Tetrapod-like axial regionalization in an early ray-finned fish

Lauren Cole Sallan

doi:10.1098/rspb.2012.0784

Tetrapod-like axial regionalization in an early ray-finned fish

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2012.0784 ◽

2012 ◽

Vol 279 (1741) ◽

pp. 3264-3271 ◽

Cited By ~ 16

Author(s):

Lauren Cole Sallan

Keyword(s):

Weight Bearing ◽

Expression Patterns ◽

Early Carboniferous ◽

Alternative Scenario ◽

Walking Gait ◽

Pelvic Area ◽

Early Tetrapods ◽

Primitive State ◽

Functional Explanations

Tetrapods possess up to five morphologically distinct vertebral series: cervical, thoracic, lumbar, sacral and caudal. The evolution of axial regionalization has been linked to derived Hox expression patterns during development and the demands of weight-bearing and walking on land. These evolutionary and functional explanations are supported by an absence of similar traits in fishes, living and extinct. Here, I show that, Tarrasius problematicus , a marine ray-finned fish from the Mississippian (Early Carboniferous; 359–318 Ma) of Scotland, is the first non-tetrapod known to possess tetrapod-like axial regionalization. Tarrasius exhibits five vertebral regions, including a seven-vertebrae ‘cervical’ series and a reinforced ‘sacrum’ over the pelvic area. Most vertebrae possess processes for intervertebral contact similar to tetrapod zygapophyses. The fully aquatic Tarrasius evolved these morphologies alongside other traits convergent with early tetrapods, including a naked trunk, and a single median continuous fin. Regional modifications in Tarrasius probably facilitated pelagic swimming , rather than a terrestrial lifestyle or walking gait, presenting an alternative scenario for the evolution of such traits in tetrapods. Axial regionalization in Tarrasius could indicate tetrapod-like Hox expression patterns, possibly representing the primitive state for jawed vertebrates. Alternately, it could signal a weaker relationship, or even a complete disconnect, between Hox expression domains and vertebrate axial plans.

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Locomotory behaviour of early tetrapods from Blue Beach, Nova Scotia, revealed by novel microanatomical analysis

Royal Society Open Science ◽

10.1098/rsos.210281 ◽

2021 ◽

Vol 8 (5) ◽

pp. 210281

Author(s):

Kendra I. Lennie ◽

Sarah L. Manske ◽

Chris F. Mansky ◽

Jason S. Anderson

Keyword(s):

Nova Scotia ◽

Fossil Record ◽

Early Carboniferous ◽

Late Devonian ◽

Ground Reaction Forces ◽

Limb Bones ◽

Additional Information ◽

Reaction Forces ◽

Early Tetrapods ◽

Locomotory Behaviour

Evidence for terrestriality in early tetrapods is fundamentally contradictory. Fossil trackways attributed to early terrestrial tetrapods long predate the first body fossils from the Late Devonian. However, the Devonian body fossils demonstrate an obligatorily aquatic lifestyle. Complicating our understanding of the transition from water to land is a pronounced gap in the fossil record between the aquatic Devonian taxa and presumably terrestrial tetrapods from the later Early Carboniferous. Recent work suggests that an obligatorily aquatic habit persists much higher in the tetrapod tree than previously recognized. Here, we present independent microanatomical data of locomotor capability from the earliest Carboniferous of Blue Beach, Nova Scotia. The site preserves limb bones from taxa representative of Late Devonian to mid-Carboniferous faunas as well as a rich trackway record. Given that bone remodels in response to functional stresses including gravity and ground reaction forces, we analysed both the midshaft compactness profiles and trabecular anisotropy, the latter using a new whole bone approach. Our findings suggest that early tetrapods retained an aquatic lifestyle despite varied limb morphologies, prior to their emergence onto land. These results suggest that trackways attributed to early tetrapods be closely scrutinized for additional information regarding their creation conditions, and demand an expansion of sampling to better identify the first terrestrial tetrapods.

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Bony lesions in early tetrapods and the evolution of mineralized tissue repair

Paleobiology ◽

10.1017/pab.2019.31 ◽

2019 ◽

Vol 45 (4) ◽

pp. 676-697 ◽

Cited By ~ 2

Author(s):

Eva C. Herbst ◽

Michael Doube ◽

Timothy R. Smithson ◽

Jennifer A. Clack ◽

John R. Hutchinson

Keyword(s):

Bone Healing ◽

Tissue Repair ◽

Bone Structure ◽

Early Carboniferous ◽

Skeletal Tissue ◽

Mineralized Tissues ◽

Repair Mechanisms ◽

Evolutionary Context ◽

Bony Lesions ◽

Early Tetrapods

AbstractBone healing is an important survival mechanism, allowing vertebrates to recover from injury and disease. Here we describe newly recognized paleopathologies in the hindlimbs of the early tetrapods Crassigyrinus scoticus and Eoherpeton watsoni from the early Carboniferous of Cowdenbeath, Scotland. These pathologies are among the oldest known instances of bone healing in tetrapod limb bones in the fossil record (about 325 Ma). X-ray microtomographic imaging of the internal bone structure of these lesions shows that they are characterized by a mass of trabecular bone separated from the shaft's trabeculae by a layer of cortical bone. We frame these paleopathologies in an evolutionary context, including additional data on bone healing and its pathways across extinct and extant sarcopterygians. These data allowed us to synthesize information on cell-mediated repair of bone and other mineralized tissues in all vertebrates, to reconstruct the evolutionary history of skeletal tissue repair mechanisms. We conclude that bone healing is ancestral for sarcopterygians. Furthermore, other mineralized tissues (aspidin and dentine) were also capable of healing and remodeling early in vertebrate evolution, suggesting that these repair mechanisms are synapomorphies of vertebrate mineralized tissues. The evidence for remodeling and healing in all of these tissues appears concurrently, so in addition to healing, these early vertebrates had the capacity to restore structure and strength by remodeling their skeletons. Healing appears to be an inherent property of these mineralized tissues, and its linkage to their remodeling capacity has previously been underappreciated.

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Better than fish on land? Hearing across metamorphosis in salamanders

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2014.1943 ◽

2015 ◽

Vol 282 (1802) ◽

pp. 20141943 ◽

Cited By ~ 19

Author(s):

Christian Bech Christensen ◽

Henrik Lauridsen ◽

Jakob Christensen-Dalsgaard ◽

Michael Pedersen ◽

Peter Teglberg Madsen

Keyword(s):

Imaging Techniques ◽

Experimental Studies ◽

Early Carboniferous ◽

Impedance Mismatch ◽

Hearing Sensitivity ◽

Airborne Sound ◽

Ear Morphology ◽

Early Tetrapods ◽

Underwater Hearing ◽

Better Than

Early tetrapods faced an auditory challenge from the impedance mismatch between air and tissue in the transition from aquatic to terrestrial lifestyles during the Early Carboniferous (350 Ma). Consequently, tetrapods may have been deaf to airborne sounds for up to 100 Myr until tympanic middle ears evolved during the Triassic. The middle ear morphology of recent urodeles is similar to that of early ‘lepospondyl’ microsaur tetrapods, and experimental studies on their hearing capabilities are therefore useful to understand the evolutionary and functional drivers behind the shift from aquatic to aerial hearing in early tetrapods. Here, we combine imaging techniques with neurophysiological measurements to resolve how the change from aquatic larvae to terrestrial adult affects the ear morphology and sensory capabilities of salamanders. We show that air-induced pressure detection enhances underwater hearing sensitivity of salamanders at frequencies above 120 Hz, and that both terrestrial adults and fully aquatic juvenile salamanders can detect airborne sound. Collectively, these findings suggest that early atympanic tetrapods may have been pre-equipped to aerial hearing and are able to hear airborne sound better than fish on land. When selected for, this rudimentary hearing could have led to the evolution of tympanic middle ears.

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A new tetrapod from Romer's Gap reveals an early adaptation for walking

Earth and Environmental Science Transactions of the Royal Society of Edinburgh ◽

10.1017/s1755691018000075 ◽

2017 ◽

Vol 108 (1) ◽

pp. 89-97 ◽

Cited By ~ 6

Author(s):

Timothy R. Smithson ◽

Jennifer A. Clack

Keyword(s):

Comparative Analysis ◽

Blood Vessel ◽

Brachial Artery ◽

Stride Length ◽

Early Carboniferous ◽

Ventral Surface ◽

Terrestrial Locomotion ◽

New Material ◽

Humeral Torsion ◽

Early Tetrapods

ABSTRACTA new early tetrapod, Mesanerpeton woodi gen. et sp. nov., collected by Stan Wood from the Ballagan Formation, Tournaisian CM palynozone, at Willie's Hole, Scottish Borders, is described. It includes vertebrae like those of Crassigyrinus, with poorly developed neural arches, a well ossified ulna with a large olecranon, and a humerus that is structurally intermediate between the pleisiomorphic condition of Devonian taxa and that of all later forms. A comparative analysis of this new material and other tetrapodomorph humeri revealed how an increase in humeral torsion transformed the course of the brachial artery and median nerve through the bone, from an entirely ventral path to one in which the blood vessel and nerve passed through the entepicondyle from the dorsal to the ventral surface. Increasing humeral torsion is suggested to improve walking in early tetrapods by potentially contributing to an increase in stride length, and is one of a number of changes to limb morphology during the Early Carboniferous that led to the development of terrestrial locomotion.

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Tooth histology patterns in early tetrapods and the presence of ‘dark dentine’

Transactions of the Royal Society of Edinburgh Earth Sciences ◽

10.1017/s0263593305000064 ◽

2005 ◽

Vol 96 (02) ◽

pp. 113

Keyword(s):

Tooth Histology ◽

Early Tetrapods

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Applications of CCEM to Environmental Health Problems

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100117558 ◽

1985 ◽

Vol 43 ◽

pp. 102-103

Author(s):

R. J. Lee ◽

J. S. Walker

Keyword(s):

Electron Microscopy ◽

Image Analysis ◽

Environmental Health ◽

Computer Control ◽

External Agent ◽

External Agents ◽

Computer Controlled ◽

Primitive State ◽

Textural Changes ◽

General Aspects

Electron microscopy (EM), with the advent of computer control and image analysis techniques, is rapidly evolving from an interpretative science into a quantitative technique. Electron microscopy is potentially of value in two general aspects of environmental health: exposure and diagnosis.In diagnosis, electron microscopy is essentially an extension of optical microscopy. The goal is to characterize cellular changes induced by external agents. The external agent could be any foreign material, chemicals, or even stress. The use of electron microscopy as a diagnostic tool is well- developed, but computer-controlled electron microscopy (CCEM) has had only limited impact, mainly because it is fairly new and many institutions lack the resources to acquire the capability. In addition, major contributions to diagnosis will come from CCEM only when image analysis (IA) and processing algorithms are developed which allow the morphological and textural changes recognized by experienced medical practioners to be quantified. The application of IA techniques to compare cellular structure is still in a primitive state.

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378: 14-3-3 Expression Patterns in the Human Kidney: From Fetal Development to the Adult State to Malignant Transformation

The Journal of Urology ◽

10.1016/s0022-5347(18)34631-7 ◽

2005 ◽

Vol 173 (4S) ◽

pp. 103-103

Author(s):

Adam G. Baseman ◽

Andrew J. Kirsch ◽

Fray F. Marshall ◽

Haiyen E. Zhau ◽

Leland W.K. Chung ◽

...

Keyword(s):

Malignant Transformation ◽

Fetal Development ◽

Expression Patterns ◽

Human Kidney

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Single Hemicerclage for Lateral Type B Malleolar Fracture - A Novel, Minimal and Reliable Osteosynthesis

Swiss Surgery ◽

10.1024/1023-9332.9.6.283 ◽

2003 ◽

Vol 9 (6) ◽

pp. 283-288

Author(s):

Maurer ◽

Stamenic ◽

Stouthandel ◽

Ackermann ◽

Gonzenbach

Keyword(s):

Ankle Joint ◽

Weight Bearing ◽

Fracture Type ◽

Type B ◽

Malleolar Fracture ◽

Metallic Wire ◽

Long Term Outcome ◽

X Ray ◽

Upper Ankle Joint ◽

Upper Ankle

Aim of study: To investigate the short- and long-term outcome of patients with isolated lateral malleolar fracture type B treated with a single hemicerclage out of metallic wire or PDS cord. Methods: Over an 8-year period 97 patients were treated with a single hemicerclage for lateral malleolar fracture type B and 89 were amenable to a follow-up after mean 39 months, including interview, clinical examination and X-ray controls. Results: The median operation time was 35 minutes (range 15-85 min). X-ray controls within the first two postoperative days revealed an anatomical restoration of the upper ankle joint in all but one patient. The complication rate was 8%: hematoma (2 patients), wound infection (2), Sudeck's dystrophy (2) and deep vein thrombosis (1). Full weight-bearing was tolerated at median 6.0 weeks (range 2-26 weeks). No secondary displacement, delayed union or consecutive arthrosis of the upper ankle joint was observed. All but one patient had restored symmetric joint mobility. Ninety-seven percent of patients were satisfied or very satisfied with the outcome. Following bone healing, hemicerclage removal was necessary in 19% of osteosyntheses with metallic wire and in none with PDS cord. Conclusion: The single hemicerclage is a novel, simple and reliable osteosynthesis technique for isolated lateral type B malleolar fractures and may be considered as an alternative to the osteosynthesis procedures currently in use.

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