Tenontosaurus tilletti was an abundant ornithischian dinosaur from the Lower Cretaceous of North America, commonly regarded as a ‘basal’ iguanodontian. Here, we describe a remarkably well-preserved specimen, comprising a near-complete skeleton and skull, from the Cloverly Formation, Montana, USA, currently housed at the University of Manchester Museum, UK. Found alongside the specimen were alleged gastroliths, cycad seeds, and teeth of the contemporaneous dromaeosaur Deinonychus antirrhopus, all of which were buried in an alleged ash. We assess the credibility of these claims, using X-ray CT scanning and X-ray fluorescence (XRF) respectively, and show that the ‘seeds’ are non-organic mineral concretions, and that the ‘ash’ is actually a lime mud with a silica content of approximately 7%. We confirm the identification of the gastroliths and the Deinonychus teeth, providing further evidence to support the long-standing assertion, originally made by John Ostrom in 1970, that Tenontosaurus was a common food item for Deinonychus.

Tenontosaurus tilletti是一种来自北美下白垩统的丰富的鸟臀目恐龙，通常被认为是“基础”禽龙类。在这里，我们描述了一个保存完好的标本，包括一个近乎完整的骨骼和头骨，来自美国蒙大拿州的 Cloverly 组，目前收藏在英国曼彻斯特大学博物馆。在标本旁边发现了所谓的胃石、苏铁种子和同时代的驰龙Deinonychus antirrhopus的牙齿，所有这些都被埋在所谓的灰烬中。我们分别使用 X 射线 CT 扫描和 X 射线荧光 (XRF) 评估这些说法的可信度，并表明“种子”是非有机矿物结核，“灰”实际上是石灰泥二氧化硅含量约为 7%。我们确认了胃石和恐爪龙牙齿的鉴定，提供了进一步的证据来支持最初由约翰·奥斯特罗姆在 1970 年提出的长期断言，即腱龙是恐爪龙的常见食物。