The Cabbage Patch beds of western Montana span roughly 6.5 million years from about 29. 5 to 23 million years ago crossing the boundary between the Oligocene and the Miocene. This series of fossil-bearing horizons is located in Powell, Granite, Silver Bow, and Deer Lodge counties (Montana). The Cabbage Patch beds house a rich vertebrate (mostly mammals) and invertebrate (mostly land and freshwater snails) fauna as well as floral remains (mostly in the form of phytoliths). These beds have mostly been studied by Dr. Donald Rasmussen in the 1960s and 1970s.
I am continuing Dr. Rasmussen’s work with the goal of comparing the fauna from Cabbage Patch to faunas of the same age located in Oregon (John Day Formation) and Nebraska (Arikaree Group). I am collecting additional fossils and geological data from the field and further analyzing the fossils collected by Dr. Rasmussen housed at the University of Montana and the University of Kansas (mostly).
The goals of my dissertation are to better understand:
- The taphonomy of the Cabbage Patch deposits
- The systematics of an abundant group of mammals from Cabbage Patch
- The biogeographic relationships of Cabbage Patch with other regions at the time
- The advent of modern mammalian communities at the time of the spread of grasslands
Collaborators at the University of Washington and the University of Michigan are investigating these deposits using isotopes and phytoliths to better understand the environment at the time in Montana. You can read more about their research here.