Rosebud County - Geology and Geography
Background Info/ Historical Story:
There was a species of mammal found in Rosebud County Montana called Gypsonictops hypoconus, so named for its hypocone teeth.
“This genus is known from a number of teeth from the Wyoming Lance, including examples of P4 and of all the molars, and a detailed description of it has been prepared and will appear elsewhere. In the meantime it has seemed advisable to record it here in order that the Hell Creek lists may be as complete as the material in hand permits. The significance of the genus lies in the fact that its very probable leptictid affinities afford the first strong indication of the presence of placentals in the Lance, bv far the greater number of the trituberculates present being certainly marsupials. It is the writer's belief that Batodon and Telacodon, and perhaps some other even more doubtful forms, are also placentals, but this is very uncertain, while Gypsonictops is so like the other leptictids in all details of upper cheek-tooth structure and so unlike any known marsupial that its placental affinities can hardly be denied.”- George G. Simpson 1927, ‘Mammalian fauna of the Hell Creek Formation of Montana. American Museum novitates’
Collections Spotlight:
- Mammalian fauna of the Hell Creek Formation of Montana. American Museum novitates ; no. 267, George G. Simpson, 1902- Brown, Barnum - Mammalian fauna of the Hell Creek Formation of Montana. American Museum novitates ; no. 267
Photos, Maps, etc:
- Gypsonictops hypoconus University of California Museum of Paleontology
- gypsonictops by Nix Illustration
- Montana Geologic Map