A new solution to an old riddle: elongate dinosaur tracks explained as deep penetration of the foot, not plantigrade locomotion

The dinosaur track record features numerous examples of trackways with elongate metatarsal marks. Such “elongate tracks” are often highly variable and characterised by indistinct outlines and abbreviated or missing digit impressions. Elongate dinosaur tracks are well-known from the Paluxy River bed of Texas, where some had 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 ...

恐龙足迹记录中存在大量带有延长跖骨痕迹的足迹道案例。这类‘延长型足迹’通常具有高度变异性，其特征为轮廓模糊、趾印缩短或缺失。延长型恐龙足迹在得克萨斯州的帕卢西河河床广为人知，其中一些因表面类似人类的外观被神创论者解读为‘人类足迹’。跖骨痕迹的水平方向导致了如今被广泛接受的观点：各类大小不一的恐龙造迹者采用兼性跖行（即‘平足’）的运动模式。然而，这一假说与观测结果相矛盾：延长型足迹并未表明运动速度降低和步角值增大，反而与较低的解剖学保真度相关。我们在此将延长型足迹解释为足部在松软沉积物中的深度穿透。沉积物可能在下落足部的部分上方坍塌，留下……