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Salem BS, Lamanna MC, O'Connor PM, El-Qot GM, Shaker F, Thabet WA, El-Sayed S, Sallam HM. First definitive record of Abelisauridae (Theropoda: Ceratosauria) from the Cretaceous Bahariya Formation, Bahariya Oasis, Western Desert of Egypt. ROYAL SOCIETY OPEN SCIENCE 2022; 9:220106. [PMID: 35706658 PMCID: PMC9174736 DOI: 10.1098/rsos.220106] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 05/11/2022] [Indexed: 05/03/2023]
Abstract
Numerous non-avian theropod dinosaur fossils have been reported from the Upper Cretaceous (Cenomanian) Bahariya Formation, Bahariya Oasis, Western Desert of Egypt, but unambiguous materials of Abelisauridae have yet to be documented. Here we report Mansoura University Vertebrate Paleontology Center (MUVP) specimen 477, an isolated, well-preserved tenth cervical vertebra of a medium-sized abelisaurid from the Bahariya Formation. The new vertebra shows affinities with those of other Upper Cretaceous abelisaurids from Madagascar and South America, such as Majungasaurus crenatissimus, Carnotaurus sastrei, Viavenator exxoni and a generically indeterminate Patagonian specimen (Museo Padre Molina specimen 99). Phylogenetic analysis recovers the Bahariya form within Abelisauridae, either in a polytomy of all included abelisaurids (strict consensus tree) or as an early branching member of the otherwise South American clade Brachyrostra (50% majority rule consensus tree). MUVP 477, therefore, represents the first confirmed abelisaurid fossil from the Bahariya Formation and the oldest definitive record of the clade from Egypt and northeastern Africa more generally. The new vertebra demonstrates the wide geographical distribution of Abelisauridae across North Africa during the middle Cretaceous and augments the already extraordinarily diverse large-bodied theropod assemblage of the Bahariya Formation, a record that also includes representatives of Spinosauridae, Carcharodontosauridae and Bahariasauridae.
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Affiliation(s)
- Belal S. Salem
- Department of Geology, Faculty of Science, Benha University, Benha, Egypt
- Mansoura University Vertebrate Paleontology Center (MUVP), Department of Geology, Faculty of Science, Mansoura University, Mansoura, Egypt
- Department of Biological Sciences, Ohio University, 228 Irvine Hall, Athens, OH, USA
- Ohio Center for Ecological and Evolutionary Studies, Ohio University, Athens, OH, USA
| | - Matthew C. Lamanna
- Section of Vertebrate Paleontology, Carnegie Museum of Natural History, Pittsburgh, PA, USA
| | - Patrick M. O'Connor
- Ohio Center for Ecological and Evolutionary Studies, Ohio University, Athens, OH, USA
- Department of Biomedical Sciences, Ohio University Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, USA
| | - Gamal M. El-Qot
- Department of Geology, Faculty of Science, Benha University, Benha, Egypt
| | - Fatma Shaker
- Department of Geology, Faculty of Science, Benha University, Benha, Egypt
| | | | - Sanaa El-Sayed
- Mansoura University Vertebrate Paleontology Center (MUVP), Department of Geology, Faculty of Science, Mansoura University, Mansoura, Egypt
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA
| | - Hesham M. Sallam
- Mansoura University Vertebrate Paleontology Center (MUVP), Department of Geology, Faculty of Science, Mansoura University, Mansoura, Egypt
- Institute of Global Health and Human Ecology (I-GHHE), School of Sciences and Engineering, American University in Cairo, New Cairo, Egypt
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Suarez CA, Frederickson J, Cifelli RL, Pittman JG, Nydam RL, Hunt-Foster RK, Morgan K. A new vertebrate fauna from the Lower Cretaceous Holly Creek Formation of the Trinity Group, southwest Arkansas, USA. PeerJ 2021; 9:e12242. [PMID: 34721970 PMCID: PMC8542373 DOI: 10.7717/peerj.12242] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 09/12/2021] [Indexed: 11/20/2022] Open
Abstract
We present a previously discovered but undescribed late Early Cretaceous vertebrate fauna from the Holly Creek Formation of the Trinity Group in Arkansas. The site from the ancient Gulf Coast is dominated by semi-aquatic forms and preserves a diverse aquatic, semi-aquatic, and terrestrial fauna. Fishes include fresh- to brackish-water chondrichthyans and a variety of actinopterygians, including semionotids, an amiid, and a new pycnodontiform, Anomoeodus caddoi sp. nov. Semi-aquatic taxa include lissamphibians, the solemydid turtle Naomichelys, a trionychid turtle, and coelognathosuchian crocodyliforms. Among terrestrial forms are several members of Dinosauria and one or more squamates, one of which, Sciroseps pawhuskai gen. et sp. nov., is described herein. Among Dinosauria, both large and small theropods (Acrocanthosaurus, Deinonychus, and Richardoestesia) and titanosauriform sauropods are represented; herein we also report the first occurrence of a nodosaurid ankylosaur from the Trinity Group. The fauna of the Holly Creek Formation is similar to other, widely scattered late Early Cretaceous assemblages across North America and suggests the presence of a low-diversity, broadly distributed continental ecosystem of the Early Cretaceous following the Late Jurassic faunal turnover. This low-diversity ecosystem contrasts sharply with the highly diverse ecosystem which emerged by the Cenomanian. The contrast underpins the importance of vicariance as an evolutionary driver brought on by Sevier tectonics and climatic changes, such as rising sea level and formation of the Western Interior Seaway, impacting the early Late Cretaceous ecosystem.
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Affiliation(s)
- Celina A Suarez
- Department of Geosciences, University of Arkansas at Fayetteville, Fayetteville, Arkansas, USA
| | - Joseph Frederickson
- Weis Earth Science Museum, University of Wisconsin Oshkosh Fox Cities Campus, Menasha, WI, USA
| | - Richard L Cifelli
- Department of Vertebrate Paleontology, Sam Noble Oklahoma Museum of Natural History, University of Oklahoma, Norman, OK, USA
| | | | - Randall L Nydam
- Arizona College of Osteopathic Medicine, Midwestern University, Glendale, Arizona, USA
| | | | - Kirsty Morgan
- Department of Geosciences, University of Arkansas at Fayetteville, Fayetteville, Arkansas, USA
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Ibrahim N, Sereno PC, Varricchio DJ, Martill DM, Dutheil DB, Unwin DM, Baidder L, Larsson HCE, Zouhri S, Kaoukaya A. Geology and paleontology of the Upper Cretaceous Kem Kem Group of eastern Morocco. Zookeys 2020; 928:1-216. [PMID: 32362741 PMCID: PMC7188693 DOI: 10.3897/zookeys.928.47517] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 03/02/2020] [Indexed: 11/30/2022] Open
Abstract
The geological and paleoenvironmental setting and the vertebrate taxonomy of the fossiliferous, Cenomanian-age deltaic sediments in eastern Morocco, generally referred to as the “Kem Kem beds”, are reviewed. These strata are recognized here as the Kem Kem Group, which is composed of the lower Gara Sbaa and upper Douira formations. Both formations have yielded a similar fossil vertebrate assemblage of predominantly isolated elements pertaining to cartilaginous and bony fishes, turtles, crocodyliforms, pterosaurs, and dinosaurs, as well as invertebrate, plant, and trace fossils. These fossils, now in collections around the world, are reviewed and tabulated. The Kem Kem vertebrate fauna is biased toward large-bodied carnivores including at least four large-bodied non-avian theropods (an abelisaurid, Spinosaurus, Carcharodontosaurus, and Deltadromeus), several large-bodied pterosaurs, and several large crocodyliforms. No comparable modern terrestrial ecosystem exists with similar bias toward large-bodied carnivores. The Kem Kem vertebrate assemblage, currently the best documented association just prior to the onset of the Cenomanian-Turonian marine transgression, captures the taxonomic diversity of a widespread northern African fauna better than any other contemporary assemblage from elsewhere in Africa.
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Affiliation(s)
- Nizar Ibrahim
- Department of Biology, University of Detroit Mercy, Detroit, Michigan 48221, USA
| | - Paul C Sereno
- Department of Organismal Biology and Anatomy and Committee on Evolutionary Biology, University of Chicago, Chicago, Illinois 60637, USA
| | - David J Varricchio
- Department of Earth Sciences, Montana State University, Bozeman, Montana 59717, USA
| | - David M Martill
- School of the Environment, Geography and Geological Sciences, University of Portsmouth, Portsmouth PO1 3QL, UK
| | - Didier B Dutheil
- Centre de Recherche sur la Paléobiodiversité et les Paléoenvironnements, UMR7207 (CNRS-MNHN-UPMC), Muséum national d'Histoire naturelle, 75005 Paris, France
| | - David M Unwin
- School of Museum Studies, University of Leicester, Leicester LE1 7RF, UK
| | - Lahssen Baidder
- Laboratoire Géosciences, Département de Géologie, Faculté des Sciences Aïn Chock, Université Hassan II, Casablanca, Morocco
| | - Hans C E Larsson
- Redpath Museum, McGill University, Montreal, Quebec H3A 0C4, Canada
| | - Samir Zouhri
- Laboratoire de Biodiversité et Santé, Faculté des Sciences Aïn Chock, Université Hassan II, Casablanca, Morocco
| | - Abdelhadi Kaoukaya
- Laboratoire Géosciences, Département de Géologie, Faculté des Sciences Aïn Chock, Université Hassan II, Casablanca, Morocco
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An abelisaurid (Dinosauria: Theropoda) ilium from the Upper Cretaceous (Cenomanian) of the Kem Kem beds, Morocco. PLoS One 2019; 14:e0214055. [PMID: 30939139 PMCID: PMC6445567 DOI: 10.1371/journal.pone.0214055] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 03/06/2019] [Indexed: 11/19/2022] Open
Abstract
Abelisaurid theropods first appear in the fossil record in the early Jurassic and survived at least until the end of the Mesozoic. They were known to have dominated South America, India and Madagascar but were not so abundant in North America or Asia. Much less is known about their presence in Africa, although there has been several recent discoveries of abelisaurid material in Morocco. Here we add a partially preserved ilium to a growing body of evidence that suggests abelisaurs might also have dominated Africa.
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Ceratosaur palaeobiology: new insights on evolution and ecology of the southern rulers. Sci Rep 2018; 8:9730. [PMID: 29950661 PMCID: PMC6021374 DOI: 10.1038/s41598-018-28154-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 06/12/2018] [Indexed: 11/28/2022] Open
Abstract
Ceratosaur theropods ruled the Southern Hemisphere until the end of the Late Cretaceous. However, their origin was earlier, during the Early Jurassic, a fact which allowed the group to reach great morphological diversity. The body plans of the two main branches (Noasauridae and new name Etrigansauria: Ceratosauridae + Abelisauridae) are quite different; nevertheless, they are sister taxa. Abelisaurids have lost the ability to grasp in the most derived taxa, but the reduced forelimb might have had some display function. The ontogenetic changes are well known in Limusaurus which lost all their teeth and probably changed the dietary preference at maturity. The results presented here suggest that abelisaurids had different soft tissues on the skull. These tissues might have been associated with evolution of a strong cervicocephalic complex and should have allowed derived taxa (e.g. Majungasaurus and Carnotaurus) to have low-displacement headbutting matches. The ability to live in different semi-arid environment plus high morphological disparity allowed the ceratosaurs to become an evolutionary success.
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Maganuco S, Dal Sasso C. The smallest biggest theropod dinosaur: a tiny pedal ungual of a juvenile Spinosaurus from the Cretaceous of Morocco. PeerJ 2018; 6:e4785. [PMID: 29868253 PMCID: PMC5984586 DOI: 10.7717/peerj.4785] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 04/27/2018] [Indexed: 11/20/2022] Open
Abstract
We describe a nearly complete pedal ungual phalanx, discovered in the Kem Kem Beds (Cenomanian) of Tafilalt region, south-eastern Morocco. The bone is symmetric, pointed, low, elongate, and almost flat ventrally in lateral aspect. This peculiar morphology allows to refer the specimen to the smallest known individual of the genus Spinosaurus. The bone belongs to an early juvenile individual and it is proportionally identical to the ungual of the third digit of a large partial skeleton recently found, suggesting an isometric growth for this part of the pes and the retention of peculiar locomotor adaptations—such as traversing soft substrates or paddling—during the entire lifespan.
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Tennant JP, Chiarenza AA, Baron M. How has our knowledge of dinosaur diversity through geologic time changed through research history? PeerJ 2018; 6:e4417. [PMID: 29479504 PMCID: PMC5822849 DOI: 10.7717/peerj.4417] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 02/06/2018] [Indexed: 11/20/2022] Open
Abstract
Assessments of dinosaur macroevolution at any given time can be biased by the historical publication record. Recent studies have analysed patterns in dinosaur diversity that are based on secular variations in the numbers of published taxa. Many of these have employed a range of approaches that account for changes in the shape of the taxonomic abundance curve, which are largely dependent on databases compiled from the primary published literature. However, how these ‘corrected’ diversity patterns are influenced by the history of publication remains largely unknown. Here, we investigate the influence of publication history between 1991 and 2015 on our understanding of dinosaur evolution using raw diversity estimates and shareholder quorum subsampling for the three major subgroups: Ornithischia, Sauropodomorpha, and Theropoda. We find that, while sampling generally improves through time, there remain periods and regions in dinosaur evolutionary history where diversity estimates are highly volatile (e.g. the latest Jurassic of Europe, the mid-Cretaceous of North America, and the Late Cretaceous of South America). Our results show that historical changes in database compilation can often substantially influence our interpretations of dinosaur diversity. ‘Global’ estimates of diversity based on the fossil record are often also based on incomplete, and distinct regional signals, each subject to their own sampling history. Changes in the record of taxon abundance distribution, either through discovery of new taxa or addition of existing taxa to improve sampling evenness, are important in improving the reliability of our interpretations of dinosaur diversity. Furthermore, the number of occurrences and newly identified dinosaurs is still rapidly increasing through time, suggesting that it is entirely possible for much of what we know about dinosaurs at the present to change within the next 20 years.
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Affiliation(s)
- Jonathan P Tennant
- Department of Earth Science and Engineering, Imperial College London, London, UK
| | | | - Matthew Baron
- Department of Earth Science, University of Cambridge, Cambridge, UK.,Earth Sciences Department, Natural History Museum, London, UK
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Apesteguía S, Smith ND, Juárez Valieri R, Makovicky PJ. An Unusual New Theropod with a Didactyl Manus from the Upper Cretaceous of Patagonia, Argentina. PLoS One 2016; 11:e0157793. [PMID: 27410683 PMCID: PMC4943716 DOI: 10.1371/journal.pone.0157793] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 06/02/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Late Cretaceous terrestrial strata of the Neuquén Basin, northern Patagonia, Argentina have yielded a rich fauna of dinosaurs and other vertebrates. The diversity of saurischian dinosaurs is particularly high, especially in the late Cenomanian-early Turonian Huincul Formation, which has yielded specimens of rebacchisaurid and titanosaurian sauropods, and abelisaurid and carcharodontosaurid theropods. Continued sampling is adding to the known vertebrate diversity of this unit. METHODOLOGY/ PRINCIPAL FINDINGS A new, partially articulated mid-sized theropod was found in rocks from the Huincul Formation. It exhibits a unique combination of traits that distinguish it from other known theropods justifying erection of a new taxon, Gualicho shinyae gen. et sp. nov. Gualicho possesses a didactyl manus with the third digit reduced to a metacarpal splint reminiscent of tyrannosaurids, but both phylogenetic and multivariate analyses indicate that didactyly is convergent in these groups. Derived characters of the scapula, femur, and fibula supports the new theropod as the sister taxon of the nearly coeval African theropod Deltadromeus and as a neovenatorid carcharodontosaurian. A number of these features are independently present in ceratosaurs, and Gualicho exhibits an unusual mosaic of ceratosaurian and tetanuran synapomorphies distributed throughout the skeleton. CONCLUSIONS/ SIGNIFICANCE Gualicho shinyae gen. et sp. nov. increases the known theropod diversity of the Huincul Formation and also represents the first likely neovenatorid from this unit. It is the most basal tetatanuran to exhibit common patterns of digit III reduction that evolved independently in a number of other tetanuran lineages. A close relationship with Deltadromaeus from the Kem Kem beds of Niger adds to the already considerable biogeographic similarity between the Huincul Formation and coeval rock units in North Africa.
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Affiliation(s)
- Sebastián Apesteguía
- Área de Paleontología. Fundación de Historia Natural 'Félix de Azara', CEBBAD, Univ. Maimónides, Buenos Aires, Argentina
| | - Nathan D. Smith
- Dinosaur Institute, Natural History Museum of Los Angeles County, Los Angeles, United States of America
| | - Rubén Juárez Valieri
- Secretaría de Cultura, Gobierno de la Provincia de Río Negro, General Roca, Argentina
| | - Peter J. Makovicky
- Section of Earth Sciences, Integrative Research Center, Field Museum of Natural History, Chicago, Illinois, United States of America
- * E-mail:
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