科學家已經(jīng)根據(jù)化石牙齒上的劃痕和磨損的模式重建了鴨嘴恐龍——埃德蒙頓龍（Edmontosaurus）的飲食習慣,。
Mark Purnell根據(jù)這些痕跡確定了埃德蒙頓龍以矮生植被為食,，而不是以木質(zhì)細枝和樹葉為食。像植食性的埃德蒙頓龍這樣的恐龍在白堊紀晚期是最大型的脊椎動物之一,，而它們覓食的成功歸功于它們的頭骨結(jié)構(gòu),，與絕大多數(shù)恐龍不同，這種結(jié)構(gòu)讓它們能咀嚼并磨碎它們的食物,。盡管脊椎動物牙齒化石可以提供一些飲食的線索,，仍然不清楚埃德蒙頓龍究竟吃哪種食物，以及它們?nèi)绾尉捉浪?/p>
這組科學家發(fā)現(xiàn),，埃德蒙頓龍牙齒上的劃痕表明主要存在上下的頜骨運動,，以及一些前后運動。這支持了一種觀點,，即這種恐龍的頭骨上有一個撓性關(guān)節(jié),，而這些劃痕模式表明了緊密約束的咀嚼運動。這組科學家說,，盡管這些化石牙齒被劃痕覆蓋,，它們沒有凹坑和缺口，這標志著一種磨損的模式,，在現(xiàn)存的植食動物中該模式是吃草的動物的特征,。（生物谷Bioon.com）
生物谷推薦原始出處：
PNAS June 29, 2009, doi: 10.1073/pnas.0812631106
Quantitative analysis of dental microwear in hadrosaurid dinosaurs, and the implications for hypotheses of jaw mechanics and feeding
Vincent S. Williamsa, Paul M. Barrettb and Mark A. Purnell
Understanding the feeding mechanisms and diet of nonavian dinosaurs is fundamental to understanding the paleobiology of these taxa and their role in Mesozoic terrestrial ecosystems. Various methods, including biomechanical analysis and 3D computer modeling, have been used to generate detailed functional hypotheses, but in the absence of either direct observations of dinosaur feeding behavior, or close living functional analogues, testing these hypotheses is problematic. Microscopic scratches that form on teeth in vivo during feeding are known to record the relative motion of the tooth rows to each other during feeding and to capture evidence of tooth–food interactions. Analysis of this dental microwear provides a powerful tool for testing hypotheses of jaw mechanics, diet, and trophic niche; yet, quantitative analysis of microwear in dinosaurs has not been attempted. Here, we show that analysis of tooth microwear orientation provides direct evidence for the relative motions of jaws during feeding in hadrosaurid ornithopods, the dominant terrestrial herbivores of the Late Cretaceous. Statistical testing demonstrates that Edmontosaurus teeth preserve 4 distinct sets of scratches in different orientations. In terms of jaw mechanics, these data indicate an isognathic, near-vertical posterodorsal power stroke during feeding; near-vertical jaw opening; and propalinal movements in near anterior and near posterior directions. Our analysis supports the presence of a pleurokinetic hinge, and the straightness and parallelism of scratches indicate a tightly controlled occlusion. The dominance of scratched microwear fabrics suggests that Edmontosaurus was a grazer rather than a browser.
