A new abelisaurid dinosaur from the end Cretaceous of Patagonia and evolutionary rates among the Ceratosauria

Cladistics, Год журнала: 2024, Номер 40(3), С. 307 - 356

Опубликована: Май 21, 2024

Abstract Gondwanan dinosaur faunae during the 20 Myr preceding Cretaceous–Palaeogene (K/Pg) extinction included several lineages that were absent or poorly represented in Laurasian landmasses. Among these, South American fossil record contains diverse abelisaurids, arguably most successful groups of carnivorous dinosaurs from Gondwana Cretaceous, reaching their highest diversity towards end this period. Here we describe Koleken inakayali gen. et sp. n., a new abelisaurid La Colonia Formation (Maastrichtian, Upper Cretaceous) Patagonia. is known skull bones, an almost complete dorsal series, sacrum, caudal vertebrae, pelvic girdle and hind limbs. The shows unique set features anatomical differences Carnotaurus sastrei (the only other Formation). retrieved as brachyrostran abelisaurid, clustered with abelisaurids latest Cretaceous (Campanian–Maastrichtian), such Aucasaurus , Niebla . Leveraging our phylogeny estimates, explore rates morphological evolution across ceratosaurian lineages, finding them to be particularly high for elaphrosaurine noasaurids around base Abelisauridae, before Early radiation latter clade. Noasauridae sister clade show contrasting patterns evolution, undergoing early phase accelerated axial limb skeleton Jurassic, exhibiting sustained cranial Cretaceous. These results provide much needed context evolutionary dynamics theropods, contributing broader understanding macroevolutionary dinosaurs.

Язык: Английский

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Elemgasem nubilus: a new brachyrostran abelisaurid (Theropoda, Ceratosauria) from the Portezuelo Formation (Upper Cretaceous) of Patagonia, Argentina

Papers in Palaeontology, Год журнала: 2022, Номер 8(5)

Опубликована: Сен. 1, 2022

Abstract Abelisaurids are medium–large‐sized theropod dinosaurs that were predominant in the carnivorous fauna during Late Cretaceous of Gondwana. These predators abundant fossil strata Patagonia, which yield best record for this group. In Cretaceous, abelisaurids appear almost all regions Gondwana and stages, except Coniacian, they globally unknown. Here we describe a new abelisaurid, Elemgasem nubilus gen. et sp. nov., from Portezuelo Formation (Turonian–Coniacian), Argentina. The palaeohistology appendicular bones shows holotype was subadult individual, but had achieved sexual maturity. This taxon is based on several axial elements, diagnosed by presence marked pattern rugosity lateral surface fibula dorsoventrally deep wall calcaneum. Moreover, posterior caudal vertebrae have morphology slightly different any other abelisaurid. recovered as an unstable within Brachyrostra, given it sister Furileusauria or positions clade. Despite problematic phylogenetic relationships , important because first abelisaurid Turonian–Coniacian interval increases diversity family at time turnover tetrapod South America, global climate change, mass extinction events recorded worldwide marine realm.

Язык: Английский

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New fossils of Abelisauridae (Dinosauria: Theropoda) from the upper Maastrichtian of Morocco, North Africa

Cretaceous Research, Год журнала: 2023, Номер 152, С. 105677 - 105677

Опубликована: Авг. 22, 2023

Язык: Английский

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Osteology of the axial skeleton of Aucasaurus garridoi: phylogenetic and paleobiological inferences

PeerJ, Год журнала: 2023, Номер 11, С. e16236 - e16236

Опубликована: Ноя. 14, 2023

Aucasaurus garridoi is an abelisaurid theropod from the Anacleto Formation (lower Campanian, Upper Cretaceous) of Patagonia, Argentina. The holotype includes cranial material, axial elements, and almost complete fore- hind limbs. Here we present a detailed description skeleton this taxon, along with some paleobiological phylogenetic inferences. presacral elements are somewhat fragmentary, although these show features shared other abelisaurids. caudal series, to date most among brachyrostran abelisaurids, shows several autapomorphic including presence pneumatic recesses on dorsal surface anterior neural arches, tubercle lateral prezygapophysis mid vertebrae, marked protuberance rim transverse process small ligamentous scar near edge in anteriormost process. study has also allowed us identify characters that could be useful for future studies attempting resolve internal relationships Abelisauridae. Computed tomography scans vertebrae traits arches centra, thus first reported case taxon. Moreover, osteological correlates soft tissues especially derived brachyrostrans, underscore previously proposed increase rigidity within

Язык: Английский

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New information on paleopathologies in non-avian theropod dinosaurs: a case study on South American abelisaurids

BMC Ecology and Evolution, Год журнала: 2024, Номер 24(1)

Опубликована: Янв. 31, 2024

Studies on pathological fossil bones have allowed improving the knowledge of physiology and ecology, consequently life history extinct organisms. Among vertebrates, non-avian dinosaurs drawn attention in terms evidence, since a wide array fossilized lesions diseases were noticed these ancient Here, we evaluate conditions observed individuals different brachyrostran (Theropoda, Abelisauridae) taxa, including Aucasaurus garridoi, Elemgasem nubilus, Quilmesaurus curriei. For this, use multiple methodological approaches such as histology computed tomography, addition to macroscopic evaluation. The holotype shows several pathognomonic traits failure vertebral segmentation during development, causing presence two fused caudal vertebrae. occurrence this condition is first case be documented so far non-tetanuran theropods. Regarding Elemgasem, vertebrae an intervertebral space between centra, thus fusion limited distal rim articular surfaces. This pathology here considered spondyloarthropathy, evidence for theropod. microstructural arrangement right tibia marked variation portion outer cortex, probably due radial fibrolamellar bone tissue. Although similar tissue present other vertebrates cause its formation still debated, it could response some kind pathology. theropods, traumatic injuries are better represented than maladies (e.g., infection, congenital or metabolic diseases, etc.). These pathologies recovered mainly among large-sized theropods Abelisauridae, Allosauridae, Carcharodontosauridae, Tyrannosauridae, distributed principally axial elements. Statistical tests distribution theropod clades show strong association taxa-pathologies, body regions-pathologies, taxa-body regions, suggesting styles behaviours may underlie frequency taxa.

Язык: Английский

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Shed teeth from Portezuelo formation at Sierra del Portezuelo reveal a higher diversity of predator theropods during Turonian-Coniacian times in northern Patagonia

BMC Ecology and Evolution, Год журнала: 2024, Номер 24(1)

Опубликована: Май 10, 2024

Abstract The study of thirty-two shed crowns from the Portezuelo Formation (middle Turonian-late Coniacian) at Sierra del locality, reveals six distinct tooth morphotypes identified through cladistic, discriminant, and cluster analyses. Two were as belonging to Megaraptoridae, three Abelisauridae, one Abelisauroidea, Alvarezsauridae. Additionally, two exhibit a combination dental features typically found in megaraptorid abelisauridtheropods. These results suggest greater diversity theropods original ecosystem than previously thought, including presence second morphotype alvarezsaurid undocumented this formation. Furthermore, existence Morphotype 6 indicates potential coexistence medium-sized abelisauroids alongside larger abelisaurids same ecosystem. findings underscore importance future expeditions locality further our understanding these unknown theropod species.

Язык: Английский

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Macroevolutionary trends in Ceratosauria body size: insights of phylogenetic comparative methods

BMC Ecology and Evolution, Год журнала: 2025, Номер 25(1)

Опубликована: Апрель 12, 2025

Patterns of body size evolution in dinosaurs are relevant for understanding the evolutionary trends that have shaped disparity phenotypes observed fossil record. In this sense, previous studies suggested Abelisauridae followed Cope´s rule and Noasauridae exhibited a phylogenetic trend towards decreasing size. However, absence comprehensive analysis including ecological, socio-sexual factors make it necessary to reevaluate Ceretatosauria under modern comparative approach. Therefore, we aimed test whether evolved Ceratosauria accordance with rule, evaluate what best explain differences within examine patterns rates, selection strength constrain diversification Ceratosauria. Differences were found between specialized taxa (= Late Cretaceous abelisaurids) "generalized taxa" Outgroups + Noasauridae). This results presence feeding strategy abelisaurids was associated size, regardless topology model used. Additionally, low levels morphological disparity, rates specialist behavior Brownian motion record suggest constrained. The cursorial abilities joined predation could constrained increase after extinction carcharodontosaurids. On other hand, decreased likely avoid niche overlap medium theropods minimize structural maintenance cost while living stressful environments having generalist diet. Understanding how dynamics dinosaur communities, such as competition predator-prey interactions, operated South America during is crucial reconstructing ecological processes its unique faunal assemblage. Futures works should be focus on process-based community-evolution species distribution modeling further understand macroevolution community.

Язык: Английский

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New dinosaur remains increase theropod diversity in the Cañadón Asfalto Formation (Lower Jurassic), Chubut Province, Argentina

Journal of Systematic Palaeontology, Год журнала: 2024, Номер 22(1)

Опубликована: Апрель 9, 2024

The Jurassic record of South American theropods is scarce, being represented by only seven nominal species. Four these species (Eoabelisaurus mefi, Asfaltovenator vialidadi, Condorraptor currumili and Piatnitzkysaurus floresi) have been found in Toarcian-aged localities the Cañadón Asfalto Formation (Chubut Province, Argentina) and, as a result, this unit has highest known diversity on continent. A dentary with teeth situ (MPEF-PV 6775) was close to base formation differs from other overlapping morphology. MPEF-PV 6775 resembles Late North theropod Ceratosaurus robust bone, strong dorsal curvature lateral view, having relatively tall tooth crowns. scored two matrices that broad taxonomic sample focused Theropoda new specimen recovered large polytomies early neotheropods. third analysis conducted scoring into matrix ceratosaurs because its morphological similarities Ceratosaurus. In analysis, sister taxon Ceratosaurus, sharing later ventral margin strongly convex anteroposteriorly. These results suggest ceratosaurian probably ceratosaurid. Thus, our indicate higher particular, Formation. seems provide more evidence for presence ceratosaurids America, together isolated described Uruguay some analyses Eoabelisaurus Berberosaurus within clade.

Язык: Английский

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Reassessment of theropod material from Pichasca, Northern Chile: Presence of Abelisauridae (Theropoda: Ceratosauria) from the Quebrada La Totora Beds (Albian - Turonian)

Journal of South American Earth Sciences, Год журнала: 2023, Номер 129, С. 104494 - 104494

Опубликована: Июль 21, 2023

Язык: Английский

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A megaraptorid (Dinosauria: Theropoda) frontal from the upper Strzelecki Group (Lower Cretaceous) of Victoria, Australia

Cretaceous Research, Год журнала: 2023, Номер 154, С. 105769 - 105769

Опубликована: Ноя. 2, 2023

Cretaceous (non-avian) theropod dinosaurs from Australia are poorly understood, primarily because almost all specimens described thus far comprise isolated postcranial elements. In Australia, only three non-dental cranial elements pertaining to Theropoda have been reported: the left and right dentaries of Australovenator wintonensis Winton Formation (Cenomanian–lowermost Turonian) Queensland, an surangular Eumeralla (lower Albian) Victoria. Herein, we report first evidence non-mandibular material a non-avian Australia: frontal fused parietal fragment Lower Aptian) upper Strzelecki Group The specimen shares several synapomorphies with frontals assigned Megaraptoridae, including anteroposteriorly elongate postorbital articulation truncated nasal articular surface. Accordingly, regard this as Megaraptoridae gen. et sp. indet. We performed both parsimony-based Bayesian-based phylogenetic analyses support our assignment, placement within Megaraptoridae. However, appears possess plesiomorphic characters relative other megaraptorid frontals, lacking dorsoventrally high walls bone that emarginate prefrontal surfaces. plesiomorphies implications for evolution megaraptoran skull roof, suggesting acquisition specialised adaptations longirostry over time. This improves limited record Australian remains, provides hypothesis might originated in Australia.

Язык: Английский

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