1
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Gayford JH, Brazeau MD, Naylor GJP. Evolutionary trends in the elasmobranch neurocranium. Sci Rep 2024; 14:11471. [PMID: 38769415 PMCID: PMC11106257 DOI: 10.1038/s41598-024-62004-3] [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: 02/23/2024] [Accepted: 05/13/2024] [Indexed: 05/22/2024] Open
Abstract
The neurocranium (braincase) is one of the defining vertebrate characters. Housing the brain and other key sensory organs, articulating with the jaws and contributing to the shape of the anteriormost portion of the body, the braincase is undoubtedly of great functional importance. Through studying relationships between braincase shape and ecology we can gain an improved understanding of form-function relationships in extant and fossil taxa. Elasmobranchii (sharks and rays) represent an important case study of vertebrate braincase diversity as their neurocranium is simplified and somewhat decoupled from other components of the cranium relative to other vertebrates. Little is known about the associations between ecology and braincase shape in this clade. In this study we report patterns of mosaic cranial evolution in Elasmobranchii that differ significantly from those present in other clades. The degree of evolutionary modularity also differs between Selachii and Batoidea. In both cases innovation in the jaw suspension appears to have driven shifts in patterns of integration and modularity, subsequently facilitating ecological diversification. Our results confirm the importance of water depth and biogeography as drivers of elasmobranch cranial diversity and indicate that skeletal articulation between the neurocranium and jaws represents a major constraint upon the evolution of braincase shape in vertebrates.
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Affiliation(s)
- Joel H Gayford
- Department of Life Sciences, Silwood Park Campus, Imperial College London, London, UK.
- Shark Measurements, London, UK.
| | - Martin D Brazeau
- Department of Life Sciences, Silwood Park Campus, Imperial College London, London, UK
- The Natural History Museum, Cromwell Road, London, SW7 5BD, UK
| | - Gavin J P Naylor
- Florida Museum of Natural History, University of Florida, Gainesville, FL, USA
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2
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Klimpfinger C, Kriwet J. Morphological Variability and Function of Labial Cartilages in Sharks (Chondrichthyes, Elasmobranchii). BIOLOGY 2023; 12:1486. [PMID: 38132312 PMCID: PMC10741050 DOI: 10.3390/biology12121486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 11/29/2023] [Accepted: 12/01/2023] [Indexed: 12/23/2023]
Abstract
(1) Background: Labial cartilages (LCs), as their name suggests, lie in the folds of the connective tissue, the lips, framing the gape of elasmobranch chondrichthyans. As such, these cartilages lie laterally to the jaws and marginal teeth. They are considered to influence the ability of creating suction during the feeding process. As past studies have shown, LCs in sharks are as diverse as their varied feeding techniques and differ between species in number, size, shape, and position. This allows establishing parameters for inferring the feeding and hunting behaviors in these ecologically important fishes. (2) Methods: We present a study of LCs based on the CT scans of more than 100 extant shark species and, therefore, represent at least one member of every living family within the Euselachii, excluding batoids. (3) Results: Accordingly, sharks without labial cartilages or that have only small remnants are ram feeders or use pure biting and mainly occupy higher trophic levels (tertiary and quaternary consumers), whereas suction-feeding sharks have higher numbers (up to five pairs) of well-developed LCs and occupy slightly lower trophic levels (mainly secondary consumers). Species with unique feeding strategies, like the cookie-cutter shark (Isistius brasiliensis, an ectoparasite), display distinct shapes of LCs, while generalist species, conversely, exhibit a simpler arrangement of LCs. (4) Conclusions: We propose a dichotomous identification key to classify single LCs into different morphotypes and propose combinations of morphotypes that result in suction feeding differing in strength and, therefore, different hunting and feeding strategies. The conclusions of this study allow to infer information about feeding strategies not only in extant less-known sharks but also extinct sharks.
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3
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Motani R, Shimada K. Skeletal convergence in thunniform sharks, ichthyosaurs, whales, and tunas, and its possible ecological links through the marine ecosystem evolution. Sci Rep 2023; 13:16664. [PMID: 37794094 PMCID: PMC10550938 DOI: 10.1038/s41598-023-41812-z] [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: 05/25/2023] [Accepted: 08/31/2023] [Indexed: 10/06/2023] Open
Abstract
Tunas, lamnid sharks, modern whales, and derived ichthyosaurs converged on the thunniform body plan, with a fusiform body, lunate caudal fin, compressed peduncle, and peduncle joint. This evolutionary convergence has been studied for a long time but little is known about whether all four clades share any skeletal characteristics. Comparisons of vertebral centrum dimensions along the body reveal that the four clades indeed share three skeletal characteristics (e.g., thick vertebral column for its length), while an additional feature is shared by cetaceans, lamnid sharks, and ichthyosaurs and two more by lamnid sharks and ichthyosaurs alone. These vertebral features are all related to the mechanics of thunniform swimming through contributions to posterior concentration of tail-stem oscillation, tail stem stabilization, peduncle joint flexibility, and caudal fin angle fixation. Quantitative identifications of these features in fossil vertebrates would allow an inference of whether they were a thunniform swimmer. Based on measurements in the literature, mosasaurs lacked these features and were probably not thunniform swimmers, whereas a Cretaceous lamniform shark had a mosaic of thunniform and non-thunniform features. The evolution of thunniform swimming appears to be linked with the evolution of prey types and, in part, niche availability through geologic time.
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Affiliation(s)
- Ryosuke Motani
- Department of Earth and Planetary Sciences, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA.
| | - Kenshu Shimada
- Department of Environmental Science and Studies, DePaul University, 1110 West Belden Avenue, Chicago, IL, 60614, USA
- Department of Biological Sciences, DePaul University, 2325 North Clifton Avenue, Chicago, IL, 60614, USA
- Sternberg Museum of Natural History, Fort Hays State University, Hays, KS, 67601, USA
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4
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Motani R. Paleomass for R-bracketing body volume of marine vertebrates with 3D models. PeerJ 2023; 11:e15957. [PMID: 37641602 PMCID: PMC10460563 DOI: 10.7717/peerj.15957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 08/03/2023] [Indexed: 08/31/2023] Open
Abstract
Body mass is arguably the most important characteristic of an organism, yet it is often not available in biological samples that have been skeletonized, liquid-preserved, or fossilized. The lack of information is especially problematic for fossil species, for which individuals with body mass information are not available anywhere. Multiple methods are available for estimating the body mass of fossil terrestrial vertebrates but those for their marine counterparts are limited. Paleomass is a software tool for estimating the body mass of marine vertebrates from their orthogonal silhouettes through bracketing. It generates a set of two 3D models from these silhouettes, assuming superelliptical body cross-sections with different exponent values. By setting the exponents appropriately, it is possible to bracket the true volume of the animal between those of the two models. The original version phased out together with the language platform it used. A new version is reported here as an open-source package based on the R scripting language. It inherits the underlying principles of the original version but has been completely rewritten with a new architecture. For example, it first produces 3D mesh models of the animal and then measures their volumes and areas with the VCG library, unlike the original version that did not produce a 3D model but instead computed the volume and area segment by segment using parametric equations. The new version also exports 3D models in polygon meshes, allowing later tests by other software. Other improvements include the use of NACA foil sections for hydrofoils such as flippers, and optional interpolation with local regression. The software has a high accuracy, with the mean absolute errors of 1.33% when the silhouettes of the animals are known.
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Affiliation(s)
- Ryosuke Motani
- Departement of Earth and Planetary Sciences, University of California, Davis, Davis, California, United States of America
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5
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López-Romero FA, Stumpf S, Kamminga P, Böhmer C, Pradel A, Brazeau MD, Kriwet J. Shark mandible evolution reveals patterns of trophic and habitat-mediated diversification. Commun Biol 2023; 6:496. [PMID: 37156994 PMCID: PMC10167336 DOI: 10.1038/s42003-023-04882-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 04/27/2023] [Indexed: 05/10/2023] Open
Abstract
Environmental controls of species diversity represent a central research focus in evolutionary biology. In the marine realm, sharks are widely distributed, occupying mainly higher trophic levels and varied dietary preferences, mirrored by several morphological traits and behaviours. Recent comparative phylogenetic studies revealed that sharks present a fairly uneven diversification across habitats, from reefs to deep-water. We show preliminary evidence that morphological diversification (disparity) in the feeding system (mandibles) follows these patterns, and we tested hypotheses linking these patterns to morphological specialisation. We conducted a 3D geometric morphometric analysis and phylogenetic comparative methods on 145 specimens representing 90 extant shark species using computed tomography models. We explored how rates of morphological evolution in the jaw correlate with habitat, size, diet, trophic level, and taxonomic order. Our findings show a relationship between disparity and environment, with higher rates of morphological evolution in reef and deep-water habitats. Deep-water species display highly divergent morphologies compared to other sharks. Strikingly, evolutionary rates of jaw disparity are associated with diversification in deep water, but not in reefs. The environmental heterogeneity of the offshore water column exposes the importance of this parameter as a driver of diversification at least in the early part of clade history.
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Affiliation(s)
- Faviel A López-Romero
- University of Vienna, Faculty of Earth Sciences, Geography and Astronomy, Department of Palaeontology, Evolutionary Morphology Research Group, Josef-Holaubek-Platz 2, 1190, Vienna, Austria.
- University of Vienna, Vienna Doctoral School of Ecology and Evolution (VDSEE), Djerassiplatz 1, 1030, Vienna, Austria.
| | - Sebastian Stumpf
- University of Vienna, Faculty of Earth Sciences, Geography and Astronomy, Department of Palaeontology, Evolutionary Morphology Research Group, Josef-Holaubek-Platz 2, 1190, Vienna, Austria
| | - Pepijn Kamminga
- Naturalis Biodiversity Center, Darwinweg 2, 2333 CR, Leiden, The Netherlands
| | - Christine Böhmer
- MECADEV UMR 7179 CNRS/MNHN, Département Adaptations du Vivant, Muséum National d'Histoire Naturelle, CP 55, 57 rue Cuvier, 75231, Paris, France
- Department für Geo- und Umweltwissenschaften und GeoBio-Center, Ludwig-Maximilians-Universität München, Richard-Wagner-Straße 10, 80333, München, Germany
- Zoologisches Institut, Christian-Albrechts-Universität zu Kiel, Am Botanischen Garten 1-9, 24118, Kiel, Germany
| | - Alan Pradel
- CR2P, Centre de Recherche en Paléontologie - Paris, Muséum National d'Histoire Naturelle-Sorbonne Université-CNRS, CP 38, 57 rue Cuvier, F75231, Paris, Cedex 05, France
| | - Martin D Brazeau
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, SL5 7PY, London, UK
- The Natural History Museum, Cromwell Road, London, SW7 5BD, UK
| | - Jürgen Kriwet
- University of Vienna, Faculty of Earth Sciences, Geography and Astronomy, Department of Palaeontology, Evolutionary Morphology Research Group, Josef-Holaubek-Platz 2, 1190, Vienna, Austria
- University of Vienna, Vienna Doctoral School of Ecology and Evolution (VDSEE), Djerassiplatz 1, 1030, Vienna, Austria
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6
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Capretz Batista Da Silva JP, Shimada K, Datovo A. The importance of the appendicular skeleton for the phylogenetic reconstruction of lamniform sharks (Chondrichthyes: Elasmobranchii). J Morphol 2023; 284:e21585. [PMID: 37059594 DOI: 10.1002/jmor.21585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 03/21/2023] [Accepted: 03/28/2023] [Indexed: 04/16/2023]
Abstract
Lamniform sharks are one of the more conspicuous groups of elasmobranchs, including several emblematic taxa as the white shark. Although their monophyly is well supported, the interrelationships of taxa within Lamniformes remains controversial because of the conflict among various previous molecular-based and morphology-based phylogenetic hypotheses. In this study, we use 31 characters related to the appendicular skeleton of lamniforms and demonstrate their ability to resolve the systematic interrelationships within this shark order. In particular, the new additional skeletal characters resolve all polytomies that were present in previous morphology-based phylogenetic analyses of lamniforms. Our study demonstrates the strength of incorporating new morphological data for phylogenetic reconstructions.
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Affiliation(s)
- João Paulo Capretz Batista Da Silva
- Departamento de Sistemática e Ecologia, Centro de Ciências Exatas e da Natureza, Universidade Federal da Paraíba, Castelo Branco, João Pessoa, Paraíba, Brazil
| | - Kenshu Shimada
- Department of Biological Sciences, DePaul University, Chicago, Illinois, USA
- Department of Environmental Science and Studies DePaul University, Chicago, Illinois, USA
- Sternberg Museum of Natural History, Fort Hays State University, Hays, Kansas, USA
| | - Aléssio Datovo
- Museu de Zoologia da Universidade de São Paulo, São Paulo, São Paulo, Brazil
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7
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Staggl MA, Ruthensteiner B, Straube N. Head anatomy of a lantern shark wet-collection specimen (Chondrichthyes: Etmopteridae). J Anat 2023; 242:872-890. [PMID: 36695312 PMCID: PMC10093163 DOI: 10.1111/joa.13822] [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: 05/11/2022] [Revised: 12/16/2022] [Accepted: 12/23/2022] [Indexed: 01/26/2023] Open
Abstract
In this study, we apply a two-step (untreated and soft tissue stained) diffusible iodine-based contrast-enhanced micro-computed tomography array to a wet-collection Lantern Shark specimen of Etmopterus lucifer. The focus of our scanning approach is the head anatomy. The unstained CT data allow the imaging of mineralized (skeletal) tissue, while results for soft tissue were achieved after staining for 120 h in a 1% ethanolic iodine solution. Three-dimensional visualization after the segmentation of hard as well as soft tissue reveals new details of tissue organization and allows us to draw conclusions on the significance of organs in their function. Outstanding are the ampullae of Lorenzini for electroreception, which appear as the dominant sense along with the olfactory system. Corresponding brain areas of these sensory organs are significantly enlarged as well and likely reflect adaptations to the lantern sharks' deep-sea habitat. While electroreception supports the capture of living prey, the enlarged olfactory system can guide the scavenging of these opportunistic feeders. Compared to other approaches based on the manual dissection of similar species, CT scanning is superior in some but not all aspects. For example, fenestrae of the cranial nerves within the chondrocranium cannot be identified reflecting the limitations of the method, however, CT scanning is less invasive, and the staining is mostly reversible and can be rinsed out.
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Affiliation(s)
- Manuel Andreas Staggl
- Department of Biology II, Ludwig-Maximilians-Universität München, München, Germany.,SNSB-Bavarian State Collection of Zoology, Munich, Germany.,Department of Palaeontology, Faculty of Earth Sciences, Geography and Astronomy, University of Vienna, Vienna, Austria.,Vienna Doctoral School of Ecology and Evolution (VDSEE), University of Vienna, Vienna, Austria
| | | | - Nicolas Straube
- SNSB-Bavarian State Collection of Zoology, Munich, Germany.,Department of Natural History, University Museum of Bergen, Bergen, Norway
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8
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Dearden RP, Giles S. Diverse stem-chondrichthyan oral structures and evidence for an independently acquired acanthodid dentition. ROYAL SOCIETY OPEN SCIENCE 2021; 8:210822. [PMID: 34804566 PMCID: PMC8580420 DOI: 10.1098/rsos.210822] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Accepted: 10/22/2021] [Indexed: 06/13/2023]
Abstract
The teeth of sharks famously form a series of transversely organized files with a conveyor-belt replacement that are borne directly on the jaw cartilages, in contrast to the dermal plate-borne dentition of bony fishes that undergoes site-specific replacement. A major obstacle in understanding how this system evolved is the poorly understood relationships of the earliest chondrichthyans and the profusion of morphologically and terminologically diverse bones, cartilages, splints and whorls that they possess. Here, we use tomographic methods to investigate mandibular structures in several early branching 'acanthodian'-grade stem-chondrichthyans. We show that the dentigerous jaw bones of disparate genera of ischnacanthids are united by a common construction, being growing bones with non-shedding dentition. Mandibular splints, which support the ventro-lateral edge of the Meckel's cartilage in some taxa, are formed from dermal bone and may be an acanthodid synapomorphy. We demonstrate that the teeth of Acanthodopsis are borne directly on the mandibular cartilage and that this taxon is deeply nested within an edentulous radiation, representing an unexpected independent origin of teeth. Many or even all of the range of unusual oral structures may be apomorphic, but they should nonetheless be considered when building hypotheses of tooth and jaw evolution, both in chondrichthyans and more broadly.
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Affiliation(s)
- Richard P. Dearden
- CR2P, Centre de Recherche en Paléontologie–Paris, Muséum national d'Histoire naturelle, Sorbonne Université, Centre National de la Recherche Scientifique, CP 38, 57 Rue Cuvier, F75231 Paris Cedex 05, France
| | - Sam Giles
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
- Department of Earth Sciences, Natural History Museum, Cromwell Road, London SW7 5BD, UK
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9
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Araújo J, Rodrigues R, Sousa F, Moura L, Silva A, Pessoa G, Macedo K, Costa F, Leitão K, Carvalho P, Alves F. Anatomical description of the skulls of peccaries (Tayassu tajacu, Linnaeus 1758) by computed tomography. ARQ BRAS MED VET ZOO 2021. [DOI: 10.1590/1678-4162-11979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
ABSTRACT The aim of this study was to evaluate the anatomical structures of the skulls of peccaries to establish the basis for their clinical study and future preclinical research. Ten skulls of adult peccaries were subjected to tomographic examination. The data obtained were processed via three-dimensional image reconstruction software (3D images). The reconstructions obtained from the neurocranium of the studied specimens allowed the identification and description of the following structures: nasal bone, frontal bone, parietal bones, incisor bone, maxillary bone, zygomatic bone, temporal bone, palatal bone, occipital bone, vomer bone, pterygoid bone, sphenoid bone, paranasal sinuses and orbit. Computed tomography proved to be an important diagnostic tool in the investigation of the skull of this species, allowing the acquisition of anatomical values not yet documented for the species in the literature.
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Affiliation(s)
| | | | | | | | | | | | | | - F.S. Costa
- Universidade Federal Rural de Pernambuco, Brazil
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10
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C. B. da Silva JP, B. Vaz DF. A redescription of the appendicular skeleton of
Squalus acanthias
(Elasmobranchii: Squaliformes: Squalidae). ACTA ZOOL-STOCKHOLM 2021. [DOI: 10.1111/azo.12394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- João Paulo C. B. da Silva
- Departamento de Sistemática e Ecologia Centro de Ciências Exatas e da Natureza Universidade Federal da Paraíba João Pessoa Brazil
| | - Diego F. B. Vaz
- Museum of Comparative Zoology Harvard University Cambridge MA USA
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11
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Cross-sectional anatomy, computed tomography, and magnetic resonance imaging of the banded houndshark (Triakis scyllium). Sci Rep 2021; 11:1165. [PMID: 33441855 PMCID: PMC7806778 DOI: 10.1038/s41598-020-80823-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 12/29/2020] [Indexed: 11/08/2022] Open
Abstract
Due to their important phylogenetic position among extant vertebrates, sharks are an invaluable group in evolutionary developmental biology studies. A thorough understanding of shark anatomy is essential to facilitate these studies and documentation of this iconic taxon. With the increasing availability of cross-sectional imaging techniques, the complicated anatomy of both cartilaginous and soft tissues can be analyzed non-invasively, quickly, and accurately. The aim of this study is to provide a detailed anatomical description of the normal banded houndshark (Triakis scyllium) using computed tomography (CT) and magnetic resonance imaging (MRI) along with cryosection images. Three banded houndsharks were scanned using a 64-detector row spiral CT scanner and a 3 T MRI scanner. All images were digitally stored and assessed using open-source Digital Imaging and Communications in Medicine viewer software in the transverse, sagittal, and dorsal dimensions. The banded houndshark cadavers were then cryosectioned at approximately 1-cm intervals. Corresponding transverse cryosection images were chosen to identify the best anatomical correlations for transverse CT and MRI images. The resulting images provided excellent detail of the major anatomical structures of the banded houndshark. The illustrations in the present study could be considered as a useful reference for interpretation of normal and pathological imaging studies of sharks.
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12
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Coatham SJ, Vinther J, Rayfield EJ, Klug C. Was the Devonian placoderm Titanichthys a suspension feeder? ROYAL SOCIETY OPEN SCIENCE 2020; 7:200272. [PMID: 32537223 PMCID: PMC7277245 DOI: 10.1098/rsos.200272] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 04/23/2020] [Indexed: 05/08/2023]
Abstract
Large nektonic suspension feeders have evolved multiple times. The apparent trend among apex predators for some evolving into feeding on small zooplankton is of interest for understanding the associated shifts in anatomy and behaviour, while the spatial and temporal distribution gives clues to an inherent relationship with ocean primary productivity and how past and future perturbations to these may impact on the different tiers of the food web. The evolution of large nektonic suspension feeders-'gentle giants'-occurred four times among chondrichthyan fishes (e.g. whale sharks, basking sharks and manta rays), as well as in baleen whales (mysticetes), the Mesozoic pachycormid fishes and at least twice in radiodontan stem group arthropods (Anomalocaridids) during the Cambrian explosion. The Late Devonian placoderm Titanichthys has tentatively been considered to have been a megaplanktivore, primarily due to its gigantic size and narrow, edentulous jaws while no suspension-feeding apparatus have ever been reported. Here, the potential for microphagy and other feeding behaviours in Titanichthys is assessed via a comparative study of jaw mechanics in Titanichthys and other placoderms with presumably differing feeding habits (macrophagy and durophagy). Finite-element models of the lower jaws of Titanichthys termieri in comparison to Dunkleosteus terrelli and Tafilalichthys lavocati reveal considerably less resistance to von Mises stress in this taxon. Comparisons with a selection of large-bodied extant taxa of similar ecological diversity reveal similar disparities in jaw stress resistance. Our results, therefore, conform to the hypothesis that Titanichthys was a suspension feeder with jaws ill-suited for biting and crushing but well suited for gaping ram feeding.
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Affiliation(s)
- Samuel J. Coatham
- Life Sciences Building, University of Bristol, 24 Tyndall Avenue, Bristol, UK
- Author for correspondence: Samuel J. Coatham e-mail:
| | - Jakob Vinther
- Life Sciences Building, University of Bristol, 24 Tyndall Avenue, Bristol, UK
| | - Emily J. Rayfield
- Life Sciences Building, University of Bristol, 24 Tyndall Avenue, Bristol, UK
| | - Christian Klug
- Paläontologisches Institut und Museum, Universität Zürich, Karl-Schmid-Strasse 4, 8006Zürich, Switzerland
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13
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Klimpfinger C, Kriwet J. Comparative morphology of labial cartilages in sharks (Chondrichthyes, Elasmobranchii). THE EUROPEAN ZOOLOGICAL JOURNAL 2020. [DOI: 10.1080/24750263.2020.1844323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Affiliation(s)
- C. Klimpfinger
- Department of Palaeontology, University of Vienna, Vienna, Austria
| | - J. Kriwet
- Department of Palaeontology, University of Vienna, Vienna, Austria
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14
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Gsaxner C, Wallner J, Chen X, Zemann W, Egger J. Facial model collection for medical augmented reality in oncologic cranio-maxillofacial surgery. Sci Data 2019; 6:310. [PMID: 31819060 PMCID: PMC6901520 DOI: 10.1038/s41597-019-0327-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 11/21/2019] [Indexed: 01/25/2023] Open
Abstract
Medical augmented reality (AR) is an increasingly important topic in many medical fields. AR enables x-ray vision to see through real world objects. In medicine, this offers pre-, intra- or post-interventional visualization of "hidden" structures. In contrast to a classical monitor view, AR applications provide visualization not only on but also in relation to the patient. However, research and development of medical AR applications is challenging, because of unique patient-specific anatomies and pathologies. Working with several patients during the development for weeks or even months is not feasible. One alternative are commercial patient phantoms, which are very expensive. Hence, this data set provides a unique collection of head and neck cancer patient PET-CT scans with corresponding 3D models, provided as stereolitography (STL) files. The 3D models are optimized for effective 3D printing at low cost. This data can be used in the development and evaluation of AR applications for head and neck surgery.
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Affiliation(s)
- Christina Gsaxner
- Department of Oral and Maxillofacial Surgery, Medical University of Graz, Auenbruggerplatz 6/1, 8036, Graz, Austria
- Computer Algorithms for Medicine Laboratory, Graz, Austria
- Institute for Computer Graphics and Vision, Graz University of Technology, Inffeldgasse 16c/II, 8010, Graz, Austria
| | - Jürgen Wallner
- Department of Oral and Maxillofacial Surgery, Medical University of Graz, Auenbruggerplatz 6/1, 8036, Graz, Austria.
- Computer Algorithms for Medicine Laboratory, Graz, Austria.
| | - Xiaojun Chen
- Shanghai Jiao Tong University, School of Mechanical Engineering, 800 Dong Chuan Road, Shanghai, 200240, China
| | - Wolfgang Zemann
- Department of Oral and Maxillofacial Surgery, Medical University of Graz, Auenbruggerplatz 6/1, 8036, Graz, Austria
| | - Jan Egger
- Department of Oral and Maxillofacial Surgery, Medical University of Graz, Auenbruggerplatz 6/1, 8036, Graz, Austria
- Computer Algorithms for Medicine Laboratory, Graz, Austria
- Institute for Computer Graphics and Vision, Graz University of Technology, Inffeldgasse 16c/II, 8010, Graz, Austria
- Shanghai Jiao Tong University, School of Mechanical Engineering, 800 Dong Chuan Road, Shanghai, 200240, China
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15
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Computed tomography data collection of the complete human mandible and valid clinical ground truth models. Sci Data 2019; 6:190003. [PMID: 30694227 PMCID: PMC6350631 DOI: 10.1038/sdata.2019.3] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 12/14/2018] [Indexed: 11/08/2022] Open
Abstract
Image-based algorithmic software segmentation is an increasingly important topic in many medical fields. Algorithmic segmentation is used for medical three-dimensional visualization, diagnosis or treatment support, especially in complex medical cases. However, accessible medical databases are limited, and valid medical ground truth databases for the evaluation of algorithms are rare and usually comprise only a few images. Inaccuracy or invalidity of medical ground truth data and image-based artefacts also limit the creation of such databases, which is especially relevant for CT data sets of the maxillomandibular complex. This contribution provides a unique and accessible data set of the complete mandible, including 20 valid ground truth segmentation models originating from 10 CT scans from clinical practice without artefacts or faulty slices. From each CT scan, two 3D ground truth models were created by clinical experts through independent manual slice-by-slice segmentation, and the models were statistically compared to prove their validity. These data could be used to conduct serial image studies of the human mandible, evaluating segmentation algorithms and developing adequate image tools.
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Simões TR, Caldwell MW, Tałanda M, Bernardi M, Palci A, Vernygora O, Bernardini F, Mancini L, Nydam RL. X-ray computed microtomography of Megachirella wachtleri. Sci Data 2018; 5:180244. [PMID: 30398474 PMCID: PMC6219415 DOI: 10.1038/sdata.2018.244] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 09/19/2018] [Indexed: 11/09/2022] Open
Abstract
Understanding the origin and early evolution of squamates has been a considerable challenge given the extremely scarce fossil record of early squamates and their poor degree of preservation. In order to overcome those limitations, we conducted high-resolution X-ray computed tomography (CT) studies on the fossil reptile Megachirella wachtleri (Middle Triassic, northern Italy), which revealed an important set of features indicating this is the oldest known fossil squamate in the world, predating the previous oldest record by ca. 75 million years. We also compiled a new phylogenetic data set comprising a large sample of diapsid reptiles (including morphological and molecular data) to investigate the phylogenetic relationships of early squamates and other reptile groups along with the divergence time of those lineages. The re-description of Megachirella and a new phylogenetic hypothesis of diapsid relationships are presented in a separate study. Here we present the data descriptors for the tomographic scans of Megachirella, which holds fundamental information to our understanding on the early evolution of one of the largest vertebrate groups on Earth today.
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Affiliation(s)
- Tiago R Simões
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
| | - Michael W Caldwell
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada.,Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
| | - Mateusz Tałanda
- Department of Palaeobiology and Evolution, Faculty of Biology, University of Warsaw, Żwirki we Wigury 101, 02-089 Warsaw, Poland
| | - Massimo Bernardi
- MUSE - Museo delle Scienze di Trento, Corso del Lavoro e della Scienza 3, Trento, 38123 Italy.,School of Earth Sciences, University of Bristol, Bristol, BS81RJ, UK
| | - Alessandro Palci
- College of Science and Engineering, Flinders University, Adelaide, South Australia 5042, Australia.,South Australian Museum, North Terrace, Adelaide, South Australia 5000, Australia
| | - Oksana Vernygora
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
| | - Federico Bernardini
- Museo Storico della Fisica e Centro di Studi e Ricerche "Enrico Fermi", Piazza del Viminale 1, 00184 Roma, Italy.,The "Abdus Salam" International Centre for Theoretical Physics, Strada Costiera 11, Trieste, 34151 Italy
| | - Lucia Mancini
- Elettra - Sincrotrone Trieste S.C.p.A., SS 14, Km 163.5, Area Science Park, Basovizza, 34149 Trieste, Italy
| | - Randall L Nydam
- Department of Anatomy, Arizona College of Osteopathic Medicine, Midwestern University, 19555N. 59th Dr., Glendale, AZ 85383, USA
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