Dinosaur Paleoecology, Judith River Formation, South CentralMontana

蒙大拿州的朱迪思河组具有历史意义 作为美国第一批恐龙化石的来源， 约瑟夫·莱迪于1856年在费城描述的。 但 作为恐龙的来源， 化石 在阿尔伯塔北部和更远的地方， 蒙大拿州中北部的西部地区被证明更有生产力。 1981年在朱迪思河沉积物中发现的恐龙骨床 在蒙大拿州中南部肖穆特附近， 蒙大拿州朱迪思河，最南端的生产基地 从这个编队。 在代表的分类群中有一个新属 角口类（Avaceratops lammersi Dodson 1986），一个巨大的 鸭嘴龙，一种非常罕见的厚头龙科的后颅， 幼年鸭嘴龙和角龙类， 频率比其他大多数当代遗址都要高。 工作 最初专注于粗心溪采石场，但勘探 已经揭示了该地区的一些地点，因此建议 建立一个从西到东的环境样带， 内海航道。 已建立了一个25公里的样带， 其东端有牡蛎、鲨鱼和硬骨鱼。 分析整个样带的动物群变化将允许 更好地了解恐龙的生态决定因素 分布

The Judith River Formation of Montana has historical significance as the source of America's first dinosaur fossils, which were described in Philadelphia by Joseph Leidy in 1856. However, the formation has since been frustrating as a source of dinosaur fossils. Beds of similar age farther north in Alberta and farther west in north central Montana have proved to be more productive. A dinsosaur bonebed discovered in 1981 in Judith River sediments near Shawmut, south central Montana, is the richest yet found in the Montana Judith River, and the southernmost productive site from this formation. Among the taxa represented are a new genus of ceratopsid (Avaceratops lammersi Dodson 1986), a giant hadrosaur, very rare postcrania of a pachycephalosaurid, and juvenile hadrosaurs and ceratopsids that occur with a higher frequency here than at most other contemporary sites. Work initially focused on the Careless Creek Quarry, but prospecting has revealed a number of sites in the area, so it is proposed to establish an environmental transect from west to east towards the Interior Seaway. A 25 km transect has been established, at the eastern end of which are found oysters, sharks and teleost fishes. Analysis of faunal changes across the transect will permit a better understanding of the ecological determinants of dinosaur distribution.