The vertebrate fauna of the Judith River Formation, Montana. Bulletin of the AMNH ; v. 147, article 6

dc.contributor.authorSahni, Ashok.en_US
dc.date.accessioned2005-10-06T14:53:27Z
dc.date.available2005-10-06T14:53:27Z
dc.date.issued1972en_US
dc.descriptionp. 323-412, [1] folded leaf of plates : ill., maps ; 27 cm.en_US
dc.descriptionIncludes bibliographical references (p. 404-412).en_US
dc.description.abstract"Geologic investigation of the late Cretaceous Judith River Formation in the area just north of the Judith River on the Missouri River in north-central Montana has resulted in the discovery of varied vertebrate forms. The beds are mainly freshwater continental deposits consisting of crossbedded channel sandstones, gray siltstones, and carbonaceous shales with occasional seams of lignitic coal. The stratigraphic sequence consists of the Marias River Shale overlain by the Eagle, Claggett, Judith River, and Bearpaw formations. The last four constitute Montana Group. The Judith River Formation is Campanian in age as determined by its position between the fossiliferous marine Claggett and Bearpaw shales. The fauna was obtained from the upper 50 feet of the formation. The bone concentration in the productive sandstone is the result of size sorting leading to underrepresentation of the larger dinosaurs. Three orders of mammals are represented, the Eutheria by a single genus, the Allotheria by five, and the Metatheria by at least three genera. Teiid and parasaniwid lizards are frequent. Only a fraction of the large number of described dinosaur genera, however, is represented in the collection by isolated teeth. Fish and amphibians form a sizable portion of the fauna. Vertebrates from the Judith River Formation are more primitive than, but generally similar to, later Maestrichtian species. The mammals differ from their descendants in the Lance Formation at the species level. The community structure and the paleoecology of the fauna of the Judith River Formation resemble those of the Lance Formation. The greatest difference between the two communities is the greater variety of dinosaurs in the earlier formation"--P. 325.en_US
dc.format.extent30823717 bytes
dc.format.mimetypeapplication/pdf
dc.identifier.urihttp://hdl.handle.net/2246/1099
dc.languageengen_US
dc.language.isoen_US
dc.publisherNew York : [American Museum of Natural History]en_US
dc.relation.ispartofseriesBulletin of the American Museum of Natural History ; v. 147, article 6en_US
dc.subject.lccQH1 .A4 vol.147, art.6, 1972en_US
dc.subject.lcshVertebrates, Fossil -- Montana.en_US
dc.subject.lcshPaleontology -- Cretaceous -- Montana.en_US
dc.subject.lcshPaleontology -- Montana.en_US
dc.subject.lcshPaleontology -- Judith River Formation.en_US
dc.subject.lcshJudith River Formation.en_US
dc.titleThe vertebrate fauna of the Judith River Formation, Montana. Bulletin of the AMNH ; v. 147, article 6en_US
dc.typetexten_US

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