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Otero A, Bishop PJ, Hutchinson JR. Hindlimb biomechanics of Lagosuchus talampayensis (Archosauria, Dinosauriformes), with comments on skeletal morphology. J Anat 2025; 246:948-973. [PMID: 39630643 PMCID: PMC12079757 DOI: 10.1111/joa.14183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2024] [Revised: 11/07/2024] [Accepted: 11/11/2024] [Indexed: 12/07/2024] Open
Abstract
Lagosuchus talampayensis is a small-bodied (~0.5 m long) Late Triassic dinosauriform archosaur from Argentina. Lagosuchus long has been a pivotal taxon for reconstructing the evolution of form and function on the dinosaur lineage. This importance is because it has a mix of ancestral archosaurian traits, such as a small pelvis with a mostly closed acetabulum lacking prominences that would restrict hip mobility much, with derived "dinosaurian" traits such as bipedalism, proximally shifted thigh muscle insertions, elongate hindlimbs, "advanced mesotarsal" ankle joints and digitigrade feet. Here, to quantify key functional traits related to the locomotor biomechanics of Lagosuchus, we build a three-dimensional musculoskeletal model, focussing on morphofunctional analysis of the pelvic limb. We survey skeletal material that we have digitised, pointing out hitherto undescribed features and elements, many of which are from taxa other than Lagosuchus. Next, we select ideal elements amongst these to construct a composite model, and articulate adjacent body segments into joints, then estimate body shape including centre of mass, and add muscle paths to create a musculoskeletal model. Finally, we use two methods to quantify the hindlimb muscle parameters ("architecture") in the model. We find that they produce similar estimates of force-generating capacities, and compare these data to the few available data from other archosaurs in an evolutionary context, to reconstruct fundamental patterns of changes in muscle architecture and pelvic limb morphology. Our model forms a valuable basis for future quantitative analyses of locomotor function and its evolution in early archosaurs, and an example of how to navigate decision-making for modelling problematic specimens.
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Affiliation(s)
- Alejandro Otero
- CONICET División Paleontología de Vertebrados (Anexo Laboratorios)La PlataArgentina
| | - Peter J. Bishop
- Structure and Motion Laboratory, Department of Comparative Biomedical SciencesRoyal Veterinary CollegeNorth MymmsHatfieldUK
- Museum of Comparative Zoology and Department of Organismic and Evolutionary BiologyHarvard UniversityCambridgeMassachusettsUSA
- Geosciences ProgramQueensland MuseumBrisbaneQueenslandAustralia
| | - John R. Hutchinson
- Structure and Motion Laboratory, Department of Comparative Biomedical SciencesRoyal Veterinary CollegeNorth MymmsHatfieldUK
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2
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Dempsey M, Cross SRR, Maidment SCR, Hutchinson JR, Bates KT. New perspectives on body size and shape evolution in dinosaurs. Biol Rev Camb Philos Soc 2025. [PMID: 40344351 DOI: 10.1111/brv.70026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 03/31/2025] [Accepted: 04/07/2025] [Indexed: 05/11/2025]
Abstract
Diversity in the body shapes and sizes of dinosaurs was foundational to their widespread success during the Mesozoic era. The ability to quantify body size and form reliably is therefore critical to the study of dinosaur biology and evolution. Body mass estimates for any given fossil animal are, in theory, most informative when derived from volumetric models that account for the three-dimensional shapes of the entire body. In addition to providing estimates of total body mass, volumetric approaches can be used to determine the inertial properties of specific body segments and the overall distribution of mass throughout the body, each of which are essential for the modelling and interpretation of form-function relationships and their associations with ecology. However, the determination of body volumes in fossil taxa is often subjective, and may be sensitive to varied artistic inference. This highlights the need for an approach to body mass estimation in which body segment volumes are systematically constrained by quantitative scaling relationships between the hard tissues that fossilise and the soft tissues only observable in extant taxa. To this end, we used recently published skeletal to soft tissue volumetric scaling factors derived from CT data of extant sauropsids to estimate body segment mass properties from skeletal models of 52 non-avian dinosaurs representing the majority of major clades and body plans. The body masses estimated by this study range from less than 200 g in the tiny avialan Yixianornis to over 60 tonnes in the giant sauropod Patagotitan, which is currently the largest dinosaur known from mostly complete skeletal remains. From our models, we infer that many previous reconstructions of soft tissue envelopes may be too small, and that many dinosaurs were therefore heavier than previous estimates. Our models generally overlap with the range of body mass estimates derived from limb bone shaft dimensions, but with considerable quantitative variability among major clades. This suggests that different taxa either differed in skeletal to soft tissue volume ratios, or that their limb bone dimensions varied relative to body mass, perhaps related to differences in locomotor dynamics and postural evolution. Our models also allowed us to investigate variation in mass distribution and body proportions across different dinosaurs from a perspective grounded in extant anatomical data, framing long-standing hypotheses about their form, function, and behaviour in a quantitative context. For example, reconstructed disparity in whole-body centres of mass reflects a broad array of postures in different dinosaur clades, while the lack of strong positive allometry in the dimensions of the weight-bearing limb segments relative to total body mass corroborates previous studies suggesting an overall decrease in dinosaur locomotor performance as body size increased.
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Affiliation(s)
- Matthew Dempsey
- Department of Musculoskeletal & Ageing Science, Institute of Life Course & Medical Sciences, University of Liverpool, The William Henry Duncan Building, 6 West Derby Street, Liverpool, L7 8TX, UK
- Fossil Reptiles, Amphibians and Birds Section, The Natural History Museum, Cromwell Road, London, SW7 5BD, UK
| | - Samuel R R Cross
- Department of Musculoskeletal & Ageing Science, Institute of Life Course & Medical Sciences, University of Liverpool, The William Henry Duncan Building, 6 West Derby Street, Liverpool, L7 8TX, UK
| | - Susannah C R Maidment
- Fossil Reptiles, Amphibians and Birds Section, The Natural History Museum, Cromwell Road, London, SW7 5BD, UK
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - John R Hutchinson
- Structure and Motion Laboratory, Department of Comparative Biomedical Sciences, Royal Veterinary College, Hatfield, AL9 7TA, UK
| | - Karl T Bates
- Department of Musculoskeletal & Ageing Science, Institute of Life Course & Medical Sciences, University of Liverpool, The William Henry Duncan Building, 6 West Derby Street, Liverpool, L7 8TX, UK
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Gilmer JI, Coltman SK, Cuenu G, Hutchinson JR, Huber D, Person AL, Al Borno M. A novel biomechanical model of the proximal mouse forelimb predicts muscle activity in optimal control simulations of reaching movements. J Neurophysiol 2025; 133:1266-1278. [PMID: 40098414 DOI: 10.1152/jn.00499.2024] [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: 10/25/2024] [Revised: 11/19/2024] [Accepted: 03/04/2025] [Indexed: 03/19/2025] Open
Abstract
Mice are key model organisms in neuroscience and motor systems physiology. Fine motor control tasks performed by mice have become widely used in assaying neural and biophysical motor system mechanisms. Although fine motor tasks provide useful insights into behaviors that require complex multi-joint motor control, there is no previously developed physiological biomechanical model of the adult mouse forelimb available for estimating kinematics, muscle activity, or kinetics during behaviors. Here, we developed a musculoskeletal model based on high-resolution imaging of the mouse forelimb that includes muscles spanning the neck, trunk, shoulder, and limbs. Physics-based optimal control simulations of the forelimb model were used to estimate in vivo muscle activity present when constrained to the tracked kinematics during reaching movements. The activity of a subset of muscles was recorded and used to assess the accuracy of the muscle patterning in simulation. We found that the synthesized muscle patterning in the forelimb model had a strong resemblance to empirical muscle patterning, suggesting that our model has utility in providing a realistic set of estimated muscle excitations over time when given a kinematic template. The strength of the similarity between empirical muscle activity and optimal control predictions increases as mice performance improves throughout learning of the reaching task. Our computational tools are available as open-source in the OpenSim physics and modeling platform. Our model can enhance research into limb control across broad research topics and can inform analyses of motor learning, muscle synergies, neural patterning, and behavioral research that would otherwise be inaccessible.NEW & NOTEWORTHY Investigations into motor planning and execution lack an accurate and complete model of the forelimb, which could bolster or expand on findings. We sought to construct such a model using high-detail scans of murine anatomy and prior research into muscle physiology. We then used the model to predict muscle excitations in a set of reaching movements and found that it provided accurate estimations and provided insight into an optimal-control framework of motor learning.
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Affiliation(s)
- Jesse I Gilmer
- Department of Computer Science and Engineering, Computational Bioscience Program, University of Colorado Denver | Anschutz Medical Campus, Denver, Colorado, United States
| | - Susan K Coltman
- Department of Kinesiology, The Pennsylvania State University, University Park, Pennsylvania, United States
| | - Geraldine Cuenu
- Department of Basic Neuroscience, University of Geneva, Geneva, Switzerland
| | - John R Hutchinson
- Department of Comparative Biomedical Sciences, Royal Veterinary College, London, United Kingdom
| | - Daniel Huber
- Department of Basic Neuroscience, University of Geneva, Geneva, Switzerland
| | - Abigail L Person
- Department of Physiology and Biophysics, University of Colorado Denver | Anschutz Medical Campus, Denver, Colorado, United States
| | - Mazen Al Borno
- Department of Computer Science and Engineering, Computational Bioscience Program, University of Colorado Denver | Anschutz Medical Campus, Denver, Colorado, United States
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von Baczko MB, Zariwala J, Ballentine SE, Desojo JB, Hutchinson JR. Biomechanical modeling of musculoskeletal function related to the terrestrial locomotion of Riojasuchus tenuisceps (Archosauria: Ornithosuchidae). Anat Rec (Hoboken) 2025; 308:369-393. [PMID: 38943347 PMCID: PMC11725706 DOI: 10.1002/ar.25528] [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: 04/17/2024] [Revised: 05/30/2024] [Accepted: 06/11/2024] [Indexed: 07/01/2024]
Abstract
Riojasuchus tenuisceps was a pseudosuchian archosaur from the Late Triassic period in Argentina. Like other ornithosuchids, it had unusual morphology such as a unique "crocodile-reversed" ankle joint, a lesser trochanter as in dinosaurs and a few other archosaurs, robust vertebrae, and somewhat shortened, gracile forelimbs. Such traits have fuelled controversies about its locomotor function-were its limbs erect or "semi-erect"? Was it quadrupedal or bipedal, or a mixture thereof? These controversies seem to persist because analyses have been qualitative (functional morphology) or correlative (morphometrics) rather than explicitly, quantitatively testing mechanistic hypotheses about locomotor function. Here, we develop a 3D whole-body model of R. tenuisceps with the musculoskeletal apparatus of the hindlimbs represented in detail using a new muscle reconstruction. We use this model to quantify the body dimensions and hindlimb muscle leverages of this enigmatic taxon, and to estimate joint ranges of motion and qualitative joint functions. Our model supports prior arguments that R. tenuisceps used an erect posture, parasagittal gait and plantigrade pes. However, some of our inferences illuminate the rather contradictory nature of evidence from the musculoskeletal system of R. tenuisceps-different features support (or are ambiguous regarding) quadrupedalism or bipedalism. Deeper analyses of our biomechanical model could move toward a consensus regarding ornithosuchid locomotion. Answering these questions would not only help understand the palaeobiology and bizarre morphology of this clade, but also more broadly if (or how) locomotor abilities played a role in the survival versus extinction of various archosaur lineages during the end-Triassic mass extinction event.
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Affiliation(s)
- M. Belen von Baczko
- Sección Paleontología de VertebradosMuseo Argentino de Ciencias Naturales Bernardino RivadaviaCiudad Autónoma de Buenos AiresArgentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)Ciudad Autónoma de Buenos AiresArgentina
| | - Juned Zariwala
- Structure & Motion Laboratory, Department of Comparative Biomedical SciencesRoyal Veterinary CollegeHatfieldHertfordshireUK
- School of Life and Environmental Sciences, College of Health and SciencesUniversity of Lincoln, Brayford Pool CampusLincolnUK
| | - Sarah Elizabeth Ballentine
- Structure & Motion Laboratory, Department of Comparative Biomedical SciencesRoyal Veterinary CollegeHatfieldHertfordshireUK
| | - Julia B. Desojo
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)Ciudad Autónoma de Buenos AiresArgentina
- División Paleontología VertebradosFacultad de Ciencias Naturales y MuseoLa PlataArgentina
| | - John R. Hutchinson
- Structure & Motion Laboratory, Department of Comparative Biomedical SciencesRoyal Veterinary CollegeHatfieldHertfordshireUK
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Falkingham PL. Reconstructing dinosaur locomotion. Biol Lett 2025; 21:20240441. [PMID: 39809325 PMCID: PMC11732409 DOI: 10.1098/rsbl.2024.0441] [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: 07/31/2024] [Revised: 10/07/2024] [Accepted: 11/14/2024] [Indexed: 01/16/2025] Open
Abstract
Dinosaur locomotor biomechanics are of major interest. Locomotion of an animal affects many, if not most, aspects of life reconstruction, including behaviour, performance, ecology and appearance. Yet locomotion is one aspect of non-avian dinosaurs that we cannot directly observe. To shed light on how dinosaurs moved, we must draw from multiple sources of evidence. Extant taxa provide the basic principles of locomotion, bracket soft-tissue reconstructions and provide validation data for methods and hypotheses applied to dinosaurs. The skeletal evidence itself can be used directly to reconstruct posture, range of motion and mass (segment and whole-body). Building on skeletal reconstructions, musculoskeletal models inform muscle function and form the basis of simulations to test hypotheses of locomotor performance. Finally, fossilized footprints are our only direct record of motion and can provide important snapshots of extinct animals, shedding light on speed, gait and posture. Building confident reconstructions of dinosaur locomotion requires evidence from all four sources of information. This review explores recent work in these areas, with a methodological focus.
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Affiliation(s)
- Peter L. Falkingham
- School of Biological and Environmental Sciences, Liverpool John Moores University, Liverpool, UK
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Lin Y, Rankin JW, Lamas LP, Moazen M, Hutchinson JR. Hindlimb kinematics, kinetics and muscle dynamics during sit-to-stand and sit-to-walk transitions in emus (Dromaius novaehollandiae). J Exp Biol 2024; 227:jeb247519. [PMID: 39445465 PMCID: PMC11708823 DOI: 10.1242/jeb.247519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Accepted: 10/10/2024] [Indexed: 10/25/2024]
Abstract
Terrestrial animals not only need to walk and run but also lie prone to rest and then stand up. Sit-to-stand (STS) and sit-to-walk (STW) transitions are vital behaviours little studied in species other than humans so far, but likely impose biomechanical constraints on limb design because they involve near-maximal excursions of limb joints that should require large length changes and force production from muscles. By integrating data from experiments into musculoskeletal simulations, we analysed joint motions, ground reaction forces, and muscle dynamics during STS and STW in a large terrestrial, bipedal and cursorial bird: the emu (Dromaius novaehollandiae; body mass ∼30 kg). Simulation results suggest that in both STS and STW, emus operate near the functional limits (∼50% of shortening/lengthening) of some of their hindlimb muscles, particularly in distal muscles with limited capacity for length change and leverage. Both movements involved high muscle activations (>50%) and force generation of the major joint extensor muscles early in the transition. STW required larger net joint moments and non-sagittal motions than STS, entailing greater demands for muscle capacity. Whilst our study involves multiple assumptions, our findings lay the groundwork for future studies to understand, for example, how tendon contributions may reduce excessive muscle demands, especially in the distal hindlimb. As the first investigation into how an avian species stands up, this study provides a foundational framework for future comparative studies investigating organismal morphofunctional specialisations and evolution, offering potential robotics and animal welfare applications.
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Affiliation(s)
- Yuting Lin
- Structure and Motion Laboratory, Department of Comparative Biomedical Sciences, Royal Veterinary College, Hatfield AL9 7TA, UK
| | - Jeffery W. Rankin
- Pathokinesiology Laboratory, Rancho Los Amigos National Rehabilitation Center, Downey, CA 90242, USA
| | - Luís P. Lamas
- CIISA, Faculty of Veterinary Medicine, University of Lisbon, Lisbon 1300-477, Portugal
| | - Mehran Moazen
- Department of Mechanical Engineering, University College London, London WC1E 7JE, UK
| | - John R. Hutchinson
- Structure and Motion Laboratory, Department of Comparative Biomedical Sciences, Royal Veterinary College, Hatfield AL9 7TA, UK
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Bishop PJ, Pierce SE. Late acquisition of erect hindlimb posture and function in the forerunners of therian mammals. SCIENCE ADVANCES 2024; 10:eadr2722. [PMID: 39454012 PMCID: PMC11506245 DOI: 10.1126/sciadv.adr2722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2024] [Accepted: 09/20/2024] [Indexed: 10/27/2024]
Abstract
The evolutionary transition from early synapsids to therian mammals involved profound reorganization in locomotor anatomy and function, centered around a shift from "sprawled" to "erect" limb postures. When and how this functional shift was accomplished has remained difficult to decipher from the fossil record alone. Through biomechanical modeling of hindlimb force-generating performance in eight exemplar fossil synapsids, we demonstrate that the erect locomotor regime typifying modern therians did not evolve until just before crown Theria. Modeling also identifies a transient phase of increased performance in therapsids and early cynodonts, before crown mammals. Further, quantifying the global actions of major hip muscle groups indicates a protracted juxtaposition of functional redeployment and conservatism, highlighting the intricate interplay between anatomical reorganization and function across postural transitions. We infer a complex history of synapsid locomotor evolution and suggest that major evolutionary transitions between contrasting locomotor behaviors may follow highly nonlinear trajectories.
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Affiliation(s)
- Peter J. Bishop
- Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
- Geosciences Program, Queensland Museum, Brisbane, Queensland, Australia
| | - Stephanie E. Pierce
- Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
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Ishida M, Berio F, Di Santo V, Shubin NH, Iida F. Paleoinspired robotics as an experimental approach to the history of life. Sci Robot 2024; 9:eadn1125. [PMID: 39441900 DOI: 10.1126/scirobotics.adn1125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 09/25/2024] [Indexed: 10/25/2024]
Abstract
Paleontologists must confront the challenge of studying the forms and functions of extinct species for which data from preserved fossils are extremely limited, yielding only a fragmented picture of life in deep time. In response to this hurdle, we describe the nascent field of paleoinspired robotics, an innovative method that builds upon established techniques in bioinspired robotics, enabling the exploration of the biology of ancient organisms and their evolutionary trajectories. This Review presents ways in which robotic platforms can fill gaps in existing research using the exemplars of notable transitions in vertebrate locomotion. We examine recent case studies in experimental paleontology, highlighting substantial contributions made by engineering and robotics techniques, and further assess how the efficient application of robotic technologies in close collaboration with paleontologists and biologists can offer additional insights into the study of evolution that were previously unattainable.
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Affiliation(s)
- Michael Ishida
- Department of Engineering, University of Cambridge, Trumpington Street, Cambridge CB2 1PZ, UK
| | - Fidji Berio
- Department of Zoology, Stockholm University, Svante Arrhenius väg 18B, 114 18 Stockholm, Sweden
| | - Valentina Di Santo
- Department of Zoology, Stockholm University, Svante Arrhenius väg 18B, 114 18 Stockholm, Sweden
| | - Neil H Shubin
- Department of Organismal Biology and Anatomy, University of Chicago, 1027 E 57th Street, Chicago, IL 60637, USA
| | - Fumiya Iida
- Department of Engineering, University of Cambridge, Trumpington Street, Cambridge CB2 1PZ, UK
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van Bijlert PA, Geijtenbeek T, Smit IH, Schulp AS, Bates KT. Muscle-Driven Predictive Physics Simulations of Quadrupedal Locomotion in the Horse. Integr Comp Biol 2024; 64:694-714. [PMID: 39003243 PMCID: PMC11428545 DOI: 10.1093/icb/icae095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 05/24/2024] [Accepted: 06/15/2024] [Indexed: 07/15/2024] Open
Abstract
Musculoskeletal simulations can provide insights into the underlying mechanisms that govern animal locomotion. In this study, we describe the development of a new musculoskeletal model of the horse, and to our knowledge present the first fully muscle-driven, predictive simulations of equine locomotion. Our goal was to simulate a model that captures only the gross musculoskeletal structure of a horse, without specialized morphological features. We mostly present simulations acquired using feedforward control, without state feedback ("top-down control"). Without using kinematics or motion capture data as an input, we have simulated a variety of gaits that are commonly used by horses (walk, pace, trot, tölt, and collected gallop). We also found a selection of gaits that are not normally seen in horses (half bound, extended gallop, ambling). Due to the clinical relevance of the trot, we performed a tracking simulation that included empirical joint angle deviations in the cost function. To further demonstrate the flexibility of our model, we also present a simulation acquired using spinal feedback control, where muscle control signals are wholly determined by gait kinematics. Despite simplifications to the musculature, simulated footfalls and ground reaction forces followed empirical patterns. In the tracking simulation, kinematics improved with respect to the fully predictive simulations, and muscle activations showed a reasonable correspondence to electromyographic signals, although we did not predict any anticipatory firing of muscles. When sequentially increasing the target speed, our simulations spontaneously predicted walk-to-run transitions at the empirically determined speed. However, predicted stride lengths were too short over nearly the entire speed range unless explicitly prescribed in the controller, and we also did not recover spontaneous transitions to asymmetric gaits such as galloping. Taken together, our model performed adequately when simulating individual gaits, but our simulation workflow was not able to capture all aspects of gait selection. We point out certain aspects of our workflow that may have caused this, including anatomical simplifications and the use of massless Hill-type actuators. Our model is an extensible, generalized horse model, with considerable scope for adding anatomical complexity. This project is intended as a starting point for continual development of the model and code that we make available in extensible open-source formats.
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Affiliation(s)
- Pasha A van Bijlert
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Vening Meinesz Building A, Princetonlaan 8A, 3584 CB Utrecht, the Netherlands
- Vertebrate evolution, development and ecology, Naturalis Biodiversity Center, Darwinweg 2, 2333 CR Leiden, the Netherlands
| | | | - Ineke H Smit
- Department of Equine Musculoskeletal Biology, Faculty of Veterinary Sciences, Utrecht University, Yalelaan 112-114, 3584 CM Utrecht, the Netherlands
| | - Anne S Schulp
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Vening Meinesz Building A, Princetonlaan 8A, 3584 CB Utrecht, the Netherlands
- Vertebrate evolution, development and ecology, Naturalis Biodiversity Center, Darwinweg 2, 2333 CR Leiden, the Netherlands
| | - Karl T Bates
- Department of Musculoskeletal & Ageing Science, Institute of Life Course & Medical Sciences, University of Liverpool, The William Henry Duncan Building, 6 West Derby Street, Liverpool L7 8TX, UK
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Wright MA, Cavanaugh TJ, Pierce SE. Volumetric versus Element-scaling Mass Estimation and Its Application to Permo-Triassic Tetrapods. Integr Org Biol 2024; 6:obae034. [PMID: 39346809 PMCID: PMC11438236 DOI: 10.1093/iob/obae034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 08/22/2024] [Accepted: 09/03/2024] [Indexed: 10/01/2024] Open
Abstract
Size has an impact on various aspects of an animal's biology, including physiology, biomechanics, and ecology. Accurately and precisely estimating size, in particular body mass, is therefore a core objective of paleobiologists. Two approaches for estimating body mass are common: whole-body volumetric models and individual element-scaling (e.g., bones, teeth). The latter has been argued to be more accurate, while the former more precise. Here, we use minimum convex hulls (MCHs) to generate a predictive volumetric model for estimating body mass across a broad taxonomic and size range (127 g - 2735 kg). We compare our MCH model to stylopodial-scaling, incorporating data from the literature, and find that MCH body mass estimation is both more accurate and more precise than stylopodial estimation. An explanation for the difference between methods is that reptile and mammal stylopod circumference and length dimensions scale differentially (slope 1.179 ± 0.102 vs. 1.038 ± 0.031, respectively), such that reptiles have more robust bones for a given size. Consequently, a mammalian-weighted stylopodial-scaling sample overestimates the body mass of larger reptiles, and this error increases with size. We apply both estimation equations to a sample of 12 Permo-Triassic tetrapods and find that stylopodial-scaling consistently estimates a higher body mass than MCH estimation, due to even more robust bones in extinct species (slope = 1.319 ± 0.213). Finally, we take advantage of our MCH models to explore constraints regarding the position of the center of mass (CoM) and find that relative body proportions (i.e., skull:tail ratio) influence CoM position differently in mammals, crocodylians, and Permo-Triassic tetrapods. Further, we find that clade-specific body segment expansion factors do not affect group comparisons but may be important for individual specimens with rather disproportionate bodies (e.g., the small-headed and large-tailed Edaphosaurus). Our findings suggest that the whole-body volumetric approach is better suited for estimating body mass than element-scaling when anatomies are beyond the scope of the sample used to generate the scaling equations and provides added benefits such as the ability to measure inertial properties.
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Affiliation(s)
- M A Wright
- Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138, USA
| | - T J Cavanaugh
- Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138, USA
- Harvard Extension School, Harvard University, Cambridge, Massachusetts 02138, USA
| | - S E Pierce
- Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138, USA
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11
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Etienne C, Houssaye A, Fagan MJ, Hutchinson JR. Estimation of the forces exerted on the limb long bones of a white rhinoceros (Ceratotherium simum) using musculoskeletal modelling and simulation. J Anat 2024; 245:240-257. [PMID: 38558391 PMCID: PMC11259748 DOI: 10.1111/joa.14041] [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: 08/23/2023] [Revised: 02/10/2024] [Accepted: 03/10/2024] [Indexed: 04/04/2024] Open
Abstract
Heavy animals incur large forces on their limb bones, due to the transmission of body weight and ground reaction forces, and the contractions of the various muscles of the limbs. This is particularly true for rhinoceroses, the heaviest extant animals capable of galloping. Several studies have examined their musculoskeletal system and the forces their bones incur, but no detailed quantification has ever been attempted. Such quantification could help understand better the link between form and function in giant land animals. Here we constructed three-dimensional musculoskeletal models of the forelimb and hindlimb of Ceratotherium simum, the heaviest extant rhino species, and used static optimisation (inverse) simulations to estimate the forces applied on the bones when standing at rest, including magnitudes and directions. Overall, unsurprisingly, the most active muscles were antigravity muscles, which generate moments opposing body weight (thereby incurring the ground reaction force), and thus keep the joints extended, avoiding joint collapse via flexion. Some muscles have an antigravity action around several joints, and thus were found to be highly active, likely specialised in body weight support (ulnaris lateralis; digital flexors). The humerus was subjected to the greatest amount of forces in terms of total magnitude; forces on the humerus furthermore came from a great variety of directions. The radius was mainly subject to high-magnitude compressive joint reaction forces, but to little muscular tension, whereas the opposite pattern was observed for the ulna. The femur had a pattern similar to that of the humerus, and the tibia's pattern was intermediate, being subject to great compression in its caudal side but to great tension in its cranial side (i.e. bending). The fibula was subject to by far the lowest force magnitude. Overall, the forces estimated were consistent with the documented morphofunctional adaptations of C. simum's long bones, which have larger insertion areas for several muscles and a greater robusticity overall than those of lighter rhinos, likely reflecting the intense forces we estimated here. Our estimates of muscle and bone (joint) loading regimes for this giant tetrapod improve the understanding of the links between form and function in supportive tissues and could be extended to other aspects of bone morphology, such as microanatomy.
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Affiliation(s)
- Cyril Etienne
- UMR 7179 Mécanismes adaptatifs et Évolution (MECADEV), Centre National de la Recherche Scientifique, Muséum National d'Histoire NaturelleParisFrance
| | - Alexandra Houssaye
- UMR 7179 Mécanismes adaptatifs et Évolution (MECADEV), Centre National de la Recherche Scientifique, Muséum National d'Histoire NaturelleParisFrance
| | - Michael J. Fagan
- Department of Engineering, Medical and Biological Engineering Research GroupUniversity of HullHullUK
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12
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Fu X, Withers J, Miyamae JA, Moore TY. ArborSim: Articulated, branching, OpenSim routing for constructing models of multi-jointed appendages with complex muscle-tendon architecture. PLoS Comput Biol 2024; 20:e1012243. [PMID: 38968305 PMCID: PMC11253963 DOI: 10.1371/journal.pcbi.1012243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 07/17/2024] [Accepted: 06/10/2024] [Indexed: 07/07/2024] Open
Abstract
Computational models of musculoskeletal systems are essential tools for understanding how muscles, tendons, bones, and actuation signals generate motion. In particular, the OpenSim family of models has facilitated a wide range of studies on diverse human motions, clinical studies of gait, and even non-human locomotion. However, biological structures with many joints, such as fingers, necks, tails, and spines, have been a longstanding challenge to the OpenSim modeling community, especially because these structures comprise numerous bones and are frequently actuated by extrinsic muscles that span multiple joints-often more than three-and act through a complex network of branching tendons. Existing model building software, typically optimized for limb structures, makes it difficult to build OpenSim models that accurately reflect these intricacies. Here, we introduce ArborSim, customized software that efficiently creates musculoskeletal models of highly jointed structures and can build branched muscle-tendon architectures. We used ArborSim to construct toy models of articulated structures to determine which morphological features make a structure most sensitive to branching. By comparing the joint kinematics of models constructed with branched and parallel muscle-tendon units, we found that among various parameters-the number of tendon branches, the number of joints between branches, and the ratio of muscle fiber length to muscle tendon unit length-the number of tendon branches and the number of joints between branches are most sensitive to branching modeling method. Notably, the differences between these models showed no predictable pattern with increased complexity. As the proportion of muscle increased, the kinematic differences between branched and parallel models units also increased. Our findings suggest that stress and strain interactions between distal tendon branches and proximal tendon and muscle greatly affect the overall kinematics of a musculoskeletal system. By incorporating complex muscle-tendon branching into OpenSim models using ArborSim, we can gain deeper insight into the interactions between the axial and appendicular skeleton, model the evolution and function of diverse animal tails, and understand the mechanics of more complex motions and tasks.
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Affiliation(s)
- Xun Fu
- Robotics, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Jack Withers
- Computer Science, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Juri A. Miyamae
- Robotics, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Talia Y. Moore
- Robotics, University of Michigan, Ann Arbor, Michigan, United States of America
- Mechanical Engineering, University of Michigan, Ann Arbor, Michigan, United States of America
- Ecology and Evolutionary Biology, Museum of Zoology, University of Michigan, Ann Arbor, Michigan, United States of America
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13
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Pintore R, Hutchinson JR, Bishop PJ, Tsai HP, Houssaye A. The evolution of femoral morphology in giant non-avian theropod dinosaurs. PALEOBIOLOGY 2024; 50:308-329. [PMID: 38846629 PMCID: PMC7616063 DOI: 10.1017/pab.2024.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2024]
Abstract
Theropods are obligate bipedal dinosaurs that appeared 230 million years ago and are still extant as birds. Their history is characterized by extreme variations in body mass, with gigantism evolving convergently between many lineages. However, no quantification of hindlimb functional morphology has shown if these body mass increases led to similar specializations between distinct lineages. Here we studied femoral shape variation across 41 species of theropods (n= 68 specimens) using a high-density 3D geometric morphometric approach. We demonstrated that the heaviest theropods evolved wider epiphyses and a more distally located fourth trochanter, as previously demonstrated in early archosaurs, along with an upturned femoral head and a mediodistal crest that extended proximally along the shaft. Phylogenetically informed analyses highlighted that these traits evolved convergently within six major theropod lineages, regardless of their maximum body mass. Conversely, the most gracile femora were distinct from the rest of the dataset, which we interpret as a femoral specialization to "miniaturization" evolving close to Avialae (bird lineage). Our results support a gradual evolution of known "avian" features, such as the fusion between lesser and greater trochanters and a reduction of the epiphyses' offset, independently from body mass variations, which may relate to a more "avian" type of locomotion (more knee-than hip-driven). The distinction between body mass variations and a more "avian" locomotion is represented by a decoupling in the mediodistal crest morphology, whose biomechanical nature should be studied to better understand the importance of its functional role in gigantism, miniaturization and higher parasagittal abilities.
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Affiliation(s)
- Romain Pintore
- Mécanismes adaptatifs et évolution (MECADEV) / UMR 7179. CNRS / Muséum National d’Histoire Naturelle, Paris, FR
- Structure and Motion Laboratory, Royal Veterinary College, Hatfield, UK
| | | | - Peter J. Bishop
- Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, USA
- Geosciences Program, Queensland Museum, Brisbane, Queensland, AU
| | - Henry P. Tsai
- Department of Biology, Southern Connecticut State University, New Haven, USA
| | - Alexandra Houssaye
- Mécanismes adaptatifs et évolution (MECADEV) / UMR 7179. CNRS / Muséum National d’Histoire Naturelle, Paris, FR
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14
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Wiseman AL, Charles JP, Hutchinson JR. Static versus dynamic muscle modelling in extinct species: a biomechanical case study of the Australopithecus afarensis pelvis and lower extremity. PeerJ 2024; 12:e16821. [PMID: 38313026 PMCID: PMC10838096 DOI: 10.7717/peerj.16821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 01/02/2024] [Indexed: 02/06/2024] Open
Abstract
The force a muscle generates is dependent on muscle structure, in which fibre length, pennation angle and tendon slack length all influence force production. Muscles are not preserved in the fossil record and these parameters must be estimated when constructing a musculoskeletal model. Here, we test the capability of digitally reconstructed muscles of the Australopithecus afarensis model (specimen AL 288-1) to maintain an upright, single-support limb posture. Our aim was to ascertain the influence that different architectural estimation methods have on muscle specialisation and on the subsequent inferences that can be extrapolated about limb function. Parameters were estimated for 36 muscles in the pelvis and lower limb and seven different musculoskeletal models of AL 288-1 were produced. These parameters represented either a 'static' Hill-type muscle model (n = 4 variants) which only incorporated force, or instead a 'dynamic' Hill-type muscle model with an elastic tendon and fibres that could vary force-length-velocity properties (n = 3 variants). Each muscle's fibre length, pennation angle, tendon slack length and maximal isometric force were calculated based upon different input variables. Static (inverse) simulations were computed in which the vertical and mediolateral ground reaction forces (GRF) were incrementally increased until limb collapse (simulation failure). All AL 288-1 variants produced somewhat similar simulated muscle activation patterns, but the maximum vertical GRF that could be exerted on a single limb was not consistent between models. Three of the four static-muscle models were unable to support >1.8 times body weight and produced models that under-performed. The dynamic-muscle models were stronger. Comparative results with a human model imply that similar muscle group activations between species are needed to sustain single-limb support at maximally applied GRFs in terms of the simplified static simulations (e.g., same walking pose) used here. This approach demonstrated the range of outputs that can be generated for a model of an extinct individual. Despite mostly comparable outputs, the models diverged mostly in terms of strength.
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Affiliation(s)
- Ashleigh L.A. Wiseman
- McDonald Institute for Archaeological Research, University of Cambridge, Cambridge, United Kingdom
| | - James P. Charles
- Evolutionary Morphology and Biomechanics Lab, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
| | - John R. Hutchinson
- Structure and Motion Laboratory, Department of Comparative Biomedical Sciences, Royal Veterinary College, Hatfield, United Kingdom
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15
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Wang Z, Zhang W, Li J, Wang J, Yang Y, Bao T, Wu J, Wang B. Animating fossilized invertebrates by motion reconstruction. Natl Sci Rev 2023; 10:nwad268. [PMID: 38033735 PMCID: PMC10684265 DOI: 10.1093/nsr/nwad268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 10/12/2023] [Accepted: 10/12/2023] [Indexed: 12/02/2023] Open
Abstract
Taking the motion reconstruction of the Cretaceous hell ants as an example, this study shows how to achieve motion reconstruction in fossil invertebrates and discusses potential challenges and opportunities.
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Affiliation(s)
- Zixin Wang
- School of Advanced Manufacturing, Sun Yat-sen University, China
- School of Engineering and Technology, China University of Geosciences (Beijing), China
| | - Wei Zhang
- Department of Mechanical Engineering, City University of Hong Kong, China
- School of Aeronautics and Astronautics, Sun Yat-sen University, China
| | - Jiahao Li
- State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, China
- University of Chinese Academy of Sciences, China
| | - Ji Wang
- School of Aeronautics and Astronautics, Sun Yat-sen University, China
| | - Yunqiang Yang
- School of Engineering and Technology, China University of Geosciences (Beijing), China
| | - Tong Bao
- School of Ecology, Sun Yat-sen University, China
| | - Jianing Wu
- School of Advanced Manufacturing, Sun Yat-sen University, China
| | - Bo Wang
- State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, China
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16
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Desatnik R, Patterson ZJ, Gorzelak P, Zamora S, LeDuc P, Majidi C. Soft robotics informs how an early echinoderm moved. Proc Natl Acad Sci U S A 2023; 120:e2306580120. [PMID: 37931097 PMCID: PMC10655572 DOI: 10.1073/pnas.2306580120] [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: 04/24/2023] [Accepted: 08/03/2023] [Indexed: 11/08/2023] Open
Abstract
The transition from sessile suspension to active mobile detritus feeding in early echinoderms (c.a. 500 Mya) required sophisticated locomotion strategies. However, understanding locomotion adopted by extinct animals in the absence of trace fossils and modern analogues is extremely challenging. Here, we develop a biomimetic soft robot testbed with accompanying computational simulation to understand fundamental principles of locomotion in one of the most enigmatic mobile groups of early stalked echinoderms-pleurocystitids. We show that these Paleozoic echinoderms were likely able to move over the sea bottom by means of a muscular stem that pushed the animal forward (anteriorly). We also demonstrate that wide, sweeping gaits could have been the most effective for these echinoderms and that increasing stem length might have significantly increased velocity with minimal additional energy cost. The overall approach followed here, which we call "Paleobionics," is a nascent but rapidly developing research agenda in which robots are designed based on extinct organisms to generate insights in engineering and evolution.
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Affiliation(s)
- Richard Desatnik
- Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA15213
| | - Zach J. Patterson
- Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA15213
- Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, MA02139
| | | | - Samuel Zamora
- Instituto Geológico y Minero de España - Consejo Superior de Investigaciones Científicas, Residencia, Campus Aula Dei, Zaragoza50059, Spain
| | - Philip LeDuc
- Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA15213
- Biological Sciences, Carnegie Mellon University, Pittsburgh, PA15213
- Computational Biology, Carnegie Mellon University, Pittsburgh, PA15213
- Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA15213
| | - Carmel Majidi
- Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA15213
- Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA15213
- Robotics Institute, Carnegie Mellon University, Pittsburgh, PA15213
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17
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Anderson L, Brassey C, Pond S, Bates K, Sellers WI. Investigating the quadrupedal abilities of Scutellosaurus lawleri and its implications for locomotor behavior evolution among dinosaurs. Anat Rec (Hoboken) 2023; 306:2514-2536. [PMID: 36896818 DOI: 10.1002/ar.25189] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 01/19/2023] [Accepted: 02/08/2023] [Indexed: 03/11/2023]
Abstract
A reversion to secondary quadrupedality is exceptionally rare in nature, yet the convergent re-evolution of this locomotor style occurred at least four separate times within Dinosauria. Facultative quadrupedality, an intermediate state between obligate bipedality and obligate quadrupedality, may have been an important transitional step in this locomotor shift, and is proposed for a range of basal ornithischians and sauropodomorphs. Advances in virtual biomechanical modeling and simulation have allowed for the investigation of limb anatomy and function in a range of extinct dinosaurian species, yet this technique has not been widely applied to explore facultatively quadrupedal gait generation. This study places its focus on Scutellosaurus, a basal thyreophoran that has previously been described as both an obligate biped and a facultative quadruped. The functional anatomy of the musculoskeletal system (myology, mass properties, and joint ranges of motion) has been reconstructed using extant phylogenetic bracketing and comparative anatomical datasets. This information was used to create a multi-body dynamic locomotor simulation that demonstrates that whil quadrupedal gaits were physically possible, they did not outperform bipedal gaits is any tested metric. Scutellosaurus cannot therefore be described as an obligate biped, but we would predict its use of quadrupedality would be very rare, and perhaps restricted to specific activities such as foraging. This finding suggests that basal thyreophorans are still overwhelmingly bipedal but is perhaps indicative of an adaptive pathway for later evolution of quadrupedality.
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18
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Stanchak KE, Miller KE, Shikiar D, Brunton BW, Perkel DJ. Mechanistic Hypotheses for Proprioceptive Sensing Within the Avian Lumbosacral Spinal Cord. Integr Comp Biol 2023; 63:474-483. [PMID: 37279454 DOI: 10.1093/icb/icad052] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 05/14/2023] [Accepted: 05/24/2023] [Indexed: 06/08/2023] Open
Abstract
Animals need to accurately sense changes in their body position to perform complex movements. It is increasingly clear that the vertebrate central nervous system contains a variety of cells capable of detecting body motion, in addition to the comparatively well-understood mechanosensory cells of the vestibular system and the peripheral proprioceptors. One such intriguing system is the lower spinal cord and column in birds, also known as the avian lumbosacral organ (LSO), which is thought to act as a set of balance sensors that allow birds to detect body movements separately from head movements detected by the vestibular system. Here, we take what is known about proprioceptive, mechanosensory spinal neurons in other vertebrates to explore hypotheses for how the LSO might sense mechanical information related to movement. Although the LSO is found only in birds, recent immunohistochemical studies of the avian LSO have hinted at similarities between cells in the LSO and the known spinal proprioceptors in other vertebrates. In addition to describing possible connections between avian spinal anatomy and recent findings on spinal proprioception as well as sensory and sensorimotor spinal networks, we also present some new data that suggest a role for sensory afferent peptides in LSO function. Thus, this perspective articulates a set of testable ideas on mechanisms of LSO function grounded in the emerging spinal proprioception scientific literature.
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Affiliation(s)
| | - Kimberly E Miller
- Department of Biology, University of Washington, Seattle, WA 98195, USA
- Department of Psychology, University of Washington, Seattle WA 98195, USA
| | - Devany Shikiar
- Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - Bingni W Brunton
- Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - David J Perkel
- Department of Biology, University of Washington, Seattle, WA 98195, USA
- Department of Otolaryngology, University of Washington, Seattle, WA 98195, USA
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19
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Demuth OE, Herbst E, Polet DT, Wiseman ALA, Hutchinson JR. Modern three-dimensional digital methods for studying locomotor biomechanics in tetrapods. J Exp Biol 2023; 226:jeb245132. [PMID: 36810943 PMCID: PMC10042237 DOI: 10.1242/jeb.245132] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Here, we review the modern interface of three-dimensional (3D) empirical (e.g. motion capture) and theoretical (e.g. modelling and simulation) approaches to the study of terrestrial locomotion using appendages in tetrapod vertebrates. These tools span a spectrum from more empirical approaches such as XROMM, to potentially more intermediate approaches such as finite element analysis, to more theoretical approaches such as dynamic musculoskeletal simulations or conceptual models. These methods have much in common beyond the importance of 3D digital technologies, and are powerfully synergistic when integrated, opening a wide range of hypotheses that can be tested. We discuss the pitfalls and challenges of these 3D methods, leading to consideration of the problems and potential in their current and future usage. The tools (hardware and software) and approaches (e.g. methods for using hardware and software) in the 3D analysis of tetrapod locomotion have matured to the point where now we can use this integration to answer questions we could never have tackled 20 years ago, and apply insights gleaned from them to other fields.
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Affiliation(s)
- Oliver E. Demuth
- Department of Earth Sciences, University of Cambridge, Cambridge, CB2 3EQ, UK
| | - Eva Herbst
- Palaeontological Institute and Museum, University of Zurich, 8006 Zürich, Switzerland
| | - Delyle T. Polet
- Structure and Motion Laboratory, Department of Comparative Biomedical Sciences, Royal Veterinary College, North Mymms, AL9 7TA, UK
| | - Ashleigh L. A. Wiseman
- McDonald Institute for Archaeological Research, University of Cambridge, Cambridge, CB2 3ER, UK
| | - John R. Hutchinson
- Structure and Motion Laboratory, Department of Comparative Biomedical Sciences, Royal Veterinary College, North Mymms, AL9 7TA, UK
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20
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Anné J, Whitney M, Brocklehurst R, Donnelly K, Rothschild B. Unusual lesions seen in the caudals of the hadrosaur, Edmontosaurus annectens. Anat Rec (Hoboken) 2023; 306:594-606. [PMID: 36089756 DOI: 10.1002/ar.25078] [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: 08/04/2022] [Revised: 09/02/2022] [Accepted: 09/06/2022] [Indexed: 11/06/2022]
Abstract
The study of pathologies in the fossil record allows for unique insights into the physiology, immunology, biomechanics, and daily life history of extinct organisms. This is especially important in organisms that have body structures dissimilar to those of extant organisms as well as transitional groups whose extant relatives may have very dissimilar physiologies. Comparisons between modern groups and their fossil ancestors are further complicated by the fact that fossil groups may have experienced unique biomechanical stresses as well as possessing a mixture of anatomical features seen in their related extant groups. In this study, we present lesions in the caudal vertebrae of the hadrosaur, Edmontosaurus annectens from the Ruth Mason Dinosaur Quarry of South Dakota, which exhibit unique morphologies. X-ray microtomography was performed on the most extreme example of this morphology to allow for both a detailed and more accurate diagnosis of the pathologic condition as well as virtual conservation of the specimen. Based on the location, the overall morphology of the lesion, and the relative "normal" appearance of the internal microstructure, the most probable cause is postulated as long-term biomechanical stresses exerted on this section of the tail by both lateral and dorsoventral motions of the tail. This deduction was based on a process of elimination for a variety of known osteological conditions; however, future work is needed to determine the nature of the stresses and why this condition has not been recorded in more hadrosaurian specimens.
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Affiliation(s)
- Jennifer Anné
- The Children's Museum of Indianapolis, Indianapolis, Indiana, USA
| | - Megan Whitney
- Harvard Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts, USA
| | - Robert Brocklehurst
- Harvard Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts, USA
| | - Kevin Donnelly
- Department of Toxicology/Pathology, Eli Lilly and Co., Indianapolis, Indiana, USA
| | - Bruce Rothschild
- Laboratory of Biological Anthropology, The University of Kansas, Lawrence, Kansas, USA
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21
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Dempsey M, Maidment SCR, Hedrick BP, Bates KT. Convergent evolution of quadrupedality in ornithischian dinosaurs was achieved through disparate forelimb muscle mechanics. Proc Biol Sci 2023; 290:20222435. [PMID: 36722082 PMCID: PMC9890092 DOI: 10.1098/rspb.2022.2435] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 01/09/2023] [Indexed: 02/02/2023] Open
Abstract
The secondary evolution of quadrupedality from bipedal ancestry is a rare evolutionary transition in tetrapods yet occurred convergently at least three times within ornithischian dinosaurs. Despite convergently evolving quadrupedal gait, ornithischians exhibited variable anatomy, particularly in the forelimbs, which underwent a major functional change from assisting in foraging and feeding in bipeds to becoming principal weight-bearing components of the locomotor system in quadrupeds. Here, we use three-dimensional multi-body dynamics models to demonstrate quantitatively that different quadrupedal ornithischian clades evolved distinct forelimb musculature, particularly around the shoulder. We find that major differences in glenohumeral abduction-adduction and long axis rotation muscle leverages were key drivers of mechanical disparity, thereby refuting previous hypotheses about functional convergence in major clades. Elbow muscle leverages were also disparate across the major ornithischian lineages, although high elbow extension muscle leverages were convergent between most quadrupeds. Unlike in ornithischian hind limbs, where differences are more closely tied to functional similarity than phylogenetic relatedness, mechanical disparity in ornithischian forelimbs appears to have been shaped primarily by phylogenetic constraints. Differences in ancestral bipedal taxa within each clade may have resulted in disparate ecomorphological constraints on the evolutionary pathways driving divergence in their quadrupedal descendants.
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Affiliation(s)
- Matthew Dempsey
- Department of Musculoskeletal & Ageing Science, Institute of Life Course & Medical Sciences, University of Liverpool, The William Henry Duncan Building, 6 West Derby Street, Liverpool L7 8TX, UK
- Department of Earth Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD, UK
| | | | - Brandon P. Hedrick
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, 930 Campus Road, Ithaca, NY 14853, USA
| | - Karl T. Bates
- Department of Musculoskeletal & Ageing Science, Institute of Life Course & Medical Sciences, University of Liverpool, The William Henry Duncan Building, 6 West Derby Street, Liverpool L7 8TX, UK
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22
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Demuth OE, Wiseman ALA, Hutchinson JR. Quantitative biomechanical assessment of locomotor capabilities of the stem archosaur Euparkeria capensis. ROYAL SOCIETY OPEN SCIENCE 2023; 10:221195. [PMID: 36704253 PMCID: PMC9874271 DOI: 10.1098/rsos.221195] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 01/10/2023] [Indexed: 06/18/2023]
Abstract
Birds and crocodylians are the only remaining members of Archosauria (ruling reptiles) and they exhibit major differences in posture and gait, which are polar opposites in terms of locomotor strategies. Their broader lineages (Avemetatarsalia and Pseudosuchia) evolved a multitude of locomotor modes in the Triassic and Jurassic periods, including several occurrences of bipedalism. The exact timings and frequencies of bipedal origins within archosaurs, and thus their ancestral capabilities, are contentious. It is often suggested that archosaurs ancestrally exhibited some form of bipedalism. Euparkeria capensis is a central taxon for the investigation of locomotion in archosaurs due to its phylogenetic position and intermediate skeletal morphology, and is argued to be representative of facultative bipedalism in this group. However, no studies to date have biomechanically tested if bipedality was feasible in Eupakeria. Here, we use musculoskeletal models and static simulations in its hindlimb to test the influences of body posture and muscle parameter estimation methods on locomotor potential. Our analyses show that the resulting negative pitching moments around the centre of mass were prohibitive to sustainable bipedality. We conclude that it is unlikely that Euparkeria was facultatively bipedal, and was probably quadrupedal, rendering the inference of ancestral bipedal abilities in Archosauria unlikely.
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Affiliation(s)
- Oliver E. Demuth
- Structure and Motion Laboratory, Department of Comparative Biomedical Sciences, The Royal Veterinary College, Hatfield, UK
- Department of Earth Sciences, University of Cambridge, Cambridge, UK
| | - Ashleigh L. A. Wiseman
- Structure and Motion Laboratory, Department of Comparative Biomedical Sciences, The Royal Veterinary College, Hatfield, UK
- McDonald Institute for Archaeological Research, University of Cambridge, Cambridge, UK
| | - John R. Hutchinson
- Structure and Motion Laboratory, Department of Comparative Biomedical Sciences, The Royal Veterinary College, Hatfield, UK
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23
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Clark CJ, Hutchinson JR, Garland T. The Inverse Krogh Principle: All Organisms Are Worthy of Study. Physiol Biochem Zool 2023; 96:1-16. [PMID: 36626844 DOI: 10.1086/721620] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
AbstractKrogh's principle states, "For such a large number of problems there will be some animal of choice, or a few such animals, on which it can be most conveniently studied." The downside of picking a question first and then finding an ideal organism on which to study it is that it will inevitably leave many organisms neglected. Here, we promote the inverse Krogh principle: all organisms are worthy of study. The inverse Krogh principle and the Krogh principle are not opposites. Rather, the inverse Krogh principle emphasizes a different starting point for research: start with a biological unit, such as an organism, clade, or specific organism trait, then seek or create tractable research questions. Even the hardest-to-study species have research questions that can be asked of them: Where does it fall within the tree of life? What resources does it need to survive and reproduce? How does it differ from close relatives? Does it have unique adaptations? The Krogh and inverse Krogh approaches are complementary, and many research programs naturally include both. Other considerations for picking a study species include extreme species, species informative for phylogenetic analyses, and the creation of models when a suitable species does not exist. The inverse Krogh principle also has pitfalls. A scientist that picks the organism first might choose a research question not really suited to the organism, and funding agencies rarely fund organism-centered grant proposals. The inverse Krogh principle does not call for all organisms to receive the same amount of research attention. As knowledge continues to accumulate, some organisms-models-will inevitably have more known about them than others. Rather, it urges a broader search across organismal diversity to find sources of inspiration for research questions and the motivation needed to pursue them.
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Cuff AR, Wiseman ALA, Bishop PJ, Michel KB, Gaignet R, Hutchinson JR. Anatomically grounded estimation of hindlimb muscle sizes in Archosauria. J Anat 2022; 242:289-311. [PMID: 36206401 PMCID: PMC9877486 DOI: 10.1111/joa.13767] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 08/26/2022] [Accepted: 08/31/2022] [Indexed: 02/01/2023] Open
Abstract
In vertebrates, active movement is driven by muscle forces acting on bones, either directly or through tendinous insertions. There has been much debate over how muscle size and force are reflected by the muscular attachment areas (AAs). Here we investigate the relationship between the physiological cross-sectional area (PCSA), a proxy for the force production of the muscle, and the AA of hindlimb muscles in Nile crocodiles and five bird species. The limbs were held in a fixed position whilst blunt dissection was carried out to isolate the individual muscles. AAs were digitised using a point digitiser, before the muscle was removed from the bone. Muscles were then further dissected and fibre architecture was measured, and PCSA calculated. The raw measures, as well as the ratio of PCSA to AA, were studied and compared for intra-observer error as well as intra- and interspecies differences. We found large variations in the ratio between AAs and PCSA both within and across species, but muscle fascicle lengths are conserved within individual species, whether this was Nile crocodiles or tinamou. Whilst a discriminant analysis was able to separate crocodylian and avian muscle data, the ratios for AA to cross-sectional area for all species and most muscles can be represented by a single equation. The remaining muscles have specific equations to represent their scaling, but equations often have a relatively high success at predicting the ratio of muscle AA to PCSA. We then digitised the muscle AAs of Coelophysis bauri, a dinosaur, to estimate the PCSAs and therefore maximal isometric muscle forces. The results are somewhat consistent with other methods for estimating force production, and suggest that, at least for some archosaurian muscles, that it is possible to use muscle AA to estimate muscle sizes. This method is complementary to other methods such as digital volumetric modelling.
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Affiliation(s)
- Andrew R. Cuff
- Structure and Motion Laboratory, Department of Comparative Biomedical SciencesRoyal Veterinary CollegeHatfieldUK,Human Anatomy Resource CentreUniversity of LiverpoolLiverpoolUK
| | - Ashleigh L. A. Wiseman
- Structure and Motion Laboratory, Department of Comparative Biomedical SciencesRoyal Veterinary CollegeHatfieldUK
| | - Peter J. Bishop
- Structure and Motion Laboratory, Department of Comparative Biomedical SciencesRoyal Veterinary CollegeHatfieldUK,Museum of Comparative Zoology and Department of Organismic and Evolutionary BiologyHarvard UniversityCambridgeUSA,Geosciences ProgramQueensland MuseumBrisbaneQueenslandAustralia
| | - Krijn B. Michel
- Structure and Motion Laboratory, Department of Comparative Biomedical SciencesRoyal Veterinary CollegeHatfieldUK
| | - Raphäelle Gaignet
- Structure and Motion Laboratory, Department of Comparative Biomedical SciencesRoyal Veterinary CollegeHatfieldUK
| | - John R. Hutchinson
- Structure and Motion Laboratory, Department of Comparative Biomedical SciencesRoyal Veterinary CollegeHatfieldUK
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Marcé-Nogué J. One step further in biomechanical models in palaeontology: a nonlinear finite element analysis review. PeerJ 2022; 10:e13890. [PMID: 35966920 PMCID: PMC9373974 DOI: 10.7717/peerj.13890] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 07/21/2022] [Indexed: 01/19/2023] Open
Abstract
Finite element analysis (FEA) is no longer a new technique in the fields of palaeontology, anthropology, and evolutionary biology. It is nowadays a well-established technique within the virtual functional-morphology toolkit. However, almost all the works published in these fields have only applied the most basic FEA tools i.e., linear materials in static structural problems. Linear and static approximations are commonly used because they are computationally less expensive, and the error associated with these assumptions can be accepted. Nonetheless, nonlinearities are natural to be used in biomechanical models especially when modelling soft tissues, establish contacts between separated bones or the inclusion of buckling results. The aim of this review is to, firstly, highlight the usefulness of non-linearities and secondly, showcase these FEA tool to researchers that work in functional morphology and biomechanics, as non-linearities can improve their FEA models by widening the possible applications and topics that currently are not used in palaeontology and anthropology.
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Affiliation(s)
- Jordi Marcé-Nogué
- Department of Mechanical Engineering, Universitat Rovira i Virgili Tarragona, Tarragona, Catalonia, Spain
- Institut Català de Paleontologia, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Catalonia, Spain
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Cuff AR, Demuth OE, Michel K, Otero A, Pintore R, Polet DT, Wiseman ALA, Hutchinson JR. Walking-and Running and Jumping-with Dinosaurs and Their Cousins, Viewed Through the Lens of Evolutionary Biomechanics. Integr Comp Biol 2022; 62:icac049. [PMID: 35595475 DOI: 10.1093/icb/icac049] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Archosauria diversified throughout the Triassic Period before experiencing two mass extinctions near its end ∼201 Mya, leaving only the crocodile-lineage (Crocodylomorpha) and bird-lineage (Dinosauria) as survivors; along with the pterosaurian flying reptiles. About 50 years ago, the "locomotor superiority hypothesis" (LSH) proposed that dinosaurs ultimately dominated by the Early Jurassic Period because their locomotion was superior to other archosaurs'. This idea has been debated continuously since, with taxonomic and morphological analyses suggesting dinosaurs were "lucky" rather than surviving due to being biologically superior. However, the LSH has never been tested biomechanically. Here we present integration of experimental data from locomotion in extant archosaurs with inverse and predictive simulations of the same behaviours using musculoskeletal models, showing that we can reliably predict how extant archosaurs walk, run and jump. These simulations have been guiding predictive simulations of extinct archosaurs to estimate how they moved, and we show our progress in that endeavour. The musculoskeletal models used in these simulations can also be used for simpler analyses of form and function such as muscle moment arms, which inform us about more basic biomechanical similarities and differences between archosaurs. Placing all these data into an evolutionary and biomechanical context, we take a fresh look at the LSH as part of a critical review of competing hypotheses for why dinosaurs (and a few other archosaur clades) survived the Late Triassic extinctions. Early dinosaurs had some quantifiable differences in locomotor function and performance vs. some other archosaurs, but other derived dinosaurian features (e.g., metabolic or growth rates, ventilatory abilities) are not necessarily mutually exclusive from the LSH; or maybe even an opportunistic replacement hypothesis; in explaining dinosaurs' success.
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Affiliation(s)
- A R Cuff
- Structure and Motion Laboratory, Department of Comparative Biomedical Sciences, Royal Veterinary College, United Kingdom
- Human Anatomy Resource Centre, University of Liverpool, Liverpool, United Kingdom
| | - O E Demuth
- Structure and Motion Laboratory, Department of Comparative Biomedical Sciences, Royal Veterinary College, United Kingdom
- Department of Earth Sciences, University of Cambridge, United Kingdom
| | - K Michel
- Structure and Motion Laboratory, Department of Comparative Biomedical Sciences, Royal Veterinary College, United Kingdom
| | - A Otero
- CONICET - División Paleontología de Vertebrados, Facultad de Ciencias Naturales y Museo, Anexo Laboratorios, La Plata, Argentina
| | - R Pintore
- Structure and Motion Laboratory, Department of Comparative Biomedical Sciences, Royal Veterinary College, United Kingdom
- Mécanismes adaptatifs et évolution (MECADEV) / UMR 7179, CNRS / Muséum National d'Histoire Naturelle, France
| | - D T Polet
- Structure and Motion Laboratory, Department of Comparative Biomedical Sciences, Royal Veterinary College, United Kingdom
| | - A L A Wiseman
- Structure and Motion Laboratory, Department of Comparative Biomedical Sciences, Royal Veterinary College, United Kingdom
- McDonald Institute for Archaeological Research, University of Cambridge, United Kingdom
| | - J R Hutchinson
- Structure and Motion Laboratory, Department of Comparative Biomedical Sciences, Royal Veterinary College, United Kingdom
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Polet DT, Hutchinson JR. Estimating Gaits of an Ancient Crocodile-Line Archosaur Through Trajectory Optimization, With Comparison to Fossil Trackways. Front Bioeng Biotechnol 2022; 9:800311. [PMID: 35186914 PMCID: PMC8852800 DOI: 10.3389/fbioe.2021.800311] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 12/30/2021] [Indexed: 11/22/2022] Open
Abstract
Fossil trackways provide a glimpse into the behavior of extinct animals. However, while providing information of the trackmaker size, stride, and even speed, the actual gait of the organism can be ambiguous. This is especially true of quadrupedal animals, where disparate gaits can have similar trackway patterns. Here, predictive simulation using trajectory optimization can help distinguish gaits used by trackmakers. First, we demonstrated that a planar, five-link quadrupedal biomechanical model can generate the qualitative trackway patterns made by domestic dogs, although a systematic error emerges in the track phase (relative distance between ipsilateral pes and manus prints). Next, we used trackway dimensions as inputs to a model of Batrachotomus kupferzellensis, a long-limbed, crocodile-line archosaur (clade Pseudosuchia) from the Middle Triassic of Germany. We found energetically optimal gaits and compared their predicted track phases to those of fossil trackways of Isochirotherium and Brachychirotherium. The optimal results agree with trackways at slow speeds but differ at faster speeds. However, all simulations point to a gait transition around a non-dimensional speed of 0.4 and another at 1.0. The trackways likewise exhibit stark differences in the track phase at these speeds. In all cases, including when simulations are constrained to the fossil track phase, the optimal simulations after the first gait transition do not correspond to a trot, as often used by living crocodiles. Instead, they are a diagonal sequence gait similar to the slow tölt of Icelandic horses. This is the first evidence that extinct pseudosuchians may have exhibited different gaits than their modern relatives and of a gait transition in an extinct pseudosuchian. The results of this analysis highlight areas where the models can be improved to generate more reliable predictions for fossil data while also showcasing how simple models can generate insights about the behavior of extinct animals.
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Young FR, Chiel HJ, Tresch MC, Heckman CJ, Hunt AJ, Quinn RD. Analyzing Modeled Torque Profiles to Understand Scale-Dependent Active Muscle Responses in the Hip Joint. Biomimetics (Basel) 2022; 7:biomimetics7010017. [PMID: 35225910 PMCID: PMC8883942 DOI: 10.3390/biomimetics7010017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 01/13/2022] [Accepted: 01/18/2022] [Indexed: 11/18/2022] Open
Abstract
Animal locomotion is influenced by a combination of constituent joint torques (e.g., due to limb inertia and passive viscoelasticity), which determine the necessary muscular response to move the limb. Across animal size-scales, the relative contributions of these constituent joint torques affect the muscular response in different ways. We used a multi-muscle biomechanical model to analyze how passive torque components change due to an animal’s size-scale during locomotion. By changing the size-scale of the model, we characterized emergent muscular responses at the hip as a result of the changing constituent torque profile. Specifically, we found that activation phases between extensor and flexor torques to be opposite between small and large sizes for the same kinematic motion. These results suggest general principles of how animal size affects neural control strategies. Our modeled torque profiles show a strong agreement with documented hindlimb torque during locomotion and can provide insights into the neural organization and muscle activation behavior of animals whose motion has not been extensively documented.
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Affiliation(s)
- Fletcher R. Young
- Department of Mechanical and Aerospace Engineering, Case Western Reserve University, Cleveland, OH 44106, USA;
- Correspondence:
| | - Hillel J. Chiel
- Department of Biology, Case Western Reserve University, Cleveland, OH 44106, USA;
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA
- Department of Neuroscience, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Matthew C. Tresch
- Biomedical Engineering, Physical Medicine and Rehabilitation, Physiology, Northwestern University, Chicago, IL 60611, USA;
| | - Charles J. Heckman
- Departments of Neuroscience, Physical Medicine and Rehabilitation, Physical Therapy and Human Movement Sciences, Northwestern University, Chicago, IL 60611, USA;
| | - Alexander J. Hunt
- Department of Mechanical and Materials Engineering, Portland State University, Portland, OR 97201, USA;
| | - Roger D. Quinn
- Department of Mechanical and Aerospace Engineering, Case Western Reserve University, Cleveland, OH 44106, USA;
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