4.6 Article

Mechanics of Arboreal Locomotion in Swinhoe's Striped Squirrels: A Potential Model for Early Euarchontoglires

期刊

出版社

FRONTIERS MEDIA SA
DOI: 10.3389/fevo.2021.636039

关键词

Tamiops; locomotion; support reaction forces; gait; asymmetrical locomotion

类别

资金

  1. German Research Council [DFG EXC 1027, DFG NY 63/2-1]

向作者/读者索取更多资源

The study investigated how Swinhoe's striped squirrels adjust their locomotion on different supports, finding that they predominantly use asymmetrical gaits with a preference for full bounds. The squirrels made adjustments on inclined surfaces to increase stability and optimize the loading distribution between fore- and hind limbs. These findings suggest a preference for asymmetrical gaits in early members of the Euarchontoglires, shedding light on the ancestral lifestyle of this mammalian 'superclade'.
Differences between arboreal and terrestrial supports likely pose less contrasting functional demands on the locomotor system at a small body size. For arboreal mammals of small body size, asymmetrical gaits have been demonstrated to be advantageous to increase dynamic stability. Many of the extant arboreal squirrel-related rodents display a small body size, claws on all digits, and limited prehensility, a combination that was proposed to have characterized the earliest Euarchontoglires. Thus, motion analysis of such a modern analog could shed light onto the early locomotor evolution of eurarchontoglirans. In this study, we investigated how Swinhoe's striped squirrels (Tamiops swinhoei; Scuiromorpha) adjust their locomotion when faced with different orientations on broad supports and simulated small branches. We simultaneously recorded high-Hz videos (501 trials) and support reaction forces (451 trials) of squirrels running on two types of instrumented trackways installed at either a 45 degrees incline (we recorded locomotion on inclines and declines) or with a horizontal orientation. The striped squirrels almost exclusively used asymmetrical gaits with a preference for full bounds. Locomotion on simulated branches did not differ substantially from locomotion on the flat trackway. We interpreted several of the quantified adjustments on declines and inclines (in comparison to horizontal supports) as mechanisms to increase stability (e.g., by minimizing toppling moments) and as adjustments to the differential loading of fore- and hind limbs on inclined supports. Our data, in addition to published comparative data and similarities to the locomotion of other small arboreal rodents, tree shrews, and primates as well as a likely small body size at the crown-group node of Euarchontoglires, render a preference for asymmetrical gaits in early members of the clade plausible. This contributes to our understanding of the ancestral lifestyle of this mammalian 'superclade'.

作者

我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。

评论

主要评分

4.6
评分不足

次要评分

新颖性
-
重要性
-
科学严谨性
-
评价这篇论文

推荐

暂无数据
暂无数据