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Iijima M, Mayerl CJ, Munteanu VD, Blob RW. Forelimb muscle activation patterns in American alligators: Insights into the evolution of limb posture and powered flight in archosaurs. J Anat 2024; 244:943-958. [PMID: 38242862 PMCID: PMC11095314 DOI: 10.1111/joa.14011] [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: 08/08/2023] [Revised: 01/08/2024] [Accepted: 01/09/2024] [Indexed: 01/21/2024] Open
Abstract
The evolution of archosaurs provides an important context for understanding the mechanisms behind major functional transformations in vertebrates, such as shifts from sprawling to erect limb posture and the acquisition of powered flight. While comparative anatomy and ichnology of extinct archosaurs have offered insights into musculoskeletal and gait changes associated with locomotor transitions, reconstructing the evolution of motor control requires data from extant species. However, the scarcity of electromyography (EMG) data from the forelimb, especially of crocodylians, has hindered understanding of neuromuscular evolution in archosaurs. Here, we present EMG data for nine forelimb muscles from American alligators during terrestrial locomotion. Our aim was to investigate the modulation of motor control across different limb postures and examine variations in motor control across phylogeny and locomotor modes. Among the nine muscles examined, m. pectoralis, the largest forelimb muscle and primary shoulder adductor, exhibited significantly smaller mean EMG amplitudes for steps in which the shoulder was more adducted (i.e., upright). This suggests that using a more adducted limb posture helps to reduce forelimb muscle force and work during stance. As larger alligators use a more adducted shoulder and hip posture, the sprawling to erect postural transition that occurred in the Triassic could be either the cause or consequence of the evolution of larger body size in archosaurs. Comparisons of EMG burst phases among tetrapods revealed that a bird and turtle, which have experienced major musculoskeletal transformations, displayed distinctive burst phases in comparison to those from an alligator and lizard. These results support the notion that major shifts in body plan and locomotor modes among sauropsid lineages were associated with significant changes in muscle activation patterns.
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Affiliation(s)
- Masaya Iijima
- Structure and Motion Lab, Department of Comparative Biomedical SciencesThe Royal Veterinary CollegeHertfordshireUK
- Nagoya University MuseumNagoyaJapan
| | | | - V. David Munteanu
- Department of Biological SciencesClemson UniversityClemsonSouth CarolinaUSA
| | - Richard W. Blob
- Department of Biological SciencesClemson UniversityClemsonSouth CarolinaUSA
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Yang Z, Jiang B, Benton MJ, Xu X, McNamara ME, Hone DWE. Allometric wing growth links parental care to pterosaur giantism. Proc Biol Sci 2023; 290:20231102. [PMID: 37464754 DOI: 10.1098/rspb.2023.1102] [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: 12/07/2022] [Accepted: 06/28/2023] [Indexed: 07/20/2023] Open
Abstract
Pterosaurs evolved a broad range of body sizes, from small-bodied early forms with wingspans of mostly 1-2 m to the last-surviving giants with sizes of small airplanes. Since all pterosaurs began life as small hatchlings, giant forms must have attained large adult sizes through new growth strategies, which remain largely unknown. Here we assess wing ontogeny and performance in the giant Pteranodon and the smaller-bodied anurognathids Rhamphorhynchus, Pterodactylus and Sinopterus. We show that most smaller-bodied pterosaurs shared negative allometry or isometry in the proximal elements of the fore- and hindlimbs, which were critical elements for powering both flight and terrestrial locomotion, whereas these show positive allometry in Pteranodon. Such divergent growth allometry typically signals different strategies in the precocial-altricial spectrum, suggesting more altricial development in Pteranodon. Using a biophysical model of powered and gliding flight, we test and reject the hypothesis that an aerodynamically superior wing planform could have enabled Pteranodon to attain its larger body size. We therefore propose that a shift from a plesiomorphic precocial state towards a derived state of enhanced parental care may have relaxed the constraints of small body sizes and allowed the evolution of derived flight anatomies critical for the flying giants.
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Affiliation(s)
- Zixiao Yang
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork T23 TK30, Ireland
- Environmental Research Institute, Ellen Hutchins Building, Lee Road, Cork T23 XE10, Ireland
| | - Baoyu Jiang
- Center for Research and Education on Biological Evolution and Environments, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, People's Republic of China
| | - Michael J Benton
- School of Earth Sciences, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Xing Xu
- Center for Vertebrate Evolutionary Biology, Yunnan University, Kunming 650031, People's Republic of China
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, People's Republic of China
| | - Maria E McNamara
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork T23 TK30, Ireland
- Environmental Research Institute, Ellen Hutchins Building, Lee Road, Cork T23 XE10, Ireland
| | - David W E Hone
- School of Biological and Behavioural Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
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Goto Y, Yoda K, Weimerskirch H, Sato K. How did extinct giant birds and pterosaurs fly? A comprehensive modeling approach to evaluate soaring performance. PNAS NEXUS 2022; 1:pgac023. [PMID: 36712794 PMCID: PMC9802081 DOI: 10.1093/pnasnexus/pgac023] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 02/18/2022] [Accepted: 03/03/2022] [Indexed: 02/01/2023]
Abstract
The largest extinct volant birds (Pelagornis sandersi and Argentavis magnificens) and pterosaurs (Pteranodon and Quetzalcoatlus) are thought to have used wind-dependent soaring flight, similar to modern large birds. There are 2 types of soaring: thermal soaring, used by condors and frigatebirds, which involves the use of updrafts to ascend and then glide horizontally; and dynamic soaring, used by albatrosses, which involves the use of wind speed differences with height above the sea surface. Previous studies have suggested that P. sandersi used dynamic soaring, while A. magnificens and Quetzalcoatlus used thermal soaring. For Pteranodon, there is debate over whether they used dynamic or thermal soaring. However, the performance and wind speed requirements of dynamic and thermal soaring for these species have not yet been quantified comprehensively. We quantified these values using aerodynamic models and compared them with that of extant birds. For dynamic soaring, we quantified maximum travel speeds and maximum upwind speeds. For thermal soaring, we quantified the animal's sinking speed circling at a given radius and how far it could glide losing a given height. Our results confirmed those from previous studies that A. magnificens and Pteranodon used thermal soaring. Conversely, the results for P. sandersi and Quetzalcoatlus were contrary to those from previous studies. P. sandersi used thermal soaring, and Quetzalcoatlus had a poor ability both in dynamic and thermal soaring. Our results demonstrate the need for comprehensive assessments of performance and required wind conditions when estimating soaring styles of extinct flying species.
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Affiliation(s)
| | - Ken Yoda
- Graduate School of Environmental Studies, Nagoya University, Furo, Chikusa, Nagoya 464-8601, Japan
| | - Henri Weimerskirch
- Centre d'Etudes Biologiques de Chizé, CNRS, 79360 Villiers En Bois, France
| | - Katsufumi Sato
- Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwanoha, Kashiwa, Chiba, 277-8564, Japan
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Martin-Silverstone E, Habib MB, Hone DWE. Volant Fossil Vertebrates: Potential for Bioinspired Flight Technology. Trends Ecol Evol 2020; 35:618-629. [PMID: 32521245 DOI: 10.1016/j.tree.2020.03.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2017] [Revised: 02/19/2020] [Accepted: 03/06/2020] [Indexed: 12/14/2022]
Abstract
Animal flight is ecologically important and has a long evolutionary history. It has evolved independently in many distantly related clades of animals. Powered flight has evolved only three times in vertebrates, making it evolutionarily rare. Major recent fossil discoveries have provided key data on fossil flying vertebrates and critical insights regarding the evolution and different arrangements of animal flight surfaces. Combined with new methodologies, these discoveries have paved the way for potentially expanding biomimetic and biologically inspired designs to incorporate lessons from fossil taxa. Here, we review the latest knowledge and literature regarding flight performance in fossil vertebrates. We then synthesise key elements to provide an overview of those cases where fossil flyers might provide new insights for applied sciences.
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Affiliation(s)
- Elizabeth Martin-Silverstone
- School of Earth Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol, BS8 1TQ, UK.
| | - Michael B Habib
- Dinosaur Institute, Natural History Museum of Los Angeles County, 900 W Exposition Boulevard, Los Angeles, CA 90007, USA
| | - David W E Hone
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
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Bestwick J, Unwin DM, Butler RJ, Henderson DM, Purnell MA. Pterosaur dietary hypotheses: a review of ideas and approaches. Biol Rev Camb Philos Soc 2018; 93:2021-2048. [PMID: 29877021 PMCID: PMC6849529 DOI: 10.1111/brv.12431] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 05/03/2018] [Accepted: 05/11/2018] [Indexed: 11/29/2022]
Abstract
Pterosaurs are an extinct group of Mesozoic flying reptiles, whose fossil record extends from approximately 210 to 66 million years ago. They were integral components of continental and marginal marine ecosystems, yet their diets remain poorly constrained. Numerous dietary hypotheses have been proposed for different pterosaur groups, including insectivory, piscivory, carnivory, durophagy, herbivory/frugivory, filter-feeding and generalism. These hypotheses, and subsequent interpretations of pterosaur diet, are supported by qualitative (content fossils, associations, ichnology, comparative anatomy) and/or quantitative (functional morphology, stable isotope analysis) evidence. Pterosaur dietary interpretations are scattered throughout the literature with little attention paid to the supporting evidence. Reaching a robustly supported consensus on pterosaur diets is important for understanding their dietary evolution, and their roles in Mesozoic ecosystems. A comprehensive examination of the pterosaur literature identified 314 dietary interpretations (dietary statement plus supporting evidence) from 126 published studies. Multiple alternative diets have been hypothesised for most principal taxonomic pterosaur groups. Some groups exhibit a high degree of consensus, supported by multiple lines of evidence, while others exhibit less consensus. Qualitative evidence supports 87.3% of dietary interpretations, with comparative anatomy most common (62.1% of total). More speciose groups of pterosaur tend to have a greater range of hypothesised diets. Consideration of dietary interpretations within alternative phylogenetic contexts reveals high levels of consensus between equivalent monofenestratan groups, and lower levels of consensus between equivalent non-monofenestratan groups. Evaluating the possible non-biological controls on apparent patterns of dietary diversity reveals that numbers of dietary interpretations through time exhibit no correlation with patterns of publication (number of peer-reviewed publications through time). 73.8% of dietary interpretations were published in the 21st century. Overall, consensus interpretations of pterosaur diets are better accounted for by non-biological signals, such as the impact of the respective quality of the fossil record of different pterosaur groups on research levels. That many interpretations are based on qualitative, often untestable lines of evidence adds significant noise to the data. More experiment-led pterosaur dietary research, with greater consideration of pterosaurs as organisms with independent evolutionary histories, will lead to more robust conclusions drawn from repeatable results. This will allow greater understanding of pterosaur dietary diversity, disparity and evolution and facilitate reconstructions of Mesozoic ecosystems.
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Affiliation(s)
- Jordan Bestwick
- School of Geography, Geology and the EnvironmentUniversity of LeicesterLeicesterLE1 7RHU.K.
| | - David M. Unwin
- School of Museum StudiesUniversity of LeicesterLeicesterLE1 7RFU.K.
| | - Richard J. Butler
- School of Geography, Earth and Environmental SciencesUniversity of BirminghamBirminghamB15 2TTU.K.
| | - Donald M. Henderson
- Royal Tyrrell Museum of Palaeontology, P.O. Box 7500DrumhellerAlberta, T0J 0Y0Canada
| | - Mark A. Purnell
- School of Geography, Geology and the EnvironmentUniversity of LeicesterLeicesterLE1 7RHU.K.
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Legendre LJ, Botha-Brink J. Digging the compromise: investigating the link between limb bone histology and fossoriality in the aardvark ( Orycteropus afer). PeerJ 2018; 6:e5216. [PMID: 30018860 PMCID: PMC6045922 DOI: 10.7717/peerj.5216] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 06/21/2018] [Indexed: 01/07/2023] Open
Abstract
Bone microstructure has long been known as a powerful tool to investigate lifestyle-related biomechanical constraints, and many studies have focused on identifying such constraints in the limb bones of aquatic or arboreal mammals in recent years. The limb bone microstructure of fossorial mammals, however, has not been extensively described. Furthermore, so far, studies on this subject have always focused on the bone histology of small burrowers, such as subterranean rodents or true moles. Physiological constraints associated with digging, however, are known to be strongly influenced by body size, and larger burrowers are likely to exhibit a histological profile more conspicuously influenced by fossorial activity. Here, we describe for the first time the limb bone histology of the aardvark (Orycteropus afer), the largest extant burrowing mammal. The general pattern is very similar for all six sampled limb bones (i.e., humerus, radius, ulna, femur, tibia, and fibula). Most of the cortex at midshaft is comprised of compacted coarse cancellous bone (CCCB), an endosteal tissue formed in the metaphyses through the compaction of bony trabeculae. Conversely, the periosteal bone is highly resorbed in all sections, and is reduced to a thin outer layer, suggesting a pattern of strong cortical drift. This pattern contrasts with that of most large mammals, in which cortical bone is of mostly periosteal origin, and CCCB, being a very compliant bone tissue type, is usually resorbed or remodeled during ontogeny. The link between histology and muscle attachment sites, as well as the influence of the semi-arid environment and ant-eating habits of the aardvark on its bone microstructure, are discussed. We hypothesize that the unusual histological profile of the aardvark is likely the outcome of physiological constraints due to both extensive digging behavior and strong metabolic restrictions. Adaptations to fossoriality are thus the result of a physiological compromise between limited food availability, an environment with high temperature variability, and the need for biomechanical resistance during digging. These results highlight the difficulties of deciphering all factors potentially involved in bone formation in fossorial mammals. Even though the formation and maintaining of CCCB through ontogeny in the aardvark cannot be unambiguously linked with its fossorial habits, a high amount of CCCB has been observed in the limb bones of other large burrowing mammals. The inclusion of such large burrowers in future histological studies is thus likely to improve our understanding of the functional link between bone growth and fossorial lifestyle in an evolutionary context.
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Affiliation(s)
- Lucas J Legendre
- Karoo Palaeontology Department, National Museum, Bloemfontein, South Africa
| | - Jennifer Botha-Brink
- Karoo Palaeontology Department, National Museum, Bloemfontein, South Africa.,Department of Zoology and Entomology, University of the Free State, Bloemfontein, South Africa
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Navarro CA, Martin-Silverstone E, Stubbs TL. Morphometric assessment of pterosaur jaw disparity. ROYAL SOCIETY OPEN SCIENCE 2018; 5:172130. [PMID: 29765665 PMCID: PMC5936930 DOI: 10.1098/rsos.172130] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 03/26/2018] [Indexed: 05/28/2023]
Abstract
Pterosaurs were a successful group of Mesozoic flying reptiles. They were the first vertebrate group to achieve powered flight and varied enormously in morphology and ecology, occupying a variety of niches and developing specialized feeding strategies. Ecomorphological principles suggest this variation should be reflected by great morphological diversity in the lower jaw, given that the mandible served as the primary apparatus for prey acquisition. Here we present the first study of mandibular shape disparity in pterosaurs and aim to characterize major aspects of variation. We use a combination of geometric morphometric approaches, incorporating both outline analysis using elliptical Fourier analysis and semi-landmark approaches. Our results show that morphological convergence is prevalent and many pterosaurs, belonging to diverse dietary groups and subclades, overlap in morphospace and possessed relatively simple 'rod-shaped' jaws. There is no clear trend of size distributions in pterosaur mandibular morphospace, and larger forms are widely distributed. Additionally, there is limited functional signal within pterosaur lower jaw morphospace. Instead, the development of a large anterior ventral crest represents the major component of disparity. This suggests that a socio-sexual trait was a key driver for innovation in pterosaur lower jaw shape.
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Affiliation(s)
- Charlie A. Navarro
- School of Earth Sciences, University of Bristol, Wills Memorial Building, Queen's Road, Bristol BS8 1RJ, UK
| | - Elizabeth Martin-Silverstone
- School of Earth Sciences, University of Bristol, Wills Memorial Building, Queen's Road, Bristol BS8 1RJ, UK
- Ocean and Earth Science, National Oceanography Centre, University of Southampton, European Way, Southampton SO14 3ZH, UK
| | - Thomas L. Stubbs
- School of Earth Sciences, University of Bristol, Wills Memorial Building, Queen's Road, Bristol BS8 1RJ, UK
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8
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Abstract
Pterosaurs have fascinated scientists and nonscientists alike for over 200 years, as one of the three known clades of vertebrates to have evolved flapping flight. The smallest pterosaurs were comparable in size to the smallest extant birds and bats, but the largest pterosaurs were vastly larger than any extant flier. This immense size range, coupled with poor preservation and adaptations for flight unknown in extant vertebrates, have made interpretations of pterosaur flight problematic and often contentious. Here we review the anatomical, evolutionary, and phylogenetic history of pterosaurs, as well as the views, perspectives, and biases regarding their interpretation. In recent years, three areas of pterosaur biology have faced challenges and made advances: structure of the wing membrane, function of the pteroid, body size and mass estimates, as well as flight mechanics and aerodynamics. Comparative anatomical and fossil study, simulated bone loading, and aerodynamic modeling have all proved successful in furthering our understanding of pterosaur flight. We agree with previous authors that pterosaurs should be studied as pterosaurs, a diverse but phylogenetically, anatomically, and mechanically constrained clade that can offer new insights into the diversity of vertebrate flight.
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Affiliation(s)
- K.M. Middleton
- Department of Pathology and Anatomical Sciences, University of Missouri School of Medicine, Medical Sciences Building M263, 1 Hospital Drive, Columbia, MO 65212, USA
| | - L.T. English
- Jackson School of Geosciences, Department of Geological Sciences, University of Texas at Austin, Austin, TX 78712-1722, USA
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9
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Abstract
Animals that fly must be able to do so over a huge range of aerodynamic conditions, determined by weather, wind speed and the nature of their environment. No single parameter can be used to determine-let alone measure-optimum flight performance as it relates to wing shape. Reconstructing the wings of the extinct pterosaurs has therefore proved especially problematic: these Mesozoic flying reptiles had a soft-tissue membranous flight surface that is rarely preserved in the fossil record. Here, we review basic mechanical and aerodynamic constraints that influenced the wing shape of pterosaurs, and, building on this, present a series of theoretical modelling results. These results allow us to predict the most likely wing shapes that could have been employed by these ancient reptiles, and further show that a combination of anterior sweep and a reflexed proximal wing section provides an aerodynamically balanced and efficient theoretical pterosaur wing shape, with clear benefits for their flight stability.
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Affiliation(s)
- Colin Palmer
- Department of Earth Sciences, University of Bristol, Bristol, UK.
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Prondvai E, Stein K, Osi A, Sander MP. Life history of Rhamphorhynchus inferred from bone histology and the diversity of pterosaurian growth strategies. PLoS One 2012; 7:e31392. [PMID: 22355361 PMCID: PMC3280310 DOI: 10.1371/journal.pone.0031392] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Accepted: 01/06/2012] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Rhamphorhynchus from the Solnhofen Limestones is the most prevalent long tailed pterosaur with a debated life history. Whereas morphological studies suggested a slow crocodile-like growth strategy and superprecocial volant hatchlings, the only histological study hitherto conducted on Rhamphorhynchus concluded a relatively high growth rate for the genus. These controversial conclusions can be tested by a bone histological survey of an ontogenetic series of Rhamphorhynchus. METHODOLOGY/PRINCIPAL FINDINGS Our results suggest that Bennett's second size category does not reflect real ontogenetic stage. Significant body size differences of histologically as well as morphologically adult specimens suggest developmental plasticity. Contrasting the 'superprecocial hatchling' hypothesis, the dominance of fibrolamellar bone in early juveniles implies that hatchlings sustained high growth rate, however only up to the attainment of 30-50% and 7-20% of adult wingspan and body mass, respectively. The early fast growth phase was followed by a prolonged, slow-growth phase indicated by parallel-fibred bone deposition and lines of arrested growth in the cortex, a transition which has also been observed in Pterodaustro. An external fundamental system is absent in all investigated specimens, but due to the restricted sample size, neither determinate nor indeterminate growth could be confirmed in Rhamphorhynchus. CONCLUSIONS/SIGNIFICANCE The initial rapid growth phase early in Rhamphorhynchus ontogeny supports the non-volant nature of its hatchlings, and refutes the widely accepted 'superprecocial hatchling' hypothesis. We suggest the onset of powered flight, and not of reproduction as the cause of the transition from the fast growth phase to a prolonged slower growth phase. Rapidly growing early juveniles may have been attended by their parents, or could have been independent precocial, but non-volant arboreal creatures until attaining a certain somatic maturity to get airborne. This study adds to the understanding on the diversity of pterosaurian growth strategies.
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Affiliation(s)
- Edina Prondvai
- Hungarian Academy of Sciences-Eötvös Loránd University Lendület Dinosaur Research Group, Eötvös Loránd University, Budapest, Hungary.
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Abstract
There has been recent discussion about the evolutionary pressures underlying the long necks of extant giraffes and extinct sauropod dinosaurs. Here we summarise these debates and place them in a wider taxonomic context. We consider the evolution of long necks across a wide range of (both living and extinct) taxa and ask whether there has been a common selective factor or whether each case has a separate explanation. We conclude that in most cases long necks can be explained in terms of foraging requirements, and that alternative explanations in terms of sexual selection, thermoregulation and predation pressure are not as well supported. Specifically, in giraffe, tortoises, and perhaps sauropods there is likely to have been selection for high browsing. It the last case there may also have been selection for reaching otherwise inaccessible aquatic plants or for increasing the energetic efficiency of low browsing. For camels, wading birds and ratites, original selection was likely for increased leg length, with correlated selection for a longer neck to allow feeding and drinking at or near substrate level. For fish-eating long-necked birds and plesiosaurs a small head at the end of a long neck allows fast acceleration of the mouth to allow capture of elusive prey. A swan's long neck allows access to benthic vegetation, for vultures the long neck allows reaching deep into a carcass. Geese may be an unusual case where anti-predator vigilance is important, but so may be energetically efficient low browsing. The one group for which we feel unable to draw firm conclusions are the pterosaurs, this is in keeping with the current uncertainty about the biology of this group. Despite foraging emerging as a dominant theme in selection for long necks, for almost every taxonomic group we have identified useful empirical work that would increase understanding of the selective costs and benefits of a long neck.
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Affiliation(s)
- David M Wilkinson
- School of Natural Science and Psychology, Liverpool John Moores University, Byrom Street, Liverpool, L3 3AF, UK.
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Anderson PSL, Bright JA, Gill PG, Palmer C, Rayfield EJ. Models in palaeontological functional analysis. Biol Lett 2011; 8:119-22. [PMID: 21865242 DOI: 10.1098/rsbl.2011.0674] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Models are a principal tool of modern science. By definition, and in practice, models are not literal representations of reality but provide simplifications or substitutes of the events, scenarios or behaviours that are being studied or predicted. All models make assumptions, and palaeontological models in particular require additional assumptions to study unobservable events in deep time. In the case of functional analysis, the degree of missing data associated with reconstructing musculoskeletal anatomy and neuronal control in extinct organisms has, in the eyes of some scientists, rendered detailed functional analysis of fossils intractable. Such a prognosis may indeed be realized if palaeontologists attempt to recreate elaborate biomechanical models based on missing data and loosely justified assumptions. Yet multiple enabling methodologies and techniques now exist: tools for bracketing boundaries of reality; more rigorous consideration of soft tissues and missing data and methods drawing on physical principles that all organisms must adhere to. As with many aspects of science, the utility of such biomechanical models depends on the questions they seek to address, and the accuracy and validity of the models themselves.
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