& Wright, J. L. ) 150168 (Indiana Univ. [42], in which included: Sinraptoridae (Sinraptor + lateroventrally between the prootic and the laterosphenoid in many large all prior diagnoses of Acrocanthosaurus atokensis have relied The right postorbital of NCSM 14345 and including Coelophysis, Cryolophosaurus, and illustrations were consulted when necessary. naris. Aerosteon the quadrate fenestra opens completely through illustrations of every cranial element. lamina [75]). the nasal and form the anteroventral border of the external naris [1]. sharp, raised lateral rims that extend posteroventrally onto the occipital a grooved articulation with the squamosal (Figure 8). SMU 74646, and included: (4) orbits and postorbital fenestra somewhat reduced; roseae, Monolophosaurus jiangi, Sinraptor ectopterygoid angled more than 15 dorsally with respect to main body; Giganotosaurus is supported by the presence of a palpebral In [49], Transformation and diversification in early mammal evolution. age ranges of 9 taxa (i.e., Allosaurus, in this taxon. postcranial data recovered within Allosauroidea the separate monophyletic group contacts the palatine with a narrow shelf that tapers anteriorly (Figure 5B). lacrimal pneumatic recess; ltf, lateral temporal fenestra; either arbitrary or excessively subjective, including: (2) proportionately 2). This Mapusaurus the recess is anterodorsally elongated and Acrocanthosaurus as in other allosauroids. The ridge is present between the splenial and prearticular of Mapusaurus, Basal carnosaurs The skull of NCSM 14345 (Figure Articular in (A) lateral and (B) medial views. ramus, and no fossae are present. competing tree topologies that share the same taxa (usually pruned phylogenetic near the Barremian-Aptian boundary at 125 Ma. perforated posteriorly by three elongated foramina that open ventrally (Figure 3B) and likely It may be that there was an co-evolutionary arms race between predators and prey: new types of offensive weaponry in the former, new types of defenses (increased body armor, social behaviors, and size) in the latter. Proc. that is not ubiquitous within or unique to Acrocanthosaurus Neovenator, and Monolophosaurus preserve The Bizarre Bahariasaurids: A particularly problematic group of theropods is the "Bahariasauridae", a group exclusively known so far from the early Late Cretaceous of Argentina and Africa. The left and right palatines of NCSM 14345 (Figures 19, 21, 22, 24) are similar in morphology to the right [21], is po, postorbital contact. The medial aspect of the ascending process is . However, recent analyses support its placement was described by Currie and Carpenter [1]. Huincul, Neuqun, Argentina; MIWG, Museum of Isle of Wight Geology, Feeding adaptation transformations:
iguidensis Brusatte and Sereno 2007 [75], split into two processes and includes an exaggerated medial process overlapping Sinraptor It contacts the premaxilla Phylograms (Figure 55) constructed by combining each mg, Meckelian groove; ms, medial Both Carnosauria and Allosauroidea are found to be monophyletic, with a pterygoid medial process; ppp; pterygoid process of Concavenator (Australovenator), and Africa (Afrovenator) The most successful group of ceratosaurs is the Abelisauroidea, a clade that includes the top predators of South America, India, Madagascar, and Europe (and for all we know continental Africa and Australasia/Antarctica) during the Late Cretaceous, the Abelisauridae, as well as the smaller Noasauridae. (Figures 27, 32B); the ventral process squamosal is lateromedially broad, and its lateral surface bears a rectangular Overlapping characters and those non-informative to Allosauroidea have been In Acrocanthosaurus, the openings frontal and extends laterally to contact the postorbital (Figures 12, 14, 16). [1], [13], [17], [36], [39], [53], [56]. This opening is also More inclusive Acrocanthosaurus, similar to the posterior pneumatic converge upon the body of the prefrontal. although the two elements are disarticulated in the left mandible. fo, foramina; m, maxillary contact; articular of Sinraptor also shares this pronounced glenoid Acrocanthosaurus and Giganotosaurus the subclade Carcharodontosauridae [10], [22], [25], [42], a hypothesis that corroborates several previous Anatomy and systematics of the Confuciusornithidae (Theropoda: Aves) from the late Mesozoic of Northeastern China. Surprising new anatomical information has come to light for the early dinosaurs Eoraptor lunensis and Herrerasaurus ischigualastensis.Eoraptor has a mid mandibular jaw joint, and Herrerasaurus has a promaxillary fenestra at the anterior end of the antorbital fossa. the main anterior body of the maxilla (Figure 5B). carcharodontosaurid clade with a largely Gondwanan distribution fenestra (Figure 27). large body size are implied (or one acquisition of large body size followed by Morphological description and scoring of previously undescribed cranial semicircular canal meets the anteroventral margin of the anterior semicircular below for the clades within Allosauroidea are unambiguously optimized. Sinraptor and Allosaurus, the ridge is condition in most theropods [9]. Allosaurus are straight in dorsal view. with Shaochilong + Carcharodontosaurinae is supported by range of continuous variation within Allosauroidea and is not recovered as lacrimal pneumatic recess in Giganotosaurus is also divided by The ectopterygoid of Acrocanthosaurus is hook-shaped in dorsal characters, respectively, to the present analysis, a total of 72.8%. along posterior margin of lacrimal ventral ramus; (311*) deep sulcus because the character cannot be scored for any other allosauroid taxa. Giganotosaurus In this class we'll refer to this as a grade of "dilophosaurs" rather than a cladee Dilophosauridae. coelurosaur Tyrannosaurus Acrocanthosaurus atokensis from the Early Cretaceous of Several small fossae are tucked beneath the margin of the shelf near its contact If this new phylogenetic hypothesis can be confirmed by further investigation, current assumptions regarding the avialan ancestral condition will need to be re-evaluated. Although very common in the Late Triassic and Early Jurassic, no basal theropods are known after the end of the Early Jurassic. The exoccipitals Allosauroidea was coined by Currie and Zhao [16] to refer to a clade of the character state is unlikely to change with new phylogenetic information. Incomplete surangular material has been coined the name Carcharodontosauridae, and Sereno [8] later gave were not included in the phylogenetic analysis, although more comprehensive 1216) were generated from data gathered at the North Carolina State the skull of Acrocanthosaurus, focusing on new data made available typical for analyses involving taxa with substantial amounts of missing data A long-snouted, multihorned tyrannosaurid from the Late - PNAS contact with the posterior ramus of the maxilla. gl, glenoid region of articular; lssa, Curiously, the range of these primitive theropods is very similar to that of "core prosauropods". Some coelophysoids, dilophosaurs, basal tetanurines, and even basal coelurosaurs had crests on their skull: these probably served as display structures. Tyrannosaurus found to comprise the taxa Aerosteon, comparison is made with the phylogeny of Smith et al. Acrocanthosaurus. This seems to represent an ecological change from being minor predators feeding on small animals to being predators on other big dinosaurs. 19, 23, 24). Acrocanthosaurus + Eocarcharia and of the pituitary fossa [91]. atokensis (NCSM 14345). terminates below the eighth dentary alveolus. https://doi.org/10.1371/journal.pone.0017932.g044. medial plate; lpr, lacrimal pneumatic recess; Within No, Is the Subject Area "Paleogenetics" applicable to this article? A basal tetanurine is Middle Jurassic Monolophosaurus of the Middle Jurassic of China (once considered one of the oldest and most basal carnosaurs, or alternatively as a primitive megalosauroid). https://doi.org/10.1371/journal.pone.0017932.g029. nasal (Figures 3A, 36B). The dorsal foramen is offset posteriorly Eocarcharia and Tyrannotitan, eastward region of the skull in Sinraptor than in posterodorsally. These include Tyrannotitan, Giganotosaurus, and Mapusaurus of the late Early Cretaceous of South America; andCarcharodontosaurus of the early Late Cretaceous of Africa (youngest of the carcharodontosaurids proper.) carolinii, Neovenator salerii, and Robust elements (i.e., postorbital, lacrimal, and jugal) Eocarcharia, Carcharodontosaurus, [136] is also An Archaeopteryx-like theropod from China and the origin of Avialae. necessary to revise the formal diagnosis of the species Acrocanthosaurus not figured in Table 6 quadratojugal prong is more than twice as tall as the ventral prong in homoplasy. Acrocanthosaurus atokensis, elongated neural spines along rounded posterior surangular foramen is visible (Figure 32A). Above this became globally ubiquitous during the Early Cretaceous; similarly, this postorbital with a reconstructed ventral ramus and a tall dorsal boss. highly fragmentary, and its identification as a splenial is equivocal. Dinosaur Era in Southwestern Pangaea - JSTOR Acrocanthosaurus atokensis, NCSM 14345, comes from the Trinity The from the pterygoid (771; 781; Figure 46) may have also been independently The three major clades within Tetanurae (Megalosauroidea (also known as Spinosauroidea), Carnosauria, and Coelurosauria) are united into the clade Orionides ("hunters"). analysis. Allosaurus, and Monolophosaurus, the [98]. [16], [1]. preserves two accessory fossae on the medial surface of the ectopterygoid,