DESCRIPTION AND DISTRIBUTION OF MIOCENE VERTEBRATE FOSSILS OF THE MOKELUMNE WATERSHED

During the Miocene epoch, vertebrates in northern California reflected ecological changes from climatic shifts, with fossils deposited in the Mokelumne watershed via debris flows from eroding uplifted volcanoes. Preliminary fossil descriptions and their distribution within the site were crucial to illustrating the paleoecological changes. Using learned techniques to identify unique characteristics amongst the anatomy of taxa from professionals and academia, we identified specimens down to at least a family or, at most, a species in some well- preserved specimens. We also included specific taphonomic attributes such as pathologies, and the matrix the fossils were preserved in. These assessments were conducted at California State University of Chico, Gateway Science Museum, and University of California Museum of Paleontology. This information was put into a database, such as a locality and an official identification number. After undergoing quality assurance, the data was transferred to geographic information system to facilitate interconnection for inquiry into specimen characteristics to allow visualization of these characteristics alongside their distribution. This allowed us to deduce specific relationships, such as members of the order Proboscidea only being found in the site’s northern portion. Upon evaluating our results, it was clear that browsing herbivores were concentrated towards the north western side of the map whilst grazing herbivores seemed to have concentrated on both the northern and southern side of the field area. We concluded that these southern deposits represent a cooler time in the late Miocene due to representation of grazing animals while the northern portion represents hotter times where browsing herbivores would have flourished. This preliminary does not include stratigraphy, which can use this preliminary information to juxtapose relationships amongst these organisms.