1
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Widrig KE, Navalón G, Field DJ. Paleoneurology of stem palaeognaths clarifies the plesiomorphic condition of the crown bird central nervous system. J Morphol 2024; 285:e21710. [PMID: 38760949 DOI: 10.1002/jmor.21710] [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: 04/08/2024] [Revised: 04/29/2024] [Accepted: 05/03/2024] [Indexed: 05/20/2024]
Abstract
Lithornithidae, an assemblage of volant Palaeogene fossil birds, provide our clearest insights into the early evolutionary history of Palaeognathae, the clade that today includes the flightless ratites and volant tinamous. The neotype specimen of Lithornis vulturinus, from the early Eocene (approximately 53 million years ago) of Europe, includes a partial neurocranium that has never been thoroughly investigated. Here, we describe these cranial remains including the nearly complete digital endocasts of the brain and bony labyrinth. The telencephalon of Lithornis is expanded and its optic lobes are ventrally shifted, as is typical for crown birds. The foramen magnum is positioned caudally, rather than flexed ventrally as in some crown birds, with the optic lobes, cerebellum, and foramen magnum shifted further ventrally. The overall brain shape is similar to that of tinamous, the only extant clade of flying palaeognaths, suggesting that several aspects of tinamou neuroanatomy may have been evolutionarily conserved since at least the early Cenozoic. The estimated ratio of the optic lobe's surface area relative to the total brain suggests a diurnal ecology. Lithornis may provide the clearest insights to date into the neuroanatomy of the ancestral crown bird, combining an ancestrally unflexed brain with a caudally oriented connection with the spinal cord, a moderately enlarged telencephalon, and ventrally shifted, enlarged optic lobes.
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Affiliation(s)
- Klara E Widrig
- Department of Earth Sciences, University of Cambridge, Cambridge, UK
| | - Guillermo Navalón
- Department of Earth Sciences, University of Cambridge, Cambridge, UK
| | - Daniel J Field
- Department of Earth Sciences, University of Cambridge, Cambridge, UK
- Museum of Zoology, University of Cambridge, Cambridge, UK
- Fossil Reptiles, Amphibians and Birds Section, The Natural History Museum, London, UK
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2
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Desojo JB, von Baczko MB, Ezcurra MD, Fiorelli LE, Martinelli AG, Bona P, Trotteyn MJ, Lacerda M. Cranial osteology and paleoneurology of Tarjadia ruthae: An erpetosuchid pseudosuchian from the Triassic Chañares Formation (late Ladinian-?early Carnian) of Argentina. Anat Rec (Hoboken) 2024; 307:890-924. [PMID: 38263705 DOI: 10.1002/ar.25382] [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: 09/29/2023] [Revised: 12/22/2023] [Accepted: 12/29/2023] [Indexed: 01/25/2024]
Abstract
Tarjadia ruthae is a quadrupedal terrestrial pseudosuchian from the Middle-early Upper Triassic of the Chañares Formation, La Rioja Province, Argentina. Originally, this species was identified as an indeterminate archosaur and later as a doswelliid archosauriform based on very fragmentary specimens characterized by the ornamentation of the skull roof and osteoderms. Additional specimens (including skulls and postcrania) recovered in the last decade show that Tarjadia is an erpetosuchid, an enigmatic pseudosuchian group composed of six species registered in Middle-Upper Triassic continental units of Tanzania, Germany, Scotland, North America, Brazil, and Argentina. Tarjadia ruthae from Argentina and Parringtonia gracilis from Tanzania are the best preserved and more abundant species. Although the monophyly of Erpetosuchidae is well supported, alternative high-level positions within Archosauria have been suggested, such as sister taxon to Crocodylomorpha, Aetosauria, or Ornithosuchidae. In order to improve the knowledge about the erpetosuchids, we performed a detailed description and paleoneurological reconstruction of the skull of Tarjadia ruthae, based on two articulated partial skulls (CRILAR-Pv 478 and CRILAR-Pv 495) and other fragmentary specimens. We analyzed the stratigraphic and geographic occurrence of historical and new specimens of Tarjadia and provided a new emended diagnosis (the same for the genus as for the species, due to monotypy) along with a comparative description of the cranial endocast. The skull of Tarjadia is robust, with a thick and strongly ornamented skull roof, triangular in dorsal view, with concave lateral margins at mid-length that form an abrupt widened posterior region. The external nares are the smallest openings of the skull. The antorbital fossa is deeply excavated and has a small heart-shaped fenestra with both lobes pointing anteriorly. The supratemporal fenestrae are as large and rounded as the orbits, and the infratemporal fenestrae are L-shaped with an extensive excavation along the jugal, quadratojugal and quadrate. The hemimandibles are low, slightly concave on the dentigerous region and strongly convex on the posterior region, conferring them a S-shaped profile in dorsal view. The external mandibular fenestra is small and elliptic, being twice longer than high. The maxillary dentition is restricted to the anterior to mid region of the rostrum. Since the braincase of both specimens is partially damaged, the dorsal surface of the brain could not be entirely reconstructed. As a result, the endocast is anteroposteriorly elongated and seemingly flat, and the cephalic flexure seems to be lower than expected for a suchian. The labyrinth is twice wider than high, the semicircular canals are remarkably straight, and the anterior canal is longer than the posterior one.
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Affiliation(s)
- J B Desojo
- División Paleontología Vertebrados, Facultad de Ciencias Naturales y Museo, La Plata, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | - M B von Baczko
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad Autónoma de Buenos Aires, Argentina
- Sección Paleontología de Vertebrados, Museo Argentino de Ciencias Naturales Bernardino Rivadavia, Ciudad Autónoma de Buenos Aires, Argentina
| | - M D Ezcurra
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad Autónoma de Buenos Aires, Argentina
- Sección Paleontología de Vertebrados, Museo Argentino de Ciencias Naturales Bernardino Rivadavia, Ciudad Autónoma de Buenos Aires, Argentina
| | - L E Fiorelli
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad Autónoma de Buenos Aires, Argentina
- Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja (CRILAR), UNLAR, SEGEMAR, UNCa, CONICET, Anillaco, La Rioja, Argentina
| | - A G Martinelli
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad Autónoma de Buenos Aires, Argentina
- Sección Paleontología de Vertebrados, Museo Argentino de Ciencias Naturales Bernardino Rivadavia, Ciudad Autónoma de Buenos Aires, Argentina
| | - P Bona
- División Paleontología Vertebrados, Facultad de Ciencias Naturales y Museo, La Plata, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | - M J Trotteyn
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad Autónoma de Buenos Aires, Argentina
- Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de San Juan, San Juan, Argentina
| | - M Lacerda
- Programa de Pós-Graduação em Zoologia, Museu Nacional, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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3
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Ollonen J, Khannoon ER, Macrì S, Vergilov V, Kuurne J, Saarikivi J, Soukainen A, Aalto IM, Werneburg I, Diaz RE, Di-Poï N. Dynamic evolutionary interplay between ontogenetic skull patterning and whole-head integration. Nat Ecol Evol 2024; 8:536-551. [PMID: 38200368 DOI: 10.1038/s41559-023-02295-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 11/29/2023] [Indexed: 01/12/2024]
Abstract
The arrangement and morphology of the vertebrate skull reflect functional and ecological demands, making it a highly adaptable structure. However, the fundamental developmental and macroevolutionary mechanisms leading to different vertebrate skull phenotypes remain unclear. Here we exploit the morphological diversity of squamate reptiles to assess the developmental and evolutionary patterns of skull variation and covariation in the whole head. Our geometric morphometric analysis of a complex squamate ontogenetic dataset (209 specimens, 169 embryos, 44 species), covering stages from craniofacial primordia to fully ossified bones, reveals that morphological differences between snake and lizard skulls arose gradually through changes in spatial relationships (heterotopy) followed by alterations in developmental timing or rate (heterochrony). Along with dynamic spatiotemporal changes in the integration pattern of skull bone shape and topology with surrounding brain tissues and sensory organs, we identify a relatively higher phenotypic integration of the developing snake head compared with lizards. The eye, nasal cavity and Jacobson's organ are pivotal in skull morphogenesis, highlighting the importance of sensory rearrangements in snake evolution. Furthermore, our findings demonstrate the importance of early embryonic, ontogenetic and tissue interactions in shaping craniofacial evolution and ecological diversification in squamates, with implications for the nature of cranio-cerebral relations across vertebrates.
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Affiliation(s)
- Joni Ollonen
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Eraqi R Khannoon
- Biology Department, College of Science, Taibah University, Al Madinah Al Munawwarah, Saudi Arabia
- Zoology Department, Faculty of Science, Fayoum University, Fayoum, Egypt
| | - Simone Macrì
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Vladislav Vergilov
- National Museum of Natural History, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Jaakko Kuurne
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Jarmo Saarikivi
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Arttu Soukainen
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Ida-Maria Aalto
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Ingmar Werneburg
- Senckenberg Centre for Human Evolution and Palaeoenvironment, Eberhard Karls Universität, Tübingen, Germany
- Fachbereich Geowissenschaften, Eberhard Karls Universität, Tübingen, Germany
| | - Raul E Diaz
- Department of Biological Sciences, California State University, Los Angeles, CA, USA
- Department of Herpetology, Natural History Museum of Los Angeles County, Los Angeles, CA, USA
| | - Nicolas Di-Poï
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland.
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4
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Yu C, Watanabe A, Qin Z, Logan King J, Witmer LM, Ma Q, Xu X. Avialan-like brain morphology in Sinovenator (Troodontidae, Theropoda). Commun Biol 2024; 7:168. [PMID: 38341492 PMCID: PMC10858883 DOI: 10.1038/s42003-024-05832-3] [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: 12/31/2022] [Accepted: 01/18/2024] [Indexed: 02/12/2024] Open
Abstract
Many modifications to the skull and brain anatomy occurred along the lineage encompassing non-avialan theropod dinosaurs and modern birds. Anatomical changes to the endocranium include an enlarged endocranial cavity, relatively larger optic lobes that imply elevated visual acuity, and proportionately smaller olfactory bulbs that suggest reduced olfactory capacity. Here, we use micro-computed tomographic (μCT) imaging to reconstruct the endocranium and its neuroanatomical features from an exceptionally well-preserved skull of Sinovenator changii (Troodontidae, Theropoda). While its overall morphology resembles the typical endocranium of other troodontids, Sinovenator also exhibits unique endocranial features that are similar to other paravian taxa and non-maniraptoran theropods. Landmark-based geometric morphometric analysis on endocranial shape of non-avialan and avialan dinosaurs points to the overall brain morphology of Sinovenator most closely resembling that of Archaeopteryx, thus indicating acquisition of avialan-grade brain morphology in troodontids and wide existence of such architecture in Maniraptora.
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Affiliation(s)
- Congyu Yu
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation & Institute of Sedimentary Geology, Chengdu University of Technology, Chengdu, 610059, China
- Key Laboratory of Deep-time Geography and Environment Reconstruction and Applications of Ministry of Natural Resources, Chengdu University of Technology, Chengdu, 610059, China
- Division of Paleontology, American Museum of Natural History, New York, NY, 10024, USA
| | - Akinobu Watanabe
- Division of Paleontology, American Museum of Natural History, New York, NY, 10024, USA
- Department of Anatomy, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY, 11568, USA
- Department of Life Sciences, Natural History Museum, London, SW7 5BD, UK
| | - Zichuan Qin
- Palaeontology Research Group, School of Earth Sciences, University of Bristol, Bristol, BS8 1RJ, UK
| | - J Logan King
- Palaeontology Research Group, School of Earth Sciences, University of Bristol, Bristol, BS8 1RJ, UK
- Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, 100044, China
| | - Lawrence M Witmer
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio Center for Ecological and Evolutionary Studies, Ohio University, Athens, OH, 45701, USA
| | - Qingyu Ma
- Chongqing Laboratory of Geological Heritage Protection and Research, No. 208 Hydrogeological and Engineering Geological Team, Chongqing Bureau of Geology and Minerals Exploration, Chongqing, 401121, China
| | - Xing Xu
- Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, 100044, China.
- Centre for Vertebrate Evolutionary Biology, Yunnan University, Kunming, 650091, China.
- Paleontological Museum of Liaoning, Shenyang Normal University, Liaoning Province, 253 North Huanghe Street, Shenyang, 110034, China.
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5
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Park J, Son M, Park J, Bang SY, Ha J, Moon H, Lee YN, Lee SI, Jablonski PG. Escape behaviors in prey and the evolution of pennaceous plumage in dinosaurs. Sci Rep 2024; 14:549. [PMID: 38272887 PMCID: PMC10811223 DOI: 10.1038/s41598-023-50225-x] [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: 04/26/2023] [Accepted: 12/16/2023] [Indexed: 01/27/2024] Open
Abstract
Numerous non-avian dinosaurs possessed pennaceous feathers on their forelimbs (proto-wings) and tail. Their functions remain unclear. We propose that these pennaceous feathers were used in displays to flush hiding prey through stimulation of sensory-neural escape pathways in prey, allowing the dinosaurs to pursue the flushed prey. We evaluated the escape behavior of grasshoppers to hypothetical visual flush-displays by a robotic dinosaur, and we recorded neurophysiological responses of grasshoppers' escape pathway to computer animations of the hypothetical flush-displays by dinosaurs. We show that the prey of dinosaurs would have fled more often when proto-wings were present, especially distally and with contrasting patterns, and when caudal plumage, especially of a large area, was used during the hypothetical flush-displays. The reinforcing loop between flush and pursue functions could have contributed to the evolution of larger and stiffer feathers for faster running, maneuverability, and stronger flush-displays, promoting foraging based on the flush-pursue strategy. The flush-pursue hypothesis can explain the presence and distribution of the pennaceous feathers, plumage color contrasts, as well as a number of other features observed in early pennaraptorans. This scenario highlights that sensory-neural processes underlying prey's antipredatory reactions may contribute to the origin of major evolutionary innovations in predators.
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Affiliation(s)
- Jinseok Park
- School of Biological Sciences, Seoul National University, Seoul, South Korea
| | - Minyoung Son
- School of Earth and Environmental Sciences, Seoul National University, Seoul, South Korea
- Department of Earth and Environmental Sciences, University of Minnesota, Minneapolis, MN, USA
| | - Jeongyeol Park
- Department of Mechanical Engineering, Sungkyunkwan University, Suwon, South Korea
| | - Sang Yun Bang
- School of Biological Sciences, Seoul National University, Seoul, South Korea
| | - Jungmoon Ha
- School of Biological Sciences, Seoul National University, Seoul, South Korea
| | - Hyungpil Moon
- Department of Mechanical Engineering, Sungkyunkwan University, Suwon, South Korea.
| | - Yuong-Nam Lee
- School of Earth and Environmental Sciences, Seoul National University, Seoul, South Korea.
| | - Sang-Im Lee
- Department of New Biology, DGIST, Taegu, South Korea.
| | - Piotr G Jablonski
- School of Biological Sciences, Seoul National University, Seoul, South Korea.
- Museum and Institute of Zoology, Polish Academy of Sciences, Warsaw, Poland.
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6
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Button DJ, Zanno LE. Neuroanatomy of the late Cretaceous Thescelosaurus neglectus (Neornithischia: Thescelosauridae) reveals novel ecological specialisations within Dinosauria. Sci Rep 2023; 13:19224. [PMID: 37932280 PMCID: PMC10628235 DOI: 10.1038/s41598-023-45658-3] [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: 06/06/2023] [Accepted: 10/22/2023] [Indexed: 11/08/2023] Open
Abstract
Ornithischian dinosaurs exhibited a diversity of ecologies, locomotory modes, and social structures, making them an ideal clade in which to study the evolution of neuroanatomy and behaviour. Here, we present a 3D digital reconstruction of the endocranial spaces of the latest Cretaceous neornithischian Thescelosaurus neglectus, in order to interpret the neuroanatomy and paleobiology of one of the last surviving non-avian dinosaurs. Results demonstrate that the brain of Thescelosaurus was relatively small compared to most other neornithischians, instead suggesting cognitive capabilities within the range of extant reptiles. Other traits include a narrow hearing range, with limited ability to distinguish high frequencies, paired with unusually well-developed olfactory lobes and anterior semicircular canals, indicating acute olfaction and vestibular sensitivity. This character combination, in conjunction with features of the postcranial anatomy, is consistent with specializations for burrowing behaviours in the clade, as evidenced by trace and skeletal fossil evidence in earlier-diverging thescelosaurids, although whether they reflect ecological adaptations or phylogenetic inheritance in T. neglectus itself is unclear. Nonetheless, our results provide the first evidence of neurological specializations to burrowing identified within Ornithischia, and non-avian dinosaurs more generally, expanding the range of ecological adaptations recognized within this major clade.
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Affiliation(s)
- David J Button
- Bristol Palaeobiology Group, School of Earth Sciences, University of Bristol, Bristol, BS8 1TQ, UK.
| | - Lindsay E Zanno
- Paleontology, North Carolina Museum of Natural Sciences, Raleigh, NC, USA
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, USA
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7
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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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8
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Norton LA, Abdala F, Benoit J. Craniodental anatomy in Permian-Jurassic Cynodontia and Mammaliaformes (Synapsida, Therapsida) as a gateway to defining mammalian soft tissue and behavioural traits. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220084. [PMID: 37183903 PMCID: PMC10184251 DOI: 10.1098/rstb.2022.0084] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023] Open
Abstract
Mammals are diagnosed by more than 30 osteological characters (e.g. squamosal-dentary jaw joint, three inner ear ossicles, etc.) that are readily preserved in the fossil record. However, it is the suite of physiological, soft tissue and behavioural characters (e.g. endothermy, hair, lactation, isocortex and parental care), the evolutionary origins of which have eluded scholars for decades, that most prominently distinguishes living mammals from other amniotes. Here, we review recent works that illustrate how evolutionary changes concentrated in the cranial and dental morphology of mammalian ancestors, the Permian-Jurassic Cynodontia and Mammaliaformes, can potentially be used to document the origin of some of the most crucial defining features of mammals. We discuss how these soft tissue and behavioural traits are highly integrated, and how their evolution is intermingled with that of craniodental traits, thus enabling the tracing of their previously out-of-reach phylogenetic history. Most of these osteological and dental proxies, such as the maxillary canal, bony labyrinth and dental replacement only recently became more easily accessible-thanks, in large part, to the widespread use of X-ray microtomography scanning in palaeontology-because they are linked to internal cranial characters. This article is part of the theme issue 'The mammalian skull: development, structure and function'.
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Affiliation(s)
- Luke A Norton
- Evolutionary Studies Institute, University of the Witwatersrand, Private Bag 3, Wits 2050, Johannesburg, South Africa
| | - Fernando Abdala
- Evolutionary Studies Institute, University of the Witwatersrand, Private Bag 3, Wits 2050, Johannesburg, South Africa
- Unidad Ejecutora Lillo, CONICET-Fundación Miguel Lillo, Miguel Lillo 251, Tucumán 4000, Argentina
| | - Julien Benoit
- Evolutionary Studies Institute, University of the Witwatersrand, Private Bag 3, Wits 2050, Johannesburg, South Africa
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9
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Bazzana KD, Evans DC, Bevitt JJ, Reisz RR. Endocasts of the basal sauropsid Captorhinus reveal unexpected neurological diversity in early reptiles. Anat Rec (Hoboken) 2023; 306:552-563. [PMID: 36240106 DOI: 10.1002/ar.25100] [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: 06/24/2022] [Revised: 09/30/2022] [Accepted: 10/08/2022] [Indexed: 11/11/2022]
Abstract
Captorhinids are a group of Paleozoic amniotes that represents one of the earliest-diverging clades of eureptiles. Although captorhinids are one of the best-known and most well-studied clades of early amniotes, their palaeoneuroanatomy has gone largely unexamined. We utilized neutron computed tomography to study the virtual cranial and otic endocasts of two captorhinid specimens. The neurosensory anatomy of captorhinids shows a mixture of traits considered plesiomorphic for sauropsids (no expansions of the cerebrum or olfactory bulbs, low degree of encephalization, low ossification of the otic capsule) and those considered more derived, including moderate cephalic and pontine flexures and a dorsoventrally tall bony labyrinth. The inner ear clearly preserves the elliptical, sub-orthogonal canals and the short, rounded vestibule, along with an unusually enlarged lateral canal and a unique curvature of the posterior canal. The reconstructed neurosensory anatomy indicates that captorhinids were sensitive to slightly higher frequencies than many of their contemporaries, likely reflecting differences in body size across taxa, while the morphology of the maxillary canal suggests a simple, tubular condition as the plesiomorphic state for Sauropsida and contributes to the ongoing discussions regarding the phylogenetic placement of varanopids. This study represents the first detailed tomographic study of the brain and inner ear of any basal eureptile. The new data described here reveal that the neuroanatomy of early sauropsids is far more complex and diverse than previously anticipated, and provide impetus for further exploration of the palaeoneuroanatomy of early amniotes.
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Affiliation(s)
- Kayla D Bazzana
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada.,Department of Natural History, Royal Ontario Museum, Toronto, Ontario, Canada
| | - David C Evans
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada.,Department of Natural History, Royal Ontario Museum, Toronto, Ontario, Canada
| | - Joseph J Bevitt
- Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation, Lucas Heights, New South Wales, Australia
| | - Robert R Reisz
- Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada
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10
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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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11
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Evers SW, Joyce WG, Choiniere JN, Ferreira GS, Foth C, Hermanson G, Yi H, Johnson CM, Werneburg I, Benson RBJ. Independent origin of large labyrinth size in turtles. Nat Commun 2022; 13:5807. [PMID: 36220806 PMCID: PMC9553989 DOI: 10.1038/s41467-022-33091-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 09/01/2022] [Indexed: 11/30/2022] Open
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.
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Affiliation(s)
- Serjoscha W Evers
- Department of Geosciences, University of Fribourg, Chemin du Musée 6, 1700, Fribourg, Switzerland.
- Department of Earth Sciences, University of Oxford, South Parks Road, Oxford, OX1 3AN, United Kingdom.
| | - Walter G Joyce
- Department of Geosciences, University of Fribourg, Chemin du Musée 6, 1700, Fribourg, Switzerland
| | - Jonah N Choiniere
- Evolutionary Studies Institute, University of the Witwatersrand, 1 Jan Smuts Avenue, Johannesburg, 2000, South Africa
| | - Gabriel S Ferreira
- Senckenberg Centre for Human Evolution and Paleoenvironment an der Universität Tübingen, Sigwartstraße 10, 72076, Tübingen, Germany
- Fachbereich Geowissenschaften, Universität Tübingen, Hölderlinstraße 12, 72074, Tübingen, Germany
| | - Christian Foth
- Department of Geosciences, University of Fribourg, Chemin du Musée 6, 1700, Fribourg, Switzerland
| | - Guilherme Hermanson
- Department of Geosciences, University of Fribourg, Chemin du Musée 6, 1700, Fribourg, Switzerland
- Laboratório de Paleontologia de Ribeirão Preto, FFCLRP, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Hongyu Yi
- Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences Beijing, 100049, Beijing, China
- CAS Center for Excellence in Life and Paleoenvironment Beijing, 100044, Beijing, China
| | - Catherine M Johnson
- Department of Earth Sciences, University of Oxford, South Parks Road, Oxford, OX1 3AN, United Kingdom
| | - Ingmar Werneburg
- Senckenberg Centre for Human Evolution and Paleoenvironment an der Universität Tübingen, Sigwartstraße 10, 72076, Tübingen, Germany
- Fachbereich Geowissenschaften, Universität Tübingen, Hölderlinstraße 12, 72074, Tübingen, Germany
| | - Roger B J Benson
- Department of Earth Sciences, University of Oxford, South Parks Road, Oxford, OX1 3AN, United Kingdom
- Evolutionary Studies Institute, University of the Witwatersrand, 1 Jan Smuts Avenue, Johannesburg, 2000, South Africa
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12
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Navalón G, Chiappe LM, Martinelli AG, Nava W, Field DJ. Fossil basicranium clarifies the origin of the avian central nervous system and inner ear. Proc Biol Sci 2022; 289:20221398. [PMID: 36168759 PMCID: PMC9515635 DOI: 10.1098/rspb.2022.1398] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Among terrestrial vertebrates, only crown birds (Neornithes) rival mammals in terms of relative brain size and behavioural complexity. Relatedly, the anatomy of the avian central nervous system and associated sensory structures, such as the vestibular system of the inner ear, are highly modified with respect to those of other extant reptile lineages. However, a dearth of three-dimensional Mesozoic fossils has limited our knowledge of the origins of the distinctive endocranial structures of crown birds. Traits such as an expanded, flexed brain, a ventral connection between the brain and spinal column, and a modified vestibular system have been regarded as exclusive to Neornithes. Here, we demonstrate all of these ‘advanced’ traits in an undistorted braincase from an Upper Cretaceous enantiornithine bonebed in southeastern Brazil. Our discovery suggests that these crown bird-like endocranial traits may have originated prior to the split between Enantiornithes and the more crownward portion of avian phylogeny over 140 Ma, while coexisting with a remarkably plesiomorphic cranial base and posterior palate region. Altogether, our results support the interpretation that the distinctive endocranial morphologies of crown birds and their Mesozoic relatives are affected by complex trade-offs between spatial constraints during development.
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Affiliation(s)
- Guillermo Navalón
- Unidad de Paleontología, Departamento de Biología, Universidad Autónoma de Madrid, Madrid, Spain.,Department of Earth Sciences, University of Cambridge, Cambridge, UK
| | - Luis M Chiappe
- Dinosaur Institute, Natural History Museum of Los Angeles, 900 Exposition Boulevard, Los Angeles, CA 90007, USA
| | - Agustín G Martinelli
- Sección Paleontología de Vertebrados, CONICET-Museo Argentino de Ciencias Naturales 'Bernardino Rivadavia', Buenos Aires, Argentina
| | - William Nava
- Museu de Paleontologia de Marília, Marília, São Paulo, Brazil
| | - Daniel J Field
- Department of Earth Sciences, University of Cambridge, Cambridge, UK.,Museum of Zoology, University of Cambridge, Cambridge, UK
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13
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David R, Bronzati M, Benson RBJ. Comment on "The early origin of a birdlike inner ear and the evolution of dinosaurian movement and vocalization". Science 2022; 376:eabl6710. [PMID: 35737763 DOI: 10.1126/science.abl6710] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Hanson et al. (Research Articles, 7 May 2021, p. 601) claim that the shape of the vestibular apparatus reflects the evolution of reptilian locomotion. Using biomechanics, we demonstrate that semicircular canal shape is a dubious predictor of semicircular duct function. Additionally, we show that the inference methods used by Hanson et al. largely overestimate relationships between semicircular canal shape and locomotion.
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Affiliation(s)
- Romain David
- Centre for Human Evolution Research, Natural History Museum, London, UK
| | - Mario Bronzati
- Department of Biology, University of São Paulo, Ribeirão Preto, Brazil
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14
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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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15
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Tahara R, Larsson HCE. Paratympanic sinuses in juvenile Alligator. Anat Rec (Hoboken) 2022; 305:2926-2979. [PMID: 35591791 DOI: 10.1002/ar.24932] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 02/14/2022] [Accepted: 03/09/2022] [Indexed: 11/12/2022]
Abstract
Crocodylia has an extensive epithelial pneumatic space in the middle ear, paratympanic sinus system. Although fossil and extant crocodylian paratympanic sinus systems have been studied recently using the computed tomography (CT) and three-dimensional (3D) reconstruction data, due to the soft tissue nature of the pneumatic system and presence of its surrounding soft tissue structures, some boundaries, and definitions of each extension remain ambiguous. We describe the comprehensive paratympanic sinus system in posthatched alligator using soft tissue enhanced CT data with 3D reconstructions. The data are compared to the available data to discuss the ontogenetic pattern in alligator. We introduce further divided entities of the pneumatic system based on their associated bony and soft tissue structures and epithelial membrane and clarify the pneumatic terminologies. We then re-visit the potential homology of the paratympanic sinus in Archosauria. Epithelial boundaries of the ventral portion of the pneumatic system from the histological data suggest that the dual origin of the basioccipital diverticulum derived from the tympanic sinus and basicranial diverticulum medially. The presence of the epithelial boundary and pneumatic changes in ontogeny suggests that the middle ear may function differently in developmental stages. Lastly, a morphogenetic tree is constructed to help future work of comparative developmental studies of the paratympanic sinus system between crocodiles and birds.
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Affiliation(s)
- Rui Tahara
- Redpath Museum, McGill University, Montreal, Quebec, Canada
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16
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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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17
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Schade M, Stumpf S, Kriwet J, Kettler C, Pfaff C. Neuroanatomy of the nodosaurid Struthiosaurus austriacus (Dinosauria: Thyreophora) supports potential ecological differentiations within Ankylosauria. Sci Rep 2022; 12:144. [PMID: 34996895 PMCID: PMC8741922 DOI: 10.1038/s41598-021-03599-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 12/06/2021] [Indexed: 11/09/2022] Open
Abstract
Nodosauridae is a group of thyreophoran dinosaurs characterized by a collar of prominent osteoderms. In comparison to its sister group, the often club-tailed ankylosaurids, a different lifestyle of nodosaurids could be assumed based on their neuroanatomy and weaponry, e.g., regarding applied defensive strategies. The holotype of the nodosaurid Struthiosaurus austriacus consists of a single partial braincase from the Late Cretaceous of Austria. Since neuroanatomy is considered to be associated with ecological tendencies, we created digital models of the braincase based on micro-CT data. The cranial endocast of S. austriacus generally resembles those of its relatives. A network of vascular canals surrounding the brain cavity further supports special thermoregulatory adaptations within Ankylosauria. The horizontal orientation of the lateral semicircular canal independently confirms previous appraisals of head posture for S. austriacus and, hence, strengthens the usage of the LSC as proxy for habitual head posture in fossil tetrapods. The short anterior and angular lateral semicircular canals, combined with the relatively shortest dinosaurian cochlear duct known so far and the lack of a floccular recess suggest a rather inert lifestyle without the necessity of sophisticated senses for equilibrium and hearing in S. austriacus. These observations agree with an animal that adapted to a comparatively inactive lifestyle with limited social interactions.
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Affiliation(s)
- Marco Schade
- Institute of Geography and Geology, Palaeontology and Historical Geology, University of Greifswald, 17489, Greifswald, Germany. .,Zoological Institute and Museum, Cytology and Evolutionary Biology, University of Greifswald, 17489, Greifswald, Germany. .,Department of Earth and Environmental Sciences, Palaeontology and Geobiology, Ludwig-Maximilians-Universität, 80333, Munich, Germany.
| | - Sebastian Stumpf
- Department of Palaeontology, Faculty of Earth Sciences, Geography and Astronomy, University of Vienna, 1090, Vienna, Austria
| | - Jürgen Kriwet
- Department of Palaeontology, Faculty of Earth Sciences, Geography and Astronomy, University of Vienna, 1090, Vienna, Austria
| | - Christoph Kettler
- Department of Geology, Faculty of Earth Sciences, Geography and Astronomy, University of Vienna, 1090, Vienna, Austria
| | - Cathrin Pfaff
- Department of Palaeontology, Faculty of Earth Sciences, Geography and Astronomy, University of Vienna, 1090, Vienna, Austria.
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18
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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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19
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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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