1
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Evers SW, Al Iawati Z. Digital skull anatomy of the Oligocene North American tortoise Stylemys nebrascensis with taxonomic comments on the species and comparisons with extant testudinids of the Gopherus- Manouria clade. SWISS JOURNAL OF PALAEONTOLOGY 2024; 143:12. [PMID: 38455968 PMCID: PMC10914918 DOI: 10.1186/s13358-024-00311-y] [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: 11/22/2023] [Accepted: 02/12/2024] [Indexed: 03/09/2024]
Abstract
The anatomy of North American tortoises is poorly understood, despite a rich fossil record from the Eocene and younger strata. Stylemys nebrascensis is a particularly noteworthy turtle in this regard, as hundreds of specimens are known from Oligocene deposits, and as this species is one of the earliest fossil turtles to have been described in the scientific literature. Since its initial description based on a shell, many specimens with more complete material have been referred to Stylemys nebrascensis. Here, we review and confirm the referral of an important historic specimen to Stylemys nebrascensis, which includes shell, non-shell postcranial, and skull material. This allows us to document unique skull features of Stylemys nebrascensis (e.g., an unusual 'poststapedial canal' that connects the posterior skull surface with the cavum acustico-jugulare) and to refer another well-preserved skull to the species. Based on computed-tomography scanning of these two skulls, we provide a detailed description of the cranial and mandibular osteology of Stylemys nebrascensis. Stylemys nebrascensis has a combination of plesiomorphic skull characteristics (e.g., retention of a medial jugal process) and derived traits shared with extant gopher tortoises (e.g., median premaxillary ridge) that suggest it may be a stem-representative of the gopher tortoise lineage. This supports the hypothesis that extant and fossil tortoises from North America form a geographically restricted clade that split from Asian relatives during the Paleogene.
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Affiliation(s)
- Serjoscha W. Evers
- Department of Geosciences, University of Fribourg, Fribourg, Switzerland
| | - Zahra Al Iawati
- GeoZentrum Nordbayern, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
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2
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Schwab JA, Figueirido B, Martín-Serra A, van der Hoek J, Flink T, Kort A, Esteban Núñez JM, Jones KE. Evolutionary ecomorphology for the twenty-first century: examples from mammalian carnivores. Proc Biol Sci 2023; 290:20231400. [PMID: 38018109 PMCID: PMC10685142 DOI: 10.1098/rspb.2023.1400] [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: 06/21/2023] [Accepted: 11/06/2023] [Indexed: 11/30/2023] Open
Abstract
Carnivores (cats, dogs and kin) are a diverse group of mammals that inhabit a remarkable range of ecological niches. While the relationship between ecology and morphology has long been of interest in carnivorans, the application of quantitative techniques has resulted in a recent explosion of work in the field. Therefore, they provide a case study of how quantitative techniques, such as geometric morphometrics (GMM), have impacted our ability to tease apart complex ecological signals from skeletal anatomy, and the implications for our understanding of the relationships between form, function and ecological specialization. This review provides a synthesis of current research on carnivoran ecomorphology, with the goal of illustrating the complex interaction between ecology and morphology in the skeleton. We explore the ecomorphological diversity across major carnivoran lineages and anatomical systems. We examine cranial elements (skull, sensory systems) and postcranial elements (limbs, vertebral column) to reveal mosaic patterns of adaptation related to feeding and hunting strategies, locomotion and habitat preference. We highlight the crucial role that new approaches have played in advancing our understanding of carnivoran ecomorphology, while addressing challenges that remain in the field, such as ecological classifications, form-function relationships and multi-element analysis, offering new avenues for future research.
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Affiliation(s)
- Julia A. Schwab
- Department of Earth and Environmental Sciences, University of Manchester, M13 9PL Manchester, UK
| | - Borja Figueirido
- Departamento de Ecología y Geología, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
| | - Alberto Martín-Serra
- Departamento de Ecología y Geología, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
| | - Julien van der Hoek
- Department of Earth and Environmental Sciences, University of Manchester, M13 9PL Manchester, UK
| | - Therese Flink
- Department of Palaeobiology, Swedish Museum of Natural History, PO Box 50007, 10405 Stockholm, Sweden
| | - Anne Kort
- Department of Earth and Atmospheric Sciences, Indiana University Bloomington, 1001 E 10th St, Bloomington, IN, USA
- Department of Earth and Environmental Sciences, University of Michigan, 1100 N University Ave, Ann Arbor, MI 48109, USA
| | | | - Katrina E. Jones
- Department of Earth and Environmental Sciences, University of Manchester, M13 9PL Manchester, UK
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3
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Chapuis L, Yopak KE, Radford CA. From the morphospace to the soundscape: Exploring the diversity and functional morphology of the fish inner ear, with a focus on elasmobranchsa). THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2023; 154:1526-1538. [PMID: 37695297 DOI: 10.1121/10.0020850] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Accepted: 08/21/2023] [Indexed: 09/12/2023]
Abstract
Fishes, including elasmobranchs (sharks, rays, and skates), present an astonishing diversity in inner ear morphologies; however, the functional significance of these variations and how they confer auditory capacity is yet to be resolved. The relationship between inner ear structure and hearing performance is unclear, partly because most of the morphological and biomechanical mechanisms that underlie the hearing functions are complex and poorly known. Here, we present advanced opportunities to document discontinuities in the macroevolutionary trends of a complex biological form, like the inner ear, and test hypotheses regarding what factors may be driving morphological diversity. Three-dimensional (3D) bioimaging, geometric morphometrics, and finite element analysis are methods that can be combined to interrogate the structure-to-function links in elasmobranch fish inner ears. In addition, open-source 3D morphology datasets, advances in phylogenetic comparative methods, and methods for the analysis of highly multidimensional shape data have leveraged these opportunities. Questions that can be explored with this toolkit are identified, the different methods are justified, and remaining challenges are highlighted as avenues for future work.
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Affiliation(s)
- L Chapuis
- School of Biological Sciences, University of Bristol, Bristol BS8 1TQ, United Kingdom
| | - K E Yopak
- Department of Biology and Marine Biology, Centre for Marine Science, University of North Carolina Wilmington, Wilmington, North Carolina 28403, USA
| | - C A Radford
- Leigh Marine Laboratory, Institute of Marine Science, University of Auckland, Leigh 0985, New Zealand
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4
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Laboury A, Scheyer TM, Klein N, Stubbs TL, Fischer V. High phenotypic plasticity at the dawn of the eosauropterygian radiation. PeerJ 2023; 11:e15776. [PMID: 37671356 PMCID: PMC10476616 DOI: 10.7717/peerj.15776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 06/29/2023] [Indexed: 09/07/2023] Open
Abstract
The initial radiation of Eosauropterygia during the Triassic biotic recovery represents a key event in the dominance of reptiles secondarily adapted to marine environments. Recent studies on Mesozoic marine reptile disparity highlighted that eosauropterygians had their greatest morphological diversity during the Middle Triassic, with the co-occurrence of Pachypleurosauroidea, Nothosauroidea and Pistosauroidea, mostly along the margins of the Tethys Ocean. However, these previous studies quantitatively analysed the disparity of Eosauropterygia as a whole without focussing on Triassic taxa, thus limiting our understanding of their diversification and morphospace occupation during the Middle Triassic. Our multivariate morphometric analyses highlight a clearly distinct colonization of the ecomorphospace by the three clades, with no evidence of whole-body convergent evolution with the exception of the peculiar pistosauroid Wangosaurus brevirostris, which appears phenotypically much more similar to nothosauroids. This global pattern is mostly driven by craniodental differences and inferred feeding specializations. We also reveal noticeable regional differences among nothosauroids and pachypleurosauroids of which the latter likely experienced a remarkable diversification in the eastern Tethys during the Pelsonian. Our results demonstrate that the high phenotypic plasticity characterizing the evolution of the pelagic plesiosaurians was already present in their Triassic ancestors, casting eosauropterygians as particularly adaptable animals.
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Affiliation(s)
- Antoine Laboury
- Evolution & Diversity Dynamics Lab, Université de Liège, Liège, Belgium
| | | | - Nicole Klein
- Institute of Geosciences, Paleontology, University of Bonn, Bonn, Germany
| | - Thomas L. Stubbs
- School of Life, Health & Chemical Sciences, Open University, Milton Keynes, United Kingdom
| | - Valentin Fischer
- Evolution & Diversity Dynamics Lab, Université de Liège, Liège, Belgium
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5
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Engelschiøn VS, Roberts AJ, With R, Hammer Ø. Exceptional X-Ray contrast: Radiography imaging of a Middle Triassic mixosaurid from Svalbard. PLoS One 2023; 18:e0285939. [PMID: 37256843 DOI: 10.1371/journal.pone.0285939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 05/05/2023] [Indexed: 06/02/2023] Open
Abstract
The black shales of the Middle Triassic Botneheia Formation in Svalbard are known for their fossil richness with abundant ichthyosaur remains and beds of the bivalve Daonella. Vertebrate remains from the Muen Mountain on Edgeøya are shown to have exceptional X-ray contrast due to a combination of sulphide and sulphate permineralisation and pseudomorphing. Radiography imaging of a previously described specimen, PMO 219.250, revealed new and spectacular details such as more carpals, teeth, and skull sutures. Teeth and skull characters are taxonomically significant. supporting the referral of PMO 219.250 to Phalarodon and further suggesting an affinity to P. atavus. Three sulphur phases were identified, with the sulphide sphalerite (ZnS) being the highest temperature phase, followed by the sulphate baryte (BaSO4), and the sulphide pyrite (FeS2). Sulphate permineralisation is also seen in specimens from the Upper Jurassic on Svalbard. We suggest that sulphur-rich fluids have flowed and dissolved barium from the shales and deposited the sphalerite and baryte, and that this could be linked to the Cretaceous HALIP. The Jurassic specimens are only permineralised by baryte, while the Triassic specimens have also been permineralised, but mainly pseudomorphed by baryte with crystals of sphalerite. Lithology differences appear to have controlled the compaction of the Triassic specimens, while the Jurassic specimens have retained their three-dimensional shape due to the baryte emplacement relatively earlier in their depositional history. Although soft tissues are not preserved, the excellent X-ray contrast in the Middle Triassic specimens is reminiscent of pyritised fossil sites such as the Hunsrück Slate (Devonian), Beecher's Trilobite Bed (Ordovician), and the La Voulte-sur-Rhône marls (Jurassic).
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Affiliation(s)
| | - Aubrey J Roberts
- Natural History Museum, University of Oslo, Oslo, Norway
- Department of Earth Science, Natural History Museum, London, United Kingdom
| | - Ruben With
- Museum of Cultural History, University of Oslo, Oslo, Norway
| | - Øyvind Hammer
- Natural History Museum, University of Oslo, Oslo, Norway
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6
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Neuroanatomical Study and Three-Dimensional Cranial Reconstruction of the Brazilian Albian Pleurodiran Turtle Euraxemys essweini. DIVERSITY 2023. [DOI: 10.3390/d15030374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
Abstract
The Pleurodira represent one of the two clades that compose the crown Testudines, and their temporal range is Late Jurassic–present. However, knowledge about the neuroanatomy of extinct pleurodires is still very limited. In this context, scarce neuroanatomical information about the Cretaceous clade Euraxemydidae is currently available, limited to some characters of the Moroccan Cenomanian Dirqadim schaefferi. In the present work, we perform the detailed neuroanatomical study of its sister taxon, the Brazilian Albian Euraxemys essweini, based on the analysis of the skull of its holotype and only known individual of the species. The detailed virtual three-dimensional reconstruction of all its cranial bones is performed, also improving the information about its osseous anatomy. The different neuroanatomical cavities (i.e., cranial, nasal, and labyrinthic ones) and canals (i.e., nervous and circulatory ones) are compared with those identified thus far for other extinct and extant members of the Pleurodira in order to characterize the neuroanatomy of the extinct clade Euraxemydidae in detail.
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7
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Barker CT, Naish D, Trend J, Michels LV, Witmer L, Ridgley R, Rankin K, Clarkin CE, Schneider P, Gostling NJ. Modified skulls but conservative brains? The palaeoneurology and endocranial anatomy of baryonychine dinosaurs (Theropoda: Spinosauridae). J Anat 2023; 242:1124-1145. [PMID: 36781174 PMCID: PMC10184548 DOI: 10.1111/joa.13837] [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: 11/10/2022] [Revised: 01/17/2023] [Accepted: 01/17/2023] [Indexed: 02/15/2023] Open
Abstract
The digital reconstruction of neurocranial endocasts has elucidated the gross brain structure and potential ecological attributes of many fossil taxa, including Irritator, a spinosaurine spinosaurid from the "mid" Cretaceous (Aptian) of Brazil. With unexceptional hearing capabilities, this taxon was inferred to integrate rapid and controlled pitch-down movements of the head that perhaps aided in the predation of small and agile prey such as fish. However, the neuroanatomy of baryonychine spinosaurids remains to be described, and potentially informs on the condition of early spinosaurids. Using micro-computed tomographic scanning (μCT), we reconstruct the braincase endocasts of Baryonyx walkeri and Ceratosuchops inferodios from the Wealden Supergroup (Lower Cretaceous) of England. We show that the gross endocranial morphology is similar to other non-maniraptoriform theropods, and corroborates previous observations of overall endocranial conservatism amongst more basal theropods. Several differences of unknown taxonomic utility are noted between the pair. Baryonychine neurosensory capabilities include low-frequency hearing and unexceptional olfaction, whilst the differing morphology of the floccular lobe tentatively suggests less developed gaze stabilisation mechanisms relative to spinosaurines. Given the morphological similarities observed with other basal tetanurans, baryonychines likely possessed comparable behavioural sophistication, suggesting that the transition from terrestrial hypercarnivorous ancestors to semi-aquatic "generalists" during the evolution of Spinosauridae did not require substantial modification of the brain and sensory systems.
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Affiliation(s)
- Chris Tijani Barker
- Institute for Life Sciences, University of Southampton, University Road, Southampton, UK.,Faculty of Engineering and Physical Sciences, University of Southampton, University Road, Southampton, UK
| | - Darren Naish
- School of Biological Sciences, Faculty of Environment and Life Sciences, University of Southampton, University Road, Southampton, UK
| | - Jacob Trend
- School of Biological Sciences, Faculty of Environment and Life Sciences, University of Southampton, University Road, Southampton, UK
| | - Lysanne Veerle Michels
- School of Biological Sciences, Faculty of Environment and Life Sciences, University of Southampton, University Road, Southampton, UK
| | - Lawrence Witmer
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio Center for Ecology and Evolutionary Studies, Ohio University, Athens, Ohio, USA
| | - Ryan Ridgley
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio Center for Ecology and Evolutionary Studies, Ohio University, Athens, Ohio, USA
| | - Katy Rankin
- μ-VIS X-ray Imaging Centre, Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, UK
| | - Claire E Clarkin
- School of Biological Sciences, Faculty of Environment and Life Sciences, University of Southampton, University Road, Southampton, UK
| | - Philipp Schneider
- Bioengineering Science Research Group, Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, UK.,High-Performance Vision Systems, Center for Vision, Automation and Control, AIT Austrian Institute of Technology, Vienna, Austria
| | - Neil J Gostling
- Institute for Life Sciences, University of Southampton, University Road, Southampton, UK.,School of Biological Sciences, Faculty of Environment and Life Sciences, University of Southampton, University Road, Southampton, UK
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8
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Lessner EJ, Dollman KN, Clark JM, Xu X, Holliday CM. Ecomorphological patterns in trigeminal canal branching among sauropsids reveal sensory shift in suchians. J Anat 2023; 242:927-952. [PMID: 36680380 PMCID: PMC10093182 DOI: 10.1111/joa.13826] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 01/03/2023] [Accepted: 01/03/2023] [Indexed: 01/22/2023] Open
Abstract
The vertebrate trigeminal nerve is the primary mediator of somatosensory information from nerve endings across the face, extending nerve branches through bony canals in the face and mandibles, terminating in sensory receptors. Reptiles evolved several extreme forms of cranial somatosensation in which enhanced trigeminal tissues are present in species engaging in unique mechanosensory behaviors. However, morphology varies by clade and ecology among reptiles. Few lineages approach the extreme degree of tactile somatosensation possessed by crocodylians, the only remaining members of a clade that underwent an ecological transition from the terrestrial to semiaquatic habitat, also evolving a specialized trigeminal system. It remains to be understood how trigeminal osteological correlates inform how adaptations for enhanced cranial sensation evolved in crocodylians. Here we identify an increase in sensory abilities in Early Jurassic crocodylomorphs, preceding the transitions to a semiaquatic habitat. Through quantification of trigeminal neurovascular canal branching patterns in an extant phylogenetic bracket we quantify and identify morphologies associated with sensory behaviors in representative fossil taxa, we find stepwise progression of increasing neurovascular canal density, complexity, and distribution from the primitive archosaurian to the derived crocodilian condition. Model-based inferences of sensory ecologies tested on quantified morphologies of extant taxa with known sensory behaviors indicate a parallel increase in sensory abilities among pseudosuchians. These findings establish patterns of reptile trigeminal ecomorphology, revealing evolutionary patterns of somatosensory ecology.
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Affiliation(s)
- Emily J Lessner
- Department of Pathology and Anatomical Sciences, University of Missouri, Columbia, Missouri, USA
| | | | - James M Clark
- Department of Biological Sciences, George Washington University, Washington, District of Columbia, USA
| | - Xing Xu
- Centre for Vertebrate Evolutionary Biology, Yunnan University, Kunming, China.,Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China
| | - Casey M Holliday
- Department of Pathology and Anatomical Sciences, University of Missouri, Columbia, Missouri, USA
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9
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Abstract
The labyrinth of the vertebrate inner ear is a sensory system that governs the perception of head rotations. Central hypotheses predict that labyrinth shape and size are related to ecological adaptations, but this is under debate and has rarely been tested outside of mammals. We analyze the evolution of labyrinth morphology and its ecological drivers in living and fossil turtles, an understudied group that underwent multiple locomotory transitions during 230 million years of evolution. We show that turtles have unexpectedly large labyrinths that evolved during the origin of aquatic habits. Turtle labyrinths are relatively larger than those of mammals, and comparable to many birds, undermining the hypothesis that labyrinth size correlates directly with agility across vertebrates. We also find that labyrinth shape variation does not correlate with ecology in turtles, undermining the widespread expectation that reptilian labyrinth shapes convey behavioral signal, and demonstrating the importance of understudied groups, like turtles. The size and shape of the inner ear, or bony labyrinth, is thought to be related to ecological adaptations in vertebrates. Here, the authors examine this relationship in turtles across 230 million years of evolution, unexpectedly finding large labyrinth size and no association with ecology.
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10
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Hanson M, Hoffman EA, Norell MA, Bhullar BAS. Response to Comment on "The early origin of a birdlike inner ear and the evolution of dinosaurian movement and vocalization". Science 2022; 376:eabl8181. [PMID: 35737783 DOI: 10.1126/science.abl8181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
David et al. claim that vestibular shape does not reflect function and that we did not use phylogenetic inference methods in our primary analyses. We show that their claims are countered by comparative and direct experimental evidence from across Vertebrata and that their models are empirically unverified. We did use phylogenetic methods to test our hypotheses. Moreover, their phylogenetic correction attempts are methodologically inappropriate.
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Affiliation(s)
- Michael Hanson
- Department of Earth and Planetary Sciences, Yale University, New Haven, CT, USA.,Peabody Museum of Natural History, Yale University, New Haven, CT, USA
| | - Eva A Hoffman
- Division of Paleontology, American Museum of Natural History, New York, NY, USA
| | - Mark A Norell
- Division of Paleontology, American Museum of Natural History, New York, NY, USA
| | - Bhart-Anjan S Bhullar
- Department of Earth and Planetary Sciences, Yale University, New Haven, CT, USA.,Peabody Museum of Natural History, Yale University, New Haven, CT, USA
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11
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Schwab JA, Young MT, Walsh SA, Witmer LM, Herrera Y, Brochu CA, Butler IB, Brusatte SL. Ontogenetic variation in the crocodylian vestibular system. J Anat 2022; 240:821-832. [PMID: 34841534 PMCID: PMC9005688 DOI: 10.1111/joa.13601] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 10/29/2021] [Accepted: 11/19/2021] [Indexed: 01/20/2023] Open
Abstract
Crocodylians today live in tropical to subtropical environments, occupying mostly shallow waters. Their body size changes drastically during ontogeny, as do their skull dimensions and bite forces, which are associated with changes in prey preferences. Endocranial neurosensory structures have also shown to change ontogenetically, but less is known about the vestibular system of the inner ear. Here we use 30 high-resolution computed tomography (CT) scans and three-dimensional geometric morphometrics to investigate the size and shape changes of crocodylian endosseous labyrinths throughout ontogeny, across four stages (hatchling, juvenile, subadult and adult). We find two major patterns of ontogenetic change. First, the labyrinth increases in size during ontogeny, with negative allometry in relation to skull size. Second, labyrinth shape changes significantly, with hatchlings having shorter semicircular canal radii, with thicker diameters and an overall dorsoventrally shorter labyrinth than those of more mature individuals. We argue that the modification of the labyrinth during crocodylian ontogeny is related to constraints imposed by skull growth, due to fundamental changes in the crocodylian braincase during ontogeny (e.g. verticalisation of the basicranium), rather than changes in locomotion, diet, or other biological functions or behaviours.
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Affiliation(s)
- Julia A. Schwab
- School of GeoSciencesGrant InstituteUniversity of EdinburghEdinburghUK
| | - Mark T. Young
- School of GeoSciencesGrant InstituteUniversity of EdinburghEdinburghUK
| | - Stig A. Walsh
- School of GeoSciencesGrant InstituteUniversity of EdinburghEdinburghUK
- National Museum of ScotlandEdinburghUK
| | - Lawrence M. Witmer
- Department of Biomedical SciencesHeritage College of Osteopathic MedicineOhio Center for Ecology and Evolutionary StudiesOhio UniversityAthensOhioUSA
| | - Yanina Herrera
- CONICET. División Paleontología VertebradosMuseo de La Plata, FCNyMUNLPLa PlataArgentina
| | | | - Ian B. Butler
- School of GeoSciencesGrant InstituteUniversity of EdinburghEdinburghUK
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12
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Schwab JA, Young MT, Walsh SA, Witmer LM, Herrera Y, Timmons ZL, Butler IB, Brusatte SL. 'Ear stones' in crocodylians: a cross-species comparative and ontogenetic survey of otolith structures. ROYAL SOCIETY OPEN SCIENCE 2022; 9:211633. [PMID: 35345438 PMCID: PMC8941411 DOI: 10.1098/rsos.211633] [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: 10/14/2021] [Accepted: 02/25/2022] [Indexed: 05/03/2023]
Abstract
The vestibular system of the inner ear is a crucial sensory organ, involved in the sensation of balance and equilibrium. It consists of three semicircular canals that sense angular rotations of the head and the vestibule that detects linear acceleration and gravity. The vestibule often contains structures, known as the otoliths or 'ear stones'. Otoliths are present in many vertebrates and are particularly well known from the fossil record of fish, but surprisingly have not been described in detail in most tetrapods, living or extinct. Here, we present for the first time a survey of the otoliths of a broad sample of extant crocodylian species, based on computed tomography scans. We find that otoliths are present in numerous crocodylian species of different growth stages, and they continue to increase in size during ontogeny, with positive allometry compared to skull length. Our results confirm that otoliths are a common component of the crocodylian vestibular system, and suggest they play an important role in sensory detection. Otoliths are likely common, but overlooked, constituents of the inner ear in tetrapods, and a broader study of their size, shape and distribution promises insight into sensory abilities.
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Affiliation(s)
- Julia A. Schwab
- School of GeoSciences, Grant Institute, University of Edinburgh, James Hutton Road, The King's Buildings, Edinburgh EH9 3FE, UK
| | - Mark T. Young
- School of GeoSciences, Grant Institute, University of Edinburgh, James Hutton Road, The King's Buildings, Edinburgh EH9 3FE, UK
| | - Stig A. Walsh
- School of GeoSciences, Grant Institute, University of Edinburgh, James Hutton Road, The King's Buildings, Edinburgh EH9 3FE, UK
- National Museum of Scotland, Chambers Street, Edinburgh EH 1 1JF, UK
| | - Lawrence M. Witmer
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA
| | - Yanina Herrera
- CONICET. División Paleontología Vertebrados, Museo de La Plata, FCNyM, UNLP, La Plata, Argentina
| | - Zena L. Timmons
- National Museum of Scotland, Chambers Street, Edinburgh EH 1 1JF, UK
| | - Ian B. Butler
- School of GeoSciences, Grant Institute, University of Edinburgh, James Hutton Road, The King's Buildings, Edinburgh EH9 3FE, UK
| | - Stephen L. Brusatte
- School of GeoSciences, Grant Institute, University of Edinburgh, James Hutton Road, The King's Buildings, Edinburgh EH9 3FE, UK
- National Museum of Scotland, Chambers Street, Edinburgh EH 1 1JF, UK
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13
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Schade M, Knötschke N, Hörnig MK, Paetzel C, Stumpf S. Neurovascular anatomy of dwarf dinosaur implies precociality in sauropods. eLife 2022; 11:82190. [PMID: 36537069 PMCID: PMC9767461 DOI: 10.7554/elife.82190] [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: 07/26/2022] [Accepted: 11/11/2022] [Indexed: 12/24/2022] Open
Abstract
Macronaria, a group of mostly colossal sauropod dinosaurs, comprised the largest terrestrial vertebrates of Earth's history. However, some of the smallest sauropods belong to this group as well. The Late Jurassic macronarian island dwarf Europasaurus holgeri is one of the most peculiar and best-studied sauropods worldwide. So far, the braincase material of this taxon from Germany pended greater attention. With the aid of micro-computed tomography (microCT), we report on the neuroanatomy of the nearly complete braincase of an adult individual, as well as the inner ears (endosseous labyrinths) of one other adult and several juveniles (the latter also containing novel vascular cavities). The presence of large and morphologically adult inner ears in juvenile material suggests precociality. Our findings add to the diversity of neurovascular anatomy in sauropod braincases and buttress the perception of sauropods as fast-growing and autonomous giants with manifold facets of reproductive and social behaviour. This suggests that - apart from sheer size - little separated Europasaurus from its large-bodied relatives.
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Affiliation(s)
- Marco Schade
- University of Greifswald, Institute of Geography and Geology, Palaeontology and HistoricalGreifswaldGermany,University of Greifswald, Zoological Institute and Museum, Cytology and Evolutionary BiologyGreifswaldGermany
| | | | - Marie K Hörnig
- University of Greifswald, Zoological Institute and Museum, Cytology and Evolutionary BiologyGreifswaldGermany
| | - Carina Paetzel
- University of Greifswald, Zoological Institute and Museum, Cytology and Evolutionary BiologyGreifswaldGermany
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14
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Lanzetti A, Crouch N, Portela Miguez R, Fernandez V, Goswami A. Developing echolocation: distinctive patterns in the ontogeny of the tympanoperiotic complex in baleen and toothed whales (Cetacea). Biol J Linn Soc Lond 2021. [DOI: 10.1093/biolinnean/blab160] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Abstract
Cetaceans (baleen and toothed whales) present a unique set of adaptations for life in water. Among other abilities, the two living groups can hear and produce different sound frequencies: baleen whales use low frequencies primarily for communication, whereas toothed whales acquired the ability to echolocate using high-frequency sounds. Both groups exhibit modifications to the morphology of the ear bones (tympanic bulla and periotic) that closely track their behaviour and ecology. The evolution of sound reception in whales is being investigated thoroughly, whereas the changes in prenatal development (ontogeny) that generate these disparate ear bone morphologies remain mostly unknown. In this study, we characterize the ontogeny of the ear bones in Cetacea by looking at the progression of ossification and associated changes in morphology using a combination of traditional measurements and an innovative landmark-free method to quantify shape on a newly assembled three-dimensional dataset spanning the ontogeny and phylogeny of extant Cetacea. We have found that the two groups of Cetacea share some aspects of ear ontogeny, such as a common growth trajectory of the periotic. However, differences in ossification, allometry and growth trajectory, particularly in the periotic bone, reflect their divergent inner ear morphology and hearing abilities.
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Affiliation(s)
- Agnese Lanzetti
- Department of Life Sciences, Natural History Museum, Cromwell Road, Kensington, London, UK
| | - Natasha Crouch
- Department of Life Sciences, Natural History Museum, Cromwell Road, Kensington, London, UK
| | - Roberto Portela Miguez
- Department of Life Sciences, Natural History Museum, Cromwell Road, Kensington, London, UK
| | - Vincent Fernandez
- Imaging and Analysis Centre, Natural History Museum, Cromwell Road, Kensington, London, UK
| | - Anjali Goswami
- Department of Life Sciences, Natural History Museum, Cromwell Road, Kensington, London, UK
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15
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Oteiza P, Baldwin MW. Evolution of sensory systems. Curr Opin Neurobiol 2021; 71:52-59. [PMID: 34600187 DOI: 10.1016/j.conb.2021.08.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 08/26/2021] [Indexed: 01/14/2023]
Abstract
Sensory systems evolve and enable organisms to perceive their sensory Umwelt, the unique set of cues relevant for their survival. The multiple components that comprise sensory systems - the receptors, cells, organs, and dedicated high-order circuits - can vary greatly across species. Sensory receptor gene families can expand and contract across lineages, resulting in enormous sensory diversity. Comparative studies of sensory receptor function have uncovered the molecular basis of receptor properties and identified novel sensory receptor classes and noncanonical sensory strategies. Phylogenetically informed comparisons of sensory systems across multiple species can pinpoint when sensory changes evolve and highlight the role of contingency in sensory system evolution.
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Affiliation(s)
- Pablo Oteiza
- Flow Sensing Research Group, Max Planck Institute for Ornithology, Seewiesen, Germany.
| | - Maude W Baldwin
- Evolution of Sensory Systems Research Group, Max Planck Institute for Ornithology, Seewiesen, Germany.
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16
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Marx MP, Mateus O, Polcyn MJ, Schulp AS, Gonçalves AO, Jacobs LL. The cranial anatomy and relationships of Cardiocorax mukulu (Plesiosauria: Elasmosauridae) from Bentiaba, Angola. PLoS One 2021; 16:e0255773. [PMID: 34403433 PMCID: PMC8370651 DOI: 10.1371/journal.pone.0255773] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 07/26/2021] [Indexed: 11/21/2022] Open
Abstract
We report a new specimen of the plesiosaur Cardiocorax mukulu that includes the most complete plesiosaur skull from sub-Saharan Africa. The well-preserved three-dimensional nature of the skull offers rare insight into the cranial anatomy of elasmosaurid plesiosaurians. The new specimen of Cardiocorax mukulu was recovered from Bentiaba, Namibe Province in Angola, approximately three meters above the holotype. The new specimen also includes an atlas-axis complex, seventeen postaxial cervical vertebrae, partial ribs, a femur, and limb elements. It is identified as Cardiocorax mukulu based on an apomorphy shared with the holotype where the cervical neural spine is approximately as long anteroposteriorly as the centrum and exhibits a sinusoidal anterior margin. The new specimen is nearly identical to the holotype and previously referred material in all other aspects. Cardiocorax mukulu is returned in an early-branching or intermediate position in Elasmosauridae in four out of the six of our phylogenetic analyses. Cardiocorax mukulu lacks the elongated cervical vertebrae that is characteristic of the extremely long-necked elasmosaurines, and the broad skull with and a high number of maxillary teeth (28-40) which is characteristic of Aristonectinae. Currently, the most parsimonious explanation concerning elasmosaurid evolutionary relationships, is that Cardiocorax mukulu represents an older lineage of elasmosaurids in the Maastrichtian.
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Affiliation(s)
- Miguel P. Marx
- Huffington Department of Earth Sciences, ISEM at Southern Methodist University, Dallas, Texas, United States of America
- GeoBioTec + Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
- Museu da Lourinhã, Lourinhã, Portugal
| | - Octávio Mateus
- GeoBioTec + Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
- Museu da Lourinhã, Lourinhã, Portugal
| | - Michael J. Polcyn
- Huffington Department of Earth Sciences, ISEM at Southern Methodist University, Dallas, Texas, United States of America
| | - Anne S. Schulp
- Naturalis Biodiversity Center, Leiden, The Netherlands
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands
| | - A. Olímpio Gonçalves
- Departamento de Geologia, Faculdade de Ciências, Universidade Agostinho Neto, Luanda, Angola
| | - Louis L. Jacobs
- Huffington Department of Earth Sciences, ISEM at Southern Methodist University, Dallas, Texas, United States of America
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17
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Pommery Y, Scheyer TM, Neenan JM, Reich T, Fernandez V, Voeten DFAE, Losko AS, Werneburg I. Dentition and feeding in Placodontia: tooth replacement in Henodus chelyops. BMC Ecol Evol 2021; 21:136. [PMID: 34225664 PMCID: PMC8256584 DOI: 10.1186/s12862-021-01835-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 05/17/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Placodontia is a Triassic sauropterygian reptile group characterized by flat and enlarged crushing teeth adapted to a durophagous diet. The enigmatic placodont Henodus chelyops has numerous autapomorphic character states, including extreme tooth count reduction to only a single pair of palatine and dentary crushing teeth. This renders the species unusual among placodonts and challenges identification of its phylogenetic position. RESULTS The skulls of two Henodus chelyops specimens were visualized with synchrotron tomography to investigate the complete anatomy of their functional and replacement crushing dentition in 3D. All teeth of both specimens were segmented, measured, and statistically compared to reveal that H. chelyops teeth are much smaller than the posterior palatine teeth of other cyamodontoid placodonts with the exception of Parahenodus atancensis from the Iberian Peninsula. The replacement teeth of this species are quite similar in size and morphology to the functional teeth. CONCLUSION As other placodonts, Henodus chelyops exhibits vertical tooth replacement. This suggests that vertical tooth replacement arose relatively early in placodont phylogeny. Analysis of dental morphology in H. chelyops revealed a concave shape of the occlusal surface and the notable absence of a central cusp. This dental morphology could have reduced dental wear and protected against failure. Hence, the concave teeth of H. chelyops appear to be adapted to process small invertebrate items, such as branchiopod crustaceans. Small gastropods were encountered in the matrix close to both studied skulls.
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Affiliation(s)
- Yannick Pommery
- Senckenberg Centre for Human Evolution and Palaeoenvironment (HEP) an der Eberhard-Karls-Universität Tübingen, Sigwartstraße 10, 72076, Tübingen, Germany.,Fachbereich Geowissenschaften, Eberhard-Karls-Universität Tübingen, Hölderlinstraße 12, 72074, Tübingen, Germany.,Université de Bourgogne-Franche-Comté, Esplanade Erasme, 21000, Dijon, France
| | - Torsten M Scheyer
- Universität Zürich, Paläontologisches Institut und Museum, Karl Schmid-Strasse 4, 8006, Zürich, Switzerland
| | - James M Neenan
- Oxford University Museum of Natural History, University of Oxford, Oxford, UK
| | - Tobias Reich
- Universität Zürich, Paläontologisches Institut und Museum, Karl Schmid-Strasse 4, 8006, Zürich, Switzerland
| | - Vincent Fernandez
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs, 38000, Grenoble, France.,The Natural History Museum, Cromwell Road, London, SW7 5BD, UK
| | - Dennis F A E Voeten
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs, 38000, Grenoble, France.,Department of Organismal Biology, Uppsala University, Norbyvägen 18 A, 752 36, Uppsala, Sweden.,Naturalis Biodiversity Center, Darwinweg 2, 2333 CR, Leiden, the Netherlands
| | - Adrian S Losko
- Forschungs-Neutronenquelle Heinz Maier-Leibnitz, Lichtenbergstr. 1, 85748, Garching, Germany
| | - Ingmar Werneburg
- Senckenberg Centre for Human Evolution and Palaeoenvironment (HEP) an der Eberhard-Karls-Universität Tübingen, Sigwartstraße 10, 72076, Tübingen, Germany. .,Fachbereich Geowissenschaften, Eberhard-Karls-Universität Tübingen, Hölderlinstraße 12, 72074, Tübingen, Germany.
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18
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Neuroanatomical Study and Three-Dimensional Reconstruction of the Skull of a Bothremydid Turtle (Pleurodira) Based on the European Eocene Tartaruscola teodorii. DIVERSITY 2021. [DOI: 10.3390/d13070298] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Bothremydidae is a successful lineage of pleurodiran turtles that lived from the Cretaceous to the Paleogene, and are found in most continents of both Laurasia and Gondwana. Despite numerous known cranial remains of this clade, no study on the complete neuroanatomical reconstruction of any of its representatives has been published so far. Tartaruscola teodorii is a French lower Eocene member of Foxemydina (Bothremydini), known by two skulls. It is one of the few bothremydids identified in the Cenozoic record of Europe. The present study includes the complete three-dimensional reconstruction of each of the cranial bones of both the holotype and the paratype of T. teodorii, increasing the anatomical information about this species. The virtual reconstruction of its neuroanatomical structures is presented here, including the cranial cavity, nerves, nasal cavity, inner ears, and carotid arteries. This analysis is the first detailed neuroanatomical study performed for a member of Bothremydidae. In addition, the virtual reconstruction of the neuroanatomical structures of some extant taxa belonging to several pleurodiran lineages (Chelidae, Pelomedusidae and Podocnemididae), are also carried out and analyzed, so that the comparative framework for Pleurodira is remarkably improved.
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19
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Evers SW, Rollot Y, Joyce WG. New interpretation of the cranial osteology of the Early Cretaceous turtle Arundelemys dardeni (Paracryptodira) based on a CT-based re-evaluation of the holotype. PeerJ 2021; 9:e11495. [PMID: 34131522 PMCID: PMC8174147 DOI: 10.7717/peerj.11495] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 04/30/2021] [Indexed: 12/18/2022] Open
Abstract
Arundelemys dardeni is an Early Cretaceous paracryptodire known from a single, incomplete, but generally well-preserved skull. Phylogenetic hypotheses of paracryptodires often find Arundelemys dardeni as an early branching baenid. As such, it has a central role in understanding the early evolution of the successful clade Baenidae, which survived the Cretaceous-Paleogene mass extinction, as well as the diversification of Paracryptodira into its subclades, which recent research suggests to perhaps include helochelydrids, compsemydids, pleurosternids, and baenids. Computer tomography scans of the holotype material that were produced for the initial description of Arundelemeys dardeni reveal several errors in the initial anatomical description of the species, which we correct based on element-by-element segmentation. In addition, we provide entirely novel anatomical information, including descriptions of several previously undescribed cranial bones, the endosseous labyrinth, and the cranial scutes, the latter of which are unknown for most paracryptodires. We provide an interpretation of cranial scutes which homologizes the scutes of Arundelemys dardeni with those of other stem turtles.
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Affiliation(s)
- Serjoscha W. Evers
- Department of Geosciences, University of Fribourg, Fribourg, Switzerland
| | - Yann Rollot
- Department of Geosciences, University of Fribourg, Fribourg, Switzerland
| | - Walter G. Joyce
- Department of Geosciences, University of Fribourg, Fribourg, Switzerland
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20
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Hanson M, Hoffman EA, Norell MA, Bhullar BAS. The early origin of a birdlike inner ear and the evolution of dinosaurian movement and vocalization. Science 2021; 372:601-609. [PMID: 33958471 DOI: 10.1126/science.abb4305] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 03/09/2021] [Indexed: 12/27/2022]
Abstract
Reptiles, including birds, exhibit a range of behaviorally relevant adaptations that are reflected in changes to the structure of the inner ear. These adaptations include the capacity for flight and sensitivity to high-frequency sound. We used three-dimensional morphometric analyses of a large sample of extant and extinct reptiles to investigate inner ear correlates of locomotor ability and hearing acuity. Statistical analyses revealed three vestibular morphotypes, best explained by three locomotor categories-quadrupeds, bipeds and simple fliers (including bipedal nonavialan dinosaurs), and high-maneuverability fliers. Troodontids fall with Archaeopteryx among the extant low-maneuverability fliers. Analyses of cochlear shape revealed a single instance of elongation, on the stem of Archosauria. We suggest that this transformation coincided with the origin of both high-pitched juvenile location, alarm, and hatching-synchronization calls and adult responses to them.
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Affiliation(s)
- Michael Hanson
- Department of Earth and Planetary Sciences, Yale University, New Haven, CT, USA.,Peabody Museum of Natural History, Yale University, New Haven, CT, USA
| | - Eva A Hoffman
- Division of Paleontology, American Museum of Natural History, New York, NY, USA
| | - Mark A Norell
- Division of Paleontology, American Museum of Natural History, New York, NY, USA
| | - Bhart-Anjan S Bhullar
- Department of Earth and Planetary Sciences, Yale University, New Haven, CT, USA. .,Peabody Museum of Natural History, Yale University, New Haven, CT, USA
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21
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Witmer LM. Making sense of dinosaurs and birds. Science 2021; 372:575-576. [PMID: 33958465 DOI: 10.1126/science.abi5697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Lawrence M Witmer
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA.
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22
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Bronzati M, Benson RBJ, Evers SW, Ezcurra MD, Cabreira SF, Choiniere J, Dollman KN, Paulina-Carabajal A, Radermacher VJ, Roberto-da-Silva L, Sobral G, Stocker MR, Witmer LM, Langer MC, Nesbitt SJ. Deep evolutionary diversification of semicircular canals in archosaurs. Curr Biol 2021; 31:2520-2529.e6. [PMID: 33930303 DOI: 10.1016/j.cub.2021.03.086] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 02/04/2021] [Accepted: 03/25/2021] [Indexed: 01/02/2023]
Abstract
Living archosaurs (birds and crocodylians) have disparate locomotor strategies that evolved since their divergence ∼250 mya. Little is known about the early evolution of the sensory structures that are coupled with these changes, mostly due to limited sampling of early fossils on key stem lineages. In particular, the morphology of the semicircular canals (SCCs) of the endosseous labyrinth has a long-hypothesized relationship with locomotion. Here, we analyze SCC shapes and sizes of living and extinct archosaurs encompassing diverse locomotor habits, including bipedal, semi-aquatic, and flying taxa. We test form-function hypotheses of the SCCs and chronicle their evolution during deep archosaurian divergences. We find that SCC shape is statistically associated with both flight and bipedalism. However, this shape variation is small and is more likely explained by changes in braincase geometry than by locomotor changes. We demonstrate high disparity of both shape and size among stem-archosaurs and a deep divergence of SCC morphologies at the bird-crocodylian split. Stem-crocodylians exhibit diverse morphologies, including aspects also present in birds and distinct from other reptiles. Therefore, extant crocodylian SCC morphologies do not reflect retention of a "primitive" reptilian condition. Key aspects of bird SCC morphology that hitherto were interpreted as flight related, including large SCC size and enhanced sensitivity, appeared early on the bird stem-lineage in non-flying dinosaur precursors. Taken together, our results indicate a deep divergence of SCC traits at the bird-crocodylian split and that living archosaurs evolved from an early radiation with high sensory diversity. VIDEO ABSTRACT.
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Affiliation(s)
- Mario Bronzati
- Departamento de Biologia, Universidade de São Paulo, Av. Bandeirantes 1900, Ribeirão Preto-SP 14040-091, Brazil.
| | - Roger B J Benson
- Department of Earth Sciences, University of Oxford, South Parks Road, OX13AN Oxford, UK; Evolutionary Studies Institute, University of the Witwatersrand, Braamfontein, Private Bag 3, Johannesburg WITS2050, South Africa.
| | - Serjoscha W Evers
- Department of Earth Sciences, University of Oxford, South Parks Road, OX13AN Oxford, UK; Department of Geosciences, University of Fribourg, Chemin du Musée 4, 1700 Fribourg, Switzerland
| | - Martín D Ezcurra
- Sección Paleontología de Vertebrados, CONICET-Museo Argentino de Ciencias Naturales "Bernardino Rivadavia", Ángel Gallardo 470, C1405DJR Buenos Aires, Argentina; School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, B15 2TT Birmingham, UK
| | - Sergio F Cabreira
- Avenida Antônio Bozzetto 305, Faxinal do Soturno-RS 97220-000, Brazil
| | - Jonah Choiniere
- Evolutionary Studies Institute, University of the Witwatersrand, Braamfontein, Private Bag 3, Johannesburg WITS2050, South Africa
| | - Kathleen N Dollman
- Evolutionary Studies Institute, University of the Witwatersrand, Braamfontein, Private Bag 3, Johannesburg WITS2050, South Africa
| | - Ariana Paulina-Carabajal
- Instituto de Investigaciones en Biodiversidad y Medioambiente (INIBIOMA), CONICET-Universidad Nacional del Comahue, Quintral 1250 (8400), San Carlos de Bariloche, Argentina
| | - Viktor J Radermacher
- Evolutionary Studies Institute, University of the Witwatersrand, Braamfontein, Private Bag 3, Johannesburg WITS2050, South Africa
| | | | - Gabriela Sobral
- Staatliches Museum für Naturkunde Stuttgart, Rosenstein 1, Suttgart 70191, Germany
| | - Michelle R Stocker
- Department of Geosciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA 24061, USA
| | - Lawrence M Witmer
- Department of Biomedical Science, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA
| | - Max C Langer
- Departamento de Biologia, Universidade de São Paulo, Av. Bandeirantes 1900, Ribeirão Preto-SP 14040-091, Brazil
| | - Sterling J Nesbitt
- Department of Geosciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA 24061, USA.
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23
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Ezcurra MD, Nesbitt SJ, Bronzati M, Dalla Vecchia FM, Agnolin FL, Benson RBJ, Brissón Egli F, Cabreira SF, Evers SW, Gentil AR, Irmis RB, Martinelli AG, Novas FE, Roberto da Silva L, Smith ND, Stocker MR, Turner AH, Langer MC. Enigmatic dinosaur precursors bridge the gap to the origin of Pterosauria. Nature 2020; 588:445-449. [DOI: 10.1038/s41586-020-3011-4] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 09/25/2020] [Indexed: 11/09/2022]
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24
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Spiekman SNF, Neenan JM, Fraser NC, Fernandez V, Rieppel O, Nosotti S, Scheyer TM. The cranial morphology of Tanystropheus hydroides (Tanystropheidae, Archosauromorpha) as revealed by synchrotron microtomography. PeerJ 2020; 8:e10299. [PMID: 33240633 PMCID: PMC7682440 DOI: 10.7717/peerj.10299] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 10/14/2020] [Indexed: 12/19/2022] Open
Abstract
The postcranial morphology of the extremely long-necked Tanystropheus hydroides is well-known, but observations of skull morphology were previously limited due to compression of the known specimens. Here we provide a detailed description of the skull of PIMUZ T 2790, including a partial endocast and endosseous labyrinth, based on synchrotron microtomographic data, and compare its morphology to that of other early Archosauromorpha. In many features, such as the wide and flattened snout and the configuration of the temporal and palatal regions, Tanystropheus hydroides differs strongly from other early archosauromorphs. The braincase possesses a combination of derived archosaur traits, such as the presence of a laterosphenoid and the ossification of the lateral wall of the braincase, but also differs from archosauriforms in the morphology of the ventral ramus of the opisthotic, the horizontal orientation of the parabasisphenoid, and the absence of a clearly defined crista prootica. Tanystropheus hydroides was a ram-feeder that likely caught its prey through a laterally directed snapping bite. Although the cranial morphology of other archosauromorph lineages is relatively well-represented, the skulls of most tanystropheid taxa remain poorly understood due to compressed and often fragmentary specimens. The recent descriptions of the skulls of Macrocnemus bassanii and now Tanystropheus hydroides reveal a large cranial disparity in the clade, reflecting wide ecological diversity, and highlighting the importance of non-archosauriform Archosauromorpha to both terrestrial and aquatic ecosystems during the Triassic.
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Affiliation(s)
- Stephan N F Spiekman
- University of Zurich, Palaeontological Institute and Museum, Zurich, Switzerland
| | | | | | - Vincent Fernandez
- European Synchrotron Radiation Facility, Grenoble, France.,The Natural History Museum, London, UK
| | | | | | - Torsten M Scheyer
- University of Zurich, Palaeontological Institute and Museum, Zurich, Switzerland
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25
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Spiekman SN, Neenan JM, Fraser NC, Fernandez V, Rieppel O, Nosotti S, Scheyer TM. Aquatic Habits and Niche Partitioning in the Extraordinarily Long-Necked Triassic Reptile Tanystropheus. Curr Biol 2020; 30:3889-3895.e2. [DOI: 10.1016/j.cub.2020.07.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 06/30/2020] [Accepted: 07/08/2020] [Indexed: 12/13/2022]
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26
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Schade M, Rauhut OWM, Evers SW. Neuroanatomy of the spinosaurid Irritator challengeri (Dinosauria: Theropoda) indicates potential adaptations for piscivory. Sci Rep 2020; 10:9259. [PMID: 32518236 PMCID: PMC7283278 DOI: 10.1038/s41598-020-66261-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 05/18/2020] [Indexed: 11/18/2022] Open
Abstract
Spinosauridae, a theropod group characterized by elongated snouts, conical teeth, enlarged forelimbs, and often elongated neural spines, show evidence for semiaquatic adaptations and piscivory. It is currently debated if these animals represent terrestrial carnivores with adaptations for a piscivorous diet, or if they largely lived and foraged in aquatic habitats. The holotype of Irritator challengeri, a nearly complete skull from the late Early Cretaceous Santana Formation of northeastern Brazil, includes one of the few preserved spinosaurid braincases and can provide insights into neuroanatomical structures that might be expected to reflect ecological affinities. We generated digital models of the neuroanatomical cavities within the braincase, using computer tomography (CT) data. The cranial endocast of Irritator is generally similar to that of other non-maniraptoriform theropods, with weakly developed distinctions of hindbrain and midbrain features, relatively pronounced cranial flexures and relatively long olfactory tracts. The endosseous labyrinth has a long anterior semicircular canal, a posteriorly inclined common crus and a very large floccular recess fills the area between the semicircular canals. These features indicate that Irritator had the ability for fast and well-controlled pitch-down head movements. The skull table and lateral semicircular canal plane are strongly angled to one another, suggesting a downward angling of approximately 45° of the snout, which reduces interference of the snout with the field of vision of Irritator. These neuroanatomical features are consistent with fast, downward snatching movements in the act of predation, such as are needed for piscivory.
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Affiliation(s)
- Marco Schade
- Institute of Geography and Geology, Palaeontology and Historical Geology, University of Greifswald, 17489, Greifswald, Germany. .,Department of Earth and Environmental Sciences, Palaeontology and Geobiology, Ludwig-Maximilians-Universität, 80333, München, Germany.
| | - Oliver W M Rauhut
- Department of Earth and Environmental Sciences, Palaeontology and Geobiology, Ludwig-Maximilians-Universität, 80333, München, Germany.,Bayerische Staatssammlung für Paläntologie und Geologie, Staatliche Naturwissenschaftliche Sammlungen Bayerns (SNSB), 80333, München, Germany.,GeoBioCenter, Ludwig-Maximilians-Universität, 80333, München, Germany
| | - Serjoscha W Evers
- Department of Geosciences, University of Fribourg, 17000, Fribourg, Switzerland
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27
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Schwab JA, Young MT, Neenan JM, Walsh SA, Witmer LM, Herrera Y, Allain R, Brochu CA, Choiniere JN, Clark JM, Dollman KN, Etches S, Fritsch G, Gignac PM, Ruebenstahl A, Sachs S, Turner AH, Vignaud P, Wilberg EW, Xu X, Zanno LE, Brusatte SL. Inner ear sensory system changes as extinct crocodylomorphs transitioned from land to water. Proc Natl Acad Sci U S A 2020; 117:10422-10428. [PMID: 32312812 PMCID: PMC7229756 DOI: 10.1073/pnas.2002146117] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Major evolutionary transitions, in which animals develop new body plans and adapt to dramatically new habitats and lifestyles, have punctuated the history of life. The origin of cetaceans from land-living mammals is among the most famous of these events. Much earlier, during the Mesozoic Era, many reptile groups also moved from land to water, but these transitions are more poorly understood. We use computed tomography to study changes in the inner ear vestibular system, involved in sensing balance and equilibrium, as one of these groups, extinct crocodile relatives called thalattosuchians, transitioned from terrestrial ancestors into pelagic (open ocean) swimmers. We find that the morphology of the vestibular system corresponds to habitat, with pelagic thalattosuchians exhibiting a more compact labyrinth with wider semicircular canal diameters and an enlarged vestibule, reminiscent of modified and miniaturized labyrinths of other marine reptiles and cetaceans. Pelagic thalattosuchians with modified inner ears were the culmination of an evolutionary trend with a long semiaquatic phase, and their pelagic vestibular systems appeared after the first changes to the postcranial skeleton that enhanced their ability to swim. This is strikingly different from cetaceans, which miniaturized their labyrinths soon after entering the water, without a prolonged semiaquatic stage. Thus, thalattosuchians and cetaceans became secondarily aquatic in different ways and at different paces, showing that there are different routes for the same type of transition.
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Affiliation(s)
- Julia A Schwab
- School of GeoSciences, Grant Institute, University of Edinburgh, EH9 3FE Edinburgh, United Kingdom;
| | - Mark T Young
- School of GeoSciences, Grant Institute, University of Edinburgh, EH9 3FE Edinburgh, United Kingdom
| | - James M Neenan
- Oxford University Museum of Natural History, OX1 3PW Oxford, United Kingdom
| | - Stig A Walsh
- School of GeoSciences, Grant Institute, University of Edinburgh, EH9 3FE Edinburgh, United Kingdom
- Department of Natural Sciences, National Museum of Scotland, EH1 1JF Edinburgh, United Kingdom
| | - Lawrence M Witmer
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701
| | - Yanina Herrera
- Consejo Nacional de Investigaciones Científicas y Técnicas, División Paleontología Vertebrados, Museo de La Plata, Facultad de Ciencias Naturales y Museo, National University of La Plata, B1900 La Plata, Buenos Aires, Argentina
| | - Ronan Allain
- Centre de Recherche sur la Paléobiodiversité et les Paléoenvironnements, Muséum National d'Histoire Naturelle, 75005 Paris, France
| | - Christopher A Brochu
- Department of Earth and Environmental Sciences, University of Iowa, Iowa City, IA 52242
| | - Jonah N Choiniere
- Evolutionary Studies Institute, University of the Witwatersrand, 2000 Johannesburg, South Africa
| | - James M Clark
- Department of Biological Sciences, George Washington University, Washington, DC 20052
| | - Kathleen N Dollman
- Evolutionary Studies Institute, University of the Witwatersrand, 2000 Johannesburg, South Africa
- School of Geosciences, University of the Witwatersrand, 2000 Johannesburg, South Africa
| | - Steve Etches
- Museum of Jurassic Marine Life, BH20 5PE Kimmeridge, United Kingdom
| | - Guido Fritsch
- Department of Reproduction Management, Leibniz Institute for Zoo and Wildlife Research, 10315 Berlin, Germany
| | - Paul M Gignac
- Department of Anatomy and Cell Biology, Oklahoma State University Center for Health Sciences, Tulsa, OK 74107
| | | | - Sven Sachs
- Abteilung Geowissenschaften, Naturkunde-Museum Bielefeld, Abteilung Geowissenschaften, 33602 Bielefeld, Germany
| | - Alan H Turner
- Department of Anatomical Sciences, Stony Brook University, Stony Brook, NY 11794
| | - Patrick Vignaud
- Laboratoire de Paléontologie, Evolution, Paléoécosystèmes et Paléoprimatologie, CNRS UMR 7262, Department of Geosciences, University of Poitiers, 86073 Poitiers Cedex 9, France
| | - Eric W Wilberg
- Department of Anatomical Sciences, Stony Brook University, Stony Brook, NY 11794
| | - Xing Xu
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, 100044 Beijing, China
| | - Lindsay E Zanno
- Paleontology, North Carolina Museum of Natural Sciences, Raleigh, NC 27601
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695
| | - Stephen L Brusatte
- School of GeoSciences, Grant Institute, University of Edinburgh, EH9 3FE Edinburgh, United Kingdom
- Department of Natural Sciences, National Museum of Scotland, EH1 1JF Edinburgh, United Kingdom
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28
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Dudgeon TW, Maddin HC, Evans DC, Mallon JC. The internal cranial anatomy of Champsosaurus (Choristodera: Champsosauridae): Implications for neurosensory function. Sci Rep 2020; 10:7122. [PMID: 32346021 PMCID: PMC7188685 DOI: 10.1038/s41598-020-63956-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 04/06/2020] [Indexed: 11/09/2022] Open
Abstract
Although isolated Champsosaurus remains are common in Upper Cretaceous sediments of North America, the braincase of these animals is enigmatic due to the fragility of their skulls. Here, two well-preserved specimens of Champsosaurus (CMN 8920 and CMN 8919) are CT scanned to describe their neurosensory structures and infer sensory capability. The anterior portion of the braincase was poorly ossified and thus does not permit visualization of a complete endocast; however, impressions of the olfactory stalks indicate that they were elongate and likely facilitated good olfaction. The posterior portion of the braincase is ossified and morphologically similar to that of other extinct diapsids. The absence of an otic notch and an expansion of the pars inferior of the inner ear suggests Champsosaurus was limited to detecting low frequency sounds. Comparison of the shapes of semicircular canals with lepidosaurs and archosauromorphs demonstrates that the semicircular canals of Champsosaurus are most similar to those of aquatic reptiles, suggesting that Champsosaurus was well adapted for sensing movement in an aquatic environment. This analysis also demonstrates that birds, non-avian archosauromorphs, and lepidosaurs possess significantly different canal morphologies, and represents the first morphometric analysis of semicircular canals across Diapsida.
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Affiliation(s)
- Thomas W Dudgeon
- Department of Earth Sciences, Carleton University, Ottawa, Canada.
| | - Hillary C Maddin
- Department of Earth Sciences, Carleton University, Ottawa, Canada
| | - David C Evans
- Vertebrate Palaeontology, Royal Ontario Museum, Toronto, Canada.,Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada
| | - Jordan C Mallon
- Department of Earth Sciences, Carleton University, Ottawa, Canada.,Beaty Centre for Species Discovery and Palaeobiology Section, Canadian Museum of Nature, Ottawa, Canada
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29
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Evers SW, Joyce WG. A re-description of Sandownia harrisi (Testudinata: Sandownidae) from the Aptian of the Isle of Wight based on computed tomography scans. ROYAL SOCIETY OPEN SCIENCE 2020; 7:191936. [PMID: 32257345 PMCID: PMC7062094 DOI: 10.1098/rsos.191936] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 01/27/2020] [Indexed: 05/26/2023]
Abstract
Sandownidae is an enigmatic group of Cretaceous-Paleogene turtles with highly derived cranial anatomy. Although sandownid monophyly is not debated, relationships with other turtles remain unclear. Sandownids have been recovered in significantly different parts of the turtle tree: as stem-turtles, stem-cryptodires and stem-chelonioid sea turtles. Latest phylogenetic studies find sandownids as the sister-group of the Late Jurassic thalassochelydians and as stem-turtles. Here, we provide a detailed study of the cranial and mandibular anatomy of Sandownia harrisi from the Aptian of the Isle of Wight, based on high resolution computed tomography scanning of the holotype. Our results confirm a high number of anatomical similarities with thalassochelydians and particularly Solnhofia parsonsi, which is interpreted as an early member of the sandownid lineage. Sandownids + Solnhofia show many cranial modifications related to the secondary palate and a durophagous diet. Sandownia is additionally highly derived in features related to its arterial circulation and neuroanatomy, including the endosseous labyrinth. Our results imply rapid morphological evolution during the early history of sandownids. Sandownids likely evolved in central Europe from thalassochelydian ancestors during the Late Jurassic. The durophagous diet of sandownids possibly facilitated their survival of the Cretaceous/Paleogene mass extinction.
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30
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Pusch LC, Ponstein J, Kammerer CF, Fröbisch J. Novel Endocranial Data on the Early Therocephalian Lycosuchus vanderrieti Underpin High Character Variability in Early Theriodont Evolution. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2019.00464] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
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31
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Fleischle CV, Sander PM, Wintrich T, Caspar KR. Hematological convergence between Mesozoic marine reptiles (Sauropterygia) and extant aquatic amniotes elucidates diving adaptations in plesiosaurs. PeerJ 2019; 7:e8022. [PMID: 31763069 PMCID: PMC6873879 DOI: 10.7717/peerj.8022] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 10/10/2019] [Indexed: 12/15/2022] Open
Abstract
Plesiosaurs are a prominent group of Mesozoic marine reptiles, belonging to the more inclusive clades Pistosauroidea and Sauropterygia. In the Middle Triassic, the early pistosauroid ancestors of plesiosaurs left their ancestral coastal habitats and increasingly adapted to a life in the open ocean. This ecological shift was accompanied by profound changes in locomotion, sensory ecology and metabolism. However, investigations of physiological adaptations on the cellular level related to the pelagic lifestyle are lacking so far. Using vascular canal diameter, derived from osteohistological thin-sections, we show that inferred red blood cell size significantly increases in pistosauroids compared to more basal sauropterygians. This change appears to have occurred in conjunction with the dispersal to open marine environments, with cell size remaining consistently large in plesiosaurs. Enlarged red blood cells likely represent an adaptation of plesiosaurs repeated deep dives in the pelagic habitat and mirror conditions found in extant marine mammals and birds. Our results emphasize physiological aspects of adaptive convergence among fossil and extant marine amniotes and add to our current understanding of plesiosaur evolution.
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Affiliation(s)
- Corinna V. Fleischle
- Section Paleontology, Institute of Geosciences, University of Bonn, Bonn, Germany
| | - P. Martin Sander
- Section Paleontology, Institute of Geosciences, University of Bonn, Bonn, Germany
- Dinosaur Institute, Natural History Museum of Los Angeles County, Los Angeles, CA, USA
| | - Tanja Wintrich
- Section Paleontology, Institute of Geosciences, University of Bonn, Bonn, Germany
- Institute of Anatomy, University of Bonn, Bonn, Germany
| | - Kai R. Caspar
- Section Paleontology, Institute of Geosciences, University of Bonn, Bonn, Germany
- Department of General Zoology, Faculty of Biology, University of Duisburg-Essen, Essen, Germany
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32
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Park T, Mennecart B, Costeur L, Grohé C, Cooper N. Convergent evolution in toothed whale cochleae. BMC Evol Biol 2019; 19:195. [PMID: 31651234 PMCID: PMC6813997 DOI: 10.1186/s12862-019-1525-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 10/01/2019] [Indexed: 11/10/2022] Open
Abstract
Background Odontocetes (toothed whales) are the most species-rich marine mammal lineage. The catalyst for their evolutionary success is echolocation - a form of biological sonar that uses high-frequency sound, produced in the forehead and ultimately detected by the cochlea. The ubiquity of echolocation in odontocetes across a wide range of physical and acoustic environments suggests that convergent evolution of cochlear shape is likely to have occurred. To test this, we used SURFACE; a method that fits Ornstein-Uhlenbeck (OU) models with stepwise AIC (Akaike Information Criterion) to identify convergent regimes on the odontocete phylogeny, and then tested whether convergence in these regimes was significantly greater than expected by chance. Results We identified three convergent regimes: (1) True’s (Mesoplodon mirus) and Cuvier’s (Ziphius cavirostris) beaked whales; (2) sperm whales (Physeter macrocephalus) and all other beaked whales sampled; and (3) pygmy (Kogia breviceps) and dwarf (Kogia sima) sperm whales and Dall’s porpoise (Phocoenoides dalli). Interestingly the ‘river dolphins’, a group notorious for their convergent morphologies and riverine ecologies, do not have convergent cochlear shapes. The first two regimes were significantly convergent, with habitat type and dive type significantly correlated with membership of the sperm whale + beaked whale regime. Conclusions The extreme acoustic environment of the deep ocean likely constrains cochlear shape, causing the cochlear morphology of sperm and beaked whales to converge. This study adds support for cochlear morphology being used to predict the ecology of extinct cetaceans.
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Affiliation(s)
- Travis Park
- Department of Life Sciences, Natural History Museum, Cromwell Road, SW7 5BD, London, UK.
| | - Bastien Mennecart
- Naturhistorisches Museum Basel, Augustinergasse 2, 4001, Basel, Switzerland.,Naturhistorisches Museum Wien, Burgring 7, 1010, Vienna, Austria
| | - Loïc Costeur
- Naturhistorisches Museum Basel, Augustinergasse 2, 4001, Basel, Switzerland
| | - Camille Grohé
- Division of Paleontology, American Museum of Natural History, Central Park West at 79th Street, New York, NY, 10024, USA.,Laboratory Paleontology Evolution Paleoecosystems Paleoprimatology (PALEVOPRIM) - UMR 7262, CNRS-INEE/University of Poitiers, 86073, Poitiers Cedex 9, France
| | - Natalie Cooper
- Department of Life Sciences, Natural History Museum, Cromwell Road, SW7 5BD, London, UK
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33
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Evers SW, Neenan JM, Ferreira GS, Werneburg I, Barrett PM, Benson RBJ. Neurovascular anatomy of the protostegid turtle Rhinochelys pulchriceps and comparisons of membranous and endosseous labyrinth shape in an extant turtle. Zool J Linn Soc 2019. [DOI: 10.1093/zoolinnean/zlz063] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
AbstractChelonioid turtles are the only surviving group of reptiles that secondarily evolved marine lifestyles during the Mesozoic Early chelonioid evolution is documented by fossils of their stem group, such as protostegids, which yield insights into the evolution of marine adaptation. Neuroanatomical features are commonly used to infer palaeoecology owing to the functional adaptation of the senses of an organism to its environment. We investigated the neuroanatomy and carotid circulation of the early Late Cretaceous protostegid Rhinochelys pulchriceps based on micro-computed tomography data. We show that the trigeminal foramen of turtles is not homologous to that of other reptiles. The endosseous labyrinth of R. pulchriceps has thick semicircular canals and a high aspect ratio. Comparisons among turtles and other reptiles show that the endosseous labyrinth aspect ratio is not a reliable predictor of the degree of aquatic adaptation, contradicting previous hypotheses. We provide the first models of neuroanatomical soft tissues of an extant turtle. Turtle brain morphology is not reflected by the brain cavity, and the endosseous labyrinth provides an incomplete reflection of membranous semicircular duct morphology. Membranous labyrinth geometry is conserved across gnathostomes, which allows approximate reconstruction of the total membranous labyrinth morphology from the endosseous labyrinth despite their poor reflection of duct morphology.
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Affiliation(s)
- Serjoscha W Evers
- Department of Earth Sciences, University of Oxford, Oxford, UK
- Department of Earth Sciences, Natural History Museum, London, UK
| | | | - Gabriel S Ferreira
- Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
- Fachbereich Geowissenschaften der Eberhard-Karls-Universität Tübingen, Hölderlinstraße, Tübingen, Germany
| | - Ingmar Werneburg
- Fachbereich Geowissenschaften der Eberhard-Karls-Universität Tübingen, Hölderlinstraße, Tübingen, Germany
- Senckenberg Center for Human Evolution and Palaeoenvironment (HEP) an der Eberhard Karls Universität, Sigwartstraße, Tübingen, Germany
| | - Paul M Barrett
- Department of Earth Sciences, Natural History Museum, London, UK
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34
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Cerio DG, Witmer LM. Intraspecific variation and symmetry of the inner-ear labyrinth in a population of wild turkeys: implications for paleontological reconstructions. PeerJ 2019; 7:e7355. [PMID: 31372322 PMCID: PMC6659666 DOI: 10.7717/peerj.7355] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 06/26/2019] [Indexed: 12/25/2022] Open
Abstract
The cochlea and semicircular canals (SCCs) of the inner ear are vital neurosensory devices. There are associations between the anatomy of these sensorineural structures, their function, and the function of related biological systems, for example, hearing ability, gaze stabilization, locomotor agility, and posture. The endosseous labyrinth is frequently used as a proxy to infer the performance of the hearing and vestibular systems, locomotor abilities, and ecology of extinct species. Such fossil inferences are often based on single specimens or even a single ear, representing an entire species. To address whether a single ear is representative of a population, we used geometric morphometrics to quantitatively assess the variation in shape and symmetry in a sample of endosseous labyrinths of wild turkeys Meleagris gallopavo of southern Ohio. We predicted that ears would be symmetrical both within individuals and across the sample; that labyrinth shape and size would covary; that labyrinth shape would vary with the size of the brain, measured as width of the endocranium at the cerebellum; and that labyrinths would be morphologically integrated. To test these predictions, we microCT-scanned the heads of 26 cadaveric turkeys, digitally segmented their endosseous labyrinths in Avizo, and assigned 15 manual landmarks and 20 sliding semilandmarks to each digital model. Following Procrustes alignment, we conducted an analysis of bilateral symmetry, a Procrustes regression analysis for allometry and other covariates including side and replicate, and analyses of global integration and modularity. Based on Procrustes distances, no individual’s left and right ears were clearly different from each other. When comparing the ears of different specimens, statistically clear differences in shape were found in only 66 of more than 1,300 contrasts. Moreover, effects of both directional and fluctuating asymmetry were very small—generally, two orders of magnitude smaller than the variance explained by individual variation. Statistical tests disagreed on whether these asymmetric effects crossed the threshold of significance, possibly due to non-isotropic variation among landmarks. Regardless, labyrinths appeared to primarily vary in shape symmetrically. Neither labyrinth size nor endocranial width was correlated with labyrinth shape, contrary to our expectations. Finally, labyrinths were found to be moderately integrated in a global sense, but four weakly separated modules—the three SCCs and cochlea—were recovered using a maximum-likelihood analysis. The results show that both fluctuating and directional asymmetry play a larger role in shape variation than expected—but nonetheless, endosseous labyrinths are symmetrical within individuals and at the level of the population, and their shape varies symmetrically. Thus, inferences about populations, and very possibly species, may be confidently made when only a single specimen, or even a single ear, is available for study.
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Affiliation(s)
- Donald G Cerio
- Department of Biological Sciences, Ohio University, Athens, OH, USA.,Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, USA
| | - Lawrence M Witmer
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, USA
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35
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McCurry MR, Evans AR, Fitzgerald EMG, McHenry CR, Bevitt J, Pyenson ND. The repeated evolution of dental apicobasal ridges in aquatic-feeding mammals and reptiles. Biol J Linn Soc Lond 2019. [DOI: 10.1093/biolinnean/blz025] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Matthew R McCurry
- Australian Museum Research Institute, Sydney, NSW, Australia
- PANGEA Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Alistair R Evans
- School of Biological Sciences, Monash University, Melbourne, VIC, Australia
- Geosciences, Museums Victoria, Melbourne, VIC, Australia
| | | | - Colin R McHenry
- School of Engineering, University of Newcastle, Newcastle, NSW, Australia
- School of Environmental and Life Sciences, University of Newcastle, Newcastle, NSW, Australia
- Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, Australia
| | - Joseph Bevitt
- Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation, Sydney, NSW, Australia
| | - Nicholas D Pyenson
- Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
- Mammalogy and Paleontology, Burke Museum of Natural History and Culture, University of Washington, Seattle, WA, USA
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36
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Foffa D, Johnson MM, Young MT, Steel L, Brusatte SL. Revision of the Late Jurassic deep-water teleosauroid crocodylomorph Teleosaurus megarhinus Hulke, 1871 and evidence of pelagic adaptations in Teleosauroidea. PeerJ 2019; 7:e6646. [PMID: 30972249 PMCID: PMC6450380 DOI: 10.7717/peerj.6646] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 02/19/2019] [Indexed: 12/02/2022] Open
Abstract
Teleosauroids were a successful group of semi-aquatic crocodylomorphs that were an integral part of coastal marine/lagoonal faunas during the Jurassic. Their fossil record suggests that the group declined in diversity and abundance in deep water deposits during the Late Jurassic. One of the few known teleosauroid species from the deeper water horizons of the well-known Kimmeridge Clay Formation is ‘Teleosaurus’ megarhinus Hulke, 1871, a poorly studied, gracile longirostrine form. The holotype is an incomplete snout from the Aulacostephanus autissiodorensis Sub-Boreal ammonite Zone of Kimmeridge, England. The only other referred specimen is an almost complete skull from the slightly older A. eudoxus Sub-Boreal ammonite Zone of Quercy, France. Recently, the validity of this species has been called into question. Here we re-describe the holotype as well as the referred French specimen and another incomplete teleosauroid, DORCM G.05067i-v (an anterior rostrum with three osteoderms and an isolated tooth crown), from the same horizon and locality as the holotype. We demonstrate that all specimens are referable to ‘Teleosaurus’ megarhinus and that the species is indeed a valid taxon, which we assign to a new monotypic genus, Bathysuchus. In our phylogenetic analysis, the latest iteration of the ongoing Crocodylomorph SuperMatrix Project, Bathysuchus megarhinus is found as sister taxon to Aeolodon priscus within a subclade containing Mycterosuchus nasutus and Teleosaurus cadomensis. Notably Bathysuchus has an extreme reduction in dermatocranial ornamentation and osteoderm size, thickness and ornamentation. These features are mirrored in Aeolodon priscus, a species with a well-preserved post-cranial skeleton and a similar shallow and inconspicuous dermal ornamentation. Based on these morphological features, and sedimentological evidence, we hypothesise that the Bathysuchus + Aeolodon clade is the first known teleosauroid lineage that evolved a more pelagic lifestyle.
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Affiliation(s)
- Davide Foffa
- Current affiliation: Department of Natural Sciences, National Museums Scotland, Edinburgh, United Kingdom.,School of GeoSciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Michela M Johnson
- School of GeoSciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Mark T Young
- School of GeoSciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Lorna Steel
- Department of Earth Sciences, Natural History Museum, London, United Kingdom
| | - Stephen L Brusatte
- Current affiliation: Department of Natural Sciences, National Museums Scotland, Edinburgh, United Kingdom.,School of GeoSciences, University of Edinburgh, Edinburgh, United Kingdom
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37
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Schwab JA, Kriwet J, Weber GW, Pfaff C. Carnivoran hunting style and phylogeny reflected in bony labyrinth morphometry. Sci Rep 2019; 9:70. [PMID: 30635617 PMCID: PMC6329752 DOI: 10.1038/s41598-018-37106-4] [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: 07/27/2018] [Accepted: 11/30/2018] [Indexed: 11/09/2022] Open
Abstract
Carnivorans are a highly diverse and successful group of mammals, found on the top of the food chain. They originated in the Palaeocene (ca. 60 Ma) and have developed numerous lifestyles, locomotion modes and hunting strategies during their evolutionary history. Mechanosensory organs, such as the inner ear (which houses senses of equilibrium and hearing), represent informative anatomical systems to obtain insights into function, ecology and phylogeny of extant and extinct vertebrates. Using µCT scans, we examined bony labyrinths of a broad sample of various carnivoran species, to obtain new information about hunting behaviours of ancient carnivorans. Bony labyrinths were digitally reconstructed and measurements were taken directly from these 3D models. Principal component analyses generally separated various hunting strategies (pursuit, pounce, ambush and occasional), but also support their phylogenetic relationships (Canoidea vs. Feloidea). The height, width and length of all three semicircular canals show functional morphological adaptations, whereas the diameter of the canals, the height of the cochlea and particularly the angle between the lateral semicircular canal and the cochlea indicate a phylogenetic signal. The results demonstrate that the bony labyrinth provides a powerful ecological proxy reflecting both predatory habits as well as phylogenetic relationships in extinct and extant carnivorans.
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Affiliation(s)
- Julia A Schwab
- Department of Palaeontology, Faculty of Earth Science, Geography and Astronomy, University of Vienna, Geozentrum, Althanstraße 14, 1090, Vienna, Austria. .,School of GeoSciences, Grant Institute, University of Edinburgh, The King's Buildings, James Hutton Road, Edinburgh, EH9 3JW, UK.
| | - Jürgen Kriwet
- Department of Palaeontology, Faculty of Earth Science, Geography and Astronomy, University of Vienna, Geozentrum, Althanstraße 14, 1090, Vienna, Austria
| | - Gerhard W Weber
- Department of Anthropology & Core Facility for Micro-Computed Tomography, Faculty of Life Science, University of Vienna, Althanstraße 14, 1090, Vienna, Austria
| | - Cathrin Pfaff
- Department of Palaeontology, Faculty of Earth Science, Geography and Astronomy, University of Vienna, Geozentrum, Althanstraße 14, 1090, Vienna, Austria
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38
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Kelley N. Paleontology: Scanning for Sea Monsters. Curr Biol 2017; 27:R1316-R1318. [PMID: 29257966 DOI: 10.1016/j.cub.2017.11.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Land vertebrates have returned to the ocean several times, radically transforming their outward anatomy in the process. A new study of Mesozoic marine reptiles shows how minute balance organs in the inner ear transformed at the same time.
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Affiliation(s)
- Neil Kelley
- Department of Earth and Environmental Sciences, Vanderbilt University, Nashville, TN 37240, USA.
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