• Talar trochlear morphology may not be a good skeletal indicator of loco

    From Primum Sapienti@21:1/5 to All on Sun Dec 19 23:21:22 2021
    https://www.nature.com/articles/s41598-021-03429-y

    Abstract
    To reconstruct locomotor behaviors of fossil hominins and understand the evolution of bipedal locomotion in the human lineage, it is important to clarify the functional morphology of the talar trochlea in humans and extant great apes. Therefore, the present study aimed to investigate the interspecific-differences of the talar trochlear morphology among humans, chimpanzees, gorillas, and orangutans by means of cone frustum
    approximation to calculate an apical angle and geometric morphometrics for detailed variability in the shape of the talar trochlea. The apical angles in gorillas and orangutans were significantly greater than those in humans and chimpanzees, but no statistical difference was observed between humans and chimpanzees, indicating that the apical angle did not necessarily correspond with the degree of arboreality in hominoids. The geometric morphometrics revealed clear interspecific differences in the trochlear morphology, but no clear association between the morphological characteristics of the trochlea
    and locomotor behavior was observed. The morphology of the trochlea may
    not be a distinct skeletal correlate of locomotor behavior, possibly because the morphology is determined not only by locomotor behavior, but also by
    other factors such as phylogeny and body size.

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  • From littoral.homo@gmail.com@21:1/5 to All on Tue Dec 21 12:18:00 2021
    https://www.nature.com/articles/s41598-021-03429-y

    See the comment there:
    "Interesting comparative article, but if we want to "understand the evolution of bipedal locomotion in the human lineage", we must first realize that bipedalism is not unique to the human lineage:
    most likely, early hominoids were already bipedal,
    - not for running over open African savannas as traditionally still often believed,
    - but simply for wading upright in forest swamps and for climbing arms overhead in the branches above the swamp, as we still can see in bonobos wading bipedally in search of waterlilies, and in lowland gorillas wading for sedges,
    google illustrations e.g. "bonobo wading" or "gorilla bai".
    The Trachilos footprints on the island of Crete c 6 Ma show that hominoids that predate the Homo/Pan split c 5 Ma were walking bipedally there, see the recent paper of Uwe Kirschner cs 2021 Scientific Reports 11, 19427.
    For an overview of how hominoid and human bipedalism evolved, google e.g. "ape human evolution made easy PPT Verhaegen" (+ references therein).

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