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Baiano MA, Cerda IA, Bertozzo F, Pol D. New information on paleopathologies in non-avian theropod dinosaurs: a case study on South American abelisaurids. BMC Ecol Evol 2024; 24:6. [PMID: 38291378 PMCID: PMC10829224 DOI: 10.1186/s12862-023-02187-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 12/06/2023] [Indexed: 02/01/2024] Open
Abstract
Studies on pathological fossil bones have allowed improving the knowledge of physiology and ecology, and consequently the life history of extinct organisms. Among extinct vertebrates, non-avian dinosaurs have drawn attention in terms of pathological evidence, since a wide array of fossilized lesions and diseases were noticed in these ancient organisms. Here, we evaluate the pathological conditions observed in individuals of different brachyrostran (Theropoda, Abelisauridae) taxa, including Aucasaurus garridoi, Elemgasem nubilus, and Quilmesaurus curriei. For this, we use multiple methodological approaches such as histology and computed tomography, in addition to the macroscopic evaluation. The holotype of Aucasaurus shows several pathognomonic traits of a failure of the vertebral segmentation during development, causing the presence of two fused caudal vertebrae. The occurrence of this condition in Aucasaurus is the first case to be documented so far in non-tetanuran theropods. Regarding the holotype of Elemgasem, the histology of two fused vertebrae shows an intervertebral space between the centra, thus the fusion is limited to the distal rim of the articular surfaces. This pathology is here considered as spondyloarthropathy, the first evidence for a non-tetanuran theropod. The microstructural arrangement of the right tibia of Quilmesaurus shows a marked variation in a portion of the outer cortex, probably due to the presence of the radial fibrolamellar bone tissue. Although similar bone tissue is present in other extinct vertebrates and the cause of its formation is still debated, it could be a response to some kind of pathology. Among non-avian theropods, traumatic injuries are better represented than other maladies (e.g., infection, congenital or metabolic diseases, etc.). These pathologies are recovered mainly among large-sized theropods such as Abelisauridae, Allosauridae, Carcharodontosauridae, and Tyrannosauridae, and distributed principally among axial elements. Statistical tests on the distribution of injuries in these theropod clades show a strong association between taxa-pathologies, body regions-pathologies, and taxa-body regions, suggesting different life styles and behaviours may underlie the frequency of different injuries among theropod taxa.
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Affiliation(s)
- Mattia A Baiano
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Godoy Cruz 2290, 1425, Ciudad Autónoma de Buenos Aires, Argentina.
- Area Laboratorio e Investigación, Museo Municipal 'Ernesto Bachmann', Dr Natali S/N, 8311, Villa El Chocon, Neuquén, Argentina.
- Universidad Nacional de Río Negro (UNRN), Isidro Lobo 516, 8332, General Roca, Río Negro, Argentina.
| | - Ignacio A Cerda
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Godoy Cruz 2290, 1425, Ciudad Autónoma de Buenos Aires, Argentina
- Universidad Nacional de Río Negro (UNRN), Isidro Lobo 516, 8332, General Roca, Río Negro, Argentina
- Instituto de Investigacion en Paleobiología y Geología (IIPG), Av. Roca 1242, 8332, General Roca, Río Negro, Argentina
- Museo Carlos Ameghino, Belgrano 1700 (Paraje Pichi Ruca, Predio Marabunta), 8324, Cipolletti, Río Negro, Argentina
| | - Filippo Bertozzo
- Operational Directorate Earth and History of Life, Royal Belgian Institute of Natural Sciences, Brussels, Belgium
| | - Diego Pol
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Godoy Cruz 2290, 1425, Ciudad Autónoma de Buenos Aires, Argentina
- Museo Paleontológico Egidio Feruglio, Av. Fontana 140, 9100, Trelew, Chubut, Argentina
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2
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Baiano MA, Coria R, Chiappe LM, Zurriaguz V, Coria L. Osteology of the axial skeleton of Aucasaurus garridoi: phylogenetic and paleobiological inferences. PeerJ 2023; 11:e16236. [PMID: 38025666 PMCID: PMC10655716 DOI: 10.7717/peerj.16236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 09/14/2023] [Indexed: 12/01/2023] Open
Abstract
Aucasaurus garridoi is an abelisaurid theropod from the Anacleto Formation (lower Campanian, Upper Cretaceous) of Patagonia, Argentina. The holotype of Aucasaurus garridoi includes cranial material, axial elements, and almost complete fore- and hind limbs. Here we present a detailed description of the axial skeleton of this taxon, along with some paleobiological and phylogenetic inferences. The presacral elements are somewhat fragmentary, although these show features shared with other abelisaurids. The caudal series, to date the most complete among brachyrostran abelisaurids, shows several autapomorphic features including the presence of pneumatic recesses on the dorsal surface of the anterior caudal neural arches, a tubercle lateral to the prezygapophysis of mid caudal vertebrae, a marked protuberance on the lateral rim of the transverse process of the caudal vertebrae, and the presence of a small ligamentous scar near the anterior edge of the dorsal surface in the anteriormost caudal transverse process. The detailed study of the axial skeleton of Aucasaurus garridoi has also allowed us to identify characters that could be useful for future studies attempting to resolve the internal phylogenetic relationships of Abelisauridae. Computed tomography scans of some caudal vertebrae show pneumatic traits in neural arches and centra, and thus the first reported case for an abelisaurid taxon. Moreover, some osteological correlates of soft tissues present in Aucasaurus and other abelisaurids, especially derived brachyrostrans, underscore a previously proposed increase in axial rigidity within Abelisauridae.
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Affiliation(s)
- Mattia Antonio Baiano
- Chinese University of Hong Kong, Hong Kong, Hong Kong
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
- Museo Municipal Ernesto Bachmann, Villa el Chocón, Argentina
- Universidad Nacional de Río Negro, General Roca, Argentina
| | - Rodolfo Coria
- Universidad Nacional de Río Negro, General Roca, Argentina
- Museo Municipal Carmen Funes, Plaza Huincul, Argentina
| | - Luis M. Chiappe
- Dinosaur Institute, Natural History Museum of Los Angeles County, Los Angeles, United States of America
| | - Virginia Zurriaguz
- Instituto de Investigación en Paleobiología y Geología (IIPG), General Roca, Argentina
| | - Ludmila Coria
- Museo Municipal Carmen Funes, Plaza Huincul, Argentina
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3
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Pahl CC, Ruedas LA. Big boned: How fat storage and other adaptations influenced large theropod foraging ecology. PLoS One 2023; 18:e0290459. [PMID: 37910492 PMCID: PMC10619836 DOI: 10.1371/journal.pone.0290459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 08/08/2023] [Indexed: 11/03/2023] Open
Abstract
Dinosaur foraging ecology has been the subject of scientific interest for decades, yet much of what we understand about it remains hypothetical. We wrote an agent-based model (ABM) to simulate meat energy sources present in dinosaur environments, including carcasses of giant sauropods, along with living, huntable prey. Theropod dinosaurs modeled in this environment (specifically allosauroids, and more particularly, Allosaurus Marsh, 1877) were instantiated with heritable traits favorable to either hunting success or scavenging success. If hunter phenotypes were more reproductively successful, their traits were propagated into the population through their offspring, resulting in predator specialists. If selective pressure favored scavenger phenotypes, the population would evolve to acquire most of their calories from carrion. Data generated from this model strongly suggest that theropods in sauropod-dominated systems evolved to detect carcasses, consume and store large quantities of fat, and dominate carcass sites. Broadly speaking, selective forces did not favor predatory adaptations, because sauropod carrion resource pools, as we modeled them, were too profitable for prey-based resource pools to be significant. This is the first research to test selective pressure patterns in dinosaurs, and the first to estimate theropod mass based on metabolic constraints.
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Affiliation(s)
- Cameron C. Pahl
- Department of Biology and Museum of Vertebrate Biology, Science Research and Teaching Center—246, Portland State University, Portland, Oregon, United States of America
| | - Luis A. Ruedas
- Department of Biology and Museum of Vertebrate Biology, Science Research and Teaching Center—246, Portland State University, Portland, Oregon, United States of America
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4
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Winchell KM, Losos JB, Verrelli BC. Urban evolutionary ecology brings exaptation back into focus. Trends Ecol Evol 2023:S0169-5347(23)00060-5. [PMID: 37024381 DOI: 10.1016/j.tree.2023.03.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 03/12/2023] [Accepted: 03/14/2023] [Indexed: 04/08/2023]
Abstract
The contribution of pre-existing phenotypic variation to evolution in novel environments has long been appreciated. Nevertheless, evolutionary ecologists have struggled with communicating these aspects of the adaptive process. In 1982, Gould and Vrba proposed terminology to distinguish character states shaped via natural selection for the roles they currently serve ('adaptations') from those shaped under preceding selective regimes ('exaptations'), with the intention of replacing the inaccurate 'preadaptation'. Forty years later, we revisit Gould and Vrba's ideas which, while often controversial, continue to be widely debated and highly cited. We use the recent emergence of urban evolutionary ecology as a timely opportunity to reintroduce the ideas of Gould and Vrba as an integrated framework to understand contemporary evolution in novel environments.
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Affiliation(s)
- Kristin M Winchell
- Department of Biology, New York University, New York, NY 10003, USA; Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA; Department of Biology, Washington University, St Louis, MO 63130, USA.
| | - Jonathan B Losos
- Department of Biology, Washington University, St Louis, MO 63130, USA
| | - Brian C Verrelli
- Center for Biological Data Science, Virginia Commonwealth University, Richmond, VA 23284, USA
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5
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Allosaurus was predominantly a scavenger. Ecol Modell 2023. [DOI: 10.1016/j.ecolmodel.2022.110261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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6
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Kane A, Healy K, Ruxton GD. Was Allosaurus really predominantly a scavenger? Ecol Modell 2023. [DOI: 10.1016/j.ecolmodel.2022.110247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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7
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Chinzorig T, Beguesse KA, Canoville A, Phillips G, Zanno LE. Chronic fracture and osteomyelitis in a large-bodied ornithomimosaur with implications for the identification of unusual endosteal bone in the fossil record. Anat Rec (Hoboken) 2022. [PMID: 36193654 DOI: 10.1002/ar.25069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 07/19/2022] [Accepted: 08/15/2022] [Indexed: 11/07/2022]
Abstract
Paleopathological diagnoses provide key information on the macroevolutionary origin of disease as well as behavioral and physiological inferences that are inaccessible via direct observation of extinct organisms. Here we describe the external gross morphology and internal architecture of a pathologic right second metatarsal (MMNS VP-6332) of a large-bodied ornithomimid (~432 kg) from the Santonian (Upper Cretaceous) Eutaw Formation in Mississippi, using a combination of X-ray computed microtomography (microCT) and petrographic histological analyses. X-ray microCT imaging and histopathologic features are consistent with multiple complete, oblique to comminuted, minimally displaced mid-diaphyseal cortical fractures that produce a "butterfly" fragment fracture pattern, and secondary osteomyelitis with a bone fistula formation. We interpret this as evidence of blunt force trauma to the foot that could have resulted from intra- or interspecific competition or predator-prey interaction, and probably impaired the function of the metatarsal as a weight-bearing element until the animal's death. Of particular interest is the apparent decoupling of endosteal and periosteal pathological bone deposition in MMNS VP-6332, which produces transverse sections exhibiting homogenously thick endosteal pathological bone in the absence of localized periosteal reactive bone. These distribution and depositional patterns are used as criteria for ruling out a pathological origin in favor of a reproductive one for unusual endosteal bone in fossil specimens. On the basis of MMNS VP-6332, we suggest caution in their use to substantiate a medullary bone identification in extinct archosaurians.
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Affiliation(s)
- Tsogtbaatar Chinzorig
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, USA.,Paleontology Research Laboratory, North Carolina Museum of Natural Sciences, Raleigh, North Carolina, USA
| | - Kyla A Beguesse
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, USA.,Paleontology Research Laboratory, North Carolina Museum of Natural Sciences, Raleigh, North Carolina, USA
| | - Aurore Canoville
- Stiftung Schloss Friedenstein, Gotha & Museum für Naturkunde, Berlin, Germany
| | - George Phillips
- Conservation & Biodiversity Section, Mississippi Museum of Natural Science, Jackson, Mississippi, USA
| | - Lindsay E Zanno
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, USA.,Paleontology Research Laboratory, North Carolina Museum of Natural Sciences, Raleigh, North Carolina, USA
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8
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Hendrickx C, Bell PR, Pittman M, Milner ARC, Cuesta E, O'Connor J, Loewen M, Currie PJ, Mateus O, Kaye TG, Delcourt R. Morphology and distribution of scales, dermal ossifications, and other non-feather integumentary structures in non-avialan theropod dinosaurs. Biol Rev Camb Philos Soc 2022; 97:960-1004. [PMID: 34991180 DOI: 10.1111/brv.12829] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 12/10/2021] [Accepted: 12/14/2021] [Indexed: 12/14/2022]
Abstract
Modern birds are typified by the presence of feathers, complex evolutionary innovations that were already widespread in the group of theropod dinosaurs (Maniraptoriformes) that include crown Aves. Squamous or scaly reptilian-like skin is, however, considered the plesiomorphic condition for theropods and dinosaurs more broadly. Here, we review the morphology and distribution of non-feathered integumentary structures in non-avialan theropods, covering squamous skin and naked skin as well as dermal ossifications. The integumentary record of non-averostran theropods is limited to tracks, which ubiquitously show a covering of tiny reticulate scales on the plantar surface of the pes. This is consistent also with younger averostran body fossils, which confirm an arthral arrangement of the digital pads. Among averostrans, squamous skin is confirmed in Ceratosauria (Carnotaurus), Allosauroidea (Allosaurus, Concavenator, Lourinhanosaurus), Compsognathidae (Juravenator), and Tyrannosauroidea (Santanaraptor, Albertosaurus, Daspletosaurus, Gorgosaurus, Tarbosaurus, Tyrannosaurus), whereas dermal ossifications consisting of sagittate and mosaic osteoderms are restricted to Ceratosaurus. Naked, non-scale bearing skin is found in the contentious tetanuran Sciurumimus, ornithomimosaurians (Ornithomimus) and possibly tyrannosauroids (Santanaraptor), and also on the patagia of scansoriopterygids (Ambopteryx, Yi). Scales are surprisingly conservative among non-avialan theropods compared to some dinosaurian groups (e.g. hadrosaurids); however, the limited preservation of tegument on most specimens hinders further interrogation. Scale patterns vary among and/or within body regions in Carnotaurus, Concavenator and Juravenator, and include polarised, snake-like ventral scales on the tail of the latter two genera. Unusual but more uniformly distributed patterning also occurs in Tyrannosaurus, whereas feature scales are present only in Albertosaurus and Carnotaurus. Few theropods currently show compelling evidence for the co-occurrence of scales and feathers (e.g. Juravenator, Sinornithosaurus), although reticulate scales were probably retained on the mani and pedes of many theropods with a heavy plumage. Feathers and filamentous structures appear to have replaced widespread scaly integuments in maniraptorans. Theropod skin, and that of dinosaurs more broadly, remains a virtually untapped area of study and the appropriation of commonly used techniques in other palaeontological fields to the study of skin holds great promise for future insights into the biology, taphonomy and relationships of these extinct animals.
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Affiliation(s)
- Christophe Hendrickx
- Unidad Ejecutora Lillo, CONICET-Fundación Miguel Lillo, 251 Miguel Lillo, San Miguel de Tucumán, Tucumán, 4000, Argentina
| | - Phil R Bell
- School of Environmental and Rural Science, University of New England, Armidale, NSW, 2351, Australia
| | - Michael Pittman
- Vertebrate Palaeontology Laboratory, Department of Earth Sciences, The University of Hong Kong, Pokfulam, Hong Kong, SAR, China.,Department of Earth Sciences, University College London, WC1E 6BT, United Kingdom
| | - Andrew R C Milner
- St. George Dinosaur Discovery Site at Johnson Farm, 2180 East Riverside Drive, St. George, UT, U.S.A
| | - Elena Cuesta
- Bayerische Staatssammlung für Paläontologie und Geologie, Richard-Wagner-Str. 10, Munich, 80333, Germany
| | - Jingmai O'Connor
- Field Museum of Natural History, 1400 S Lake Shore Drive, Chicago, IL, 60605, U.S.A
| | - Mark Loewen
- Department of Geology and Geophysics, University of Utah, Frederick Albert Sutton Building, 115 South 1460 East, Salt Lake City, UT, 84112, U.S.A.,Natural History Museum of Utah, 301 Wakara Way, Salt Lake City, UT, 84108, U.S.A
| | - Philip J Currie
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Octávio Mateus
- GeoBioTec, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal.,Museu da Lourinhã, 95 Rua João Luis de Moura, Lourinhã, 2530-158, Portugal
| | - Thomas G Kaye
- Foundation for Scientific Advancement, 7023 Alhambra Dr., Sierra Vista, AZ, 85650, U.S.A
| | - Rafael Delcourt
- Universidade Estadual de Campinas (UNICAMP), Instituto de Geociências, Cidade Universitária, Rua Carlos Gomes, 250, Campinas, SP, 13083-855, Brazil
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Hamm CA, Hampe O, Schwarz D, Witzmann F, Makovicky PJ, Brochu CA, Reiter R, Asbach P. A comprehensive diagnostic approach combining phylogenetic disease bracketing and CT imaging reveals osteomyelitis in a Tyrannosaurus rex. Sci Rep 2020; 10:18897. [PMID: 33144637 PMCID: PMC7642268 DOI: 10.1038/s41598-020-75731-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 10/14/2020] [Indexed: 01/25/2023] Open
Abstract
Traditional palaeontological techniques of disease characterisation are limited to the analysis of osseous fossils, requiring several lines of evidence to support diagnoses. This study presents a novel stepwise concept for comprehensive diagnosis of pathologies in fossils by computed tomography imaging for morphological assessment combined with likelihood estimation based on systematic phylogenetic disease bracketing. This approach was applied to characterise pathologies of the left fibula and fused caudal vertebrae of the non-avian dinosaur Tyrannosaurus rex. Initial morphological assessment narrowed the differential diagnosis to neoplasia or infection. Subsequent data review from phylogenetically closely related species at the clade level revealed neoplasia rates as low as 3.1% and 1.8%, while infectious-disease rates were 32.0% and 53.9% in extant dinosaurs (birds) and non-avian reptiles, respectively. Furthermore, the survey of literature revealed that within the phylogenetic disease bracket the oldest case of bone infection (osteomyelitis) was identified in the mandible of a 275-million-year-old captorhinid eureptile Labidosaurus. These findings demonstrate low probability of a neoplastic aetiology of the examined pathologies in the Tyrannosaurus rex and in turn, suggest that they correspond to multiple foci of osteomyelitis.
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Affiliation(s)
- C A Hamm
- Department of Radiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Charitéplatz 1, 10117, Berlin, Germany
- Institute for Diagnostic Radiology and Neuroradiology, Greifswald University Hospital, Ferdinand-Sauerbruch-Straße, 17475, Greifswald, Germany
| | - O Hampe
- Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, Invalidenstraße 43, 10115, Berlin, Germany
| | - D Schwarz
- Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, Invalidenstraße 43, 10115, Berlin, Germany
| | - F Witzmann
- Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, Invalidenstraße 43, 10115, Berlin, Germany
| | - P J Makovicky
- Department of Earth and Environmental Sciences, University of Minnesota, Minneapolis, MN, 55455, USA
- Field Museum of Natural History, 1400 S. Lake Shore Dr, Chicago, IL, 60605, USA
| | - C A Brochu
- Department of Earth and Environmental Sciences, University of Iowa, Iowa City, IA, 52242, USA
| | - R Reiter
- Department of Radiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Charitéplatz 1, 10117, Berlin, Germany
- Richard and Loan Hill Department of Bioengineering, University of Illinois, Chicago, IL, 60607, USA
| | - P Asbach
- Department of Radiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Charitéplatz 1, 10117, Berlin, Germany.
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10
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Evers SW, Foth C, Rauhut OWM. Notes on the cheek region of the Late Jurassic theropod dinosaur Allosaurus. PeerJ 2020; 8:e8493. [PMID: 32076581 PMCID: PMC7008823 DOI: 10.7717/peerj.8493] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 12/30/2019] [Indexed: 11/24/2022] Open
Abstract
Allosaurus, from the Late Jurassic of North America and Europe, is a model taxon for Jurassic basal tetanuran theropod dinosaurs. It has achieved an almost iconic status due to its early discovery in the late, 19th century, and due to the abundance of material from the Morrison Formation of the western U.S.A., making Allosaurus one of the best-known theropod taxa. Despite this, various aspects of the cranial anatomy of Allosaurus are surprisingly poorly understood. Here, we discuss the osteology of the cheek region, comprised by the jugal, maxilla, and lacrimal. This region of the skull is of importance for Allosaurus taxonomy and phylogeny, particularly because Allosaurus has traditionally been reconstructed with an unusual cheek configuration, and because the European species Allosaurus europaeus has been said to be different from North American material in the configuration of these bones. Based on re-examination of articulated and disarticulated material from a number of repositories, we show that the jugal participates in the antorbital fenestra, contradicting the common interpretation. The jugal laterally overlies the lacrimal, and forms an extended antorbital fossa with this bone. Furthermore, we document previously unrecorded pneumatic features of the jugal of Allosaurus.
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Affiliation(s)
- Serjoscha W Evers
- Department of Geosciences, University of Fribourg, Fribourg, Switzerland
| | - Christian Foth
- Department of Geosciences, University of Fribourg, Fribourg, Switzerland
| | - Oliver W M Rauhut
- Bayerische Staatssammlung für Paläntologie und Geologie, Staatliche Naturwissenschaftliche Sammlungen Bayerns (SNSB), München, Germany.,Department of Earth and Environmental Sciences, Palaeontology and Geobiology, Ludwig-Maximilians-Universität, München, Germany.,GeoBioCenter, Ludwig-Maximilians-Universität, München, Germany
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11
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Chure DJ, Loewen MA. Cranial anatomy of Allosaurus jimmadseni, a new species from the lower part of the Morrison Formation (Upper Jurassic) of Western North America. PeerJ 2020; 8:e7803. [PMID: 32002317 PMCID: PMC6984342 DOI: 10.7717/peerj.7803] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 08/31/2019] [Indexed: 11/20/2022] Open
Abstract
Allosaurus is one of the best known theropod dinosaurs from the Jurassic and a crucial taxon in phylogenetic analyses. On the basis of an in-depth, firsthand study of the bulk of Allosaurus specimens housed in North American institutions, we describe here a new theropod dinosaur from the Upper Jurassic Morrison Formation of Western North America, Allosaurus jimmadseni sp. nov., based upon a remarkably complete articulated skeleton and skull and a second specimen with an articulated skull and associated skeleton. The present study also assigns several other specimens to this new species, Allosaurus jimmadseni, which is characterized by a number of autapomorphies present on the dermal skull roof and additional characters present in the postcrania. In particular, whereas the ventral margin of the jugal of Allosaurus fragilis has pronounced sigmoidal convexity, the ventral margin is virtually straight in Allosaurus jimmadseni. The paired nasals of Allosaurus jimmadseni possess bilateral, blade-like crests along the lateral margin, forming a pronounced nasolacrimal crest that is absent in Allosaurus fragilis.
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Affiliation(s)
- Daniel J Chure
- Dinosaur National Monument (retired), Jensen, UT, USA.,Independent Researcher, Jensen, UT, USA
| | - Mark A Loewen
- Natural History Museum of Utah, University of Utah, Salt Lake City, UT, USA.,Department of Geology and Geophysics, University of Utah, Salt Lake City, UT, USA
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12
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Jentgen-Ceschino B, Stein K, Fischer V. Case study of radial fibrolamellar bone tissues in the outer cortex of basal sauropods. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190143. [PMID: 31928196 DOI: 10.1098/rstb.2019.0143] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The histology of sauropod long bones often appears uniform and conservative along their evolutionary tree. One of the main aspects of their bone histology is to exhibit a fibrolamellar complex in the cortex of their long bones. Here, we report another bone tissue, the radial fibrolamellar bone (RFB), in the outer cortex of the humeri of a young adult cf. Isanosaurus (Early to Late Jurassic, Thailand) and an adult Spinophorosaurus nigerensis (Early to Middle Jurassic, Niger) that do not exhibit any pathological feature on the bone surface. Its location within the cortex is unexpected, because RFB is a rapidly deposited bone tissue that would rather be expected early in the ontogeny. A palaeopathological survey was conducted for these sampled specimens. Observed RFB occurrences are regarded as spiculated periosteal reactive bone, which is an aggressive form of periosteal reaction. A 'hair-on-end' pattern of neoplasmic origin (resembling a Ewing's sarcoma) is favoured for cf. Isanosaurus, while a sunburst pattern of viral or neoplasmic origin (resembling an avian osteopetrosis or haemangioma) is favoured for Spinophorosaurus. This study highlights the importance of bone histology in assessing the frequency and nature of palaeopathologies. This article is part of the theme issue 'Vertebrate palaeophysiology'.
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Affiliation(s)
- Benjamin Jentgen-Ceschino
- Department of Geology, Université de Liège, 14 Allée du 6 Aout, Liège 4000, Belgium.,Earth System Science - AMGC, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - Koen Stein
- Earth System Science - AMGC, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium.,Royal Belgian Institute of Natural Sciences, Directorate 'Earth and History of Life', Rue Vautier 29, 1000 Brussels, Belgium
| | - Valentin Fischer
- Department of Geology, Université de Liège, 14 Allée du 6 Aout, Liège 4000, Belgium
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13
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Kato KM, Rega EA, Sidor CA, Huttenlocker AK. Investigation of a bone lesion in a gorgonopsian (Synapsida) from the Permian of Zambia and periosteal reactions in fossil non-mammalian tetrapods. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190144. [PMID: 31928188 DOI: 10.1098/rstb.2019.0144] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
While only distantly related to mammals, the anatomy of Permian gorgonopsians has shed light on the functional biology of non-mammalian synapsids and on the origins of iconic 'mammal-like' anatomical traits. However, little is known of gorgonopsian behaviour or physiology, which would aid in reconstructing the paleobiological context in which familiar mammalian features arose. Using multi-modal imaging, we report a discrete osseous lesion in the forelimb of a late Permian-aged gorgonopsian synapsid, recording reactive periosteal bone deposition and providing insights into the origins and diversity of skeletal healing responses in premammalian synapsids. We suggest that the localized lesion on the anterolateral (preaxial) shaft of the left radius represents acute periostitis and, conservatively, most likely developed as a subperiosteal haematoma with subsequent bone deposition and limited internal remodelling. The site records an inner zone of reactive cortical bone forming irregular to radial bony spicules and an outer, denser zone of slowed subperiosteal bone apposition, all of which likely occurred within a single growing season. In surveys of modern reptiles-crocodylians, varanids-such haematomas are rare compared to other documented osteopathologies. The extent and rapidity of the healing response is reminiscent of mammalian and dinosaurian bone pathologies, and may indicate differing behaviour or bone physiology compared to non-dinosaurian reptiles. This report adds to a growing list of putative disease entities recognized in early synapsids and broadens comparative baselines for pathologies and the evolution of bone response to disease in mammalian forebears. This article is part of the theme issue 'Vertebrate palaeophysiology'.
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Affiliation(s)
- Kyle M Kato
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089-0371, USA
| | - Elizabeth A Rega
- College of Osteopathic Medicine of the Pacific and the Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766-1854, USA
| | - Christian A Sidor
- Department of Biology and Burke Museum, University of Washington, Seattle, WA 98105, USA
| | - Adam K Huttenlocker
- Department of Integrative Anatomical Sciences, University of Southern California, Los Angeles, CA 90033, USA
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Tschopp E, Maidment SC, Lamanna MC, Norell MA. Reassessment of a Historical Collection of Sauropod Dinosaurs from the Northern Morrison Formation of Wyoming, with Implications for Sauropod Biogeography. BULLETIN OF THE AMERICAN MUSEUM OF NATURAL HISTORY 2019. [DOI: 10.1206/0003-0090.437.1.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Emanuel Tschopp
- American Museum of Natural History, Division of Paleontology, New York; Museu da Lourinhã, Lourinhã, Portugal
| | | | - Matthew C. Lamanna
- Section of Vertebrate Paleontology, Carnegie Museum of Natural History, Pittsburgh
| | - Mark A. Norell
- American Museum of Natural History, Division of Paleontology, New York
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15
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Hearn L, Williams ACDC. Pain in dinosaurs: what is the evidence? Philos Trans R Soc Lond B Biol Sci 2019; 374:20190370. [PMID: 31544618 DOI: 10.1098/rstb.2019.0370] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
How far back can we trace behaviour associated with pain? Behaviour is not preserved in the palaeontological record, so, for dinosaurs, we are restricted to what we can deduce from fossilized bones and tracks. This review is a thought experiment using circumstantial evidence from dinosaur fossils and from the behaviour of their extant relatives to describe probable responses of dinosaurs to serious injuries. Searches yielded 196 papers and chapters with: reports of healed serious injuries, and limping gait and injured feet in trackways; information about physiology and behaviour relevant to healing; evidence of evolutionary connections with birds and crocodilians, and their behaviour; and information about relevant aspects of evolution. Clearly, many dinosaurs survived injuries that would have seriously hampered mobility, impairing hunting or escape from predators, and affecting social interactions. Recovery from severe injuries implies pain-mediated responses. Rates of healing seem faster than for other reptiles, possibily aided by warm-bloodedness. Nesting was often communal, raising the possibility of parental and group protection for injured young. The existence of family groups, packs or herds raises the possibility of protection or feeding from pack kills. This is the first study, to our knowledge, of possible pain behaviour and responses to injury in dinosaurs. This article is part of the Theo Murphy meeting issue 'Evolution of mechanisms and behaviour important for pain'.
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Affiliation(s)
- Les Hearn
- Cochrane Pain, Palliative and Supportive Care Review Group, Oxford, UK
| | - Amanda C de C Williams
- Research Department of Clinical, Educational and Health Psychology, University College London, London, UK
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First Documented Pathologies in Tenontosaurus tilletti with Comments on Infection in Non-Avian Dinosaurs. Sci Rep 2019; 9:8705. [PMID: 31213629 PMCID: PMC6581885 DOI: 10.1038/s41598-019-45101-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 05/24/2019] [Indexed: 11/15/2022] Open
Abstract
In 2001, a nearly complete sub-adult Tenontosaurus tilletti was collected from the Antlers Formation (Aptian-Albian) of southeastern Oklahoma. Beyond its exceptional preservation, computed tomography (CT) and physical examination revealed this specimen has five pathological elements with four of the pathologies a result of trauma. Left pedal phalanx I-1 and left dorsal rib 10 are both fractured with extensive callus formation in the later stages of healing. Left dorsal rib 7 (L7) and right dorsal rib 10 (R10) exhibit impacted fractures compressed 26 mm and 24 mm, respectively. The fracture morphologies in L7 and R10 indicate this animal suffered a strong compressive force coincident with the long axis of the ribs. All three rib pathologies and the pathological left phalanx I-1 are consistent with injuries sustained in a fall. However, it is clear from the healing exhibited by these fractures that this individual survived the fall. In addition to traumatic fractures, left dorsal rib 10 and possibly left phalanx I-1 have a morphology consistent with post-traumatic infection in the form of osteomyelitis. The CT scans of left metacarpal IV revealed the presence of an abscess within the medullary cavity consistent with a subacute form of hematogenous osteomyelitis termed a Brodie abscess. This is only the second reported Brodie abscess in non-avian dinosaurs and the first documented occurrence in herbivorous dinosaurs. The presence of a Brodie abscess, known only in mammalian pathological literature, suggest mammalian descriptors for bone infection may be applicable to non-avian dinosaurs.
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Tschopp E, Mateus O. Osteology of Galeamopus pabsti sp. nov. (Sauropoda: Diplodocidae), with implications for neurocentral closure timing, and the cervico-dorsal transition in diplodocids. PeerJ 2017; 5:e3179. [PMID: 28480132 PMCID: PMC5417106 DOI: 10.7717/peerj.3179] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 03/14/2017] [Indexed: 11/20/2022] Open
Abstract
Diplodocids are among the best known sauropod dinosaurs. Numerous specimens of currently 15 accepted species belonging to ten genera have been reported from the Late Jurassic to Early Cretaceous of North and South America, Europe, and Africa. The highest diversity is known from the Upper Jurassic Morrison Formation of the western United States: a recent review recognized 12 valid, named species, and possibly three additional, yet unnamed ones. One of these is herein described in detail and referred to the genus Galeamopus. The holotype specimen of Galeamopus pabsti sp. nov., SMA 0011, is represented by material from all body parts but the tail, and was found at the Howe-Scott Quarry in the northern Bighorn Basin in Wyoming, USA. Autapomorphic features of the new species include a horizontal canal on the maxilla that connects the posterior margin of the preantorbital and the ventral margin of the antorbital fenestrae, a vertical midline groove marking the sagittal nuchal crest, the presence of a large foramen connecting the postzygapophyseal centrodiapophyseal fossa and the spinopostzygapophyseal fossa of mid- and posterior cervical vertebrae, a very robust humerus, a laterally placed, rugose tubercle on the concave proximal portion of the anterior surface of the humerus, a relatively stout radius, the absence of a distinct ambiens process on the pubis, and a distinctly concave posteroventral margin of the ascending process of the astragalus. In addition to the holotype specimen SMA 0011, the skull USNM 2673 can also be referred to Galeamopus pabsti. Histology shows that the type specimen SMA 0011 is sexually mature, although neurocentral closure was not completed at the time of death. Because SMA 0011 has highly pneumatized cervical vertebrae, the development of the lamination appears a more important indicator for individual age than neurocentral fusion patterns. SMA 0011 is one of very few sauropod specimens that preserves the cervico-dorsal transition in both vertebrae and ribs. The association of ribs with their respective vertebrae shows that the transition between cervical and dorsal vertebrae is significantly different in Galeamopus pabsti than in Diplodocus carnegii or Apatosaurus louisae, being represented by a considerable shortening of the centra from the last cervical to the first dorsal vertebra. Diplodocids show a surprisingly high diversity in the Morrison Formation. This can possibly be explained by a combination of geographical and temporal segregation, and niche partitioning.
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Affiliation(s)
- Emanuel Tschopp
- Dipartimento di Scienze della Terra, Università di Torino, Torino, Italy
- GeoBioTec, Faculdade de Ciencia e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
- Museu da Lourinhã, Lourinhã, Portugal
| | - Octávio Mateus
- GeoBioTec, Faculdade de Ciencia e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
- GeoBioTec + Departamento de Ciências da Terra, Faculdade de Ciencia e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
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18
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Anné J, Hedrick BP, Schein JP. First diagnosis of septic arthritis in a dinosaur. ROYAL SOCIETY OPEN SCIENCE 2016; 3:160222. [PMID: 27853597 PMCID: PMC5108947 DOI: 10.1098/rsos.160222] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 06/29/2016] [Indexed: 05/19/2023]
Abstract
Identification and interpretation of pathologies in the fossil record allows for unique insights into the life histories of extinct organisms. However, the rarity of such finds limits not only the sample size for palaeopathologic studies, but also the types of analyses that may be performed. In this study, we present the first occurrence of a palaeopathology in a vertebrate from the Mesozoic of the East Coast of North America (Appalachia), a pathologic ulna and radius of an indeterminate hadrosaur from the Navesink Formation (New Jersey). X-ray microtomography allowed for both detailed and more accurate diagnosis of the pathologic condition as well as virtual conservation of the specimen. Based on extant archosaurian comparisons, the hadrosaur was diagnosed with severe septic arthritis affecting the proximal ulna and radius. Diagnosis was based on erosion of the joint and highly reactive periosteal bone growth and fusion of the elements. To the best of our knowledge, this is the first recorded account of septic arthritis in dinosaurs. The severity of the pathology suggests the animal suffered with this condition for some time before death. Unfortunately, only the ulna and radius were found. Thus, the extent to which the condition spread to other parts of the body is unknown.
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Affiliation(s)
- Jennifer Anné
- School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Manchester M13 9PL, UK
- Author for correspondence: Jennifer Anné e-mail:
| | - Brandon P. Hedrick
- Department of Biology, University of Massachusetts Amherst, Amherst, MA 01003, USA
| | - Jason P. Schein
- Bureau of Natural History, New Jersey State Museum, Trenton, NJ 08625, USA
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19
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Vertebral Adaptations to Large Body Size in Theropod Dinosaurs. PLoS One 2016; 11:e0158962. [PMID: 27442509 PMCID: PMC4956032 DOI: 10.1371/journal.pone.0158962] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Accepted: 06/26/2016] [Indexed: 11/26/2022] Open
Abstract
Rugose projections on the anterior and posterior aspects of vertebral neural spines appear throughout Amniota and result from the mineralization of the supraspinous and interspinous ligaments via metaplasia, the process of permanent tissue-type transformation. In mammals, this metaplasia is generally pathological or stress induced, but is a normal part of development in some clades of birds. Such structures, though phylogenetically sporadic, appear throughout the fossil record of non-avian theropod dinosaurs, yet their physiological and adaptive significance has remained unexamined. Here we show novel histologic and phylogenetic evidence that neural spine projections were a physiological response to biomechanical stress in large-bodied theropod species. Metaplastic projections also appear to vary between immature and mature individuals of the same species, with immature animals either lacking them or exhibiting smaller projections, supporting the hypothesis that these structures develop through ontogeny as a result of increasing bending stress subjected to the spinal column. Metaplastic mineralization of spinal ligaments would likely affect the flexibility of the spinal column, increasing passive support for body weight. A stiff spinal column would also provide biomechanical support for the primary hip flexors and, therefore, may have played a role in locomotor efficiency and mobility in large-bodied species. This new association of interspinal ligament metaplasia in Theropoda with large body size contributes additional insight to our understanding of the diverse biomechanical coping mechanisms developed throughout Dinosauria, and stresses the significance of phylogenetic methods when testing for biological trends, evolutionary or not.
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Anné J, Garwood RJ, Lowe T, Withers PJ, Manning PL. Interpreting pathologies in extant and extinct archosaurs using micro-CT. PeerJ 2015; 3:e1130. [PMID: 26246971 PMCID: PMC4525691 DOI: 10.7717/peerj.1130] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 07/06/2015] [Indexed: 11/21/2022] Open
Abstract
Palaeopathology offers unique insight to the healing strategies of extinct organisms, permitting questions concerning bone physiology to be answered in greater depth. Unfortunately, most palaeopathological studies are confined to external morphological interpretations due to the destructive nature of traditional methods of study. This limits the degree of reliable diagnosis and interpretation possible. X-ray MicroTomography (micro-CT, XMT) provides a non-destructive means of analysing the internal three-dimensional structure of pathologies in both extant and extinct individuals, at higher resolutions than possible with medical scanners. In this study, we present external and internal descriptions of pathologies in extant and extinct archosaurs using XMT. This work demonstrates that the combination of external/internal diagnosis that X-ray microtomography facilitates is crucial when differentiating between pathological conditions. Furthermore, we show that the use of comparative species, both through direct analysis and from the literature, provides key information for diagnosing between vertebrate groups in the typical pathological conditions and physiological processes. Micro-CT imaging, combined with comparative observations of extant species, provides more detailed and reliable interpretation of palaeopathologies. Micro-CT is an increasingly accessible tool, which will provide key insights for correctly interpreting vertebrate pathologies in the future.
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Affiliation(s)
- Jennifer Anné
- School of Earth, Atmospheric and Environmental Sciences, University of Manchester , Manchester , UK
| | - Russell J Garwood
- School of Earth, Atmospheric and Environmental Sciences, University of Manchester , Manchester , UK
| | - Tristan Lowe
- Manchester X-ray Imaging Facility, School of Materials, University of Manchester , Manchester , UK
| | - Philip J Withers
- Manchester X-ray Imaging Facility, School of Materials, University of Manchester , Manchester , UK
| | - Phillip L Manning
- School of Earth, Atmospheric and Environmental Sciences, University of Manchester , Manchester , UK
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