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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Cui X, Friedman M, Yu Y, Zhu YA, Zhu M. Bony-fish-like scales in a Silurian maxillate placoderm. Nat Commun 2023; 14:7622. [PMID: 37993457 PMCID: PMC10665347 DOI: 10.1038/s41467-023-43557-9] [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: 06/12/2023] [Accepted: 11/13/2023] [Indexed: 11/24/2023] Open
Abstract
Major groups of jawed vertebrates exhibit contrasting conditions of dermal plates and scales. But the transition between these conditions remains unclear due to rare information on taxa occupying key phylogenetic positions. The 425-million-year-old fish Entelognathus combines an unusual mosaic of characters typically associated with jawed stem gnathostomes or crown gnathostomes. However, only the anterior part of the exoskeleton was previously known for this very crownward member of the gnathostome stem. Here, we report a near-complete post-thoracic exoskeleton of Entelognathus. Strikingly, its scales are large and some are rhomboid, bearing distinctive peg-and-socket articulations; this combination was previously only known in osteichthyans and considered a synapomorphy of that group. The presence in Entelognathus of an anal fin spine, previously only found in some stem chondrichthyans, further illustrates that many characters previously thought to be restricted to specific lineages within the gnathostome crown likely arose before the common ancestor of living jawed vertebrates.
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Affiliation(s)
- Xindong Cui
- Key Laboratory of Orogenic Belts and Crustal Evolution, School of Earth and Space Sciences, Peking University, 100871, Beijing, China
- CAS Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, 100044, Beijing, China
| | - Matt Friedman
- Museum of Paleontology and Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Yilun Yu
- CAS Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, 100044, Beijing, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - You-An Zhu
- CAS Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, 100044, Beijing, China.
| | - Min Zhu
- CAS Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, 100044, Beijing, China.
- University of Chinese Academy of Sciences, 100049, Beijing, China.
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3
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Brazeau MD, Castiello M, El Fassi El Fehri A, Hamilton L, Ivanov AO, Johanson Z, Friedman M. Fossil evidence for a pharyngeal origin of the vertebrate pectoral girdle. Nature 2023; 623:550-554. [PMID: 37914937 PMCID: PMC10651482 DOI: 10.1038/s41586-023-06702-4] [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: 04/14/2023] [Accepted: 10/02/2023] [Indexed: 11/03/2023]
Abstract
The origin of vertebrate paired appendages is one of the most investigated and debated examples of evolutionary novelty1-7. Paired appendages are widely considered as key innovations that enabled new opportunities for controlled swimming and gill ventilation and were prerequisites for the eventual transition from water to land. The past 150 years of debate8-10 has been shaped by two contentious theories4,5: the ventrolateral fin-fold hypothesis9,10 and the archipterygium hypothesis8. The latter proposes that fins and girdles evolved from an ancestral gill arch. Although studies in animal development have revived interest in this idea11-13, it is apparently unsupported by fossil evidence. Here we present palaeontological support for a pharyngeal basis for the vertebrate shoulder girdle. We use computed tomography scanning to reveal details of the braincase of Kolymaspis sibirica14, an Early Devonian placoderm fish from Siberia, that suggests a pharyngeal component of the shoulder. We combine these findings with refreshed comparative anatomy of placoderms and jawless outgroups to place the origin of the shoulder girdle on the sixth branchial arch. These findings provide a novel framework for understanding the origin of the pectoral girdle. Our evidence clarifies the location of the presumptive head-trunk interface in jawless fishes and explains the constraint on branchial arch number in gnathostomes15. The results revive a key aspect of the archipterygium hypothesis and help reconcile it with the ventrolateral fin-fold model.
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Affiliation(s)
- Martin D Brazeau
- Department of Life Sciences, Imperial College London, Ascot, UK.
- The Natural History Museum, London, UK.
| | - Marco Castiello
- Department of Life Sciences, Imperial College London, Ascot, UK
- London Academy of Excellence, London, United Kingdom
| | - Amin El Fassi El Fehri
- Department of Life Sciences, Imperial College London, Ascot, UK
- Paläontologisches Institut und Museum, Universität Zürich, Zurich, Switzerland
| | - Louis Hamilton
- Department of Life Sciences, Imperial College London, Ascot, UK
| | - Alexander O Ivanov
- Department of Sedimentary Geology, Institute of Earth Sciences, St Petersburg State University, St Petersburg, Russia
- Institute of Geology and Petroleum Technologies, Kazan Federal University, Kazan, Russia
| | | | - Matt Friedman
- The Natural History Museum, London, UK
- Museum of Paleontology, University of Michigan, Ann Arbor, MI, USA
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA
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4
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Klug C, Coates M, Frey L, Greif M, Jobbins M, Pohle A, Lagnaoui A, Haouz WB, Ginter M. Broad snouted cladoselachian with sensory specialization at the base of modern chondrichthyans. SWISS JOURNAL OF PALAEONTOLOGY 2023; 142:2. [PMID: 37009301 PMCID: PMC10050047 DOI: 10.1186/s13358-023-00266-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 02/11/2023] [Indexed: 06/19/2023]
Abstract
UNLABELLED Throughout the Silurian and Devonian, cartilaginous fish successively evolved their specialized skeletal and dental characteristics, and increasingly refined their sensory systems. The Late Devonian shark taxon Maghriboselache mohamezanei gen. et sp. n. from the eastern Anti-Atlas of Morocco is known from multiple specimens preserving most of its skeletal features, which in some instances are preserved in three dimensions. Key details of the dentition, jaws, and pectoral skeleton are shared with the iconic genus Cladoselache. Phylogenetic analyses place the family Cladoselachidae as the sister group of symmoriiforms and these groups as sister group of the holocephalans. Further phylogenetic results corroborate that the initial evolutionary radiation of crown chondrichthyans occurred within or before the Late Devonian. Remarkably, this new stem holocephalan is equipped with a wide snout and large laterally separated nasal capsules: the earliest known example of this condition in the chondrichthyan and (perhaps) gnathostome record. This suggests sensory specialization approaching that of extant broad-rostrum elasmobranchs and represents a significant addition to increasingly apparent ecomorphological diversity among early chondrichthyans. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1186/s13358-023-00266-6.
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Affiliation(s)
- Christian Klug
- Paläontologisches Institut und Museum, University of Zurich, Karl-Schmid-Strasse 4, 8006 Zürich, Switzerland
| | - Michael Coates
- Department of Organismal Biology and Anatomy, University of Chicago, 1027 E. 57Th St., Chicago, 60637 USA
| | - Linda Frey
- Paläontologisches Institut und Museum, University of Zurich, Karl-Schmid-Strasse 4, 8006 Zürich, Switzerland
| | - Merle Greif
- Paläontologisches Institut und Museum, University of Zurich, Karl-Schmid-Strasse 4, 8006 Zürich, Switzerland
| | - Melina Jobbins
- Paläontologisches Institut und Museum, University of Zurich, Karl-Schmid-Strasse 4, 8006 Zürich, Switzerland
| | - Alexander Pohle
- Institute for Geology, Mineralogy, and Geophysics, Ruhr University Bochum, Universitätsstraβe 150, 44801 Bochum, Germany
| | - Abdelouahed Lagnaoui
- Interdisciplinary Research Laboratory in Sciences, Education and Training, Higher School of Education and Training Berrechid (ESEFB), Hassan First University, Avenue de l’Université, B.P:218, 26100 Berrechid, Morocco
- Laboratory of Stratigraphy of Oil-and-Gas Bearing Reservoirs, Department of Paleontology and Stratigraphy, Institute of Geology and Petroleum Technologies, Federal University, Kremlyovskaya Str. 18, 420008 Kazan, Volga Region Russia
| | - Wahiba Bel Haouz
- Laboratory of Stratigraphy of Oil-and-Gas Bearing Reservoirs, Department of Paleontology and Stratigraphy, Institute of Geology and Petroleum Technologies, Federal University, Kremlyovskaya Str. 18, 420008 Kazan, Volga Region Russia
- Geosciences Laboratory, Department of Geology, Faculty of Sciences Ain Chock, Hassan II University, Km 8 Route d’El Jadida, 20100 Casablanca, Morocco
| | - Michal Ginter
- Faculty of Geology, University of Warsaw, Al. Żwirki I Wigury 93, 02-089 Warsaw, Poland
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5
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Villalobos-Segura E, Stumpf S, Türtscher J, Jambura PL, Begat A, López-Romero FA, Fischer J, Kriwet J. A Synoptic Review of the Cartilaginous Fishes (Chondrichthyes: Holocephali, Elasmobranchii) from the Upper Jurassic Konservat-Lagerstätten of Southern Germany: Taxonomy, Diversity, and Faunal Relationships. DIVERSITY 2023; 15:386. [PMID: 36950327 PMCID: PMC7614348 DOI: 10.3390/d15030386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/10/2023]
Abstract
The Late Jurassic-Early Cretaceous (164-100 Ma) represents one of the main transitional periods in life history. Recent studies unveiled a complex scenario in which abiotic and biotic factors and drivers on regional and global scales due to the fragmentation of Pangaea resulted in dramatic faunal and ecological turnovers in terrestrial and marine environments. However, chondrichthyan faunas from this interval have received surprisingly little recognition. The presence of numerous entire skeletons of chondrichthyans preserved in several localities in southern Germany, often referred to as Konservat-Lagerstätten (e.g., Nusplingen and the Solnhofen Archipelago), provides a unique opportunity of to study the taxonomic composition of these assemblages, their ecological distributions and adaptations, and evolutionary histories in detail. However, even after 160 years of study, the current knowledge of southern Germany's Late Jurassic chondrichthyan diversity remains incomplete. Over the last 20 years, the systematic study and bulk sampling of southern Germany's Late Jurassic deposits significantly increased the number of known fossil chondrichthyan genera from the region (32 in the present study). In the present work, the fossil record, and the taxonomic composition of Late Jurassic chondrichthyans from southern Germany are reviewed and compared with several contemporaneous assemblages from other sites in Europe. Our results suggest, inter alia, that the Late Jurassic chondrichthyans displayed extended distributions within Europe. However, it nevertheless also is evident that the taxonomy of Late Jurassic chondrichthyans is in urgent need of revision.
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Affiliation(s)
- Eduardo Villalobos-Segura
- Evolutionary Morphology Research Group, Department of Palaeontology, Faculty of Earth Sciences, Geography and Astronomy, University of Vienna, Josef-Holaubek-Platz 2, 1090 Vienna, Austria
| | - Sebastian Stumpf
- Evolutionary Morphology Research Group, Department of Palaeontology, Faculty of Earth Sciences, Geography and Astronomy, University of Vienna, Josef-Holaubek-Platz 2, 1090 Vienna, Austria
| | - Julia Türtscher
- Evolutionary Morphology Research Group, Department of Palaeontology, Faculty of Earth Sciences, Geography and Astronomy, University of Vienna, Josef-Holaubek-Platz 2, 1090 Vienna, Austria
- Vienna Doctoral School of Ecology and Evolution (VDSEE), University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria
| | - Patrick L. Jambura
- Evolutionary Morphology Research Group, Department of Palaeontology, Faculty of Earth Sciences, Geography and Astronomy, University of Vienna, Josef-Holaubek-Platz 2, 1090 Vienna, Austria
- Vienna Doctoral School of Ecology and Evolution (VDSEE), University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria
| | - Arnaud Begat
- Evolutionary Morphology Research Group, Department of Palaeontology, Faculty of Earth Sciences, Geography and Astronomy, University of Vienna, Josef-Holaubek-Platz 2, 1090 Vienna, Austria
- Vienna Doctoral School of Ecology and Evolution (VDSEE), University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria
| | - Faviel A. López-Romero
- Evolutionary Morphology Research Group, Department of Palaeontology, Faculty of Earth Sciences, Geography and Astronomy, University of Vienna, Josef-Holaubek-Platz 2, 1090 Vienna, Austria
| | - Jan Fischer
- Urweltmuseum GEOSKOP/Burg Lichtenberg (Pfalz), Burgstraße 19, 66871 Thallichtenberg, Germany
| | - Jürgen Kriwet
- Evolutionary Morphology Research Group, Department of Palaeontology, Faculty of Earth Sciences, Geography and Astronomy, University of Vienna, Josef-Holaubek-Platz 2, 1090 Vienna, Austria
- Vienna Doctoral School of Ecology and Evolution (VDSEE), University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria
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6
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Jambura PL, Villalobos-Segura E, Türtscher J, Begat A, Staggl MA, Stumpf S, Kindlimann R, Klug S, Lacombat F, Pohl B, Maisey JG, Naylor GJP, Kriwet J. Systematics and Phylogenetic Interrelationships of the Enigmatic Late Jurassic Shark Protospinax annectans Woodward, 1918 with Comments on the Shark-Ray Sister Group Relationship. DIVERSITY 2023; 15:311. [PMID: 36950326 PMCID: PMC7614347 DOI: 10.3390/d15030311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
The Late Jurassic elasmobranch Protospinax annectans is often regarded as a key species to our understanding of crown group elasmobranch interrelationships and the evolutionary history of this group. However, since its first description more than 100 years ago, its phylogenetic position within the Elasmobranchii (sharks and rays) has proven controversial, and a closer relationship between Protospinax and each of the posited superorders (Batomorphii, Squalomorphii, and Galeomorphii) has been proposed over the time. Here we revise this controversial taxon based on new holomorphic specimens from the Late Jurassic Konservat-Lagerstätte of the Solnhofen Archipelago in Bavaria (Germany) and review its skeletal morphology, systematics, and phylogenetic interrelationships. A data matrix with 224 morphological characters was compiled and analyzed under a molecular backbone constraint. Our results indicate a close relationship between Protospinax, angel sharks (Squatiniformes), and saw sharks (Pristiophoriformes). However, the revision of our morphological data matrix within a molecular framework highlights the lack of morphological characters defining certain groups, especially sharks of the order Squaliformes, hampering the phylogenetic resolution of Protospinax annectans with certainty. Furthermore, the monophyly of modern sharks retrieved by molecular studies is only weakly supported by morphological data, stressing the need for more characters to align morphological and molecular studies in the future.
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Affiliation(s)
- Patrick L. Jambura
- Department of Palaeontology, University of Vienna, Josef-Holaubek-Platz 2, 1090 Vienna, Austria
- Vienna Doctoral School of Ecology and Evolution (VDSEE), University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria
| | | | - Julia Türtscher
- Department of Palaeontology, University of Vienna, Josef-Holaubek-Platz 2, 1090 Vienna, Austria
- Vienna Doctoral School of Ecology and Evolution (VDSEE), University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria
| | - Arnaud Begat
- Department of Palaeontology, University of Vienna, Josef-Holaubek-Platz 2, 1090 Vienna, Austria
- Vienna Doctoral School of Ecology and Evolution (VDSEE), University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria
| | - Manuel Andreas Staggl
- Department of Palaeontology, University of Vienna, Josef-Holaubek-Platz 2, 1090 Vienna, Austria
- Vienna Doctoral School of Ecology and Evolution (VDSEE), University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria
| | - Sebastian Stumpf
- Department of Palaeontology, University of Vienna, Josef-Holaubek-Platz 2, 1090 Vienna, Austria
| | - René Kindlimann
- Haimuseum und Sammlung R. Kindlimann, 8607 Aathal-Seegräben, Switzerland
| | - Stefanie Klug
- School of Science (GAUSS), Georg–August Universität Göttingen, 37077 Göttingen, Germany
| | | | - Burkhard Pohl
- Interprospekt Group, 1724 Ferpicloz, Switzerland
- Wyoming Dinosaur Center, Thermopolis, WY 82443, USA
| | - John G. Maisey
- Department of Vertebrate Paleontology, American Natural History Museum, New York, NY 10024, USA
| | - Gavin J. P. Naylor
- Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA
| | - Jürgen Kriwet
- Department of Palaeontology, University of Vienna, Josef-Holaubek-Platz 2, 1090 Vienna, Austria
- Vienna Doctoral School of Ecology and Evolution (VDSEE), University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria
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7
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Greif M, Ferrón HG, Klug C. A new Meckel's cartilage from the Devonian Hangenberg black shale in Morocco and its position in chondrichthyan jaw morphospace. PeerJ 2022; 10:e14418. [PMID: 36573235 PMCID: PMC9789696 DOI: 10.7717/peerj.14418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 10/28/2022] [Indexed: 12/24/2022] Open
Abstract
Fossil chondrichthyan remains are mostly known from their teeth, scales or fin spines only, whereas their cartilaginous endoskeletons require exceptional preservational conditions to become fossilized. While most cartilaginous remains of Famennian (Late Devonian) chondrichthyans were found in older layers of the eastern Anti-Atlas, such fossils were unknown from the Hangenberg black shale (HBS) and only a few chondrichthyan teeth had been found therein previously. Here, we describe a Meckel's cartilage from the Hangenberg black shale in Morocco, which is the first fossil cartilage from these strata. Since no teeth or other skeletal elements have been found in articulation, we used elliptical Fourier (EFA), principal component (PCA), and hierarchical cluster (HCA) analyses to morphologically compare it with 41 chondrichthyan taxa of different size and age and to evaluate its possible systematic affiliation. PCA and HCA position the new specimen closest to some acanthodian and elasmobranch jaws. Accordingly, a holocephalan origin was excluded. The jaw shape as well as the presence of a polygonal pattern, typical for tessellated calcified cartilage, suggest a ctenacanth origin and we assigned the new HBS Meckel's cartilage to the order Ctenacanthiformes with reservations.
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Affiliation(s)
- Merle Greif
- Palaeontological Institute and Museum, University of Zürich, Zürich, Switzerland
| | - Humberto G. Ferrón
- Instituto Cavanilles de Biodiversidad i Biología Evolutiva, Universitat de València, Paterna, Valencia, Spain
| | - Christian Klug
- Palaeontological Institute and Museum, University of Zürich, Zürich, Switzerland
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8
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The Development of the Chimaeroid Pelvic Skeleton and the Evolution of Chondrichthyan Pelvic Fins. J Dev Biol 2022; 10:jdb10040053. [PMID: 36547475 PMCID: PMC9782884 DOI: 10.3390/jdb10040053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 10/11/2022] [Accepted: 11/01/2022] [Indexed: 12/14/2022] Open
Abstract
Pelvic girdles, fins and claspers are evolutionary novelties first recorded in jawed vertebrates. Over the course of the evolution of chondrichthyans (cartilaginous fish) two trends in the morphology of the pelvic skeleton have been suggested to have occurred. These evolutionary shifts involved both an enlargement of the metapterygium (basipterygium) and a transition of fin radial articulation from the pelvic girdle to the metapterygium. To determine how these changes in morphology have occurred it is essential to understand the development of extant taxa as this can indicate potential developmental mechanisms that may have been responsible for these changes. The study of the morphology of the appendicular skeleton across development in chondrichthyans is almost entirely restricted to the historical literature with little contemporary research. Here, we have examined the morphology and development of the pelvic skeleton of a holocephalan chondrichthyan, the elephant shark (Callorhinchus milii), through a combination of dissections, histology, and nanoCT imaging and redescribed the pelvic skeleton of Cladoselache kepleri (NHMUK PV P 9269), a stem holocephalan. To put our findings in their evolutionary context we compare them with the fossil record of chondrichthyans and the literature on pelvic development in elasmobranchs from the late 19th century. Our findings demonstrate that the pelvic skeleton of C. milii initially forms as a single mesenchymal condensation, consisting of the pelvic girdle and a series of fin rays, which fuse to form the basipterygium. The girdle and fin skeleton subsequently segment into distinct components whilst chondrifying. This confirms descriptions of the early pelvic development in Scyliorhinid sharks from the historical literature and suggests that chimaeras and elasmobranchs share common developmental patterns in their pelvic anatomy. Alterations in the location and degree of radial fusion during early development may be the mechanism responsible for changes in pelvic fin morphology over the course of the evolution of both elasmobranchs and holocephalans, which appears to be an example of parallel evolution.
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9
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Zhu YA, Li Q, Lu J, Chen Y, Wang J, Gai Z, Zhao W, Wei G, Yu Y, Ahlberg PE, Zhu M. The oldest complete jawed vertebrates from the early Silurian of China. Nature 2022; 609:954-958. [PMID: 36171378 DOI: 10.1038/s41586-022-05136-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 07/22/2022] [Indexed: 11/09/2022]
Abstract
Molecular studies suggest that the origin of jawed vertebrates was no later than the Late Ordovician period (around 450 million years ago (Ma))1,2. Together with disarticulated micro-remains of putative chondrichthyans from the Ordovician and early Silurian period3-8, these analyses suggest an evolutionary proliferation of jawed vertebrates before, and immediately after, the end-Ordovician mass extinction. However, until now, the earliest complete fossils of jawed fishes for which a detailed reconstruction of their morphology was possible came from late Silurian assemblages (about 425 Ma)9-13. The dearth of articulated, whole-body fossils from before the late Silurian has long rendered the earliest history of jawed vertebrates obscure. Here we report a newly discovered Konservat-Lagerstätte, which is marked by the presence of diverse, well-preserved jawed fishes with complete bodies, from the early Silurian (Telychian age, around 436 Ma) of Chongqing, South China. The dominant species, a 'placoderm' or jawed stem gnathostome, which we name Xiushanosteus mirabilis gen. et sp. nov., combines characters from major placoderm subgroups14-17 and foreshadows the transformation of the skull roof pattern from the placoderm to the osteichthyan condition10. The chondrichthyan Shenacanthus vermiformis gen. et sp. nov. exhibits extensive thoracic armour plates that were previously unknown in this lineage, and include a large median dorsal plate as in placoderms14-16, combined with a conventional chondrichthyan bauplan18,19. Together, these species reveal a previously unseen diversification of jawed vertebrates in the early Silurian, and provide detailed insights into the whole-body morphology of the jawed vertebrates of this period.
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Affiliation(s)
- You-An Zhu
- Key CAS Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences (CAS), Beijing, China.,CAS Center for Excellence in Life and Paleoenvironment, Beijing, China
| | - Qiang Li
- Research Center of Natural History and Culture, Qujing Normal University, Qujing, China.,Chongqing Institute of Geology and Mineral Resources, Chongqing, China
| | - Jing Lu
- Key CAS Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences (CAS), Beijing, China.,CAS Center for Excellence in Life and Paleoenvironment, Beijing, China.,College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yang Chen
- Key CAS Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences (CAS), Beijing, China.,Chongqing Institute of Geology and Mineral Resources, Chongqing, China
| | - Jianhua Wang
- Research Center of Natural History and Culture, Qujing Normal University, Qujing, China
| | - Zhikun Gai
- Key CAS Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences (CAS), Beijing, China.,CAS Center for Excellence in Life and Paleoenvironment, Beijing, China
| | - Wenjin Zhao
- Key CAS Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences (CAS), Beijing, China.,CAS Center for Excellence in Life and Paleoenvironment, Beijing, China.,College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Guangbiao Wei
- Chongqing Institute of Geological Survey, Chongqing, China
| | - Yilun Yu
- Key CAS Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences (CAS), Beijing, China.,College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Per E Ahlberg
- Department of Organismal Biology, Uppsala University, Uppsala, Sweden.
| | - Min Zhu
- Key CAS Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences (CAS), Beijing, China. .,CAS Center for Excellence in Life and Paleoenvironment, Beijing, China. .,College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China.
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10
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Bottaro M. Sixth sense in the deep-sea: the electrosensory system in ghost shark Chimaera monstrosa. Sci Rep 2022; 12:9848. [PMID: 35701513 PMCID: PMC9198096 DOI: 10.1038/s41598-022-14076-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 06/01/2022] [Indexed: 11/25/2022] Open
Abstract
Animals that continually live in deep sea habitats face unique challenges and require adaptive specializations solutions in order to locate and identify food, predators, and conspecifics. The Ampullae of Lorenzini are specialized electroreceptors used by chondrichthyans for important biological functions. Ampullary organs of the ghost shark Chimaera monstrosa, a deep-sea species commonly captured as by-catch in the bottom trawl fishery, are here described for the first time using macroscopic, ultrastructural and histological approaches. The number of ampullary pores in C. monstrosa is about 700, distributed into the whole cephalic section of C. monstrosa, and organized in12 pore clusters and they are arranged into different configurations and form a distinct morphological pattern for this species, showing some anatomical peculiarities never described before in others cartilaginous fishes and may constitute an evolutionary adaptation of this ancient chondrichthyan species to the extreme environmental conditions of its deep sea niche.
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Affiliation(s)
- Massimiliano Bottaro
- Department of Integrative Marine Ecology (EMI), Genoa Marine Centre (GMC), Stazione Zoologica Anton Dohrn - Italian National Institute of Marine Biology, Ecology and Biotechnology, Villa del Principe, Piazza del Principe 4, 16126, Genoa, Italy.
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11
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Gai Z, Zhu M, Ahlberg PE, Donoghue PCJ. The Evolution of the Spiracular Region From Jawless Fishes to Tetrapods. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.887172] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The spiracular region, comprising the hyomandibular pouch together with the mandibular and hyoid arches, has a complex evolutionary history. In living vertebrates, the embryonic hyomandibular pouch may disappear in the adult, develop into a small opening between the palatoquadrate and hyomandibula containing a single gill-like pseudobranch, or create a middle ear cavity, but it never develops into a fully formed gill with two hemibranchs. The belief that a complete spiracular gill must be the ancestral condition led some 20th century researchers to search for such a gill between the mandibular and hyoid arches in early jawed vertebrates. This hypothesized ancestral state was named the aphetohyoidean condition, but so far it has not been verified in any fossil; supposed examples, such as in the acanthodian Acanthodes and symmoriid chondrichthyans, have been reinterpreted and discounted. Here we present the first confirmed example of a complete spiracular gill in any vertebrate, in the galeaspid (jawless stem gnathostome) Shuyu. Comparisons with two other groups of jawless stem gnathostomes, osteostracans and heterostracans, indicate that they also probably possessed full-sized spiracular gills and that this condition may thus be primitive for the gnathostome stem group. This contrasts with the living jawless cyclostomes, in which the mandibular and hyoid arches are strongly modified and the hyomandibular pouch is lost in the adult. While no truly aphetohyoidean spiracular gill has been found in any jawed vertebrate, the recently reported presence in acanthodians of two pseudobranchs suggests a two-step evolutionary process whereby initial miniaturization of the spiracular gill was followed, independently in chondrichthyans and osteichthyans, by the loss of the anterior pseudobranch. On the basis of these findings we present an overview of spiracular evolution among vertebrates.
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12
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Atake OJ, Eames BF. Mineralized Cartilage and Bone-Like Tissues in Chondrichthyans Offer Potential Insights Into the Evolution and Development of Mineralized Tissues in the Vertebrate Endoskeleton. Front Genet 2021; 12:762042. [PMID: 35003210 PMCID: PMC8727550 DOI: 10.3389/fgene.2021.762042] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 11/30/2021] [Indexed: 11/25/2022] Open
Abstract
The impregnation of biominerals into the extracellular matrix of living organisms, a process termed biomineralization, gives rise to diverse mineralized (or calcified) tissues in vertebrates. Preservation of mineralized tissues in the fossil record has provided insights into the evolutionary history of vertebrates and their skeletons. However, current understanding of the vertebrate skeleton and of the processes underlying its formation is biased towards biomedical models such as the tetrapods mouse and chick. Chondrichthyans (sharks, skates, rays, and chimaeras) and osteichthyans are the only vertebrate groups with extant (living) representatives that have a mineralized skeleton, but the basal phylogenetic position of chondrichthyans could potentially offer unique insights into skeletal evolution. For example, bone is a vertebrate novelty, but the internal supporting skeleton (endoskeleton) of extant chondrichthyans is commonly described as lacking bone. The molecular and developmental basis for this assertion is yet to be tested. Subperichondral tissues in the endoskeleton of some chondrichthyans display mineralization patterns and histological and molecular features of bone, thereby challenging the notion that extant chondrichthyans lack endoskeletal bone. Additionally, the chondrichthyan endoskeleton demonstrates some unique features and others that are potentially homologous with other vertebrates, including a polygonal mineralization pattern, a trabecular mineralization pattern, and an unconstricted perichordal sheath. Because of the basal phylogenetic position of chondrichthyans among all other extant vertebrates with a mineralized skeleton, developmental and molecular studies of chondrichthyans are critical to flesh out the evolution of vertebrate skeletal tissues, but only a handful of such studies have been carried out to date. This review discusses morphological and molecular features of chondrichthyan endoskeletal tissues and cell types, ultimately emphasizing how comparative embryology and transcriptomics can reveal homology of mineralized skeletal tissues (and their cell types) between chondrichthyans and other vertebrates.
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Affiliation(s)
| | - B. Frank Eames
- Department of Anatomy, Physiology, and Pharmacology, University of Saskatchewan, Saskatoon, SK, Canada
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13
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Tan M, Redmond AK, Dooley H, Nozu R, Sato K, Kuraku S, Koren S, Phillippy AM, Dove ADM, Read T. The whale shark genome reveals patterns of vertebrate gene family evolution. eLife 2021; 10:e65394. [PMID: 34409936 PMCID: PMC8455134 DOI: 10.7554/elife.65394] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 08/18/2021] [Indexed: 02/06/2023] Open
Abstract
Chondrichthyes (cartilaginous fishes) are fundamental for understanding vertebrate evolution, yet their genomes are understudied. We report long-read sequencing of the whale shark genome to generate the best gapless chondrichthyan genome assembly yet with higher contig contiguity than all other cartilaginous fish genomes, and studied vertebrate genomic evolution of ancestral gene families, immunity, and gigantism. We found a major increase in gene families at the origin of gnathostomes (jawed vertebrates) independent of their genome duplication. We studied vertebrate pathogen recognition receptors (PRRs), which are key in initiating innate immune defense, and found diverse patterns of gene family evolution, demonstrating that adaptive immunity in gnathostomes did not fully displace germline-encoded PRR innovation. We also discovered a new toll-like receptor (TLR29) and three NOD1 copies in the whale shark. We found chondrichthyan and giant vertebrate genomes had decreased substitution rates compared to other vertebrates, but gene family expansion rates varied among vertebrate giants, suggesting substitution and expansion rates of gene families are decoupled in vertebrate genomes. Finally, we found gene families that shifted in expansion rate in vertebrate giants were enriched for human cancer-related genes, consistent with gigantism requiring adaptations to suppress cancer.
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Affiliation(s)
- Milton Tan
- Illinois Natural History Survey at University of Illinois Urbana-ChampaignChampaignUnited States
| | | | - Helen Dooley
- University of Maryland School of Medicine, Institute of Marine & Environmental TechnologyBaltimoreUnited States
| | - Ryo Nozu
- Okinawa Churashima Research Center, Okinawa Churashima FoundationOkinawaJapan
| | - Keiichi Sato
- Okinawa Churashima Research Center, Okinawa Churashima FoundationOkinawaJapan
- Okinawa Churaumi Aquarium, MotobuOkinawaJapan
| | - Shigehiro Kuraku
- RIKEN Center for Biosystems Dynamics Research (BDR), RIKENKobeJapan
| | - Sergey Koren
- National Human Genome Research Institute, National Institutes of HealthBethesdaUnited States
| | - Adam M Phillippy
- National Human Genome Research Institute, National Institutes of HealthBethesdaUnited States
| | | | - Timothy Read
- Department of Infectious Diseases, Emory University School of MedicineAtlantaUnited States
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14
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Endocast and Bony Labyrinth of a Devonian "Placoderm" Challenges Stem Gnathostome Phylogeny. Curr Biol 2021; 31:1112-1118.e4. [PMID: 33508218 DOI: 10.1016/j.cub.2020.12.046] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 11/24/2020] [Accepted: 12/23/2020] [Indexed: 11/20/2022]
Abstract
Our understanding of the earliest evolution of jawed vertebrates depends on a credible phylogenetic framework for the jawed stem gnathostomes collectively known as "placoderms".1 However, their relationships, and whether placoderms represent a single radiation or a paraphyletic array, remain contentious.2-13 This uncertainty is compounded by an uneven understanding of anatomy across the group, particularly of the phylogenetically informative braincase and brain cavity-endocast. Based on new tomographic data, we here describe the endocast and bony labyrinth of Brindabellaspis stensioi from the Early Devonian of New South Wales.14 The taxon was commonly recovered as branching near the base of placoderms.5-9,11,12,15-17 Previous studies of Brindabellaspis emphasized its resemblances with fossil jawless fishes in the braincase anatomy14 and endocast proportions1,18 and its distinctive features were interpreted as autapomorphies, such as the elongated premedian region.19 Although our three-dimensional data confirmed the resemblance of its endocast to those of jawless vertebrates, we discovered that the inner ear and endolymphatic complex display a repertoire of previously unrecognized characters close to modern or crown-group jawed vertebrates, including a pronounced sinus superior and a vertical duct that connects the endolymphatic sac and the labyrinth cavity. Both parsimony and Bayesian analyses suggest that prevailing hypotheses of placoderm relationships are unstable, with newly revealed anatomy pointing to a radical revision of early gnathostome evolution. Our results call into question the appropriateness of arthrodire-like placoderms as models of primitive gnathostome anatomy and raise questions of homology relating to key cranial features.
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15
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Bi X, Wang K, Yang L, Pan H, Jiang H, Wei Q, Fang M, Yu H, Zhu C, Cai Y, He Y, Gan X, Zeng H, Yu D, Zhu Y, Jiang H, Qiu Q, Yang H, Zhang YE, Wang W, Zhu M, He S, Zhang G. Tracing the genetic footprints of vertebrate landing in non-teleost ray-finned fishes. Cell 2021; 184:1377-1391.e14. [PMID: 33545088 DOI: 10.1016/j.cell.2021.01.046] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 11/11/2020] [Accepted: 01/27/2021] [Indexed: 01/20/2023]
Abstract
Rich fossil evidence suggests that many traits and functions related to terrestrial evolution were present long before the ancestor of lobe- and ray-finned fishes. Here, we present genome sequences of the bichir, paddlefish, bowfin, and alligator gar, covering all major early divergent lineages of ray-finned fishes. Our analyses show that these species exhibit many mosaic genomic features of lobe- and ray-finned fishes. In particular, many regulatory elements for limb development are present in these fishes, supporting the hypothesis that the relevant ancestral regulation networks emerged before the origin of tetrapods. Transcriptome analyses confirm the homology between the lung and swim bladder and reveal the presence of functional lung-related genes in early ray-finned fishes. Furthermore, we functionally validate the essential role of a jawed vertebrate highly conserved element for cardiovascular development. Our results imply the ancestors of jawed vertebrates already had the potential gene networks for cardio-respiratory systems supporting air breathing.
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Affiliation(s)
- Xupeng Bi
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; BGI-Shenzhen, Shenzhen 518083, China
| | - Kun Wang
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Liandong Yang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | | | - Haifeng Jiang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Qiwei Wei
- Key Laboratory of Freshwater Biodiversity Conservation, Ministry of Agriculture and Rural Affairs, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan, China
| | | | - Hao Yu
- BGI-Shenzhen, Shenzhen 518083, China
| | - Chenglong Zhu
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Yiran Cai
- BGI-Shenzhen, Shenzhen 518083, China
| | - Yuming He
- BGI-Shenzhen, Shenzhen 518083, China
| | - Xiaoni Gan
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Honghui Zeng
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Daqi Yu
- Key Laboratory of Zoological Systematics and Evolution and State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Youan Zhu
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, 142 Xi-zhi-men-wai Street, Beijing 100044, China; CAS Center for Excellence in Life and Paleoenvironment, Beijing 100044, China
| | - Huifeng Jiang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Qiang Qiu
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Huanming Yang
- BGI-Shenzhen, Shenzhen 518083, China; James D. Watson Institute of Genome Sciences, Hangzhou, China; Guangdong Provincial Academician Workstation of BGI Synthetic Genomics, BGI-Shenzhen, Shenzhen 518120, China
| | - Yong E Zhang
- Key Laboratory of Zoological Systematics and Evolution and State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, 32 Jiaochang Donglu, Kunming 650223, China
| | - Wen Wang
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China; Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, 32 Jiaochang Donglu, Kunming 650223, China; State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China.
| | - Min Zhu
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, 142 Xi-zhi-men-wai Street, Beijing 100044, China; CAS Center for Excellence in Life and Paleoenvironment, Beijing 100044, China; College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Shunping He
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, 32 Jiaochang Donglu, Kunming 650223, China; Institute of Deep-Sea Science and Engineering, Chinese Academy of Sciences, Sanya 572000, China.
| | - Guojie Zhang
- BGI-Shenzhen, Shenzhen 518083, China; Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, 32 Jiaochang Donglu, Kunming 650223, China; State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China; Villum Center for Biodiversity Genomics, Section for Ecology and Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
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16
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Dearden RP, Mansuit R, Cuckovic A, Herrel A, Didier D, Tafforeau P, Pradel A. The morphology and evolution of chondrichthyan cranial muscles: A digital dissection of the elephantfish Callorhinchus milii and the catshark Scyliorhinus canicula. J Anat 2021; 238:1082-1105. [PMID: 33415764 PMCID: PMC8053583 DOI: 10.1111/joa.13362] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 09/25/2020] [Accepted: 10/29/2020] [Indexed: 11/30/2022] Open
Abstract
The anatomy of sharks, rays, and chimaeras (chondrichthyans) is crucial to understanding the evolution of the cranial system in vertebrates due to their position as the sister group to bony fishes (osteichthyans). Strikingly different arrangements of the head in the two constituent chondrichthyan groups-holocephalans and elasmobranchs-have played a pivotal role in the formation of evolutionary hypotheses targeting major cranial structures such as the jaws and pharynx. However, despite the advent of digital dissections as a means of easily visualizing and sharing the results of anatomical studies in three dimensions, information on the musculoskeletal systems of the chondrichthyan head remains largely limited to traditional accounts, many of which are at least a century old. Here, we use synchrotron tomographic data to carry out a digital dissection of a holocephalan and an elasmobranch widely used as model species: the elephantfish, Callorhinchus milii, and the small-spotted catshark, Scyliorhinus canicula. We describe and figure the skeletal anatomy of the head, labial, mandibular, hyoid, and branchial cartilages in both taxa as well as the muscles of the head and pharynx. In Callorhinchus, we make several new observations regarding the branchial musculature, revealing several previously unreported or ambiguously characterized muscles, likely homologous to their counterparts in the elasmobranch pharynx. We also identify a previously unreported structure linking the pharyngohyal of Callorhinchus to the neurocranium. Finally, we review what is known about the evolution of chondrichthyan cranial muscles from their fossil record and discuss the implications for muscle homology and evolution, broadly concluding that the holocephalan pharynx is likely derived from a more elasmobranch-like form which is plesiomorphic for the chondrichthyan crown group. This dataset has great potential as a resource, particularly for researchers using these model species for zoological research, functional morphologists requiring models of musculature and skeletons, as well as for palaeontologists seeking comparative models for extinct taxa.
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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, Paris cedex 05, France
| | - Rohan Mansuit
- CR2P, Centre de Recherche en Paléontologie-Paris, Muséum national d'Histoire naturelle, Sorbonne Université, Centre National de la Recherche Scientifique, Paris cedex 05, France.,UMR 7179 (MNHN-CNRS) MECADEV, Département Adaptations du Vivant, Muséum National d'Histoire Naturelle, Paris, France
| | | | - Anthony Herrel
- UMR 7179 (MNHN-CNRS) MECADEV, Département Adaptations du Vivant, Muséum National d'Histoire Naturelle, Paris, France
| | - Dominique Didier
- Department of Biology, Millersville University, Millersville, PA, USA
| | - Paul Tafforeau
- European Synchrotron Radiation Facility, Grenoble, France
| | - Alan Pradel
- CR2P, Centre de Recherche en Paléontologie-Paris, Muséum national d'Histoire naturelle, Sorbonne Université, Centre National de la Recherche Scientifique, Paris cedex 05, France
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17
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Pears JB, Johanson Z, Trinajstic K, Dean MN, Boisvert CA. Mineralization of the Callorhinchus Vertebral Column (Holocephali; Chondrichthyes). Front Genet 2020; 11:571694. [PMID: 33329708 PMCID: PMC7732695 DOI: 10.3389/fgene.2020.571694] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 10/30/2020] [Indexed: 12/12/2022] Open
Abstract
Members of the Chondrichthyes (Elasmobranchii and Holocephali) are distinguished by their largely cartilaginous endoskeletons, which comprise an uncalcified core overlain by a mineralized layer; in the Elasmobranchii (sharks, skates, rays) most of this mineralization takes the form of calcified polygonal tiles known as tesserae. In recent years, these skeletal tissues have been described in ever increasing detail in sharks and rays, but those of Holocephali (chimaeroids) have been less well-studied, with conflicting accounts as to whether or not tesserae are present. During embryonic ontogeny in holocephalans, cervical vertebrae fuse to form a structure called the synarcual. The synarcual mineralizes early and progressively, anteroposteriorly and dorsoventrally, and therefore presents a good skeletal structure in which to observe mineralized tissues in this group. Here, we describe the development and mineralization of the synarcual in an adult and stage 36 elephant shark embryo (Callorhinchus milii). Small, discrete, but irregular blocks of cortical mineralization are present in stage 36, similar to what has been described recently in embryos of other chimaeroid taxa such as Hydrolagus, while in Callorhinchus adults, the blocks of mineralization are more irregular, but remain small. This differs from fossil members of the holocephalan crown group (Edaphodon), as well as from stem group holocephalans (e.g., Symmorida, Helodus, Iniopterygiformes), where tesserae are notably larger than in Callorhinchus and show similarities to elasmobranch tesserae, for example with respect to polygonal shape.
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Affiliation(s)
- Jacob B Pears
- School of Molecular and Life Sciences, Curtin University, Perth, WA, Australia
| | - Zerina Johanson
- Department of Earth Sciences, Natural History Museum, London, United Kingdom
| | - Kate Trinajstic
- School of Molecular and Life Sciences, Curtin University, Perth, WA, Australia
| | - Mason N Dean
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany
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18
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Frey L, Coates MI, Tietjen K, Rücklin M, Klug C. A symmoriiform from the Late Devonian of Morocco demonstrates a derived jaw function in ancient chondrichthyans. Commun Biol 2020; 3:681. [PMID: 33203942 PMCID: PMC7672094 DOI: 10.1038/s42003-020-01394-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 10/16/2020] [Indexed: 12/02/2022] Open
Abstract
The Palaeozoic record of chondrichthyans (sharks, rays, chimaeras, extinct relatives) and thus our knowledge of their anatomy and functional morphology is poor because of their predominantly cartilaginous skeletons. Here, we report a previously undescribed symmoriiform shark, Ferromirum oukherbouchi, from the Late Devonian of the Anti-Atlas. Computed tomography scanning reveals the undeformed shape of the jaws and hyoid arch, which are of a kind often used to represent primitive conditions for jawed vertebrates. Of critical importance, these closely fitting cartilages preclude the repeatedly hypothesized presence of a complete gill between mandibular and hyoid arches. We show that the jaw articulation is specialized and drives mandibular rotation outward when the mouth opens, and inward upon closure. The resultant eversion and inversion of the lower dentition presents a greater number of teeth to prey through the bite-cycle. This suggests an increased functional and ecomorphological disparity among chondrichthyans preceding and surviving the end-Devonian extinctions. Frey and colleagues describe a new fossil shark from the Late Devonian of Morocco in which the specialized jaw articulation is unusually well preserved. Biomechanical modelling reveals that the mandible rolled throughout its movement arc, engaging more of its tooth battery in a clutching bite action.
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Affiliation(s)
- Linda Frey
- Paläontologisches Institut und Museum, University of Zurich, Karl-Schmid-Strasse 4, CH-8006, Zürich, Switzerland.
| | - Michael I Coates
- Department of Organismal Biology and Anatomy, University of Chicago, 1027 E. 57th St., Chicago, IL, 60637, USA
| | - Kristen Tietjen
- Biodiversity Institute, University of Kansas, 1345 Jayhawk Blvd, Lawrence, KS, 66045, USA
| | - Martin Rücklin
- Naturalis Biodiversity Center, Vertebrate Evolution Development and Ecology, Postbus 9517, 2300 RA, Leiden, The Netherlands
| | - Christian Klug
- Paläontologisches Institut und Museum, University of Zurich, Karl-Schmid-Strasse 4, CH-8006, Zürich, Switzerland.
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19
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Hulsey CD, Cohen KE, Johanson Z, Karagic N, Meyer A, Miller CT, Sadier A, Summers AP, Fraser GJ. Grand Challenges in Comparative Tooth Biology. Integr Comp Biol 2020; 60:563-580. [PMID: 32533826 PMCID: PMC7821850 DOI: 10.1093/icb/icaa038] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Teeth are a model system for integrating developmental genomics, functional morphology, and evolution. We are at the cusp of being able to address many open issues in comparative tooth biology and we outline several of these newly tractable and exciting research directions. Like never before, technological advances and methodological approaches are allowing us to investigate the developmental machinery of vertebrates and discover both conserved and excitingly novel mechanisms of diversification. Additionally, studies of the great diversity of soft tissues, replacement teeth, and non-trophic functions of teeth are providing new insights into dental diversity. Finally, we highlight several emerging model groups of organisms that are at the forefront of increasing our appreciation of the mechanisms underlying tooth diversification.
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Affiliation(s)
- C Darrin Hulsey
- Department of Biology, University of Konstanz, Konstanz, 78464, Germany
| | - Karly E Cohen
- Friday Harbor Laboratories, School of Aquatic and Fishery Sciences, Department of Biology, University of Washington, WA 98195, USA
| | - Zerina Johanson
- Department of Earth Sciences, Natural History Museum, London SW7 5HD, UK
| | - Nidal Karagic
- Department of Biology, University of Konstanz, Konstanz, 78464, Germany
| | - Axel Meyer
- Department of Biology, University of Konstanz, Konstanz, 78464, Germany
| | - Craig T Miller
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720, USA
| | - Alexa Sadier
- Department of Ecology and Evolution, University of California Los Angeles, Los Angeles, CA 90032, USA
| | - Adam P Summers
- Friday Harbor Laboratories, School of Aquatic and Fishery Sciences, Department of Biology, University of Washington, WA 98195, USA
| | - Gareth J Fraser
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
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20
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Johanson Z, Manzanares E, Underwood C, Clark B, Fernandez V, Smith M. Evolution of the Dentition in Holocephalans (Chondrichthyes) Through Tissue Disparity. Integr Comp Biol 2020; 60:630-643. [DOI: 10.1093/icb/icaa093] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
The Holocephali is a major group of chondrichthyan fishes, the sister taxon to the sharks and rays (Elasmobranchii). However, the dentition of extant holocephalans is very different from that of the elasmobranchs, lacking individual tooth renewal, but comprising dental plates made entirely of self-renewing dentine. This renewal of all tissues occurs at the postero-lingual plate surface, as a function of their statodont condition. The fossil record of the holocephalans illuminates multiple different trends in the dentition, including shark-like teeth through to those with dentitions completely lacking individual teeth. Different taxa illustrate developmental retention of teeth but with fusion in their serial development. Dentine of different varieties comprises these teeth and composite dental plates, whose histology includes vascularized tubes within coronal dentine, merging with basal trabecular dentine. In this coronal vascularized dentine, extensive hypermineralization forms a wear resistant tissue transformed into a variety of morphologies. Through evolution, hypermineralized dentine becomes enclosed within the trabecular dentine, and specialized by reduction into specific zones within a composite dental plate, with these increasing in morphological disparity, all reflecting loss of defined teeth but retention of dentine production from the inherited developmental package.
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Affiliation(s)
- Zerina Johanson
- Department of Earth Sciences, Natural History Museum, London, UK
| | - Esther Manzanares
- Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de Valencia, Paterna, Valencia 46980, Spain
| | - Charlie Underwood
- Department of Earth Sciences, Natural History Museum, London, UK
- Department of Earth and Planetary Sciences, Birkbeck, University of London, London, UK
| | - Brett Clark
- Core Research Laboratories, Natural History Museum, London, UK
| | | | - Moya Smith
- Department of Earth Sciences, Natural History Museum, London, UK
- Centre for Craniofacial and Regenerative Biology, Oral and Craniofacial Sciences, King’s College London, London, UK
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21
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Gess RW, Whitfield AK. Estuarine fish and tetrapod evolution: insights from a Late Devonian (Famennian) Gondwanan estuarine lake and a southern African Holocene equivalent. Biol Rev Camb Philos Soc 2020; 95:865-888. [PMID: 32059074 DOI: 10.1111/brv.12590] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 01/31/2020] [Accepted: 02/05/2020] [Indexed: 01/31/2023]
Abstract
The Waterloo Farm lagerstätte in South Africa provides a uniquely well-preserved record of a Latest Devonian estuarine ecosystem. Ecological evidence from it is reviewed, contextualised, and compared with that available from the analogous Swartvlei estuarine lake, with a particular emphasis on their piscean inhabitants. Although the taxonomic affinities of the estuarine species are temporally very different, the overall patterns of utilisation prove to be remarkably congruent, with similar trophic structures. Significantly, both systems show evidence of widespread use of estuaries as fish nurseries by both resident and marine migrant taxa. Holocene estuaries are almost exclusively utilised by actinopterygians which are overwhelmingly dominated by oviparous species. Complex strategies are utilised by estuarine resident species to avoid exposure of eggs to environmental stresses that characterize these systems. By contrast, many of the groups utilising Devonian estuaries were likely live bearers, potentially allowing them to avoid the challenges faced by oviparous taxa. This may have contributed to dominance of these systems by non-actinoptergians prior to the End Devonian Mass Extinction. The association of early aquatic tetrapods at Waterloo Farm with a fish nursery environment is consistent with findings from North America, Belgium and Russia, and may be implied by the estuarine settings of a number of other Devonian tetrapods. Tetrapods apparently replace their sister group, the elpistostegids, in estuaries with both groups having been postulated to be adaptated to shallow water habitats where they could access small piscean prey. Correlation of tetrapods (and elpistostegids) with fish nursery areas in the Late Devonian lends strong support to this hypothesis, suggesting that adaptations permitting improved access to the abundant juvenile fish within the littoral zone of estuarine lakes and continental water bodies may have been pivotal in the evolution of tetrapods.
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Affiliation(s)
- Robert W Gess
- Albany Museum and Geology Department, Rhodes University, P.O. Box 94, Makhanda/Grahamstown, South Africa
| | - Alan K Whitfield
- South African Institute for Aquatic Biodiversity (SAIAB), Private Bag 1015, Makhanda/Grahamstown, South Africa
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22
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Frey L, Coates M, Ginter M, Hairapetian V, Rücklin M, Jerjen I, Klug C. The early elasmobranch Phoebodus: phylogenetic relationships, ecomorphology and a new time-scale for shark evolution. Proc Biol Sci 2019; 286:20191336. [PMID: 31575362 PMCID: PMC6790773 DOI: 10.1098/rspb.2019.1336] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 09/11/2019] [Indexed: 11/12/2022] Open
Abstract
Anatomical knowledge of early chondrichthyans and estimates of their phylogeny are improving, but many taxa are still known only from microremains. The nearly cosmopolitan and regionally abundant Devonian genus Phoebodus has long been known solely from isolated teeth and fin spines. Here, we report the first skeletal remains of Phoebodus from the Famennian (Late Devonian) of the Maïder region of Morocco, revealing an anguilliform body, specialized braincase, hyoid arch, elongate jaws and rostrum, complementing its characteristic dentition and ctenacanth fin spines preceding both dorsal fins. Several of these features corroborate a likely close relationship with the Carboniferous species Thrinacodus gracia, and phylogenetic analysis places both taxa securely as members of the elasmobranch stem lineage. Identified as such, phoebodont teeth provide a plausible marker for range extension of the elasmobranchs into the Middle Devonian, thus providing a new minimum date for the origin of the chondrichthyan crown-group. Among pre-Carboniferous jawed vertebrates, the anguilliform body shape of Phoebodus is unprecedented, and its specialized anatomy is, in several respects, most easily compared with the modern frilled shark Chlamydoselachus. These results add greatly to the morphological, and by implication ecological, disparity of the earliest elasmobranchs.
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Affiliation(s)
- Linda Frey
- Paläontologisches Institut und Museum, University of Zurich, Karl-Schmid-Strasse 4, 8006 Zürich, Switzerland
| | - Michael Coates
- Department of Organismal Biology and Anatomy, University of Chicago, 1027 E. 57th Street, Chicago, IL 60637, USA
| | - Michał Ginter
- Faculty of Geology, University of Warsaw, al. Żwirki i Wigury 93, 02-089 Warszawa, Poland
| | - Vachik Hairapetian
- Department of Geology, Khorasgan Branch, Islamic Azad University, PO Box 81595-158, Esfahan, Iran
| | - Martin Rücklin
- Naturalis Biodiversity Center, Postbus 9517, 2300 RA Leiden, The Netherlands
| | - Iwan Jerjen
- Gloor Instruments AG, Schaffhauserstrasse 121, 8302 Kloten, Switzerland
| | - Christian Klug
- Paläontologisches Institut und Museum, University of Zurich, Karl-Schmid-Strasse 4, 8006 Zürich, Switzerland
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23
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Coates MI, Tietjen K, Olsen AM, Finarelli JA. High-performance suction feeding in an early elasmobranch. SCIENCE ADVANCES 2019; 5:eaax2742. [PMID: 31535026 PMCID: PMC6739094 DOI: 10.1126/sciadv.aax2742] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 08/09/2019] [Indexed: 06/10/2023]
Abstract
High-performance suction feeding is often presented as a classic innovation of ray-finned fishes, likely contributing to their remarkable evolutionary success, whereas sharks, with seemingly less sophisticated jaws, are generally portrayed as morphologically conservative throughout their history. Here, using a combination of computational modeling, physical modeling, and quantitative three-dimensional motion simulation, we analyze the cranial skeleton of one of the earliest known stem elasmobranchs, Tristychius arcuatus from the Middle Mississippian of Scotland. The feeding apparatus is revealed as highly derived, capable of substantial oral expansion, and with clear potential for high-performance suction feeding some 50 million years before the earliest osteichthyan equivalent. This exceptional jaw performance is not apparent from standard measures of ecomorphospace using two-dimensional data. Tristychius signals the emergence of entirely new chondrichthyan ecomorphologies in the aftermath of the end-Devonian extinction and highlights sharks as significant innovators in the early radiation of the modern vertebrate biota.
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Affiliation(s)
- Michael I. Coates
- Department of Organismal Biology and Anatomy, University of Chicago, 1027 E 57th St., Chicago, IL 60637, USA
| | - Kristen Tietjen
- Department of Organismal Biology and Anatomy, University of Chicago, 1027 E 57th St., Chicago, IL 60637, USA
| | - Aaron M. Olsen
- Department of Ecology and Evolutionary Biology, Brown University, 171 Meeting St., Box G-B 204, Providence, RI 02912, USA
| | - John A. Finarelli
- UCD School of Biology and Environmental Science, UCD Science Education and Research Centre (West), UCD Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland
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24
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Reid M, Bordy EM, Taylor WL, le Roux SG, du Plessis A. A micro X-ray computed tomography dataset of fossil echinoderms in an ancient obrution bed: a robust method for taphonomic and palaeoecologic analyses. Gigascience 2019; 8:5232983. [PMID: 30534956 PMCID: PMC6505446 DOI: 10.1093/gigascience/giy156] [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: 08/24/2018] [Revised: 10/16/2018] [Accepted: 11/27/2018] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Taphonomic and palaeoecologic studies of obrution beds often employ conventional methods of investigation such as physical removal and extraction of fossils from their host rock (matrix) by mechanical preparation. This often-destructive method is not suitable for studying mold fossils, which are voids left in host rocks due to dissolution of the original organism in post-depositional processes. FINDINGS Microcomputed tomography (µCT) scan data of 24 fossiliferous rock samples revealed thousands of Paleozoic echinoderms. Digitally "stitching" together individually µCT scanned rock samples within three-dimensional (3D) space allows for quantifiable taphonomic data on a fossil echinoderm-rich obrution deposit from the Devonian (Emsian) of South Africa. Here, we provide a brief step-by-step guide on creating, segmenting, and ultimately combining sections of richly fossiliferous beds to create virtual models suited for the quantitative and qualitative taphonomic analyses of fossil invertebrate assemblages. CONCLUSIONS Visualizing the internal features of fossiliferous beds in 3D is an invaluable taphonomic tool for analyzing delicate fossils, accounting for all specimens irrespective of their preservation stages and with minimal damage. This technique is particularly useful for analyzing fossiliferous deposits with mold fossils that prove to be difficult to study with traditional methods, because the method relies on the large density contrast between the mold and host rock.
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Affiliation(s)
- Mhairi Reid
- Department of Geological Sciences, University of Cape Town, University Avenue, Upper Campus, Rondebosch, 7701, Cape Town, South Africa
| | - Emese M Bordy
- Department of Geological Sciences, University of Cape Town, University Avenue, Upper Campus, Rondebosch, 7701, Cape Town, South Africa
| | - Wendy L Taylor
- Department of Geological Sciences, University of Cape Town, University Avenue, Upper Campus, Rondebosch, 7701, Cape Town, South Africa
| | - Stephan G le Roux
- CT Scanner Facility, Central Analytical Facilities, Stellenbosch University, Private bag X1, Matieland, 7602, Stellenbosch, South Africa
| | - Anton du Plessis
- CT Scanner Facility, Central Analytical Facilities, Stellenbosch University, Private bag X1, Matieland, 7602, Stellenbosch, South Africa
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25
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Coates MI, Finarelli JA, Sansom IJ, Andreev PS, Criswell KE, Tietjen K, Rivers ML, La Riviere PJ. An early chondrichthyan and the evolutionary assembly of a shark body plan. Proc Biol Sci 2019; 285:rspb.2017.2418. [PMID: 29298937 DOI: 10.1098/rspb.2017.2418] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 11/29/2017] [Indexed: 11/12/2022] Open
Abstract
Although relationships among the major groups of living gnathostomes are well established, the relatedness of early jawed vertebrates to modern clades is intensely debated. Here, we provide a new description of Gladbachus, a Middle Devonian (Givetian approx. 385-million-year-old) stem chondrichthyan from Germany, and one of the very few early chondrichthyans in which substantial portions of the endoskeleton are preserved. Tomographic and histological techniques reveal new details of the gill skeleton, hyoid arch and jaws, neurocranium, cartilage, scales and teeth. Despite many features resembling placoderm or osteichthyan conditions, phylogenetic analysis confirms Gladbachus as a stem chondrichthyan and corroborates hypotheses that all acanthodians are stem chondrichthyans. The unfamiliar character combination displayed by Gladbachus, alongside conditions observed in acanthodians, implies that pre-Devonian stem chondrichthyans are severely under-sampled and strongly supports indications from isolated scales that the gnathostome crown group originated at the latest by the early Silurian (approx. 440 Ma). Moreover, phylogenetic results highlight the likely convergent evolution of conventional chondrichthyan conditions among earliest members of this primary gnathostome division, while skeletal morphology points towards the likely suspension feeding habits of Gladbachus, suggesting a functional origin of the gill slit condition characteristic of the vast majority of living and fossil chondrichthyans.
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Affiliation(s)
- Michael I Coates
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL 60637-1508, USA
| | - John A Finarelli
- UCD School of Biology and Environmental Science, UCD Science Education and Research Centre (West), UCD Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Ivan J Sansom
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Plamen S Andreev
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Katharine E Criswell
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL 60637-1508, USA.,Department of Zoology, Cambridge University, Cambridge CB2 3EJ, UK
| | - Kristen Tietjen
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL 60637-1508, USA
| | - Mark L Rivers
- Center for Advanced Radiation Sources, University of Chicago, Chicago, IL 60637-1508, USA
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26
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Pardo JD, Small BJ, Milner AR, Huttenlocker AK. Carboniferous–Permian climate change constrained early land vertebrate radiations. Nat Ecol Evol 2019; 3:200-206. [DOI: 10.1038/s41559-018-0776-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Accepted: 12/03/2018] [Indexed: 12/13/2022]
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27
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Higham TE, Seamone SG, Arnold A, Toews D, Janmohamed Z, Smith SJ, Rogers SM. The ontogenetic scaling of form and function in the spotted ratfish, Hydrolagus colliei (Chondrichthyes: Chimaeriformes): Fins, muscles, and locomotion. J Morphol 2018; 279:1408-1418. [PMID: 30184247 DOI: 10.1002/jmor.20876] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 06/19/2018] [Accepted: 06/27/2018] [Indexed: 11/07/2022]
Abstract
The alteration of form and function through the life of a fish can have profound impacts on the ability to move through water. Although several studies have examined morphology and function in relation to body size, there is a paucity of data for chondrichthyans, an ancient group of fishes. Ratfishes are interesting in that they utilize flapping pectoral fins to drive movement, and they diverged from elasmobranchs early in the gnathostome phylogeny. Using the spotted ratfish, Hydrolagus colliei, we quantified the scaling of traits relevant for locomotion, including median and paired fin external anatomy, the musculature of the pectoral and pelvic fins, and the kinematics of the pectoral fins. Whereas pelvic fins scaled with either positive allometry (fin span and area) or isometry (fin chord length at the base of the fin), pectoral fin measurements either scaled with negative allometry (fin span and aspect ratio) or isometry (fin area and chord length). Correspondingly, all pelvic fin muscles exhibited positive allometry, whereas pectoral muscles exhibited a mix of isometric and positively allometric growth. Caudal fin area and body frontal area both scaled with positive allometry, whereas dorsal fin area and span scale with isometry. Pectoral fin amplitude during swimming exhibited isometry, and fin beat frequency decreased with body size. Our results highlight the complex changes in form and function throughout ontogeny. Finally, we highlight that hierarchical differentiation in morphology can occur during growth, potentially leading to complex changes in performance of a functional system.
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Affiliation(s)
- Timothy E Higham
- Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, California
| | - Scott G Seamone
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
| | - Amanda Arnold
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Desiree Toews
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
| | - Zeanna Janmohamed
- Department of Applied Animal Biology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Sara J Smith
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
| | - Sean M Rogers
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
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28
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Lovejoy DA, Michalec OM, Hogg DW, Wosnick DI. Role of elasmobranchs and holocephalans in understanding peptide evolution in the vertebrates: Lessons learned from gonadotropin releasing hormone (GnRH) and corticotropin releasing factor (CRF) phylogenies. Gen Comp Endocrinol 2018; 264:78-83. [PMID: 28935583 DOI: 10.1016/j.ygcen.2017.09.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 09/06/2017] [Accepted: 09/13/2017] [Indexed: 10/18/2022]
Abstract
The cartilaginous fishes (Class Chondrichthyes) comprise two morphologically distinct subclasses; Elasmobranchii and Holocephali. Evidence indicates early divergence of these subclasses, suggesting monophyly of their lineage. However, such a phylogenetic understanding is not yet developed within two highly conserved peptide lineages, GnRH and CRF. Various GnRH forms exist across the Chondrichthyes. Although 4-7 immunoreactive forms have been described in Elasmobranchii, only one has been elucidated in Holocephali. In contrast, Chondrichthyan CRF phylogeny follows a pattern more consistent with vertebrate evolution. For example, three forms are expressed within the lamprey, with similar peptides present within the genome of the Callorhinchus milii, a holocephalan. Although these findings are consistent with recent evidence regarding the phylogenetic age of Chondrichthyan lineages, CRF evolution in vertebrates remains elusive. Assuming that the Elasmobranchii and Holocephali are part of a monocladistic clade within the Chondrichthyes, we interpret the findings of GnRH and CRF to be products of their respective lineages.
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Affiliation(s)
- David A Lovejoy
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada.
| | - Ola M Michalec
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - David W Hogg
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - David I Wosnick
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
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29
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Itano WM, Lambert LL. A new cochliodont anterior tooth plate from the Mississippian of Alabama (USA) having implications for the origin of tooth plates from tooth files. ZOOLOGICAL LETTERS 2018; 4:12. [PMID: 29930866 PMCID: PMC5991435 DOI: 10.1186/s40851-018-0097-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2017] [Accepted: 05/11/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND Paleozoic holocephalian tooth plates are rarely found articulated in their original positions. When they are found isolated, it is difficult to associate the small, anterior tooth plates with the larger, more posterior ones. Tooth plates are presumed to have evolved from fusion of tooth files. However, there is little fossil evidence for this hypothesis. RESULTS We report a tooth plate having nearly perfect bilateral symmetry from the Mississippian (Chesterian Stage) Bangor Limestone of Franklin County, Alabama, USA. The high degree of symmetry suggests that it may have occupied a symphyseal or parasymphyseal position. The tooth plate resembles Deltodopsis? bialveatus St. John and Worthen, 1883, but differs in having a sharp ridge with multiple cusps arranged along the occlusal surface of the presumed labiolingual axis, rather than a relatively smooth occlusal surface. The multicusped shape is suggestive of a fused tooth file. The middle to latest Chesterian (Serpukhovian) age is determined by conodonts found in the same bed. CONCLUSION The new tooth plate is interpreted as an anterior tooth plate of a chondrichthyan fish. It is referred to Arcuodus multicuspidatus Itano and Lambert, gen. et sp. nov. Deltodopsis? bialveatus is also referred to Arcuodus.
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Affiliation(s)
- Wayne M. Itano
- Museum of Natural History, University of Colorado, Boulder, CO 80309 USA
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30
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Riley C, Cloutier R, Grogan ED. Similarity of morphological composition and developmental patterning in paired fins of the elephant shark. Sci Rep 2017; 7:9985. [PMID: 28855616 PMCID: PMC5577158 DOI: 10.1038/s41598-017-10538-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 08/10/2017] [Indexed: 11/25/2022] Open
Abstract
Jawed vertebrates, or gnathostomes, have two sets of paired appendages, pectoral and pelvic fins in fishes and fore- and hindlimbs in tetrapods. As for paired limbs, paired fins are purported serial homologues, and the advent of pelvic fins has been hypothesized to have resulted from a duplication of the developmental mechanisms present in the pectoral fins, but re-iterated at a posterior location. Developmental similarity of gene expression between pectoral and pelvic fins has been documented in chondrichthyans, but a detailed morphological description of the progression of paired fin development for this group is still lacking. We studied paired fin development in an ontogenetic series of a phylogenetically basal chondrichthyan, the elephant shark Callorhinchus milii. A strong similarity in the morphology and progression of chondrification between the pectoral and pelvic fins was found, which could be interpretated as further evidence of serial homology in paired fins, that could have arisen by duplication. Furthermore, this high degree of morphological and developmental similarity suggests the presence of morphological and developmental modules within paired fins, as observed in paired limbs. This is the first time morphological and developmental modules are described for the paired fins of chimaeras.
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Affiliation(s)
- Cyrena Riley
- Laboratoire de Paléontologie et Biologie évolutive, Université du Québec à Rimouski, Rimouski, Québec, G5L 3A1, Canada
| | - Richard Cloutier
- Laboratoire de Paléontologie et Biologie évolutive, Université du Québec à Rimouski, Rimouski, Québec, G5L 3A1, Canada.
| | - Eileen D Grogan
- Biology Department, Saint Joseph's University, Philadelphia, Pennsylvania, 19131, USA
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31
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Irisarri I, Baurain D, Brinkmann H, Delsuc F, Sire JY, Kupfer A, Petersen J, Jarek M, Meyer A, Vences M, Philippe H. Phylotranscriptomic consolidation of the jawed vertebrate timetree. Nat Ecol Evol 2017; 1:1370-1378. [PMID: 28890940 PMCID: PMC5584656 DOI: 10.1038/s41559-017-0240-5] [Citation(s) in RCA: 169] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Phylogenomics is extremely powerful but introduces new challenges as no agreement exists on "standards" for data selection, curation and tree inference. We use jawed vertebrates (Gnathostomata) as model to address these issues. Despite considerable efforts in resolving their evolutionary history and macroevolution, few studies have included a full phylogenetic diversity of gnathostomes and some relationships remain controversial. We tested a novel bioinformatic pipeline to assemble large and accurate phylogenomic datasets from RNA sequencing and find this phylotranscriptomic approach successful and highly cost-effective. Increased sequencing effort up to ca. 10Gbp allows recovering more genes, but shallower sequencing (1.5Gbp) is sufficient to obtain thousands of full-length orthologous transcripts. We reconstruct a robust and strongly supported timetree of jawed vertebrates using 7,189 nuclear genes from 100 taxa, including 23 new transcriptomes from previously unsampled key species. Gene jackknifing of genomic data corroborates the robustness of our tree and allows calculating genome-wide divergence times by overcoming gene sampling bias. Mitochondrial genomes prove insufficient to resolve the deepest relationships because of limited signal and among-lineage rate heterogeneity. Our analyses emphasize the importance of large curated nuclear datasets to increase the accuracy of phylogenomics and provide a reference framework for the evolutionary history of jawed vertebrates.
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Affiliation(s)
- Iker Irisarri
- Lehrstuhl für Zoologie und Evolutionsbiologie, Department of Biology, University of Konstanz, Universitätsstrasse 10, Konstanz, 78464, Germany. .,Systematic Biology Program, Department of Organismal Biology, Univeristy of Uppsala, Norbyvägen 18D, Uppsala, 75236, Sweden.
| | - Denis Baurain
- InBioS-Eukaryotic Phylogenomics, Department of Life Sciences and PhytoSYSTEMS, University of Liège, Liège, 4000, Belgium
| | - Henner Brinkmann
- Leibniz-Institut DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, 38124, Germany
| | - Frédéric Delsuc
- Institut des Sciences de l'Evolution, UMR 5554, CNRS, IRD, EPHE, Université de Montpellier, Montpellier, 34095, France
| | - Jean-Yves Sire
- Institut de Biologie Paris-Seine, UMR7138, Sorbonne Universities, Paris, 75005, France
| | - Alexander Kupfer
- Department of Zoology, Stuttgart State Museum of Natural History, Stuttgart, 70191, Germany
| | - Jörn Petersen
- Leibniz-Institut DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, 38124, Germany
| | - Michael Jarek
- Department of Genome Analytics, Helmholtz Centre for Infection Research, Braunschweig, 38124, Germany
| | - Axel Meyer
- Lehrstuhl für Zoologie und Evolutionsbiologie, Department of Biology, University of Konstanz, Universitätsstrasse 10, Konstanz, 78464, Germany
| | - Miguel Vences
- Zoological Institute, Braunschweig University of Technology, Braunschweig, 38106, Germany
| | - Hervé Philippe
- Centre for Biodiversity Theory and Modelling, UMR CNRS 5321, Station of Theoretical and Experimental Ecology, Moulis, 09200, France. .,Departement de Biochimie, Université de Montréal, Montréal, QC, H3C3J7, Canada.
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32
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Brazeau MD, Friedman M, Jerve A, Atwood RC. A three-dimensional placoderm (stem-group gnathostome) pharyngeal skeleton and its implications for primitive gnathostome pharyngeal architecture. J Morphol 2017; 278:1220-1228. [PMID: 28543631 PMCID: PMC5575467 DOI: 10.1002/jmor.20706] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2017] [Revised: 04/22/2017] [Accepted: 04/26/2017] [Indexed: 11/30/2022]
Abstract
The pharyngeal skeleton is a key vertebrate anatomical system in debates on the origin of jaws and gnathostome (jawed vertebrate) feeding. Furthermore, it offers considerable potential as a source of phylogenetic data. Well‐preserved examples of pharyngeal skeletons from stem‐group gnathostomes remain poorly known. Here, we describe an articulated, nearly complete pharyngeal skeleton in an Early Devonian placoderm fish, Paraplesiobatis heinrichsi Broili, from Hunsrück Slate of Germany. Using synchrotron light tomography, we resolve and reconstruct the three‐dimensional gill arch architecture of Paraplesiobatis and compare it with other gnathostomes. The preserved pharyngeal skeleton comprises elements of the hyoid arch (probable ceratohyal) and a series of branchial arches. Limited resolution in the tomography scan causes some uncertainty in interpreting the exact number of arches preserved. However, at least four branchial arches are present. The final and penultimate arches are connected as in osteichthyans. A single median basihyal is present as in chondrichthyans. No dorsal (epibranchial or pharyngobranchial) elements are observed. The structure of the pharyngeal skeleton of Paraplesiobatis agrees well with Pseudopetalichthys from the same deposit, allowing an alternative interpretation of the latter taxon. The phylogenetic significance of Paraplesiobatis is considered. A median basihyal is likely an ancestral gnathostome character, probably with some connection to both the hyoid and the first branchial arch pair. Unpaired basibranchial bones may be independently derived in chondrichthyans and osteichthyans.
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Affiliation(s)
- Martin D Brazeau
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Buckhurst Road, SL5 7PY, United Kingdom.,Department of Earth Sciences, Natural History Museum, London, SW7 5BD, United Kingdom
| | - Matt Friedman
- Museum of Paleontology and Department of Earth and Environmental Sciences, University of Michigan, 1109 Geddes Ave, Ann Arbor, Michigan, 48109-1079
| | - Anna Jerve
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Buckhurst Road, SL5 7PY, United Kingdom
| | - Robert C Atwood
- Beamline I12-JEEP, Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire, UK, OX11 0DE
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