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Myhrvold NP, Baumgart SL, Vidal D, Fish FE, Henderson DM, Saitta ET, Sereno PC. Diving dinosaurs? Caveats on the use of bone compactness and pFDA for inferring lifestyle. PLoS One 2024; 19:e0298957. [PMID: 38446841 PMCID: PMC10917332 DOI: 10.1371/journal.pone.0298957] [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: 06/18/2023] [Accepted: 01/31/2024] [Indexed: 03/08/2024] Open
Abstract
The lifestyle of spinosaurid dinosaurs has been a topic of lively debate ever since the unveiling of important new skeletal parts for Spinosaurus aegyptiacus in 2014 and 2020. Disparate lifestyles for this taxon have been proposed in the literature; some have argued that it was semiaquatic to varying degrees, hunting fish from the margins of water bodies, or perhaps while wading or swimming on the surface; others suggest that it was a fully aquatic underwater pursuit predator. The various proposals are based on equally disparate lines of evidence. A recent study by Fabbri and coworkers sought to resolve this matter by applying the statistical method of phylogenetic flexible discriminant analysis to femur and rib bone diameters and a bone microanatomy metric called global bone compactness. From their statistical analyses of datasets based on a wide range of extant and extinct taxa, they concluded that two spinosaurid dinosaurs (S. aegyptiacus, Baryonyx walkeri) were fully submerged "subaqueous foragers," whereas a third spinosaurid (Suchomimus tenerensis) remained a terrestrial predator. We performed a thorough reexamination of the datasets, analyses, and methodological assumptions on which those conclusions were based, which reveals substantial problems in each of these areas. In the datasets of exemplar taxa, we found unsupported categorization of taxon lifestyle, inconsistent inclusion and exclusion of taxa, and inappropriate choice of taxa and independent variables. We also explored the effects of uncontrolled sources of variation in estimates of bone compactness that arise from biological factors and measurement error. We found that the ability to draw quantitative conclusions is limited when taxa are represented by single data points with potentially large intrinsic variability. The results of our analysis of the statistical method show that it has low accuracy when applied to these datasets and that the data distributions do not meet fundamental assumptions of the method. These findings not only invalidate the conclusions of the particular analysis of Fabbri et al. but also have important implications for future quantitative uses of bone compactness and discriminant analysis in paleontology.
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Affiliation(s)
| | - Stephanie L. Baumgart
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, Illinois, United States of America
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Daniel Vidal
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, Illinois, United States of America
- Facultad de Ciencias, Departamento de Física Matemática y de Fluidos, Grupo de Biología Evolutiva, UNED, Madrid, Madrid, Spain
| | - Frank E. Fish
- Department of Biology, West Chester University, West Chester, Pennsylvania, United States of America
| | | | - Evan T. Saitta
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, Illinois, United States of America
| | - Paul C. Sereno
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, Illinois, United States of America
- Committee on Evolutionary Biology, University of Chicago, Chicago, Illinois, United States of America
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Souza GADE, Bulak BA, Soares MB, Sayão JM, Weinschütz LC, Batezelli A, Kellner AWA. The Cretaceous Neornithine record and new Vegaviidae specimens from the López de Bertodano Formation (Upper Maastrichthian) of Vega Island, Antarctic Peninsula. AN ACAD BRAS CIENC 2023; 95:e20230802. [PMID: 38088642 DOI: 10.1590/0001-3765202320230802] [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: 07/18/2023] [Accepted: 10/13/2023] [Indexed: 12/18/2023] Open
Abstract
A worldwide revision of the Cretaceous record of Neornithes (crown birds) revealed that unambiguous neornithine taxa are extremely scarce, with only a few showing diagnostic features to be confidently assigned to that group. Here we report two new neornithine specimens from Vega Island (López de Bertodano Formation). The first is a synsacrum (MN 7832-V) that shows a complex pattern of transversal diverticula intercepting the canalis synsacri, as in extant neornithines. Micro-CT scanning revealed a camerate pattern of trabeculae typical of neornithines. It further shows the oldest occurrence of lumbosacral canals in Neornithes, which are related to a balance sensing system acting in the control of walking and perching. The second specimen (MN 7833-V) is a distal portion of a tarsometatarsus sharing with Vegavis iaai a straight apical border of the crista plantaris lateralis. Osteohistologically the tarsometatarsus shows a thick and highly vascularized cortex that lacks any growth marks, resembling Polarornis gregorii. The cortex is osteosclerotic as in other extinct and extant diving neornithines. These new specimens increase the occurrences of the Cretaceous avian material recovered from the Upper Cretaceous strata of the James Ross Sub-Basin, suggesting that a Vegaviidae-dominated avian assemblage was present in the Antarctic Peninsula during the upper Maastrichtian.
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Affiliation(s)
- Geovane A DE Souza
- Programa de Pós-Graduação em Zoologia, Universidade Federal do Rio de Janeiro, Museu Nacional, Parque da Quinta da Boa Vista, s/n, São Cristóvão, 20940-040 Rio de Janeiro, RJ, Brazil
| | - Bruno A Bulak
- Universidade Federal do Rio de Janeiro, Museu Nacional, Laboratório de Sistemática e Tafonomia de Vertebrados Fósseis, Quinta da Boa Vista, s/n, São Cristóvão, 20940-040 Rio de Janeiro, RJ, Brazil
| | - Marina B Soares
- Universidade Federal do Rio de Janeiro, Museu Nacional, Laboratório de Sistemática e Tafonomia de Vertebrados Fósseis, Quinta da Boa Vista, s/n, São Cristóvão, 20940-040 Rio de Janeiro, RJ, Brazil
- Universidade Federal do Rio de Janeiro, Museu Nacional, Departamento de Geologia e Paleontologia, Laboratório de Paleobiologia e Paleogeografia Antártica, Parque da Quinta da Boa Vista, s/n, São Cristóvão, 20940-040 Rio de Janeiro, RJ, Brazil
| | - Juliana M Sayão
- Universidade Federal do Rio de Janeiro, Museu Nacional, Laboratório de Sistemática e Tafonomia de Vertebrados Fósseis, Quinta da Boa Vista, s/n, São Cristóvão, 20940-040 Rio de Janeiro, RJ, Brazil
- Universidade Federal do Rio de Janeiro, Museu Nacional, Departamento de Geologia e Paleontologia, Laboratório de Paleobiologia e Paleogeografia Antártica, Parque da Quinta da Boa Vista, s/n, São Cristóvão, 20940-040 Rio de Janeiro, RJ, Brazil
| | - Luiz Carlos Weinschütz
- Centro de Pesquisa Paleontológica da UNC (CENPALEO), Universidade do Contestado, Av. Nereu Ramos, 89300-000 Mafra, SC, Brazil
| | - Alessandro Batezelli
- Universidade Estadual de Campinas, Instituto de Geociências, Departamento de Geologia e Recursos Naturais, Rua João Pandiá Calógeras, 51, Barão Geraldo, 13083-870 Campinas, SP, Brazil
| | - Alexander W A Kellner
- Universidade Federal do Rio de Janeiro, Museu Nacional, Laboratório de Sistemática e Tafonomia de Vertebrados Fósseis, Quinta da Boa Vista, s/n, São Cristóvão, 20940-040 Rio de Janeiro, RJ, Brazil
- Universidade Federal do Rio de Janeiro, Museu Nacional, Departamento de Geologia e Paleontologia, Laboratório de Paleobiologia e Paleogeografia Antártica, Parque da Quinta da Boa Vista, s/n, São Cristóvão, 20940-040 Rio de Janeiro, RJ, Brazil
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Chinsamy A. Palaeoecological deductions from osteohistology. Biol Lett 2023; 19:20230245. [PMID: 37607578 PMCID: PMC10444344 DOI: 10.1098/rsbl.2023.0245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 07/31/2023] [Indexed: 08/24/2023] Open
Abstract
Palaeoecological deductions are vital for understanding the evolution and diversification of species within prehistoric environments. This review highlights the multitude of ways in which the microanatomy and microscopic structure of bones enables palaeoecological deductions. The occurrence of growth marks in bones is discussed, and their usefulness in deducing the ontogenetic status and age of individuals is considered, as well as how such marks in bones permit the assessment of the growth dynamics of individuals and species. Here osteohistology is shown to provide insight into the structure of past populations, as well as ecological relationships between individuals. In addition, the response of bones to trauma, disease and moulting is considered. Finally, I explore how osteohistology can give insight into ecomorphological adaptations, such as filter feeding, probe feeding and saltatorial locomotion. Methodological advances in three-dimensional microtomography and synchrotron scanning bodes well for future studies in osteohistology and despite some compromises in terms of tissue identity, circumvents the crucial issue of destructive analyses.
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Affiliation(s)
- Anusuya Chinsamy
- Department of Biological Sciences, University of Cape Town, John Day Building, University Avenue, Rondebosch 7700, South Africa
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Bhat MS, Chinsamy A, Parkington J. Bone histology of Neogene angulate tortoises (Testudines: Testudinidae) from South Africa: palaeobiological and skeletochronological implications. ROYAL SOCIETY OPEN SCIENCE 2023; 10:230064. [PMID: 36908987 PMCID: PMC9993054 DOI: 10.1098/rsos.230064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 02/14/2023] [Indexed: 06/18/2023]
Abstract
Here we examine the tibial microstructure of modern and fossil angulate tortoises to assess the histology and growth from the late Miocene-early Pliocene, Pleistocene through to modern forms. The cross-sections of all the tibiae sampled revealed highly vascularized, uninterrupted, fibrolamellar bone tissue during early ontogeny, which suggests that early growth was fast. However, later in ontogeny, growth was slower, as indicated by the deposition of parallel-fibred bone tissue in the outer cortex, and even ceased periodically, as indicated by lines of arrested growth. Comparative analyses of the growth rates of the tortoises from different time periods showed that the tortoises from the late Miocene-early Pliocene Langebaanweg locality and from Diepkloof Rock Shelter had relatively slower growth rates under less optimal growth conditions. Additionally, these prehistoric specimens show extensive remodelling, and several generations of secondary osteons further suggest functional and/or metabolic stresses on the skeleton. Palaeoenvironmental reconstructions suggest that it was mostly cooler and drier with seasonal fluctuations in late Miocene-early Pliocene, and it is likely that Chersina responded to these conditions by having a lower rate of growth as compared with their modern counterparts, which thrive in the current prevailing more favourable Mediterranean type of climate.
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Affiliation(s)
- Mohd Shafi Bhat
- Department of Biological Sciences, University of Cape Town, Private Bag X3, Rhodes Gift 7701, South Africa
| | - Anusuya Chinsamy
- Department of Biological Sciences, University of Cape Town, Private Bag X3, Rhodes Gift 7701, South Africa
| | - John Parkington
- Department of Archaeology, University of Cape Town, Private Bag X3, Rhodes Gift 7701, South Africa
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Chinsamy A, Handley WD, Worthy TH. Osteohistology of
Dromornis stirtoni
(Aves: Dromornithidae) and the biological implications of the bone histology of the Australian mihirung birds. Anat Rec (Hoboken) 2022. [DOI: 10.1002/ar.25047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Anusuya Chinsamy
- Department of Biological Sciences University of Cape Town Rondebosch South Africa
| | - Warren D. Handley
- Palaeontology Group, College of Science and Engineering Flinders University Adelaide South Australia Australia
| | - Trevor H. Worthy
- Palaeontology Group, College of Science and Engineering Flinders University Adelaide South Australia Australia
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