The kinkajou ( Potos flavus ) is a South and Central American procyonid that can plantarflex and invert its hindfoot around multiple joints in order to fully reverse the hindfoot 180°. However, the myological and osteological adaptions that facilitate this behavior have not been quantified metrically. Osteological correlates of hindfoot reversal have been described in the past, but recent advances in data collection allow for a more comprehensive evaluation of shape differences. Osteological features of the astragalus (talus), calcaneus, and distal tibia of P. flavus were collected and compared to other carnivoran species, including species that are full, partial, and non-reversers of the hindfoot. Hindfoot reversing procyonids were found to possess a relatively smaller medial malleousl, a wider sustentaculum tali, narrower calcaneal tuberosity, and a relatively longer astragalus. In general, the dimensions of the astragalus tend to discriminate hindfoot reversing taxa from other locomotor categories more reliably than the dimensions of the calcaneus or distal tibia. A detailed dissection, description, and documentation of the hind limb muscles in P. flavus was undertaken, and we present the first comprehensive review of its muscular anatomy utilizing muscle maps of the pelvis, femur, tibia, and fibula. Potos flavus has well-developed plantarflexor and invertor muscles, traits which have been hypothesized to characterize species that perform hindfoot reversal. This finding contrasts with other procyonid hindfoot reversing species, such as Bassariscus astutus , which appear to lack muscular adaptations to hindfoot reversal. Muscle semimembranosus, a muscle that facilitates hind limb suspension, was also enlarged. Overall, the hind limb musculature and hindfoot osteology of the kinkajou are consistent with proposed adaptations to hindfoot reversal.

中文翻译：

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Kinkajou（Potos flavus）中后足逆转的肌肉学和骨学相关性

kinkajou ( Potos flavus ) 是一种南美洲和中美洲的河豚类动物，可以在多个关节周围进行足底弯曲和倒转后足，以将后足完全反转 180°。然而，促进这种行为的肌肉学和骨学适应尚未被量化。过去已经描述了后足逆转的骨学相关性，但数据收集的最新进展允许对形状差异进行更全面的评估。收集了黄芪（距骨）、跟骨和胫骨远端的骨骼特征，并与其他食肉动物物种进行了比较，包括后足完全、部分和非逆转的物种。发现后足逆行龙科动物具有相对较小的内踝、较宽的支托、较窄的跟骨结节、和相对较长的黄芪。一般来说，黄芪的尺寸往往比跟骨或胫骨远端的尺寸更可靠地将后足逆转类群与其他运动类别区分开来。对 P. flavus 的后肢肌肉进行了详细的解剖、描述和记录，我们首次利用骨盆、股骨、胫骨和腓骨的肌肉图对其肌肉解剖结构进行了全面审查。Potos flavus 具有发达的跖屈肌和内翻肌，这些特征已被假设为表征执行后足逆转的物种。这一发现与其他后足逆转物种（例如 Bassariscus astutus ）形成对比，后者似乎缺乏对后足逆转的肌肉适应性。肌肉半膜肌，促进后肢悬垂的肌肉也增大了。总体而言，kinkajou 的后肢肌肉组织和后足骨学与对后足逆转的拟议适应一致。