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A new large theropod dinosaur from the Upper Jurassic of Colorado

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... Material that was too damaged to be of taxonomic value, such as the three teeth referred to S. maximus, were not considered for this analysis. We also consulted descriptions of Saurophaganax maximus (Chure 1995, Chure 2000, Allosaurus fragilis (Gilmore 1920;Madsen 1976;Smith et al. 1999), Allosaurus jimmadseni (Chure 2000;Chure and Loewen 2020;Loewen 2009;Snively et al. 2013), Sinraptor dongi (Currie and Zhao 1993), Acrocanthosaurus atokensis (Harris 1998), Tyrannotitan chubutensis (Canale et al. 2015;, Lusovenator santosi (Malafaia et al. 2020), Torvosaurus tanneri (Britt 1991;Galton and Jensen 1979;Hanson and Makovicky 2013), Torvosaurus gurneyi (Hendrickx and Mateus 2014); Ceratosaurus nasicornis (Gilmore 1920); Ceratosaurus magnicornis (Madsen and Welles 2000), Ceratosaurus dentisulcatus (Madsen and Welles 2000), Dilophosaurus wetherelli (Marsh and Rowe 2020), Apatosaurus louisae (Gilmore 1936), Diplodocus carnegii (Hatcher 1901;Holland 1906), Barosaurus lentus (Hanik et al. 2017;McIntosh 2005;Melstrom et al. 2016), and Camarasaurus sp. (Madsen et al. 1995;Woodruff and Foster 2017). ...
... It can also be distinguished from both Apatosaurus and Diplodocus by being relatively short (Gilmore 1936;Osborn and Granger 1901). The humeri of both Ceratosaurus and Torvosaurus are not as prominently bowed as OMNH 1935 (Galton and Jensen 1979;Madsen and Welles 2000). The deltopectoral crest is also more prominent in the lateral view than that of Torvosaurus tanneri (Galton and Jensen 1979). ...
... The humeri of both Ceratosaurus and Torvosaurus are not as prominently bowed as OMNH 1935 (Galton and Jensen 1979;Madsen and Welles 2000). The deltopectoral crest is also more prominent in the lateral view than that of Torvosaurus tanneri (Galton and Jensen 1979). Apart from its size, OMNH Figure 15. ...
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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.
... Genus Torvosaurus Galton & Jensen, 1979 Type species: Torvosaurus tanneri Galton & Jensen, 1979 Lapparent and Zbyszewski (1957: 25, pl. 12: 17) and possibly corresponds to one of the first dinosaur remains identified in Portugal, which was mentioned by Carlos Ribeiro in 1863 (Mateus 2005). ...
... Genus Torvosaurus Galton & Jensen, 1979 Type species: Torvosaurus tanneri Galton & Jensen, 1979 Lapparent and Zbyszewski (1957: 25, pl. 12: 17) and possibly corresponds to one of the first dinosaur remains identified in Portugal, which was mentioned by Carlos Ribeiro in 1863 (Mateus 2005). ...
Article
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
... In describing MUCPv 278, we use terms and nomenclature employed in previous works (e.g., Porfiri et al. 2014). Observations of other megaraptoran specimens that preserve forelimb elements (including, in a few cases, humeri) were made from the literature (e.g., von Huene 1932;Novas 1998;Azuma and Currie 2000;Calvo et al. 2004;Currie and Azuma 2006;Porfiri et al. 2007Porfiri et al. , 2014Smith et al. 2008;Hocknull et al. 2009;Agnolín et al. 2010;White et al. 2012White et al. , 2013bWhite et al. , 2015Bell et al. 2016;Casal et al. 2016;Coria and Currie 2016;Novas et al. 2016;Poropat et al. 2019;Samathi et al. 2019;Ibiricu et al. 2020;Lamanna et al. 2020 (Digregorio 1972;Cazau and Uliana 1973;Garrido 2010) (Fig. 2). Comprised of continental deposits, the Neuquén Group includes thick, alternating sequences of sandstone, claystone, and conglomerate belonging to the Río Limay, Río Neuquén, and Río Colorado subgroups (Fig. 3) (Ramos 1981;Legarreta and Gulisano 1989;Leanza and Hugo 2001). ...
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Megaraptorans are medium- to large-bodied tetanuran theropod dinosaurs known from Cretaceous deposits in Asia, Australia, and especially South America. The megaraptoran skeleton is far from well known, and the humerus is one of the least-frequently preserved elements. Here we describe the first-documented adult humerus of a South American megaraptoran, recovered from the Upper Cretaceous (Turonian–Coniacian) Portezuelo Formation of the Neuquén Basin on the southeast coast of Lago Barreales in Neuquén Province, northern Patagonia, Argentina. The humerus is referred to the namesake megaraptoran Megaraptor namunhuaiquii Novas, 1998, based on its geographic and stratigraphic provenance as well as its morphological similarity to the corresponding element of a juvenile skeleton of the same taxon. Nevertheless, the new adult humerus exhibits osteological distinctions from that of the juvenile that we interpret as reflective of their differing ontogenetic stages. We also highlight anatomical differences between the humerus of M. namunhuaiquii and that of the enigmatic Patagonian theropod Gualicho shinyae Apesteguía et al., 2016, that show that these taxa are not closely related.
... Several hypotheses have been proposed to explain evolutionary causes and functional significance of arm reduction among theropods. Some authors proposed that forelimb shortening was related to body size increase, with the acquisition of cranially based mode of predation, and body balance for big-headed taxa (Horner and Lessem 1993;Fastovsky and Weishampel 2005;Bybee et al. 2006;Lockley et al. 2008;Padian 2022). However, these explanations were heavily criticized, and arm reduction was probably acquired by means of different developmental processes among theropod clades (Burch 2014). ...
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Carcharodontosaurids were gigantic terrestrial dinosaurs and top predators of dinosaur faunas in Gondwanan landmasses during the “Mid”-Cretaceous Period. Despite their wide geographical and stratigraphical distribution, essential parts of their anatomy are still poorly known. The present contribution aims to describe a new partial skeleton of the carcharodontosaurid Taurovenator violantei, which was previously known only by an isolated postorbital bone coming from Cenomanian–Turonian beds of northern Patagonia, Argentina. The neck of Taurovenator is composed of notably high anterior cervicals, bearing neural spines with expanded, flange-like dorsal tips which are successively imbricated. This condition has been reported previously in the carcharodontosaurid Acrocanthosaurus, but its occurrence in Taurovenator and other members of the clade suggests it may represent a synapomorphy of this theropod family. This unique neck morphology was probably related to strong modifications in musculature and restriction in the range of movements within the neck, but not with the head. The new specimen also affords valuable anatomical information on the forelimb of Patagonian carcharodontosaurids. As in other giganotosaurines, Taurovenator shows strongly reduced forelimbs, particularly the forearm, showing hand elements with elongated non-ungual phalanges, and well-marked articular surfaces and muscular insertions, suggesting highly movable digits. This new specimen of Taurovenator allows us to expand anatomical and morpho-functional discussions about the carcharodontosaurid clade.
... The specimens described herein were discovered in the DMDQ (BYU locality 725) near Delta Colorado, where the holotypes of the diplodocoid Supersaurus vivianae and the megalosauroid Torvosaurus tanneri were unearthed (Britt, 1991;Galton & Jensen, 1979;Jensen, 1985;Richmond & Morris, 1998). The locality was first discovered in 1971 by Edwin and Vivian Jones, who found a bone belonging to a large theropod and proceeded to contact Jim Jensen at Brigham Young University about the find (Britt, 1991;Richmond & Morris, 1998). ...
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A new specimen of Haplocanthosaurus is described based on bones excavated from the Late Jurassic Dry Mesa Dinosaur Quarry near Delta, Colorado. The specimen consists of seven dorsal vertebrae and a right tibia and is identified as Haplocanthosaurus based on the dorsally angled transverse processes, tall neural arch peduncles, low parapophyses relative to the diapophyses in the posterior dorsal vertebrae, and the robustness of the tibia combined with a greatly expanded distal articular surface. The discovery adds to our understanding of the biostratigraphy of Haplocanthosaurus, showing this genus is definitively present in the Brushy Basin Member of the Morrison Formation, and making this individual the geologically youngest Haplocanthosaurus specimen on the Colorado Plateau. The identification of this genus adds to the known diversity of sauropods at Dry Mesa Dinosaur Quarry (DMDQ), which is at least six distinct genera, making DMDQ the most diverse single locality of sauropods in the Morrison Formation and the world.
... Notably, megalosauroid theropods are well represented in the Guará-Batoví by Torvosaurus sp. teeth and the robust track UFRGS-PV-0207-G, but are also important components of the Kimmeridgian-Tithonian fauna recovered from the Tendaguru (Tanzania; Janensch 1920, but see Soto et al. 2020b), Morrison (USA; Galton and Jensen 1979), Villar del Arzobispo (Spain; Cobos et al. 2014;Malafaia et al. 2017), Alcobaça and Lourinhã (Portugal; e.g., Hendrickx and Mateus 2014) formations. This faunal similarity is reinforced by the occurrence of Ceratosaurus sp. and other high-level taxa in the Uruguayan Batoví Member, as well as Metatetrapous-like ankylosaur tracks in the Brazilian RSCT locality ). ...
Chapter
The Jurassic Guará Formation (Paraná Basin) was established in the early 2000's and since then dinosaur tracks and trackways have been found at the southwestern Rio Grande do Sul State of Brazil and in its Uruguayan counterpart, the Batoví Member of the Tacuarembó Formation. Sauropod, theropod, ankylosaurs and ornithopod dinosaur tracks have already been described from eolian facies of the Guará-Batoví unit, but some other new findings are reported here for first time. Saurischian tracks are the most common, being represented by narrow- to very wide-gauge sauropod trackways and at least two theropod track morphotypes, one of which comparable to the ichnogenera Iberosauripus and Jurabrontes. Ornithischian tracks are rarer but, up to this point, two lineages have been recorded. Ankylosaur tracks were recently described and compared to Metatetrapous, conjecture corroborated by new material. Ornithopod tracks are underrepresented at the Guará-Batoví. Although the dinosaur track record of the Guará-Batoví unit is mostly composed of undertracks, true tracks can also occur. This work aims to present a concise state of the art about the dinosaur ichnology of the Guará-Batoví unit. Together with invertebrate traces and the body fossil record of this unit, the paleogeographical, paleoenvironmental and paleoclimatic context of the dinosaur tracks are discussed.
... The large theropods from the Morrison Formation are currently represented by five unequivocal avetheropods, namely, Ceratosaurus nasicornis (Gilmore, 1920;Madsen & Welles, 2000), Marshosaurus bicentesimus (Madsen, 1976a), Torvosaurus tanneri (Galton & Jensen, 1979;Britt, 1991), and two species of Allosaurus, A. fragilis (Madsen, 1976b) and A. jimmadseni (Chure & Loewen, 2020). Saurophaganax maximus, considered by Smith (1998) to be a junior synonym of Allosaurus, also most likely represents a different allosaurid taxon from a higher stratigraphic level of the Morrison Formation (Chure, 1995;Foster, 2020). ...
Article
Tooth-marked bones provide important evidence for feeding choices made by extinct carnivorous animals. In the case of the dinosaurs, most bite traces are attributed to the large and robust osteophagous tyrannosaurs, but those of other large carnivores remain underreported. Here we report on an extensive survey of the literature and some fossil collections cataloging a large number of sauropod bones (68) from the Upper Jurassic Morrison Formation of the USA that bear bite traces that can be attributed to theropods. We find that such bites on large sauropods, although less common than in tyrannosaur-dominated faunas, are known in large numbers from the Morrison Formation, and that none of the observed traces showed evidence of healing. The presence of tooth wear in non-tyrannosaur theropods further shows that they were biting into bone, but it remains difficult to assign individual bite traces to theropod taxa in the presence of multiple credible candidate biters. The widespread occurrence of bite traces without evidence of perimortem bites or healed bite traces, and of theropod tooth wear in Morrison Formation taxa suggests preferential feeding by theropods on juvenile sauropods, and likely scavenging of large-sized sauropod carcasses.
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This article traces the history of the first discoveries of reptiles in the Jurassic of northeastern France in the 18th and 19th centuries. For each of the concerned departments (Ardennes, Aube, Marne, Haute-Marne, Meurthe-et-Moselle, Meuse, Moselle, Bas-Rhin and Vosges), the personalities who contributed to these discoveries are presented chronologically. An inventory of specimens preserved in several French museum and university collections is proposed. It highlights a rich fossil reptile record which spans from the Hettangian to the Tithonian and which is represented by Ichthyosauria, Plesiosauria, Thalattosuchia and Dinosauria. The formations having yielded the most abundant reptilian remains include the “Grès d’Hettange” (Hettangian), the “Calcaire à gryphées” (Hettangian to lower Sinemurian), the “Schistes cartons” and the “Marne de Flize” (lower Toarcian), the “Argiles de la Woëvre” (Callovian to lower Oxfordian), the “Marnes à exogyres” or “Marnes et calcaires à Nanogyra virgula” (upper Kimmeridgian) and the lower Tithonian limestones. This inventory also reveals a rich reptilian fossil record coming from the “Formation ferrifère” or “Minette” at the Early-Middle Jurassic transition (upper Toarcian-Aalenian), consequence of the intensive exploitation of iron ore in Lorraine during the 19th century. Scattered specimens from the Pliensbachian, Bajocian and Bathonian complete this main list. Unpublished manuscript and iconographic documents make it possible to clarify the historical context of the discoveries of important specimens, now lost or destroyed, such as the holotype of Mosellaesaurus rostrominor Monard, 1846, the holotype of Machimosaurus mosae Liénard in Sauvage & Liénard, 1879 (Thalattosuchia), and what could be one of the first ichthyosaurs found in France in the 18th century by Father Nicolas Le Bonnetier (1720-1804). These documents also made it possible to rediscover specimens which had been brought to the attention of Georges Cuvier but whose historical importance had long been forgotten.
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Noasaurus leali is a small (~2 m) carnivorous theropod and the nominal genus of the clade Noasauridae, one of the two radiations of abelisauroid ceratosaurs predominantly present in the Southern Hemisphere during the Mesozoic. This eponymous theropod from the Maastrichtian Lecho Formation of Salta, Argentina, is known from an incomplete skeleton of which the strongly curved manual ungual is the most peculiar element. We here provide for the first time a comprehensive description of the holotypic specimens of Noasaurus, whose phylogenetic position was explored using three independent datamatrices on theropod relationships. This species is diagnosed by several apomorphies such as a dorsal ridge in the maxillary fossa, a strongly arched quadrate, a cervical neural arch with anterior epipophyseal prongs, and a manual ungual with a subtriangular flexor fossa delimited by a V-shaped ridge. Results of the phylogenetic analyses recovered Noasaurus closely related to Velocisaurus, Masiakasaurus, and Laevisuchus, which together form a Late Cretaceous radiation of small-bodied noasaurids restricted to the Southern Hemisphere. The peculiar morphology of the lateral dentition and manual unguals suggests that Noasaurus was an opportunistic carnivore feeding on small prey items and a possible piscivore gaffing fish with its specialized hand claws.
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Plenty of goniopholidid species from the Mesozoic have been found in the Iberian Peninsula. A previous goniopholidid taxon, Goniopholis baryglyphaeus Schwarz, 2002, from the Late Jurassic of the Guimarota coal mine (Leiria, central Portugal) was described. This taxon corresponds to a partial skull and some postcranial material, and it marked the oldest and first ever record of goniopholidid and Goniopholis species described for the Iberian Peninsula. Here we present a well-preserved, almost complete, skull of a new species, Ophiussasuchus paimogonectes gen. et sp. nov. from Upper Jurassic deposits of Praia de Paimogo (near Lourinhã, central west Portugal). The specimen corresponds to a mesorostrine, platyrostral skull of a medium-sized goniopholidid coming from the upper Kimmeridgian within the Lourinhã Formation. Phylogenetically, the new species is recovered as the sister taxon of the Early Cretaceous European clade made by Hulkepholis and Anteophthalmosuchus. Although its position is well-resolved, this new taxon displays intermediate morphological traits, sharing characteristics with Jurassic Asian and American basal goniopholidids (e.g., presence but lesser development of the secondary choana with the nasopharyngeal duct partially open), as well as more derived characters shared with Cretaceous European taxa such as Hulkepholis (e.g., the shape of the supratemporal fenestra and the palatines). As a result, Ophiussasuchus paimogonectes gen. et sp. nov. exhibits characteristics suggesting a reversion to primitive goniopholidid conditions or intermediate states between the goniopholidid taxa of North America and Europe. These findings support the shared Late Jurassic fauna between the Morrison and Lourinhã Formations, while also having high endemism of taxa.
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