Publications by authors named "O E Demuth"

Avian skeletal morphology is associated with locomotor function, including flight style, swimming and terrestrial locomotion, and permits informed inferences on locomotion in extinct taxa. The fossil taxon (Avialae: Ornithurae) has long been regarded as highly aerial, with flight similar to terns or gulls (Laridae), and skeletal features resembling foot-propelled diving adaptations. However, rigorous testing of locomotor hypotheses has yet to be performed on , despite its notable phylogenetic position as one of the most crownward stem birds.

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Here, we review the modern interface of three-dimensional (3D) empirical (e.g. motion capture) and theoretical (e.

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Article Synopsis
  • * The origins and frequency of bipedalism in archosaurs are debated, with some suggesting they had ancestral bipedal traits.
  • * Using musculoskeletal models, the study found that negative pitching moments in the hindlimb make sustainable bipedality improbable, indicating the species in question was likely quadrupedal, challenging the idea of ancestral bipedal abilities in Archosauria.
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The postcranial skeleton of (AL 288-1) exhibits clear adaptations for bipedality, although there is some debate as to the efficiency and frequency of such upright movement. Some researchers argue that AL 288-1 walked with an erect limb like modern humans do, whilst others advocate for a "bent-hip bent-knee" (BHBK) gait, although in recent years the general consensus favors erect bipedalism. To date, no quantitative method has addressed the articulation of the AL 288-1 hip joint, nor its range of motion (ROM) with consideration for joint spacing, used as a proxy for the thickness of the articular cartilage present within the joint spacing which can affect how a joint moves.

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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.

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