cretaceous, Bauru Group) in Campina Verde Town. XXV Congresso Brasileiro de Paleontologia Boletim de Resumos. 77. Abstractthiago_abstract_brazil_2017.pdf

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Tschopp, E., & Mateus O. (2017).  Osteology of Galeamopus pabsti sp. nov. (Sauropoda: Diplodocidae), with implications for neurocentral closure timing, and the cervico-dorsal transition in diplodocids. PeerJ. 5, e3179. Abstracttschopp__mateus_2017_osteology_of_galeamopus_pabsti_sp.__nov._sauropoda__diplodocidae_.pdfWebsite

Diplodocids are among the best known sauropod dinosaurs. Numerous specimens of currently 15 accepted species belonging to ten genera have been reported from the Late Jurassic to Early Cretaceous of North and South America, Europe, and Africa. The highest diversity is known from the Upper Jurassic Morrison Formation of the western United States: a recent review recognized 12 valid, named species, and possibly three additional, yet unnamed ones. One of these is herein described in detail and referred to the genus \textit{Galeamopus}. The holotype specimen of \textit{Galeamopus pabsti} sp. nov., SMA 0011, is represented by material from all body parts but the tail, and was found at the Howe-Scott Quarry in the northern Bighorn Basin in Wyoming, USA. Autapomorphic features of the new species include a horizontal canal on the maxilla that connects the posterior margin of the preantorbital and the ventral margin of the antorbital fenestrae, a vertical midline groove marking the sagittal nuchal crest, the presence of a large foramen connecting the postzygapophyseal centrodiapophyseal fossa and the spinopostzygapophyseal fossa of mid- and posterior cervical vertebrae, a very robust humerus, a laterally placed, rugose tubercle on the concave proximal portion of the anterior surface of the humerus, a relatively stout radius, the absence of a distinct ambiens process on the pubis, and a distinctly concave posteroventral margin of the ascending process of the astragalus. In addition to the holotype specimen SMA 0011, the skull USNM 2673 can also be referred to \textit{Galeamopus pabsti}. Histology shows that the type specimen SMA 0011 is sexually mature, although neurocentral closure was not completed at the time of death. Because SMA 0011 has highly pneumatized cervical vertebrae, the development of the lamination appears a more important indicator for individual age than neurocentral fusion patterns. SMA 0011 is one of very few sauropod specimens that preserves the cervico-dorsal transition in both vertebrae and ribs. The association of ribs with their respective vertebrae shows that the transition between cervical and dorsal vertebrae is significantly different in \textit{Galeamopus pabsti} than in \textit{Diplodocus carnegii} or \textit{Apatosaurus louisae}, being represented by a considerable shortening of the centra from the last cervical to the first dorsal vertebra. Diplodocids show a surprisingly high diversity in the Morrison Formation. This can possibly be explained by a combination of geographical and temporal segregation, and niche partitioning.

Tschopp, E., Tschopp F. A., & Mateus O. (2017).  Overlap Indices: Tools to quantify the amount of anatomical overlap among groups of incomplete terminal taxa in phylogenetic analyses. Acta Zoologica. 99(2), 169-176. Abstracttschopp_et_al-2017-acta_zoologica_overlap_indices_tools_to_quantify_the_amount.pdfWebsite

Phylogenetic analyses of morphological data are often characterized by missing data due to incomplete operational taxonomic units, as in fossils. This incomplete knowledge derives from various reasons, including—in the case of fossils—the numerous filters an organism has to pass through during taphonomy, fossilization, weathering and collecting. Whereas several methods have been proposed to address issues raised by the inclusion of incomplete terminal taxa, until recently no tool existed to easily quantify the amount of anatomical overlap within a particular clade. The Overlap Indices provide such values and might prove useful for comparative cladistics. We herein describe these new indices and their applications in detail and provide an example file for their calculation. A case study of diplodocid sauropod dinosaurs shows how the Overlap Indices will help to explore and quantify, which one of a number of conflicting tree topologies is supported by more anatomical traits, which skeletal regions are underrepresented in a particular phylogenetic matrix, and which taxon would improve character state score completeness.

Mateus, O., Callapez P. M., & Puértolas-Pascual E. (2017).  The oldest Crocodylia? a new eusuchian from the Late Cretaceous (Cenomanian) of Portugal. Journal of Vertebrate Paleontology, Program and Abstracts. 2017, 160. Abstract
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Mateus, O., Callapez {P. M. }, & Puértolas-Pascual E. (2017).  The oldest Crocodylia? a new eusuchian from the Late Cretaceous (Cenomanian) of Portugal. 160. Abstract
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Correia, T., Barcelos L., Nunes T., Riff D., & Mateus O. (2017).  On a titanosaur scapula from the Marília Formation (Upper Cretaceous, Bauru Group) in Campina Verde Town. 77. Abstract
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Correia, T., Barcelos L., Nunes T., Riff D., & Mateus O. (2017).  On a titanosaur scapula from the Mar{\'ılia Formation (Upper Cretaceous, Bauru Group) in Campina Verde Town. XXV Congresso Brasileiro de Paleontologia Boletim de Resumos. 77. Abstract
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Tschopp, E., Tschopp F. A., & Mateus O. (2017).  The Overlap Index, a tool to quantify the amount of anatomical overlap among groups of incomplete terminal taxa in phylogenetic analyses. Journal of Vertebrate Paleontology, Program and Abstracts. 2017, 205-206. Abstract
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2015
Xing, L., Lockley M. G., Marty D., Zhang J., Wang Y., Klein H., McCrea R. T., Buckley L. G., Belvedere M., Mateus O., Gierliński G. D., Piñuela L., Persons, IV S. W., Wang F., Ran H., Dai H., & Xie X. (2015).  An Ornithopod-Dominated Tracksite from the Lower Cretaceous Jiaguan Formation (Barremian–Albian) of Qijiang, South-Central China: New Discoveries, Ichnotaxonomy, Preservation and Palaeoecology. PLoS ONE. 10, e0141059., 10, Number 10: Public Library of Science Abstractlida_et_al_2015_an_ornithopod-dominated_tracksite_from_the.pdfWebsite

The historically-famous Lotus Fortress site, a deep 1.5–3.0-meter-high, 200-meter-long horizonal notch high up in near-vertical sandstone cliffs comprising the Cretaceous Jiaguan Formation, has been known since the 13th Century as an impregnable defensive position. The site is also extraordinary for having multiple tetrapod track-bearing levels, of which the lower two form the floor of part of the notch, and yield very well preserved asseamblages of ornithopod, bird (avian theropod) and pterosaur tracks. Trackway counts indicate that ornithopods dominate (69%) accounting for at least 165 trackmakers, followed by bird (18%), sauropod (10%), and pterosaur (3%). Previous studies designated Lotus Fortress as the type locality of Caririchnium lotus and Wupus agilis both of which are recognized here as valid ichnotaxa. On the basis of multiple parallel trackways both are interpreted as representing the trackways of gregarious species. C. lotus is redescribed here in detail and interpreted to indicate two age cohorts representing subadults that were sometimes bipedal and larger quadrupedal adults. Two other previously described dinosaurian ichnospecies, are here reinterpreted as underprints and considered nomina dubia. Like a growing number of significant tetrapod tracksites in China the Lotus Fortress site reveals new information about the composition of tetrapod faunas from formations in which the skeletal record is sparse. In particular, the site shows the relatively high abundance of Caririchium in a region where saurischian ichnofaunas are often dominant. It is also the only site known to have yielded Wupus agilis. In combination with information from other tracksites from the Jiaguan formation and other Cretaceous formations in the region, the track record is proving increasingly impotant as a major source of information on the vertebrate faunas of the region. The Lotus Fortress site has been developed as a spectacular, geologically-, paleontologically- and a culturally-significant destination within Qijiang National Geological Park.

Hendrickx, C., Hartman S. A., & Mateus O. (2015).  An overview of non-avian theropod discoveries and classification. PalArch’s Journal of Vertebrate Palaeontology. 12(1), 1-73. Abstracthendrickx_etal_2015_non_avian_theropods_pjvp12_11.pdfWebsite

Theropods form a taxonomically and morphologically diverse group of dinosaurs that include extant birds. Inferred relationships between theropod clades are complex and have changed dramatically over the past thirty years with the emergence of cladistic techniques. Here, we present a brief historical perspective of theropod discoveries and classification, as well as an overview on the current systematics of non-avian theropods. The first scientifically recorded theropod remains dating back to the 17th and 18th centuries come from the Middle Jurassic of Oxfordshire and most likely belong to the megalosaurid Megalosaurus. The latter was the first theropod genus to be named in 1824, and subsequent theropod material found before 1850 can all be referred to megalosauroids. In the fifty years from 1856 to 1906, theropod remains were reported from all continents but Antarctica. The clade Theropoda was erected by Othniel Charles Marsh in 1881, and in its current usage corresponds to an intricate ladder-like organization of ‘family’ to ‘superfamily’ level clades. The earliest definitive theropods come from the Carnian of Argentina, and coelophysoids form the first significant theropod radiation from the Late Triassic to their extinction in the Early Jurassic. Most subsequent theropod clades such as ceratosaurs, allosauroids, tyrannosauroids, ornithomimosaurs, therizinosaurs, oviraptorosaurs, dromaeosaurids, and troodontids persisted until the end of the Cretaceous, though the megalosauroid clade did not extend into the Maastrichtian. Current debates are focused on the monophyly of deinonychosaurs, the position of dilophosaurids within coelophysoids, and megaraptorans among neovenatorids. Some recent analyses have suggested a placement of dilophosaurids outside Coelophysoidea, Megaraptora within Tyrannosauroidea, and a paraphyletic Deinonychosauria with troodontids placed more closely to avialans than dromaeosaurids.

Xing, L., Lockley M. G., Marty D., Zhang J., Wang Y., Klein H., McCrea R. T., Buckley L. G., Belvedere M., Mateus O., Gierli?ski G. D., Piñuela L., Persons W. S., Wang F., Ran H., Dai H., & Xie X. (2015).  An ornithopod-dominated tracksite from the lower Cretaceous Jiaguan Formation (Barremian-Albian) of Qijiang, South-Central China: New discoveries, ichnotaxonomy, preservation and palaeoecology. PLoS ONE. 10, , Number 10 Abstract
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Hendrickx, C., Hartman S. A., & Mateus O. (2015).  An overview of non-avian theropod discoveries and classification. PalArch’s Journal of Vertebrate Palaeontology. 12, 1-73. AbstractWebsite

Theropods form a taxonomically and morphologically diverse group of dinosaurs that include extant birds. Inferred relationships between theropod clades are complex and have changed dramatically over the past thirty years with the emergence of cladistic techniques. Here, we present a brief historical perspective of theropod discoveries and classification, as well as an overview on the current systematics of non-avian theropods. The first scientifically recorded theropod remains dating back to the 17th and 18th centuries come from the Middle Jurassic of Oxfordshire and most likely belong to the megalosaurid Megalosaurus. The latter was the first theropod genus to be named in 1824, and subsequent theropod material found before 1850 can all be referred to megalosauroids. In the fifty years from 1856 to 1906, theropod remains were reported from all continents but Antarctica. The clade Theropoda was erected by Othniel Charles Marsh in 1881, and in its current usage corresponds to an intricate ladder-like organization of ‘family’ to ‘superfamily’ level clades. The earliest definitive theropods come from the Carnian of Argentina, and coelophysoids form the first significant theropod radiation from the Late Triassic to their extinction in the Early Jurassic. Most subsequent theropod clades such as ceratosaurs, allosauroids, tyrannosauroids, ornithomimosaurs, therizinosaurs, oviraptorosaurs, dromaeosaurids, and troodontids persisted until the end of the Cretaceous, though the megalosauroid clade did not extend into the Maastrichtian. Current debates are focused on the monophyly of deinonychosaurs, the position of dilophosaurids within coelophysoids, and megaraptorans among neovenatorids. Some recent analyses have suggested a placement of dilophosaurids outside Coelophysoidea, Megaraptora within Tyrannosauroidea, and a paraphyletic Deinonychosauria with troodontids placed more closely to avialans than dromaeosaurids.

Hendrickx, C., Hartman S. A., & Mateus O. (2015).  An overview of non-avian theropod discoveries and classification. PalArch{'}s Journal of Vertebrate Palaeontology. 12, 1-73., Number 1 Abstract
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Hendrickx, C., Hartman S. A., & Mateus O. \á\}vio (2015).  An overview of non-avian theropod discoveries and classification. PalArch\’\}s Journal of Vertebrate Palaeontology. 12, 1-73. Abstract
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Hendrickx, C., Hartman S. A., & Mateus O. \á\}vio (2015).  An overview of non-avian theropod discoveries and classification. PalArch\’\}s Journal of Vertebrate Palaeontology. 12, 1-73. Abstract
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2014
2013
Mannion, P. D., Upchurch P., Barnes R. N., & Mateus O. (2013).  Osteology of the Late Jurassic Portuguese sauropod dinosaur Lusotitan atalaiensis (Macronaria) and the evolutionary history of basal titanosauriforms. Zoological Journal of the Linnean Society. 168, 98-206. Abstractmannion_et_al_2013_sauropod_lusotitan_portugal.pdfWebsite

Titanosauriforms represent a diverse and globally distributed clade of neosauropod dinosaurs, but their inter-relationships remain poorly understood. Here we redescribe Lusotitan atalaiensis from the Late Jurassic Lourinhã Formation of Portugal, a taxon previously referred to Brachiosaurus. The lectotype includes cervical, dorsal, and caudal vertebrae, and elements from the forelimb, hindlimb, and pelvic girdle. Lusotitan is a valid taxon and can be diagnosed by six autapomorphies, including the presence of elongate postzygapophyses that project well beyond the posterior margin of the neural arch in anterior-to-middle caudal vertebrae. A new phylogenetic analysis, focused on elucidating the evolutionary relationships of basal titanosauriforms, is presented, comprising 63 taxa scored for 279 characters. Many of these characters are heavily revised or novel to our study, and a number of ingroup taxa have never previously been incorporated into a phylogenetic analysis. We treated quantitative characters as discrete and continuous data in two parallel analyses, and explored the effect of implied weighting. Although we recovered monophyletic brachiosaurid and somphospondylan sister clades within Titanosauriformes, their compositions were affected by alternative treatments of quantitative data and, especially, by the weighting of such data. This suggests that the treatment of quantitative data is important and the wrong decisions might lead to incorrect tree topologies. In particular, the diversity of Titanosauria was greatly increased by the use of implied weights. Our results support the generic separation of the contemporaneous taxa Brachiosaurus, Giraffatitan, and Lusotitan, with the latter recovered as either a brachiosaurid or the sister taxon to Titanosauriformes. Although Janenschia was recovered as a basal macronarian, outside Titanosauria, the sympatric Australodocus provides body fossil evidence for the pre-Cretaceous origin of titanosaurs. We recovered evidence for a sauropod with close affinities to the Chinese taxon Mamenchisaurus in the Late Jurassic Tendaguru beds of Africa, and present new information demonstrating the wider distribution of caudal pneumaticity within Titanosauria. The earliest known titanosauriform body fossils are from the late Oxfordian (Late Jurassic), although trackway evidence indicates a Middle Jurassic origin. Diversity increased throughout the Late Jurassic, and titanosauriforms did not undergo a severe extinction across the Jurassic/Cretaceous boundary, in contrast to diplodocids and non-neosauropods. Titanosauriform diversity increased in the Barremian and Aptian–Albian as a result of radiations of derived somphospondylans and lithostrotians, respectively, but there was a severe drop (up to 40%) in species numbers at, or near, the Albian/Cenomanian boundary, representing a faunal turnover whereby basal titanosauriforms were replaced by derived titanosaurs, although this transition occurred in a spatiotemporally staggered fashion.

Mannion, P. D., Upchurch P., Barnes R. N., & Mateus O. (2013).  Osteology of the Late Jurassic Portuguese sauropod dinosaur Lusotitan atalaiensis (Macronaria) and the evolutionary history of basal titanosauriforms. Zoological Journal of the Linnean Society. 168, 98-206., Number 1 Abstract
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2012
Mateus, O. (2012).  Ontogenetical changes in the quadrate of basal tetanurans. Fundamental!. 101–104., 1 Abstract

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.

Hendrickx, C., & Mateus O. (2012).  Ontogenetical changes in the quadrate of basal tetanurans.. 10 th Annual Meeting of the European Association of Vertebrate Paleontologist ¡Fundamental! . 20, 101-104. Abstracthendrickx__mateus_2012_ontogenetical_changes_in_the_quadrate.pdf

Although nonavian theropod have received considerable interest in the last years, their ontogeny still remains poorly understood, especially the ontogenetical changes affecting their skull (Rauhut
and 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.
I

Mateus, O., Carrano M. T., & Taquet P. (2012).  Osteology of the embryonic theropods from the Late Jurassic of Paimogo, Portugal. Journal of Vertebrate Paleontology, Program and Abstracts, 2012, p.137. ISSN 1937-2809. 137.mateus_et_al_2012_embryos_paimogo_portugal_svp_2012_abstract_book_meeting_abstracts.pdf.pdf
2011
Marinheiro, J., & Mateus O. (2011).  Occurrence of the marine turtle Thalassemys in the Kimmeridgian of Oker, Germany. 71st Annual Meeting of the Society of Vertebrate Paleontology. 151., Jan: Abstracts of the 71st Annual Meeting of the Society of Vertebrate Paleontology Abstractmarinheiro__mateus_2011_turtle_thalassemys_oker_germany_svp11abstracts.pdf

A partial chelonian was collected from the Langenberg Formation quarry of Oker (near Goslar, Lower Saxony, Germany). The amniotes from this formation include other chelonians (possible Plesiochelyidae), the sauropod Europasaurus holgeri, theropods (Velociraptorinae), crocodylomorphs (Atoposauridae, Theriosuchus pusillus, Goniopholis simus, Machimosaurus hugii, Steneosaurus brevirostris) and pterosaurs (Dsungapteridae, ?Ornithocheiroidea, ?Ctenochasmatidae).

The reported specimen, DFMMh/FV 296, includes a skull part (articulated quadrate, squamosal, basisphenoid, and pterygoid), a disarticulated 40 cm long partial carapace, plastron, and one cervical vertebra.

The carapace bears fontanelles, trapezoidal suprapygal with straight edges, small last neurals

[....]
a plicated longitudinal pattern in the proximal end of the costals originating on the posterior side of the scute sulci and dissipating posteriorly, wide central opening in the plastron, xiphiplastra with little or no contact between each other, and both the hyo- and hypoplastron have digit-form buttress projections.

The specimen has a central plastra fontanelle, which is regarded as a feature of the clade including [....], Santanachelys, and Thalassemys. DFMMh/FV 296 differs from
[....]

edges and xiphiplastron participation in the central fontanelle is autapomorphic for the Thalassemys genus. A large central fontanelle with hyo and hypoplastron polygonal medial
[....]
contact between xiphiplastra and reduced size of the two last neural plates is shared between T. hugii and the Oker specimen. DFMMh/FV 296 differs from this species due to the presence of plastral projections. The different shape of the plastron (no polygonal-like margins or hyo- and hypoplastron projections) suggests that T. moseri [....]
ent genus. Therefore, we can assign this specimen to Thalassemys sp.

Mateus, O. (2011).  Occurrence of the marine turtle Thalassemys in the Kimmeridgian of Oker, Germany. Abstracts of the 71st Annual Meeting of the Society of Vertebrate Paleontology. 151., 1 Abstract
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2009
Mateus, O., Jacobs L., Polcyn M., Schulp A. S., Vineyard D., Neto A. B., & Antunes M. T. (2009).  The oldest African eucryptodiran turtle from the Cretaceous of Angola. Acta Palaeontologica Polonica. 54, 581-588., Jan: Univ Agostinho Neto, Univ Nova Lisboa, Museu Lourinha, Acad Ciencias Lisboa, Nat Hist Museum Maastricht, So Methodist Univ Abstractmateus_et_al_2009_the_oldest_african_angolachelys_angola_turtle.pdfWebsite

A new Late Cretaceous turtle, Angolachelys mbaxi gen. et sp. nov., from the Turonian (90 Mya) of Angola, represents the oldest eucryptodire from Africa. Phylogenetic analysis recovers Angolachelys mbaxi as the sister taxon of Sandownia harrisi from the Aptian of Isle of Wight, England. An unnamed turtle from the Albian Glen Rose Formation of Texas (USA) and the Kimmeridgian turtle Solnhofia parsonsi (Germany), are successively more distant sister taxa. Bootstrap analysis suggests those four taxa together form a previously unrecognized monophyletic clade of marine turtles, herein named Angolachelonia clade nov., supported by the following synapomorphies: mandibular articulation of quadrate aligned with or posterior to the occiput, and basisphenoid not visible or visibility greatly reduced in ventral view. Basal eucryptodires and angolachelonians originated in the northern hemisphere, thus Angolachelys represents one of the first marine amniote lineages to have invaded the South Atlantic after separation of Africa and South America.

Mateus, O., Jacobs L., Polcyn M., Schulp A. S., Vineyard D., Buta Neto A., & Telles Antunes M. (2009).  The oldest African eucryptodiran turtle from the Cretaceous of Angola. Acta Palaeontologica Polonica. 54, 581-588., Number 4 Abstract
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2007
Gaspar, A., Mateus O., & Almada F. (2007).  Os argumentos criacionistas em face da evidência científica. Evolução e Criacionismo: Uma Relação Impossível. 197-237., Lisboa: Quasi ed.gasparmateusealmada2007argumentosevo.pdf
Gaspar, A., Mateus O., & Almada F. (2007).  Os argumentos criacionistas em face da evidência científica. Evolução e Criacionismo: Uma Relação Impossível. 197-237., Lisboa Abstract
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2006
Jacobs, L. L., Mateus O., Polcyn M. J., Schulp A. S., Antunes M. T., Morais M. L., & da Silva Tavares T. (2006).  The occurrence and geological setting of Cretaceous dinosaurs, mosasaurs, plesiosaurs, and turtles from Angola. Paleont. Soc. Korea. 22(1), 91-110. Abstractjacobs_mateus-et_al_2006_angola.pdf

Vertebrate-bearing fossiliferous outcrops of Cretaceous age in sub-Saharan Africa are rare because of younger superficial deposits, vegetation cover, and the widespread occurrence of Precambrian metamorphic plateau basement comprising much of the continent. However, one area of extensive marine and nonmarine
Cretaceous exposures is found between the plateau and the coast in Angola. The Angolan margin was formed in conjunction with the breakup of Gondwana and subsequent growth of the South Atlantic. Cretaceous deposits are constrained in age by the emplacement of oceanic crust, which began no later than magnetozone M3
(approximately 128 Ma, Barremian). Shallow marine facies are exposed in sea cliffs but equivalent facies become increasingly terrestrial inland. Few vertebrate fossils have been described from Angola aside from sharks.
Notable exceptions are the late Turonian mosasaurs Angolasaurus bocagei and Tylosaurus iembeensis from northern Angola. Those taxa are significant because they are among the earliest derived mosasaurs. Recent field work led to the discovery of a new skull of Angolasaursus as well as sharks, fish, plesiosaurs, the skull of a new taxon of turtle, additional mosasaurs, and the articulated forelimb of a sauropod dinosaur, the first reported dinosaur from Angola. In southern Angola, marine sediments spanning the Cretaceous-Paleogene boundary are found.

Castanhinha, R., & Mateus O. (2006).  On the left-right asymmetry in dinosaurs. Journal of Vertebrate Paleontology. 26(Suppl. To 3), 48A. Abstractcastanhinhamateus2006.pdf

The study of different kinds of morphological left-right (L-R) asymmetries in all taxa is a very powerful tool to understand evolution since it is a way to measure the developmentalstability of an organism against environmental perturbations. Excluding every pathologic or subtle asymmetry and all cases of taphonomic distortion, this work focuses only on two
kinds of unambiguous asymmetries: fluctuating and adaptative asymmetry. There are several cases of conspicuous left-right asymmetry in dinosaurs and is probably more common than previously thought. The pneumatic cavities systems in skull and vertebrae of theropodsand sauropods are the most common cases reported. The shape (but not the occurrence) of pneumatic cavities might have been exposed to weak selective pressure becoming more random than other body structures. Asymmetries are rarer in the appendicular bones possibly because it represents a strong handicap in the function of the limbs, consequently in the locomotion of the individual. Teeth counting show many exceptions to the typical L-R symmetry. Peculiar cases of adaptive asymmetry are related with the plates of stegosaurs and the ear displacement in the skull of the troodontids, which may have an important role in the physiology and ecology of the animals. The asymmetric displacement maximizes the surface exposure of the stegosaurs dorsal plates. This is an advantage, either the plates were used for thermoregulation, display or specific identification. Work in progress on the braincases of some troodontids specimens shows asymmetric ear openings, which suggests thatcan be an analogy resulting from convergent evolution between troodontids and strigiformes birds, used for 3D directional acoustics. Asymmetries are more common in animals that develop under stress. Animals that lived under dramatic environmental changes periods—like mass-extinctions episodes are believed to be—should present more asymmetries.
However, much more sampling and time accuracy is required in order to be able to relate dinosaur asymmetries to extinction episodes. Asymmetries show strong intra-individual variation and should be taken in consideration in taxonomical studies.

Jacobs, L. L., Mateus O., Polcyn M. J., Schulp A. S., Antunes M. T., Morais M. L., & Tavares T. S. (2006).  The occurrence and geological setting of Cretaceous dinosaurs, mosasaurs, plesiosaurs, and turtles from Angola. Journal of the Paleontological Society of Korea. 22, , Number 1 Abstract
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Jacobs, L. L., Mateus O., Polcyn M. J., Schulp A. S., Antunes M. T., Morais M. L., & da Silva Tavares T. (2006).  The occurrence and geological setting of Cretaceous dinosaurs, mosasaurs, plesiosaurs, and turtles from Angola. JOURNAL-PALEONTOLOGICAL SOCIETY OF KOREA. 22, 91–91., Number 1 Abstract
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Castanhinha, R., & Mateus O. (2006).  On the left-right asymmetry in dinosaurs. Journal of Vertebrate Paleontology, 26 (Suppl. To 3): 48A.. 26, 48., Number Suppl. to 3 Abstract
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Castanhinha, R., & Mateus O. (2006).  On the left-right asymmetry in dinosaurs. Journal of Vertebrate Paleontology, 26 (Suppl. To 3): 48A.. 26, 48–48., Number Suppl. to Abstract
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2000
Mateus, O., & Antunes M. T. (2000).  On the presence of Ceratosaurus sp. (Dinosauria: Theropoda) in the Late Jurassic of Portugal. Abstract volume of the 31st International Geological Congress. , Rio de Janeiro, Brazil Abstract
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Mateus, O., & Antunes M. T. (2000).  On the presence of Ceratosaurus sp. (Dinosauria: Theropoda) in the Late Jurassic of Portugal. Abstract volume of the 31st International Geological Congress. , Rio de Janeiro, Brazil Abstract
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