1
|
Jones RC, Hall K, Crow KD. Are vertebrates constrained to two sets of paired appendages? The morphology, development, and evolution of pre-pelvic claspers in the Holocephali. J Morphol 2023; 284:e21632. [PMID: 37585230 DOI: 10.1002/jmor.21632] [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: 04/12/2023] [Revised: 07/10/2023] [Accepted: 08/01/2023] [Indexed: 08/17/2023]
Abstract
Holocephalans exhibit auxiliary appendages called pre-pelvic claspers (PPCs) that are located anterior to the pelvic fins, while pelvic claspers are pelvic fin modifications located posteriorly as modified metapterygia. Articulation points of the PPCs have not previously been imaged or evaluated in a comparative context, therefore, they may represent modified pelvic fin structures if they articulate with the propterygium. Alternatively, they could represent the only example of an independent third set of paired appendages in an extant taxon, if they articulate independently from any pelvic fin basal cartilages, challenging the current paradigm that extant jawed vertebrates are constrained to two sets of paired appendages. Two extinct groups, including Placoderms and Acanthodians, exhibit variation in the number of paired appendages, suggesting this may be a plesiomorphic trait. We evaluated PPC developmental growth rates, morphology, and articulation points in spotted ratfish (Hydrolagus Colliei, Holocephali). We also compared variation in PPC morphology among representatives of the three extant holocephalan families. Both, the pre-pelvic and pelvic claspers exhibit a dramatic surge in growth at sexual maturity, and then level off, suggesting synchronous development via shared hormonal regulation. While mature females are larger than males, pelvic fin growth and development is faster in males, suggesting a selective advantage to larger fins with faster development. Finally, microcomputed tomography scans revealed that PPCs are not modified propterygia, nor do they articulate with the propterygium. They articulate with the anterior pre-pelvic process on the anterior puboischiadic bar (or pelvic girdle), suggesting that while they are associated with the pelvic girdle, they may indeed represent a third, independent set of paired appendages in extant holocephalans.
Collapse
Affiliation(s)
- Riley C Jones
- Department of Biology, San Francisco State University, San Francisco, California, USA
- Department of Biology, California State University, Northridge, California, USA
| | - Kayla Hall
- Department of Biology, University of Washington, Washington, USA
| | - Karen D Crow
- Department of Biology, San Francisco State University, San Francisco, California, USA
| |
Collapse
|
2
|
da Silva JPCB, Vaz DFB. Morphology and phylogenetic significance of the pelvic articular region in elasmobranchs (Chondrichthyes). Cladistics 2023; 39:155-197. [PMID: 36856203 DOI: 10.1111/cla.12528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 01/20/2023] [Accepted: 01/21/2023] [Indexed: 03/02/2023] Open
Abstract
The morphology of paired fins is commonly overlooked in morphological studies, particularly the pelvic girdle and fins. Consequently, previous phylogenetic studies incorporating morphological data used few skeletal characters from this complex. In this paper, the phylogenetic significance of pelvic articular characters for elasmobranchs is discussed in light of the morphological variation observed in 130 species, the most comprehensive study exploring the morphology of the pelvic girdle done so far. The 10 morphological characters proposed herein for the pelvic articulation were incorporated into a molecular matrix of NADH2 sequences and submitted to an analysis of maximum parsimony employing extended implied weighting. The most stable tree was selected based on the distortion coefficients, SPR distances (subtree pruning and regrafting) and fit values. Some of the striking synapomorphies recovered within elasmobranchs include the presence of an articular surface for the first enlarged pelvic radial supporting Elasmobranchii and the pelvic articular region for the basipterygium extending from the posterolatral margin of the pelvic girdle over its lateral surface in Echinorhinus + Hexanchiformes. Additionally, the proposed characters and their distributions are discussed considering the relationships recovered and also compared with previous morphological and molecular phylogenetic hypotheses.
Collapse
Affiliation(s)
- João Paulo C B da Silva
- Departamento de Sistemática e Ecologia, Centro de Ciências Exatas e da Natureza, Universidade Federal da Paraíba, Castelo Branco, João Pessoa, 58051-900, Brazil
| | - Diego F B Vaz
- Museum of Comparative Zoology, Harvard University, 26 Oxford Street, Cambridge, MA, 02143, USA.,Biorepository Collaboratorium Guam EPSCoR, Marine Laboratory, University of Guam, 303 University Dr, UOG Station, Mangilao, GU, 96923, USA
| |
Collapse
|
3
|
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.
Collapse
|
4
|
Jobbins M, Rücklin M, Ferrón HG, Klug C. A new selenosteid placoderm from the Late Devonian of the eastern Anti-Atlas (Morocco) with preserved body outline and its ecomorphology. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.969158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Placoderms are an extinct group of early jawed vertebrates that play a key role in understanding the evolution of the gnathostome body plan, including the origin of novelties such as jaws, teeth, and pelvic fins. As placoderms have a poorly ossified axial skeleton, preservation of the mainly cartilaginous axial and fin elements is extremely rare, contrary to the heavily mineralized bones of the skull and thoracic armor. Therefore, the gross anatomy of the animals and body shape is only known from a few taxa, and reconstructions of the swimming function and ecology are speculative. Here, we describe articulated specimens preserving skull roofs, shoulder girdles, most fins, and body outlines of a newly derived arthrodire. Specimens of the selenosteid Amazichthys trinajsticae gen. et sp. nov. display a skull roof with reticular ornamentation and raised sensory lines like Driscollaspis, a median dorsal plate with a unique sharp posterior depression, the pelvic girdle, the proportions and shape of the pectoral, dorsal, and caudal fins as well as a laterally enlarged region resembling the lateral keel of a few modern sharks and bony fishes. Our new phylogenetic analyses support the monophyly of the selenosteid family and place the new genus in a clade with Melanosteus, Enseosteus, Walterosteus, and Draconichthys. The shape of its body and heterocercal caudal fin in combination with the pronounced “lateral keel” suggest Amazichthys trinajsticae was an active macropelagic swimmer capable of reaching high swimming speeds.
Collapse
|
5
|
Trinajstic K, Long JA, Sanchez S, Boisvert CA, Snitting D, Tafforeau P, Dupret V, Clement AM, Currie PD, Roelofs B, Bevitt JJ, Lee MSY, Ahlberg PE. Exceptional preservation of organs in Devonian placoderms from the Gogo lagerstätte. Science 2022; 377:1311-1314. [DOI: 10.1126/science.abf3289] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The origin and early diversification of jawed vertebrates involved major changes to skeletal and soft anatomy. Skeletal transformations can be examined directly by studying fossil stem gnathostomes; however, preservation of soft anatomy is rare. We describe the only known example of a three-dimensionally mineralized heart, thick-walled stomach, and bilobed liver from arthrodire placoderms, stem gnathostomes from the Late Devonian Gogo Formation in Western Australia. The application of synchrotron and neutron microtomography to this material shows evidence of a flat S-shaped heart, which is well separated from the liver and other abdominal organs, and the absence of lungs. Arthrodires thus show the earliest phylogenetic evidence for repositioning of the gnathostome heart associated with the evolution of the complex neck region in jawed vertebrates.
Collapse
Affiliation(s)
- Kate Trinajstic
- School of Molecular and Life Sciences, Curtin University, Bentley, WA 6102, Australia
- Western Australian Museum, Welshpool, WA 6106, Australia
| | - John A. Long
- College of Science and Engineering, Flinders University, Adelaide, SA 5001, Australia
- Museum Victoria, Melbourne, VIC 3001, Australia
| | - Sophie Sanchez
- Department of Organismal Biology, Evolutionary Biology Center, Uppsala University, 75236 Uppsala, Sweden
- European Synchrotron Radiation Facility, 38000 Grenoble, France
| | - Catherine A. Boisvert
- School of Molecular and Life Sciences, Curtin University, Bentley, WA 6102, Australia
| | - Daniel Snitting
- Department of Organismal Biology, Evolutionary Biology Center, Uppsala University, 75236 Uppsala, Sweden
| | - Paul Tafforeau
- European Synchrotron Radiation Facility, 38000 Grenoble, France
| | - Vincent Dupret
- Department of Organismal Biology, Evolutionary Biology Center, Uppsala University, 75236 Uppsala, Sweden
| | - Alice M. Clement
- College of Science and Engineering, Flinders University, Adelaide, SA 5001, Australia
| | - Peter D. Currie
- Australian Regenerative Medicine Institute and EMBL Australia, Monash University, Clayton, VIC 3800, Australia
| | - Brett Roelofs
- School of Molecular and Life Sciences, Curtin University, Bentley, WA 6102, Australia
| | - Joseph J. Bevitt
- Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW 2234, Australia
| | - Michael S. Y. Lee
- College of Science and Engineering, Flinders University, Adelaide, SA 5001, Australia
- Earth Sciences Section, South Australian Museum, Adelaide, SA 5000, Australia
| | - Per E. Ahlberg
- Department of Organismal Biology, Evolutionary Biology Center, Uppsala University, 75236 Uppsala, Sweden
| |
Collapse
|
6
|
Gillis JA, Bennett S, Criswell KE, Rees J, Sleight VA, Hirschberger C, Calzarette D, Kerr S, Dasen J. Big insight from the little skate: Leucoraja erinacea as a developmental model system. Curr Top Dev Biol 2022; 147:595-630. [PMID: 35337464 DOI: 10.1016/bs.ctdb.2021.12.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The vast majority of extant vertebrate diversity lies within the bony and cartilaginous fish lineages of jawed vertebrates. There is a long history of elegant experimental investigation of development in bony vertebrate model systems (e.g., mouse, chick, frog and zebrafish). However, studies on the development of cartilaginous fishes (sharks, skates and rays) have, until recently, been largely descriptive, owing to the challenges of embryonic manipulation and culture in this group. This, in turn, has hindered understanding of the evolution of developmental mechanisms within cartilaginous fishes and, more broadly, within jawed vertebrates. The little skate (Leucoraja erinacea) is an oviparous cartilaginous fish and has emerged as a powerful and experimentally tractable developmental model system. Here, we discuss the collection, husbandry and management of little skate brood stock and eggs, and we present an overview of key stages of skate embryonic development. We also discuss methods for the manipulation and culture of skate embryos and illustrate the range of tools and approaches available for studying this system. Finally, we summarize a selection of recent studies on skate development that highlight the utility of this system for inferring ancestral anatomical and developmental conditions for jawed vertebrates, as well as unique aspects of cartilaginous fish biology.
Collapse
Affiliation(s)
- J Andrew Gillis
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom; Marine Biological Laboratory, Woods Hole, MA, United States.
| | - Scott Bennett
- Marine Biological Laboratory, Woods Hole, MA, United States
| | | | - Jenaid Rees
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom
| | - Victoria A Sleight
- School of Biological Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | | | - Dan Calzarette
- Marine Biological Laboratory, Woods Hole, MA, United States
| | - Sarah Kerr
- Wesleyan University, Middletown, CT, United States
| | - Jeremy Dasen
- Department of Neuroscience and Physiology, NYU School of Medicine, Neuroscience Institute, NY, United States
| |
Collapse
|
7
|
Pears JB, Tillett C, Tahara R, Larsson HCE, Boisvert CA. Imaging With the Past: Revealing the Complexity of Chimaeroid Pelvic Musculature Anatomy and Development. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2021.812561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Chondrichthyans are now widely adopted as models for examining the development and evolution of the stem gnathostome body plan. The fins of some cartilaginous fish are recognized for their plesiomorphic form and mode of muscular development, i.e., epithelial extension. Despite detailed molecular and descriptive examinations of these developmental mechanisms, there has been little contemporary examination of the ontogeny and morphology of the musculature in chondrichthyans including that of the paired fins. This gap represents a need for further examination of the developmental morphology of these appendicular musculatures to gain insight into their evolution in gnathostomes. The elephant shark is a Holocephalan, the sister group of all other chondrichthyans (Holocephali: Callorhinchus milii). Here, we use nano-CT imaging and 3D reconstructions to describe the development of the pelvic musculature of a growth series of elephant shark embryos. We also use historical descriptions from the nineteenth century and traditional dissection methods to describe the adult anatomy. This combined approach, using traditional methods and historical knowledge with modern imaging techniques, has enabled a more thorough examination of the anatomy and development of the pelvic musculature revealing that chimaeroid musculatures are more complex than previously thought. These data, when compared to extant and extinct sister taxa, are essential for interpreting and reconstructing fossil musculatures as well as understanding the evolution of paired fins.
Collapse
|
8
|
Mottequin B, Goolaerts S, Hunt AP, Olive S. The erroneous chondrichthyan egg case assignments from the Devonian: implications for the knowledge on the evolution of the reproductive strategy within chondrichthyans. Naturwissenschaften 2021; 108:36. [PMID: 34432151 DOI: 10.1007/s00114-021-01751-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 08/09/2021] [Accepted: 08/16/2021] [Indexed: 10/20/2022]
Abstract
Spiraxis interstrialis, and its junior synonym Fayolia mourloni, an uppermost Famennian (Upper Devonian) fossil first described as algae and subsequently interpreted as the oldest known chondrichthyan egg case, is reinvestigated based on the discovery of several additional specimens in Belgian collections. New data, in particular from micro-CT imaging, allow to refute S. interstrialis, and by extension also Spiraxis major (the type species of Spiraxis Newberry, non Adams) and Spiraxis randalli from the Famennian of New York and Pennsylvania, as chondrichthyan egg cases. Alternative interpretations of these enigmatic helicoidal fossils are discussed. The first occurrence of oviparity in the fossil record of chondrichthyans is thus not as old as previously thought and is close to the first occurrence of viviparity in this group, both being recognised now in the Mississippian. The question of which of both conditions is plesiomorphic within chondrichthyans, and more widely within vertebrates, is discussed. Also, the presence of the genus Spiraxis in both the USA (east coast) and Belgium reinforces the strong faunal resemblance already observed in both palaeogeographical areas. It suggests important faunal exchanges between these regions of the Euramerica landmass during the Famennian.
Collapse
Affiliation(s)
- Bernard Mottequin
- O.D. Earth and History of Life, Royal Belgian Institute of Natural Sciences, rue Vautier 29, 1000, Brussels, Belgium.
| | - Stijn Goolaerts
- O.D. Earth and History of Life & Scientific Service of Heritage, Royal Belgian Institute of Natural Sciences, rue Vautier 29, 1000, Brussels, Belgium
| | - Adrian P Hunt
- Flying Heritage and Combat Armor Museum, 3407 109th St SW, Everett, WA, 98204, USA
| | - Sébastien Olive
- O.D. Earth and History of Life, Royal Belgian Institute of Natural Sciences, rue Vautier 29, 1000, Brussels, Belgium.
| |
Collapse
|
9
|
X-ray Phase-Contrast Computed Tomography for Soft Tissue Imaging at the Imaging and Medical Beamline (IMBL) of the Australian Synchrotron. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11094120] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The Imaging and Medical Beamline (IMBL) is a superconducting multipole wiggler-based beamline at the 3 GeV Australian Synchrotron operated by the Australian Nuclear Science and Technology Organisation (ANSTO). The beamline delivers hard X-rays in the 25–120 keV energy range and offers the potential for a range of biomedical X-ray applications, including radiotherapy and medical imaging experiments. One of the imaging modalities available at IMBL is propagation-based X-ray phase-contrast computed tomography (PCT). PCT produces superior results when imaging low-density materials such as soft tissue (e.g., breast mastectomies) and has the potential to be developed into a valuable medical imaging tool. We anticipate that PCT will be utilized for medical breast imaging in the near future with the advantage that it could provide better contrast than conventional X-ray absorption imaging. The unique properties of synchrotron X-ray sources such as high coherence, energy tunability, and high brightness are particularly well-suited for generating PCT data using very short exposure times on the order of less than 1 min. The coherence of synchrotron radiation allows for phase-contrast imaging with superior sensitivity to small differences in soft-tissue density. Here we also compare the results of PCT using two different detectors, as these unique source characteristics need to be complemented with a highly efficient detector. Moreover, the application of phase retrieval for PCT image reconstruction enables the use of noisier images, potentially significantly reducing the total dose received by patients during acquisition. This work is part of ongoing research into innovative tomographic methods aimed at the introduction of 3D X-ray medical imaging at the IMBL to improve the detection and diagnosis of breast cancer. Major progress in this area at the IMBL includes the characterization of a large number of mastectomy samples, both normal and cancerous, which have been scanned at clinically acceptable radiation dose levels and evaluated by expert radiologists with respect to both image quality and cancer diagnosis.
Collapse
|
10
|
Jobbins M, Rücklin M, Argyriou T, Klug C. A large Middle Devonian eubrachythoracid 'placoderm' (Arthrodira) jaw from northern Gondwana. SWISS JOURNAL OF PALAEONTOLOGY 2021; 140:2. [PMID: 33488510 PMCID: PMC7809001 DOI: 10.1186/s13358-020-00212-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 11/18/2020] [Indexed: 06/12/2023]
Abstract
For the understanding of the evolution of jawed vertebrates and jaws and teeth, 'placoderms' are crucial as they exhibit an impressive morphological disparity associated with the early stages of this process. The Devonian of Morocco is famous for its rich occurrences of arthrodire 'placoderms'. While Late Devonian strata are rich in arthrodire remains, they are less common in older strata. Here, we describe a large tooth-bearing jaw element of Leptodontichthys ziregensis gen. et sp. nov., an eubrachythoracid arthrodire from the Middle Devonian of Morocco. This species is based on a large posterior superognathal with a strong dentition. The jawbone displays features considered synapomorphies of Late Devonian eubrachythoracid arthrodires, with one posterior and one lateral row of conical teeth oriented postero-lingually. μCT-images reveal internal structures including pulp cavities and dentinous tissues. The posterior orientation of the teeth and the traces of a putative occlusal contact on the lingual side of the bone imply that these teeth were hardly used for feeding. Similar to Compagopiscis and Plourdosteus, functional teeth were possibly present during an earlier developmental stage and have been worn entirely. The morphological features of the jaw element suggest a close relationship with plourdosteids. Its size implies that the animal was rather large.
Collapse
Affiliation(s)
- Melina Jobbins
- Paläontologisches Institut und Museum, Universität Zürich, Karl-Schmid-Strasse 4, 8006 Zurich, Switzerland
| | | | - Thodoris Argyriou
- UMR 7207 (MNHN – Sorbonne Université – CNRS) Centre de Recherche en Paléontologie, Muséum National D’Histoire Naturelle, 57 rue Cuvier, 75231 Paris cedex 05, France
| | - Christian Klug
- Paläontologisches Institut und Museum, Universität Zürich, Karl-Schmid-Strasse 4, 8006 Zurich, Switzerland
| |
Collapse
|
11
|
King B, Rücklin M. A Bayesian approach to dynamic homology of morphological characters and the ancestral phenotype of jawed vertebrates. eLife 2020; 9:e62374. [PMID: 33274719 PMCID: PMC7793628 DOI: 10.7554/elife.62374] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Accepted: 12/03/2020] [Indexed: 12/22/2022] Open
Abstract
Phylogenetic analysis of morphological data proceeds from a fixed set of primary homology statements, the character-by-taxon matrix. However, there are cases where multiple conflicting homology statements can be justified from comparative anatomy. The upper jaw bones of placoderms have traditionally been considered homologous to the palatal vomer-dermopalatine series of osteichthyans. The discovery of 'maxillate' placoderms led to the alternative hypothesis that 'core' placoderm jaw bones are premaxillae and maxillae lacking external (facial) laminae. We introduce a BEAST2 package for simultaneous inference of homology and phylogeny, and find strong evidence for the latter hypothesis. Phenetic analysis of reconstructed ancestors suggests that maxillate placoderms are the most plesiomorphic known gnathostomes, and the shared cranial architecture of arthrodire placoderms, maxillate placoderms and osteichthyans is inherited. We suggest that the gnathostome ancestor possessed maxillae and premaxillae with facial and palatal laminae, and that these bones underwent divergent evolutionary trajectories in placoderms and osteichthyans.
Collapse
|
12
|
Diogo R. Cranial or postcranial—Dual origin of the pectoral appendage of vertebrates combining the fin‐fold and gill‐arch theories? Dev Dyn 2020; 249:1182-1200. [DOI: 10.1002/dvdy.192] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/22/2020] [Accepted: 05/05/2020] [Indexed: 11/10/2022] Open
Affiliation(s)
- Rui Diogo
- Department of Anatomy Howard University College of Medicine Washington District of Columbia USA
| |
Collapse
|
13
|
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.
Collapse
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
| |
Collapse
|
14
|
Charest F, Johanson Z, Cloutier R. Loss in the making: absence of pelvic fins and presence of paedomorphic pelvic girdles in a Late Devonian antiarch placoderm (jawed stem-gnathostome). Biol Lett 2019; 14:rsbl.2018.0199. [PMID: 29899132 DOI: 10.1098/rsbl.2018.0199] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 05/21/2018] [Indexed: 11/12/2022] Open
Abstract
Within jawed vertebrates, pelvic appendages have been modified or lost repeatedly, including in the most phylogenetically basal, extinct, antiarch placoderms. One Early Devonian basal antiarch, Parayunnanolepis, possessed pelvic girdles, suggesting the presence of pelvic appendages at the origin of jawed vertebrates; their absence in more derived antiarchs implies a secondary loss. Recently, paired female genital plates were identified in the Late Devonian antiarch, Bothriolepis canadensis, in the position of pelvic girdles in other placoderms. We studied these putative genital plates along an ontogenetic series of B. canadensis; ontogenetic changes in their morphology, histology and elemental composition suggest they represent endoskeletal pelvic girdles composed of perichondral and endochondral bone. We suggest that pelvic fins of derived antiarchs were lost, while pelvic girdles were retained, but reduced, relative to Parayunnanolepis This indicates developmental plasticity and evolutionary lability in pelvic appendages, shortly after these elements evolved at the origin of jawed vertebrates.
Collapse
Affiliation(s)
- France Charest
- Département de biologie, chimie et géographie, Université du Québec à Rimouski, Rimouski, Québec, Canada G5L 3A1.,Parc national de Miguasha, Nouvelle, Québec, Canada G0C 2E0
| | | | - Richard Cloutier
- Département de biologie, chimie et géographie, Université du Québec à Rimouski, Rimouski, Québec, Canada G5L 3A1
| |
Collapse
|
15
|
Hall C, Lewis R. Synchrotron radiation biomedical imaging and radiotherapy: from the UK to the Antipodes. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2019; 377:20180240. [PMID: 31030651 DOI: 10.1098/rsta.2018.0240] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/06/2019] [Indexed: 06/09/2023]
Abstract
Although the general public might think of 'X-rays' as they are applied to imaging (radiography) and for the treatment of disease (radiotherapy), the use of synchrotron radiation (SR) X-ray beams in these areas of science was a minor activity 50 years ago. The largest gains in science from SR were seen to be in those areas where signals were weakest in laboratory instruments, such as X-ray diffraction and spectroscopy. As the qualities of SR X-rays were explored and more areas of science adopted SR-based methods, this situation changed. About 30 years ago, the clinical advantages of using SR X-ray beams for radiography, radiotherapy and clinical diagnostics started to be investigated. In the UK, a multi-disciplinary group, consisting of clinicians, medical physicists and other scientists working mainly with the Synchrotron Radiation Source (SRS) in Cheshire, started to investigate techniques for diagnosis and potentially a cure for certain cancers. This preliminary work influenced the design of new facilities being constructed around the world, in particular the Imaging and Medical Beam Line on the Australian Synchrotron in Melbourne. Two authors moved from the UK to Australia to participate in this exciting venture. The following is a personal view of some of the highlights of the early-year SRS work, following through to the current activities on the new facility in Australia. This article is part of the theme issue 'Fifty years of synchrotron science: achievements and opportunities'.
Collapse
Affiliation(s)
- Christopher Hall
- 1 ANSTO Australian Synchrotron , Clayton, Victoria 3168 , Australia
- 3 Department of Medical Imaging and Radiation Sciences, Monash University , Clayton, Victoria 3600 , Australia
| | - Robert Lewis
- 2 Scott Automation , Tullamarine, Victoria 3043 , Australia
- 3 Department of Medical Imaging and Radiation Sciences, Monash University , Clayton, Victoria 3600 , Australia
- 4 Department of Medical Imaging, University of Saskatchewan , Saskatoon, Saskatchewan , Canada
| |
Collapse
|
16
|
Young M, Selleri L, Capellini TD. Genetics of scapula and pelvis development: An evolutionary perspective. Curr Top Dev Biol 2019; 132:311-349. [PMID: 30797513 PMCID: PMC6430119 DOI: 10.1016/bs.ctdb.2018.12.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
In tetrapods, the scapular and pelvic girdles perform the important function of anchoring the limbs to the trunk of the body and facilitating the movement of each appendage. This shared function, however, is one of relatively few similarities between the scapula and pelvis, which have significantly different morphologies, evolutionary histories, embryonic origins, and underlying genetic pathways. The scapula evolved in jawless fish prior to the pelvis, and its embryonic development is unique among bones in that it is derived from multiple progenitor cell populations, including the dermomyotome, somatopleure, and neural crest. Conversely, the pelvis evolved several million years later in jawed fish, and it develops from an embryonic somatopleuric cell population. The genetic networks controlling the formation of the pelvis and scapula also share similarities and differences, with a number of genes shaping only one or the other, while other gene products such as PBX transcription factors act as hierarchical developmental regulators of both girdle structures. Here, we provide a detailed review of the cellular processes and genetic networks underlying pelvis and scapula formation in tetrapods, while also highlighting unanswered questions about girdle evolution and development.
Collapse
Affiliation(s)
- Mariel Young
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, United States
| | - Licia Selleri
- Program in Craniofacial Biology, Department of Orofacial Sciences, Eli and Edythe Broad Center of Regeneration Medicine & Stem Cell Research, University of California, Institute of Human Genetics, San Francisco, CA, United States; Program in Craniofacial Biology, Department of Anatomy, Eli and Edythe Broad Center of Regeneration Medicine & Stem Cell Research, University of California, Institute of Human Genetics, San Francisco, CA, United States.
| | - Terence D Capellini
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, United States; Broad Institute of Harvard and MIT, Cambridge, MA, United States.
| |
Collapse
|
17
|
King B, Qiao T, Lee MSY, Zhu M, Long JA. Bayesian Morphological Clock Methods Resurrect Placoderm Monophyly and Reveal Rapid Early Evolution in Jawed Vertebrates. Syst Biol 2018; 66:499-516. [PMID: 27920231 DOI: 10.1093/sysbio/syw107] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 11/18/2016] [Indexed: 11/13/2022] Open
Abstract
The phylogeny of early gnathostomes provides an important framework for understanding one of the most significant evolutionary events, the origin and diversification of jawed vertebrates. A series of recent cladistic analyses have suggested that the placoderms, an extinct group of armoured fish, form a paraphyletic group basal to all other jawed vertebrates. We revised and expanded this morphological data set, most notably by sampling autapomorphies in a similar way to parsimony-informative traits, thus ensuring this data (unlike most existing morphological data sets) satisfied an important assumption of Bayesian tip-dated morphological clock approaches. We also found problems with characters supporting placoderm paraphyly, including character correlation and incorrect codings. Analysis of this data set reveals that paraphyly and monophyly of core placoderms (excluding maxillate forms) are essentially equally parsimonious. The two alternative topologies have different root positions for the jawed vertebrates but are otherwise similar. However, analysis using tip-dated clock methods reveals strong support for placoderm monophyly, due to this analysis favoring trees with more balanced rates of evolution. Furthermore, enforcing placoderm paraphyly results in higher levels and unusual patterns of rate heterogeneity among branches, similar to that generated from simulated trees reconstructed with incorrect root positions. These simulations also show that Bayesian tip-dated clock methods outperform parsimony when the outgroup is largely uninformative (e.g., due to inapplicable characters), as might be the case here. The analysis also reveals that gnathostomes underwent a rapid burst of evolution during the Silurian period which declined during the Early Devonian. This rapid evolution during a period with few articulated fossils might partly explain the difficulty in ascertaining the root position of jawed vertebrates.
Collapse
Affiliation(s)
- Benedict King
- School of Biological Sciences, Flinders University, PO Box 2100, Adelaide, South Australia 5001, Australia
| | - Tuo Qiao
- Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, PO Box 643, Beijing 100044, China
| | - Michael S Y Lee
- School of Biological Sciences, Flinders University, PO Box 2100, Adelaide, South Australia 5001, Australia.,Earth Sciences Section, South Australian Museum, North Terrace, Adelaide 5000, Australia
| | - Min Zhu
- Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, PO Box 643, Beijing 100044, China
| | - John A Long
- School of Biological Sciences, Flinders University, PO Box 2100, Adelaide, South Australia 5001, Australia
| |
Collapse
|
18
|
New morphological information on, and species of placoderm fish Africanaspis (Arthrodira, Placodermi) from the Late Devonian of South Africa. PLoS One 2017; 12:e0173169. [PMID: 28379973 PMCID: PMC5381866 DOI: 10.1371/journal.pone.0173169] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 02/11/2017] [Indexed: 11/19/2022] Open
Abstract
Here we present a new species of placoderm fish, Africanaspis edmountaini sp. nov., and redescribe Africanaspis doryssa on the basis of new material collected from the type locality of Africanaspis. The new material includes the first head shields of Africanaspis doryssa in addition to soft anatomy for both taxa. Hitherto Africanaspis was entirely described from trunk armour and no record of body and fin outlines had been recorded. In addition the first record of embryonic and juvenile specimens of Africanaspis doryssa is presented and provides a growth series from presumed hatchlings to presumed adults. The presence of a greater number of juveniles compared to adults indicates that the Waterloo Farm fossil site in South Africa represents the first nursery site of arthrodire placoderms known from a cold water environment. The preservation of an ontogenetic series demonstrates that variation within the earlier known sample, initially considered to have resulted from ontogenetic change, instead indicates the presence of a second, less common species Africanaspis edmountaini sp. nov. There is some faunal overlap between the Waterloo Farm fossil site and faunas described from Strud in Belgium and Red Hill, Pennsylvania, in north America, supporting the concept of a more cosmopolitan vertebrate fauna in the Famennian than earlier in the Devonian.
Collapse
|
19
|
Long JA. Why Australasian vertebrate animals are so unique - A palaeontological perspective. Gen Comp Endocrinol 2017; 244:2-10. [PMID: 27269378 DOI: 10.1016/j.ygcen.2016.06.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 05/20/2016] [Accepted: 06/02/2016] [Indexed: 11/25/2022]
Abstract
Australasia has a unique fauna of living vertebrates, which include the oldest known species on the planet (the lungfish Neoceratodus) as well as many diverse, highly endemic families of fish, amphibians, reptiles, birds and mammals. The origin of most of the Australian vertebrate fauna has developed from two phases. Firstly, when Australia was subsumed within the greater Gondwana landmass, migration of animals from one region to another was possible by a land connection. Many of our most primitive forms of reptiles and mammals probably entered the country at this time, such as varanids, madtsooid snakes, monotremes and basal marsupials. Secondly, following the breakup of Gondwana, the isolation of Australia for its last 40 million years and subsequent changing climatic conditions drove the radiation of marsupial, reptile and amphibian families within the continent. The gradual aridification of central Australia further divided the landmass into discrete regional areas characterised by rainfall, vegetation, and climatic zones.
Collapse
Affiliation(s)
- John A Long
- School of Biological Sciences, Flinders University, GPO Box 2100, Adelaide, South Australia 5001, Australia.
| |
Collapse
|
20
|
Stevenson AW, Crosbie JC, Hall CJ, Häusermann D, Livingstone J, Lye JE. Quantitative characterization of the X-ray beam at the Australian Synchrotron Imaging and Medical Beamline (IMBL). JOURNAL OF SYNCHROTRON RADIATION 2017; 24:110-141. [PMID: 28009552 DOI: 10.1107/s1600577516015563] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 10/04/2016] [Indexed: 06/06/2023]
Abstract
A critical early phase for any synchrotron beamline involves detailed testing, characterization and commissioning; this is especially true of a beamline as ambitious and complex as the Imaging & Medical Beamline (IMBL) at the Australian Synchrotron. IMBL staff and expert users have been performing precise experiments aimed at quantitative characterization of the primary polychromatic and monochromatic X-ray beams, with particular emphasis placed on the wiggler insertion devices (IDs), the primary-slit system and any in vacuo and ex vacuo filters. The findings from these studies will be described herein. These results will benefit IMBL and other users in the future, especially those for whom detailed knowledge of the X-ray beam spectrum (or `quality') and flux density is important. This information is critical for radiotherapy and radiobiology users, who ultimately need to know (to better than 5%) what X-ray dose or dose rate is being delivered to their samples. Various correction factors associated with ionization-chamber (IC) dosimetry have been accounted for, e.g. ion recombination, electron-loss effects. A new and innovative approach has been developed in this regard, which can provide confirmation of key parameter values such as the magnetic field in the wiggler and the effective thickness of key filters. IMBL commenced operation in December 2008 with an Advanced Photon Source (APS) wiggler as the (interim) ID. A superconducting multi-pole wiggler was installed and operational in January 2013. Results are obtained for both of these IDs and useful comparisons are made. A comprehensive model of the IMBL has been developed, embodied in a new computer program named spec.exe, which has been validated against a variety of experimental measurements. Having demonstrated the reliability and robustness of the model, it is then possible to use it in a practical and predictive manner. It is hoped that spec.exe will prove to be a useful resource for synchrotron science in general, and for hard X-ray beamlines, whether they are based on bending magnets or insertion devices, in particular. In due course, it is planned to make spec.exe freely available to other synchrotron scientists.
Collapse
Affiliation(s)
- Andrew W Stevenson
- Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168, Australia
| | - Jeffrey C Crosbie
- School of Science, RMIT University, GPO Box 2476, Melbourne, Victoria 3001, Australia
| | - Christopher J Hall
- Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168, Australia
| | - Daniel Häusermann
- Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168, Australia
| | - Jayde Livingstone
- Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168, Australia
| | - Jessica E Lye
- School of Science, RMIT University, GPO Box 2476, Melbourne, Victoria 3001, Australia
| |
Collapse
|
21
|
|
22
|
Qiao T, King B, Long JA, Ahlberg PE, Zhu M. Early Gnathostome Phylogeny Revisited: Multiple Method Consensus. PLoS One 2016; 11:e0163157. [PMID: 27649538 PMCID: PMC5029804 DOI: 10.1371/journal.pone.0163157] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 09/02/2016] [Indexed: 12/02/2022] Open
Abstract
A series of recent studies recovered consistent phylogenetic scenarios of jawed vertebrates, such as the paraphyly of placoderms with respect to crown gnathostomes, and antiarchs as the sister group of all other jawed vertebrates. However, some of the phylogenetic relationships within the group have remained controversial, such as the positions of Entelognathus, ptyctodontids, and the Guiyu-lineage that comprises Guiyu, Psarolepis and Achoania. The revision of the dataset in a recent study reveals a modified phylogenetic hypothesis, which shows that some of these phylogenetic conflicts were sourced from a few inadvertent miscodings. The interrelationships of early gnathostomes are addressed based on a combined new dataset with 103 taxa and 335 characters, which is the most comprehensive morphological dataset constructed to date. This dataset is investigated in a phylogenetic context using maximum parsimony (MP), Bayesian inference (BI) and maximum likelihood (ML) approaches in an attempt to explore the consensus and incongruence between the hypotheses of early gnathostome interrelationships recovered from different methods. Our findings consistently corroborate the paraphyly of placoderms, all 'acanthodians' as a paraphyletic stem group of chondrichthyans, Entelognathus as a stem gnathostome, and the Guiyu-lineage as stem sarcopterygians. The incongruence using different methods is less significant than the consensus, and mainly relates to the positions of the placoderm Wuttagoonaspis, the stem chondrichthyan Ramirosuarezia, and the stem osteichthyan Lophosteus-the taxa that are either poorly known or highly specialized in character complement. Given that the different performances of each phylogenetic approach, our study provides an empirical case that the multiple phylogenetic analyses of morphological data are mutually complementary rather than redundant.
Collapse
Affiliation(s)
- Tuo Qiao
- Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China
| | - Benedict King
- School of Biological Sciences, Flinders University, Adelaide, South Australia, Australia
| | - John A. Long
- School of Biological Sciences, Flinders University, Adelaide, South Australia, Australia
| | - Per E. Ahlberg
- Department of Organismal Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen, Uppsala, Sweden
| | - Min Zhu
- Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China
| |
Collapse
|
23
|
Olive S, Clément G, Daeschler EB, Dupret V. Placoderm Assemblage from the Tetrapod-Bearing Locality of Strud (Belgium, Upper Famennian) Provides Evidence for a Fish Nursery. PLoS One 2016; 11:e0161540. [PMID: 27552196 PMCID: PMC4994939 DOI: 10.1371/journal.pone.0161540] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 08/08/2016] [Indexed: 11/18/2022] Open
Abstract
The placoderm fauna of the upper Famennian tetrapod-bearing locality of Strud, Belgium, includes the antiarch Grossilepis rikiki, the arthrodire groenlandaspidid Turrisaspis strudensis and the phyllolepidid Phyllolepis undulata. Based on morphological and morphometric evidence, the placoderm specimens from Strud are predominantly recognised as immature specimens and this locality as representing a placoderm nursery. The Strud depositional environment corresponds to a channel in an alluvial plain, and the presence of a nursery in such environment could have provided nutrients and protection to the placoderm offspring. This represents one of the earliest pieces of evidence for this sort of habitat partitioning in vertebrate history, with adults living more distantly from the nursery and using the nursery only to spawn or give live birth.
Collapse
Affiliation(s)
- Sébastien Olive
- OD Earth and Life History, Royal Belgian Institute of Natural Sciences, Brussels, Belgium
- Evolution & Diversity Dynamics Lab, Department of Geology, Liège University, Liège, Belgium
- * E-mail: (SO); (VD)
| | - Gaël Clément
- Centre de Recherche sur la Paléobiodiversité et les Paléoenvironnements, UMR CR2P 7207, Sorbonne Universités, MNHN, CNRS, UPMC-Paris6, Muséum national d’Histoire Naturelle, Paris, France
| | - Edward B. Daeschler
- Academy of Natural Sciences of Drexel University, Philadelphia, Pennsylvania, United States of America
| | - Vincent Dupret
- Subdepartment of Evolution and Development, Department of Organismal Biology, Uppsala University, Uppsala, Sweden
- * E-mail: (SO); (VD)
| |
Collapse
|
24
|
Miyashita T, Diogo R. Evolution of Serial Patterns in the Vertebrate Pharyngeal Apparatus and Paired Appendages via Assimilation of Dissimilar Units. Front Ecol Evol 2016. [DOI: 10.3389/fevo.2016.00071] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
|
25
|
Sears KE, Capellini TD, Diogo R. On the serial homology of the pectoral and pelvic girdles of tetrapods. Evolution 2015; 69:2543-55. [DOI: 10.1111/evo.12773] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 09/02/2015] [Accepted: 09/09/2015] [Indexed: 12/23/2022]
Affiliation(s)
- Karen E. Sears
- School of Integrative Biology; University of Illinois; Urbana Illinois 61801
- Institute for Genomic Biology; University of Illinois; Urbana Illinois 61801
| | | | - Rui Diogo
- Howard University College of Medicine; Washington District of Columbia 20059
| |
Collapse
|
26
|
Brazeau MD, Friedman M. The origin and early phylogenetic history of jawed vertebrates. Nature 2015; 520:490-7. [PMID: 25903631 DOI: 10.1038/nature14438] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 02/09/2015] [Indexed: 11/09/2022]
Abstract
Fossils of early gnathostomes (or jawed vertebrates) have been the focus of study for nearly two centuries. They yield key clues about the evolutionary assembly of the group's common body plan, as well the divergence of the two living gnathostome lineages: the cartilaginous and bony vertebrates. A series of remarkable new palaeontological discoveries, analytical advances and innovative reinterpretations of existing fossil archives have fundamentally altered a decades-old consensus on the relationships of extinct gnathostomes, delivering a new evolutionary framework for exploring major questions that remain unanswered, including the origin of jaws.
Collapse
Affiliation(s)
- Martin D Brazeau
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot SL5 7PY, UK
| | - Matt Friedman
- Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN, UK
| |
Collapse
|
27
|
O'Shaughnessy KL, Dahn RD, Cohn MJ. Molecular development of chondrichthyan claspers and the evolution of copulatory organs. Nat Commun 2015; 6:6698. [PMID: 25868783 PMCID: PMC4403318 DOI: 10.1038/ncomms7698] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 02/19/2015] [Indexed: 11/09/2022] Open
Abstract
The earliest known vertebrate copulatory organs are claspers, paired penis-like structures that are associated with evolution of internal fertilization and viviparity in Devonian placoderms. Today, only male chondrichthyans possess claspers, which extend from posterior pelvic fins and function as intromittent organs. Here we report that clasper development from pelvic fins of male skates is controlled by hormonal regulation of the Sonic hedgehog (Shh) pathway. We show that Shh signalling is necessary for male clasper development and is sufficient to induce clasper cartilages in females. Androgen receptor (AR) controls the male-specific pattern of Shh in pelvic fins by regulation of Hand2. We identify an androgen response element (ARE) in the Hand2 locus and present biochemical evidence that AR can directly bind the Hand2 ARE. Together, our results suggest that the genetic circuit for appendage development evolved an androgen regulatory input, which prolonged signalling activity and drove clasper skeletogenesis in male fins. Claspers are copulatory organs found in male cartilaginous fishes. Here, the authors show that androgen receptor signalling maintains the Shh pathway to promote clasper development in male skates and suggest the importance of hormonal regulation in the evolution of male copulatory organs.
Collapse
Affiliation(s)
- Katherine L O'Shaughnessy
- Department of Molecular Genetics and Microbiology, UF Genetics Institute, University of Florida, PO Box 103610, Gainesville, Florida 32610, USA
| | | | - Martin J Cohn
- 1] Department of Molecular Genetics and Microbiology, UF Genetics Institute, University of Florida, PO Box 103610, Gainesville, Florida 32610, USA [2] Howard Hughes Medical Institute and Department of Biology, University of Florida, PO Box 103610, Gainesville, Florida 32610, USA
| |
Collapse
|
28
|
Copulation in antiarch placoderms and the origin of gnathostome internal fertilization. Nature 2014; 517:196-9. [DOI: 10.1038/nature13825] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 08/29/2014] [Indexed: 11/08/2022]
|