Late acquisition of erect hindlimb posture and function in the forerunners of therian mammals DOI Creative Commons
Peter J. Bishop, Stephanie E. Pierce

Science Advances, Journal Year: 2024, Volume and Issue: 10(43)

Published: Oct. 25, 2024

The evolutionary transition from early synapsids to therian mammals involved profound reorganization in locomotor anatomy and function, centered around a shift "sprawled" "erect" limb postures. When how this functional was accomplished has remained difficult decipher the fossil record alone. Through biomechanical modeling of hindlimb force-generating performance eight exemplar synapsids, we demonstrate that erect regime typifying modern therians did not evolve until just before crown Theria. Modeling also identifies transient phase increased therapsids cynodonts, mammals. Further, quantifying global actions major hip muscle groups indicates protracted juxtaposition redeployment conservatism, highlighting intricate interplay between anatomical function across postural transitions. We infer complex history synapsid evolution suggest transitions contrasting behaviors may follow highly nonlinear trajectories.

Language: Английский

3D reconstruction of shoulder muscles in hominoid primates: Correlating scapular attachment areas with muscle volume DOI Creative Commons
Julia van Beesel, Stephanie M. Melillo, Evie Vereecke

et al.

Journal of Anatomy, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 4, 2025

Abstract Digital muscle reconstructions have gained attraction in recent years, serving as powerful tools both educational and research contexts. These can be derived from various 2D 3D data sources, enabling detailed anatomical analyses. In this study, we evaluate the efficacy of surface scans accurately reconstructing volumes rotator cuff teres major muscles across a diverse sample hominoids. Additionally, investigate whether origin area, dissection‐based observation, reliably predict volume. Our findings reveal that provide sufficient coverage to reproduce situ muscles. However, volume was estimated less reliably, suggesting with distinct skeletal boundaries may present challenges for accurate reconstruction. Future studies will explore such reconstructed greater precision. Furthermore, identify significant correlation between area supraspinatus, infraspinatus, subscapularis results suggest serve reliable predictor volume, offering indicator estimating size extant extinct insights are particularly valuable paleontological reconstructions, where direct soft tissue evidence is often lacking. By establishing relationship traits our study provides framework evaluating accuracy hominoid species. This approach not only enhances understanding anatomy but also offers new avenues exploring functional morphology taxa.

Language: Английский

Citations

1
Running performance in Australopithecus afarensis DOI Creative Commons
Karl T. Bates, Shana E. McCormack,

Evie Donald

et al.

Current Biology, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 1, 2024

Language: Английский

Citations

3
Convergent evolution of quadrupedality in ornithischian dinosaurs was achieved through disparate forelimb muscle mechanics DOI Creative Commons
Matthew Dempsey, Susannah C. R. Maidment, Brandon P. Hedrick

et al.

Proceedings of the Royal Society B Biological Sciences, Journal Year: 2023, Volume and Issue: 290(1992)

Published: Feb. 1, 2023

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 evolving quadrupedal gait, ornithischians exhibited variable anatomy, particularly the forelimbs, which underwent major functional change assisting foraging and feeding bipeds to becoming principal weight-bearing components locomotor system quadrupeds. Here, we use three-dimensional multi-body dynamics models demonstrate quantitatively that different clades evolved distinct forelimb musculature, around shoulder. We find differences glenohumeral abduction–adduction long axis rotation muscle leverages were key drivers mechanical disparity, thereby refuting previous hypotheses about convergence clades. Elbow also disparate across lineages, although high elbow extension convergent between most Unlike hind limbs, where are more closely tied similarity than phylogenetic relatedness, disparity forelimbs appears have been shaped primarily by constraints. Differences ancestral taxa each clade may resulted ecomorphological constraints on pathways driving divergence their descendants.

Language: Английский

Citations

7
Biomechanical modeling of musculoskeletal function related to the terrestrial locomotion of Riojasuchus tenuisceps (Archosauria: Ornithosuchidae) DOI Creative Commons
M. Belén von Baczko, Juned Zariwala,

Sarah Elizabeth Ballentine

et al.

The Anatomical Record, Journal Year: 2024, Volume and Issue: 308(2), P. 369 - 393

Published: June 29, 2024

Abstract Riojasuchus tenuisceps was a pseudosuchian archosaur from the Late Triassic period in Argentina. Like other ornithosuchids, it had unusual morphology such as unique “crocodile‐reversed” ankle joint, lesser trochanter dinosaurs and few archosaurs, robust vertebrae, somewhat shortened, gracile forelimbs. Such traits have fuelled controversies about its locomotor function—were limbs erect or “semi‐erect”? Was quadrupedal bipedal, mixture thereof? These seem to persist because analyses been qualitative (functional morphology) correlative (morphometrics) rather than explicitly, quantitatively testing mechanistic hypotheses function. Here, we develop 3D whole‐body model of R. with musculoskeletal apparatus hindlimbs represented detail using new muscle reconstruction. We use this quantify body dimensions hindlimb leverages enigmatic taxon, estimate joint ranges motion functions. Our supports prior arguments that used an posture, parasagittal gait plantigrade pes. However, some our inferences illuminate contradictory nature evidence system —different features support (or are ambiguous regarding) quadrupedalism bipedalism. Deeper biomechanical could move toward consensus regarding ornithosuchid locomotion. Answering these questions would not only help understand palaeobiology bizarre clade, but also more broadly if how) abilities played role survival versus extinction various lineages during end‐Triassic mass event.

Language: Английский

Citations

2
Anatomically grounded estimation of hindlimb muscle sizes in Archosauria DOI Creative Commons
Andrew R. Cuff, Ashleigh L. A. Wiseman, Peter J. Bishop

et al.

Journal of Anatomy, Journal Year: 2022, Volume and Issue: 242(2), P. 289 - 311

Published: Oct. 7, 2022

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 size and force are reflected the muscular attachment areas (AAs). Here we investigate relationship between physiological cross‐sectional area (PCSA), a proxy for production of muscle, AA hindlimb muscles in Nile crocodiles five bird species. The limbs were held fixed position whilst blunt dissection was carried out to isolate individual muscles. AAs digitised using point digitiser, before removed from bone. Muscles then further dissected fibre architecture measured, PCSA calculated. raw measures, as well ratio AA, studied compared intra‐observer error intra‐ interspecies differences. We found large variations both within across species, but fascicle lengths conserved whether this tinamou. Whilst discriminant analysis able separate crocodylian avian data, ratios all species most can be represented single equation. remaining have specific equations represent their scaling, often relatively high success at predicting PCSA. Coelophysis bauri , dinosaur, estimate PCSAs therefore maximal isometric forces. results somewhat consistent with other methods estimating production, suggest that, least some archosaurian muscles, that it possible use sizes. This method complementary such digital volumetric modelling.

Language: Английский

Citations

10
Reconstruction of the pelvic girdle and hindlimb musculature of the early tetanurans Piatnitzkysauridae (Theropoda, Megalosauroidea) DOI Creative Commons
Mauro B.S. Lacerda, Jonathas S. Bittencourt, John R. Hutchinson

et al.

Journal of Anatomy, Journal Year: 2023, Volume and Issue: 244(4), P. 557 - 593

Published: Dec. 1, 2023

Abstract Piatnitzkysauridae were Jurassic theropods that represented the earliest diverging branch of Megalosauroidea, being one lineages to have evolved moderate body size. This clade's typical size and some unusual anatomical features raise questions about locomotor function specializations aid in support; other palaeobiological issues. Biomechanical models simulations can illuminate how extinct animals may moved, but require data as inputs. With a phylogenetic context, osteological evidence, neontological on anatomy, it is possible infer musculature taxa. Here, we reconstructed hindlimb ( Condorraptor , Marshosaurus Piatnitzkysaurus ). We chose this clade for future usage biomechanics, comparisons with myological reconstructions theropods, resulting evolutionary implications our reconstructions; differential preservation affects these inferences, so discuss issues well. considered 32 muscles total: attachments 29 could be inferred based correlates; meanwhile, respectively 21 12 muscles. found great similarity within Piatnitzkysauridae, differences such origin M . ambiens caudofemoralis brevis are present. Similarities evident Aves, division iliofemoralis externus iliotrochantericus caudalis broad depression gastrocnemius pars medialis cnemial crest. Nevertheless, plesiomorphic origins puboischiofemoralis internus 1 around “cuppedicus” fossa ischiotrochantericus medially ischium. As first attempt reconstruct early tetanurans, study allows more complete understanding evolution theropod pelvic appendages.

Language: Английский

Citations

5
Hindlimb and pelvic anatomy of Caiman yacare (Archosauria, Pseudosuchia): Myology and osteological correlates with emphasis on lower leg and autopodial musculature DOI
María Eugenia Pereyra, Mauricio A. Cerroni,

Agustina Lecuona

et al.

Journal of Anatomy, Journal Year: 2023, Volume and Issue: 244(5), P. 749 - 791

Published: Dec. 17, 2023

Abstract The anatomy of the archosaurian pelvis and hindlimb has adopted a diversity successful configurations allowing wide range postures during evolution group (e.g., erect, sprawling). For this reason, thorough studies structure function pelvic musculature crocodylians are required provide possibility to expand their implications for locomotion, as well identify potential new characters based on muscles bony correlates. In study, we give detailed description South American alligator Caiman yacare , providing comprehensive novel information regarding lower limb autopodial muscles. Particularly pedal muscles, propose classification dorsal ventral autopodium organisation these in successive layers. We have studied myology global background which compared with other crocodylians. sense, differences arrangement m. flexor tibialis internus 1, externus iliofibularis mm. puboischiofemorales internii 1 2, between Ca . were found. also discuss muscle attachments that different correlates among crocodylian species morphological variation. Most did not exhibit great variation compared. majority recognised identified girdle; additionally, some associated highlighted here first time. This research provides framework future comparative functional morphology, could contribute improving character definition used phylogenetic analyses understand patterns musculoskeletal evolution.

Language: Английский

Citations

4
RECONSTRUCTIONS OF HINDLIMB MUSCULATURE IN EXTINCT PRE-THERIAN SYNAPSIDS DOI
Peter J. Bishop, Stephanie E. Pierce

Bulletin of the Museum of Comparative Zoology, Journal Year: 2024, Volume and Issue: 163(9)

Published: Oct. 3, 2024

Language: Английский

Citations

1
Hindlimb biomechanics of Lagosuchus talampayensis (Archosauria, Dinosauriformes), with comments on skeletal morphology DOI Creative Commons
Alejandro Otero, Peter J. Bishop, John R. Hutchinson

et al.

Journal of Anatomy, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 4, 2024

Abstract Lagosuchus talampayensis is a small‐bodied (~0.5 m long) Late Triassic dinosauriform archosaur from Argentina. long has been pivotal taxon for reconstructing the evolution of form and function on dinosaur lineage. This importance because it mix ancestral archosaurian traits, such as small pelvis with mostly closed acetabulum lacking prominences that would restrict hip mobility much, derived “dinosaurian” traits bipedalism, proximally shifted thigh muscle insertions, elongate hindlimbs, “advanced mesotarsal” ankle joints digitigrade feet. Here, to quantify key functional related locomotor biomechanics , we build three‐dimensional musculoskeletal model, focussing morphofunctional analysis pelvic limb. We survey skeletal material have digitised, pointing out hitherto undescribed features elements, many which are taxa other than . Next, select ideal elements amongst these construct composite articulate adjacent body segments into joints, then estimate shape including centre mass, add paths create model. Finally, use two methods hindlimb parameters (“architecture”) in find they produce similar estimates force‐generating capacities, compare data few available archosaurs an evolutionary context, reconstruct fundamental patterns changes architecture limb morphology. Our model forms valuable basis future quantitative analyses its early archosaurs, example how navigate decision‐making modelling problematic specimens.

Language: Английский

Citations

0
Late acquisition of erect hindlimb posture and function in the forerunners of therian mammals DOI Creative Commons
Peter J. Bishop, Stephanie E. Pierce

Science Advances, Journal Year: 2024, Volume and Issue: 10(43)

Published: Oct. 25, 2024

The evolutionary transition from early synapsids to therian mammals involved profound reorganization in locomotor anatomy and function, centered around a shift "sprawled" "erect" limb postures. When how this functional was accomplished has remained difficult decipher the fossil record alone. Through biomechanical modeling of hindlimb force-generating performance eight exemplar synapsids, we demonstrate that erect regime typifying modern therians did not evolve until just before crown Theria. Modeling also identifies transient phase increased therapsids cynodonts, mammals. Further, quantifying global actions major hip muscle groups indicates protracted juxtaposition redeployment conservatism, highlighting intricate interplay between anatomical function across postural transitions. We infer complex history synapsid evolution suggest transitions contrasting behaviors may follow highly nonlinear trajectories.

Language: Английский

Citations

0