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The large theropod fauna of the Lourinhã Formation (Portugal) and its similarity to the Morrison Formation, with a description of a new species of Allosaurus
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Late Jurassic theropod dinosaurs have been known in Portugal since 1863 but only now are they being fully understood, with the recognition of genera such as Allosaurus, Aviatyrannis, Ceratosaurus, Lourinhanosaurus, and Torvosaurus from the Lourinhã and Alcobaça Formations (Kimmeridgian/Tithonian). Ceratosaurus dentisulcatus can now be reported from Portugal. It represents the only occurrence of this species outside the Morrison Formation. New cranial elements confirm the presence of Torvosaurus tanneri, in Portugal. Torvosaurus was the largest Late Jurassic land carnivore. New postcranial and cranial elements allow the erection of a new species from Portugal, Allosaurus europaeus n.sp. The theropod assemblage of Portugal is similar to that of the Morrison Formation. Resumo—São interpretados dinossauros terópodes em Portugal desde 1863, mas só agora começam a ser melhor conhecidos, através do reconhecimento de géneros como Ceratosaurus, Lourinhanosaurus, Torvosaurus, Allosaurus e Aviatyrannis das Formações da Lourinhã e Alcobaça (Kimmeridgiano/Titoniano). É dada a conhecer para Portugal a presença de Ceratosaurus dentisulcatus, a única ocorrência conhecida fora da Formação de Morrison. Novos elementos cranianos confirmam a presença de Torvosaurus tanneri, o maior carnívoro terrestre do Jurássico superior. Novos elementos cranianos e pós-cranianos permitem caracterizar uma nova espécie, Allosaurus europaeus n.sp. A fauna de terópodes de Portugal é muito semelhante à da Formação de Morrison.
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... The principal objective of this study is to provide a comprehensive re-description and detailed anatomical analysis of Allosaurus europaeus ML415, including the partial skull, three cervical vertebrae, and several ribs, which represent the holotype specimen [10]. The secondary objective of this study is to discover, if possible, a new set of characters present in the specimen and compare them with those of other Allosaurus species using morphometric phylogenetic analysis. ...
... Dinosauria Owen, 1842 Saurischia Seeley, 1887 Theropoda Marsh, 1881 Neotheropoda Bakker, 1986 Tetanurae Gauthier, 1986 Avetheropoda Paul, 1988 Carnosauria Huene, 1920 Allosauroidea Currie and Zhao, 1994 Allosauridae Marsh, 1878 Allosaurus Marsh, 1877 Allosaurus europaeus Mateus et al., 2006 Holotype: ML415 is comprised of two blocks and several separated fragments. The first block contains a partially articulated skull, with most of the left posterior bones preserved and part of the atlanto-axis complex, including three teeth. ...
... Since it is poorly preserved, we cannot assess its entire shape; nevertheless, by combining both fossae and according to previous reconstructions [3,10], it may suggest that it does not look so different in shape compared to other Allosaurus species. However, the ridge that delineates this fossa, as previously mentioned, is far less pronounced in this specimen compared to other Allosaurus species, creating a shallower fossa in the contact between the lacrimal and jugal bones. ...
Allosaurus is one of the most famous theropod dinosaurs, but the validity and relationships between the different species have been confusing and often questioned. Portugal is relevant to the understanding of the genus in light of the discovery of A. europaeus ML415 from the Early Tithonian of Lourinhã and Allosaurus MNHNUL/AND.001 from Andrés. However, the exact classification and validity of these two specimens has always been controversial. The presence of Allosaurus in Portugal is strong evidence for a North America–Europe Late Jurassic dispersal, later supported by other taxa. A detailed cranial description and specimen-based phylogeny were performed and resolved many of the open questions: (1) The diversity of Allosaurus is limited to three named species: A. fragilis, A. europaeus, and A. jimmadseni. (2) Nine autapomorphies were found in A. europaeus, confirming the validity of the species. (3) Phylogenetic analyses place both Portuguese specimens in the genus Allosaurus, based on the following synapomorphies: jugal bone lateral view, relative heights of quadratojugal prongs, the dorsal prong is equal in height, the jugal bone in lateral view shows shallow accessory pneumatization of the antorbital fossa, the palatine pneumatic recess shape is small, and lacrimal horn morphology has a triangular horn. (4) The Andrés specimen is placed with the A. europaeus and they are considered here to be the same species, which is paleo-geographically and biochronologically congruent. (5) A. europaeus and A. jimmadseni are sister taxa and closer to each other than to A. fragilis. The genus is distributed in occurrences from the United States, Germany, and Portugal, and from the Late Kimmeridgian to the Late Tithonian, while the Cenomanian report from Japan is reidentified as Segnosaurus.
... Antunes and Mateus 2003;Escaso et al. 2007Escaso et al. , 2014Mateus et al. 2009Mateus et al. , 2014Mocho et al. 2017Mocho et al. , 2019Ortega et al. 2017). The fauna of theropod dinosaurs currently known in these levels is diverse and includes mostly medium-and large sized taxa, including Ceratosaurus (Mateus and Antunes 2000a;Malafaia et al. 2015), Torvosaurus (Mateus and Antunes 2000b;Araújo et al. 2013;Hendrickx et al. 2014;, Lourinhanosaurus (Mateus 1998 Mateus et al. 2006), and Lusovenator . However, this record also includes several specimens, mainly represented by isolated material that has been interpreted as belonging to small sized coelurosaurian theropods (e.g. ...
... On the other hand, most taxa of medium-or large-bodied sized theropods from the Upper Jurassic of Portugal (Ceratosaurus, Torvosaurus, and Allosaurus) may have been present since the early Late Jurassic, despite their osteological fossil record in the Lusitanian Basin is particularly well known for the late Kimmeridgian to the early Berriasian interval (e.g. Pérez-Moreno et al. 1999;Mateus et al. 2006;Hendrickx et al. 2014;Malafaia et al. 2015Malafaia et al. , 2017aMalafaia et al. , 2017b. This is also possibly the case for Lourinhanosaurus, which is represented by material restricted to Kimmeridgian to lower Tithonian sequences (Mateus 1998), but the fossil record of the clade to which it has been related, the Metriachantosauridae, is known in Laurasia at least since the early Middle Jurassic (Wu et al. 2009). ...
... More precise details of this classification have been suggested, with several works attributing the eggs and embryos of Paimogo to the allosauroid theropod Lourinhanosaurus antunesi, on the basis of the similar age and geological proximity, the relative proportions of the centra of the presacral vertebrae (Riqcles et al., 2001), and the presence of a large premaxilla showing four alveoli, which is unlike Allosaurus (Carrano et al., 2013). However, both studies predate the description of two new allosauroid theropod species from the Lourinhã Formation: Allosaurus europaeus and Lusovenator santosi (Mateus et al., 2006;Malafaia, E. et al., 2020). Further detailed taxonomic studies of the embryonic material are needed to improve the taxonomic attribution of the Paimogo egg assemblage. ...
The accurate identification of dinosaur egg accumulations as nests or clutches is crucial for understanding the reproductive behaviour of these extinct species. However, existing methods often rely on the presence of complete eggs and embryo remains, and sedimentological criteria that are only applicable to well-structured sediments. In this study, we introduce an innovative approach to characterize egg accumulations in structureless
sediments, where traditional nest structures may not be preserved. Our methodology employs a unique combination of sedimentological, taphonomic, geochemical, and geophysical proxies for the study of egg accumulations. We applied this approach to the egg accumulation from Paimogo (Jurassic, Portugal), traditionally interpreted as a nest. Our findings reveal that the Paimogo egg assemblage is a secondary deposit, resulting from a flooding event in a fluvial plain that dismantled several allosauroid and crocodylomorph clutches. The eggshell vapor conductance results, coupled with sedimentological evidence, suggest that allosauroid dinosaurs buried their eggs in the dry terrain of overbank areas close to a main channel during the breeding season, likely during the dry season to prevent the
embryos from drowning. This research underscores the necessity of multidisciplinary approaches in interpreting egg accumulations and offers a novel methodology for studying these accumulations in structureless sediments. Our findings provide new insights into the breeding behaviour and nesting preferences of these extinct organisms, contributing to our understanding of dinosaur ecology.
... The Lusitanian Basin has yielded one of the most extensive fossil collections of Late Jurassic dinosaurs and other vertebrates from Europe. The similarity with coeval faunas of the North American Morrison Formation has been well-documented, with several shared genera (e.g., Stegosaurus, Escaso et al. 2007; Ceratosaurus, Mateus and Antunes 2000a;Malafaia et al. 2015;Torvosaurus, Mateus and Antunes 2000b;Hendrickx and Mateus 2014;Malafaia et al. 2017c;Allosaurus, Pérez-Moreno et al. 1999;Mateus et al. 2006). Other European Upper Jurassic fossil records are scarce (particularly for theropod dinosaurs) and mostly consist of fragmentary material with uncertain phylogenetic interpretation (e.g., Allain and Pereda Suberbiola 2003;Canudo and Ruiz-Omeñaca 2003;Ruiz-Omeñaca et al. 2008;Lubbe et al. 2009;Cobos et al. 2014;Evers and Wings 2020). ...
Malafaia, E., Mocho, P., Escaso, F., Narvaéz, I., and Ortega, F. 2024. Taxonomic and stratigraphic update of the material
historically attributed to Megalosaurus from Portugal. Acta Palaeontologica Polonica 69 (2): 127–171. https://doi.org/10.4202/app.01113.2023
... Theropods are mainly represented by medium to large-sized forms belonging to Ceratosauria or tetanurans, including members of Megalosauridae and Allosauroidea (e.g. Mateus 1998Mateus , 2006Hendrickx and Mateus et al. 2014;Malafaia et al. 2010Malafaia et al. , 20152017a, b;, but some small theropods are also recorded. The analyses of the relationship between the Late Jurassic fauna of Portugal and North America have been a source of many studies. ...
Management of Natural History collections, particularly paleontological collections, is usually structured around specimens. However, it might not be feasible when the collections are incorporated from sources where the whole cycle of specimen collection is unknown, making it hard to determine what fossils belong to a single specimen and if these specimens belong to a single fossil-assemblage, taxon or individual. The Sociedade de História Natural from Torres Vedras (Portugal) manages such collections using a management strategy approach based on the spatial location from where the fossils were found. To achieve this, we have implemented a methodology for field collection and developed a spatial database in PostgreSQL/PostGIS to manage the entire stages of paleontological collections management. On top of the database, a second layer of web services, Web GIS (Geographical Information System) applications, and desktop GIS, all based on QGIS, are also under development to facilitate access to data stored in the database to internal and external researchers and partners, as well public institutions. This effort is made in close collaboration with in-house actors and stakeholders and has yielded promising results. The development of this system provides four advantages: (i) it played an essential role in supporting the transfer of the collection to new storage facilities; (ii) it provides overviews of the distribution of the characteristics of the collections; (iii) it enhances institutional partnerships by providing consistent and reliable data and(iv) it supports the establishment and development of research lines.
Numerous trace fossils have been recorded in the rocks of the Guará Formation, in the southwest region of the state of Rio Grande do Sul, both from vertebrates and invertebrates. Among them, there are isolated tracks and trackways attributed to theropod, sauropod, ornithopod, and ankylosaur dinosaurs. This study describes new dinosaur tracks from the Guará Formation, addressing track morphology, trackmaker inference, and stratigraphic sections of the new outcrops. In addition, here are presented a very well-preserved theropod track and the second occurrence of an ankylosaur track. The theropod track exhibits exceptional preservation compared to other tracks in the Guará Formation. Unlike other tracks, this one was found within a creek, protected from vehicular traffic and other anthropogenic erosive agents, thereby preserving its three-dimensional morphology. It is a tridactyl and mesaxonic track of a left pes, having a track length/width ratio of 1.08, with an anterior triangle (AT) length/width ratio of 0.368. Here it is attributed to two possible ichnogenera, Jurabrontes or Iberosauripus. The ankylosaur track is tetradactyl and paraxonic. It is asymmetrical, with low divarication angles, and the sole is robust and rounded. This track likely represents an undertrack, due to its bidimensional and somewhat distorted preservation, surrounded by radial and concentric deformation structures, conferring a sub-optimal preservation degree. It can be attributed to two ichnogenera: Tetrapodosaurus or Metatetrapous. These rare new records are crucial for understanding the history of dinosaurs during the Upper Jurassic, filling gaps in the vertebrate history of Western Gondwana.
Saurophaganax maximus is the designation of material attributed to a massive theropod dino-saur recovered from the Kenton 1 Quarry in the Kenton Member of the Upper Jurassic Morrison Formation of Oklahoma. The theropod was originally given the name Saurophagus maximus, but was later revised to Saurophaganax maximus because the former did not conform to the International Commission on Zoological Nomenclature standards. Several autapomorphies were described for S. maximus including the postorbital lacking a postorbital boss, the atlas lacking facets for a proatlas, cervical vertebrae with nearly vertical post-zygapophyses, unique accessory laminae on the holotype neural arch, pneumatized post-pectoral dorsal cen-tra, craniocaudally expanded chevrons, laterally bowed femora, tibiae without an astragalar buttress and more prominent distomedial crest, and less distally divergent fourth metatarsals. However, our re-evaluation shows that some of the elements originally used to distinguish Saurophaganax from Allosaurus are more parsimoni-ously referred to diplodocid sauropods found in the same quarry rather than an allosaurid. Additionally, the holotype neural arch cannot be confidently assigned to a theropod, making Saurophaganax maximus a nomen dubium. The presence of at least one skeletally mature theropod was confirmed through paleohistology of a fourth metatarsal. Despite the similarity of the decisively theropod material to known species of Allosaurus, some elements feature subtle autapomorphies that suggest they pertain to a distinct species, which we de-scribe as Allosaurus anax sp. nov.
Recent fieldwork in the late Middle Jurassic Balabansai Formation of Kyrgyzstan has yielded a partial skeleton of a large theropod dinosaur. The material includes a few bones of the skull (postorbital, quadratojugal), dorsal and sacral vertebrae, fragments of the pectoral girdle and forelimbs, and an almost complete pelvic girdle and hindlimbs, and is here made the type of a new theropod taxon, Alpkarakush kyrgyzicus gen. et sp. nov. Alpkarakush can be diagnosed by an extremely developed orbital brow on the postorbital, a pneumatic opening leading into cavities in the neural arch from the centroprezygodiapophyseal fossa in the posterior dorsal vertebrae, an almost enclosed ventral sulcus in manual phalanx II-1, a narrow and deep intercondylar groove on the anterior side of the distal femur, and an epicondylar crest on the distal femur that is offset from the distal end. A second, fragmentary, and smaller specimen from the same site represents the same taxon. Based on long bone histology, the type of Alpkarakush represents a late subadult individual, whereas the smaller specimen is a juvenile, possibly indicating gregarious behaviour. Phylogenetic analysis places Alpkarakush in the Metriacanthosauridae, underlining the diversity and wide distribution of this clade in the Jurassic of Asia.
These are the proceedings of the Paleo Spring Meeting.
The femur is 64, 7 cm long and very similar to the Ceratosaurus nasicornis, the difference being that it is slightly longer. In the 58, 3 cm tibia, the relative position of the epiphysials expansions is different from C. nasicornis, being more likely C. dentisulcatus. The distal and proximal expansions are in a more turned position by the diaphysial axis.
Fossil eggs from the theropod nesting site found at Paimogo, Lourinhã (Upper Kimmeridgian -Tithonian), were identified with dinosauroid obliquiprismatic morphotype and crocodiloid basic type. Most eggshells have been affected by dissolution and recrystallization. The study of obliquiprismatic eggshell morphology indicates a high humidity nesting environment, about the same as required by crocodiles. Palavras-chave: Ninho; terópode; morfotipo obliquiprismático; tipo básico crocodiloide; diagénese; ambiente de nidificação. Resumo: Ovos fósseis do local de nidificação de terópodes encontrado em Paimogo, Lourinhã (Kimmeridgiano superior -Titoniano), foram identificados como pertencentes ao morfotipo dinossauroide obliquiprismático e ao tipo básico crocodiloide. A maior dinosaur and crocodile eggs from Paimogo nesting site. Memórias da Academia de Ciências de Lisboa, 37: 83–99. 2
A new Allosauroid dinosaur (Saurischia: Theropoda) was found at Peralta near Lourinhã, Portugal (Upper Jurassic, Lower Tithonian). It is described under the name Lourinhanosaurus antunesi. It's diagnosable by the all vertebral centra longer than tall, neural spines of the anterior caudal vertebrae with a well-developed spike- like anterior process, the pubic blade is perforated by a large vertical ellipsoidal foramen and the lesser trochanter is well separate from the main body of the femur in lateral view. In the rib cage were found 32 gastroliths. This is the first non-avian theropod found with gastroliths.
The Morrison Formation in Utah and Colorado contains many volcanic ash layers and ashy beds, now altered mostly to bentonite, that have yielded isotopic ages. The Brushy Basin Member. at the top of the formation, gives single-crystal, laser-fusion and step-heating, plateau 40 Ar/ 39 Ar ages on sanidine that range systematically between 148.1 ± 0.5 (1 std. error of mean) at the top of the member to 150.3 ± 0.3 Ma near the bottom. The Tidwell Member, at the base of the Morrison Formation, contains one ash bed about 3m above the J-5 unconformity that occurs in at least two widely separated sections. This ash has been dated by 40 Ar/ 39 Ar dating of sanidine and gives ages of 154.75 ± 0.54 Ma (Deino NTM sample, laser-fusion), 154.82 ± 0.58 Ma (Deino RAIN sample, laser-fusion), 154.87 ± 0.52 (Kunk NTM sample, plateau), and 154.8 ± 1.4 Ma (Obradovich NTM sample, laser-fusion). The Morrison Formation, therefore, ranges in age from about 148 to 155 Ma and, based upon fossil evidence appears to be entirely Late Jurassic. including the latest Oxfordian(?), Kimmeridgian, and early Tithonian Ages.
Many recent studies of theropod relationships have been focused on the phylogeny of coelurosaurs and the question of the origin of birds, but the interrelationships and evolution of basal theropods are still poorly understood. Thus, this paper presents a phylogenetic analysis of all theropods, but focuses on the basal members of this clade. The result supports the inclusion of Eoraptor and herrerasaurids in the Theropoda, but differs from other recent studies in two main aspects: (1) The taxa usually grouped as ceratosaurs form two monophyletic clades that represent successively closer outgroups to tetanurans. The more basal of these clades, the Coelophysoidea, comprise the majority of Late Triassic and Early Jurassic theropods. The other clade of basal theropods that are usually included in the Ceratosauria comprises Ceratosaurus, Elaphrosaurus, and abelisaurids. (2) Two monophyletic groups of basal tetanurans are recognized: the Spinosauroidea and the Allosauroidea. In contrast to other recent phylogenetic hypotheses, both clades are united in a monophyletic Carnosauria. The branching pattern of the present cladogram is in general accordance with the stratigraphic occurrence of theropod taxa. Despite the differences in recent analyses, there is a significant level of consensus in theropod phylogeny. At least four different radiations of non-avian theropods can be recognized. These radiations show different patterns in Laurasia and Gondwana, and there are increasing differences between the theropod faunas of the two hemispheres from the Triassic to the Cretaceous.
The species Allosaurus fragilis, from the Morrison Formation of North America (Kimmeridgian-Tithonian, Upper Jurassic), is one of the best known members of the Theropoda, the group including all predatory non-avian dinosaurs and birds. Here, we report on the first diagnostic theropod remains discovered from the Jurassic of the Iberian Peninsula. The specimen is the first evidence of A. fragilis outside North America. Thus, this taxon represents the first dinosaur species found on two different continents, and suggests the existence of a 'land bridge' between North America and Europe during the Late Jurassic.