A new solution to an old riddle: elongate dinosaur tracks explained as deep penetration of the foot, not plantigrade locomotion
A new solution to an old riddle: elongate dinosaur tracks explained as deep penetration of the foot, not plantigrade locomotion
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DOI：
10.1111/pala.12584
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发表时间：
2021-12-08
期刊：
影响因子：
2.6
通讯作者：
Falkingham, Peter L.
中科院分区：
文献类型：
--
作者：
Lallensack, Jens N.;Farlow, James O.;Falkingham, Peter L.
恐龙的足迹记录中有许多带有细长跖骨痕迹的足迹。这种“细长的足迹”通常是高度可变的，其特征是轮廓模糊，手指印缩短或缺失。细长的恐龙足迹在德克萨斯州的帕卢克西河床上很有名，其中一些被神创论者解释为“人的足迹”，因为它们表面上看起来像人类。跖骨标记的水平方向导致了一种现在被广泛接受的观点，即在各种从小到大的恐龙足迹制造者中，有一种兼性plantigrade或“平足”运动模式。然而，这一假设与观察结果不一致，即延长的轨迹并不表明运动速度降低和步伐角度值增加，而是与较低的解剖保真度相关。我们在这里将细长的足迹解释为脚在软沉积物中的深穿透。沉积物可能会在下沉的脚的部分上方塌陷，留下浅浅的表面痕迹，保留了跖骨的痕迹。跖骨标记的长度由多种因素决定，并不一定与跖骨的长度相关。其他类型的恐龙脚印后的痕迹，如拖痕和滑痕，进行了审查。
The dinosaur track record features numerous examples of trackways with elongated metatarsal marks. Such 'elongate tracks' are often highly variable and characterized by indistinct outlines and abbreviated or missing digit impressions. Elongate dinosaur tracks are well-known from the Paluxy River bed of Texas, where some have been interpreted as 'man tracks' by creationists due to their superficially human-like appearance. The horizontal orientation of the metatarsal marks led to the now widely accepted idea of a facultative plantigrade, or 'flat-footed', mode of locomotion in a variety of dinosaurian trackmakers small to large. This hypothesis, however, is at odds with the observation that elongate tracks do not indicate reduced locomotion speeds and increased pace angulation values, but instead are correlated with low anatomical fidelity. We here interpret elongate tracks as deep penetrations of the foot in soft sediment. Sediment may collapse above parts of the descending foot, leaving a shallow surface track that preserves a metatarsal mark. The length of a metatarsal mark is determined by multiple factors and is not necessarily correlated with the length of the metatarsus. Other types of posterior marks in dinosaur footprints, such as drag and slip marks, are reviewed.