Most dromaeosaurids were smallto medium-sized cursorial, scansorial, and arboreal, sometimes volant predators, but a comparatively small percentage grew to gigantic proportions. Only two such giant “raptors” have been described from North America. Here, we describe a new giant dromaeosaurid, Dakotaraptor steini gen. et sp. nov., from the Hell Creek Formation of South Dakota. The discovery repre...

U.S. Department of the Interior U.S. Geological Survey Wheeler Geologic Monument (Half Moon Pass quadrangle) provides exceptional exposures of three outflow tuff sheets erupted from the San Luis caldera complex. Lowest sheet is Rat Creek Tuff, which is nonwelded throughout but grades upward from light-tan rhyolite (~74% SiO 2 ) into pale brown dacite (~66% SiO 2 ) that contains sparse dark-brow...

This research aims to achieve a greater understanding of the structure of bacterial communities present in alkaline hot springs in Yellowstone National Park. I focus specifically on White Creek and Rabbit Creek in the Lower Geyser Basin. I show that, overall, the bacterial communities of both creeks are non-randomly assembled. However, at finer taxonomic scales, bacterial groups differ in their...