Footprint formation and interpreting fossil dinosaur tracks

【摘要】恐龙足迹为我们提供了关于灭绝已久的动物活着时的解剖结构、行为和环境的独特证据。这些足迹和轨迹被认为是对恐龙运动的无与伦比的一瞥，记录了步态、速度、肢体姿势、足部运动甚至社会行为的各个方面。单个动物的足迹可能会有很大的变化，这取决于基材的坚固程度和每一步下沉的深度。该项目旨在了解基质对运动的影响以及化石记录中轨迹多样性的起源。鸟类在不同基质上行走的三维运动将通过使用x射线视频动画的骨骼模型来测量。轨道形成的计算机模拟将揭示轨道在地表和不同深度是如何发展的。这些令人兴奋的新方法是由研究人员开发的，用于成像、量化和模拟通过可变形基底的运动，将为恐龙轨迹的“诞生”提供一个全新的、体积的视角。然后，模拟的鸟类足迹将与2亿年前的恐龙足迹进行比较，以帮助解释形状的变化并纠正之前解释中的错误。这项研究的结果将从根本上改变我们对恐龙足迹的感知和解释，通过解开以前看不见的运动和机制。【技术文摘】脚印为什么是这样的形状？单一动物如何以及为什么会产生一系列完全不同的足迹？拟议中的项目旨在继续盖茨西（古生物学、生物力学和功能解剖学）和福尔金厄姆（计算机科学、地质学和古生物学）之间富有成效的合作。pi将从两足恐龙和可变形基质之间的动态相互作用中探索足迹形态的出现。他们通过在阿默斯特学院贝内斯基自然历史博物馆的希区柯克历史技术收藏中探索不同的标本，试图了解中生代轨道多样性的起源和功能意义。pi将整合活鸟实验（XROMM: x射线运动形态重建）和基底模拟（DEM：离散元法），以揭示解剖学、运动和沉积物特性之间的重要相互作用。不同基质中珍珠鸡足迹的体积DEM模型将为解释和迭代模拟来自康涅狄格谷和格陵兰岛的特定标本提供参考。这项研究的结果将从根本上改变我们对恐龙足迹的看法和解释，通过解锁以前无法获得的足部/沉积物动力学。

New Title:Footprint formation and interpreting fossil dinosaur tracksNon-technical AbstractDinosaur tracks offer unique evidence of the anatomy, behavior, and environment of long-extinct animals when they were alive. These tracks and trackways are recognized as unrivaled glimpses into dinosaur locomotion, recording aspects of gait, speed, limb posture, foot motion, and even social behavior. A single animal's tracks can vary dramatically depending on the firmness of the substrate and how deeply it sank with each step. This project aims to understand both the effects of substrate on locomotion and the origin of track diversity in the fossil record. 3-D movement of birds walking on different substrates will be measured using skeletal models animated using X-ray video. Computer simulations of track formation will reveal how tracks develop both at the surface and at different depths. These exciting new methods developed by the researchers for imaging, quantifying, and simulating locomotion through deformable substrates will provide an entirely new, volumetric perspective on the "birth" of a dinosaur track. Simulated bird tracks will then be compared to 200 million year old dinosaur tracks to help explain variation in shape and correct errors in previous interpretations. Results from this research will fundamentally change our perception and interpretation of dinosaur tracks by unlocking previously invisible motions and mechanisms.Technical AbstractWhy are footprints shaped the way they are? How and why does a single animal produce a disparate array of tracks? The proposed project aims to continue a fruitful collaboration between Gatesy (paleontology, biomechanics, and functional anatomy) and Falkingham (computer science, geology, and paleontology). The PIs will explore the emergence of footprint morphology from the dynamic interplay between bipedal dinosaurs and deformable substrates. They seek to understand the origin and functional significance of Mesozoic track diversity by exploring disparate specimens in the historic Hitchcock Ichnology Collection at the Beneski Museum of Natural History at Amherst College. PIs will integrate living bird experiments (XROMM: X-ray Reconstruction of Moving Morphology) and substrate simulations (DEM: Discrete Element Method) to reveal important interactions among anatomy, motion, and sediment properties governing footprint formation. Volumetric DEM models of guineafowl tracks in varying substrates will serve as reference for interpreting and iteratively simulating specific specimens from the Connecticut Valley and Greenland. Results from this research will fundamentally change our perception and interpretation of dinosaur tracks by unlocking previously inaccessible foot/sediment dynamics.