It was Brodkorb's impression that chachalacas had a Nearctic origin and only during the Great American Biotic Interchange did they expand their range into South America. Although boreal today, the chachalacas from these North American fossil localities would have been much more tropical to subtropical in nature. Agate Fossil Beds National Monument. Today, the Spruce Grouse is a member of the boreal species community. Palaealectoris may represent an ancestral grouse living in a subtropical environment before the dichotomy we see today between boreal species like the Spruce Grouse and the prairie grouse like the Greater Prairie-Chicken, Tympanuchus cupido .
Pratincoles are short-legged insect feeders, which feed on the wing much like swallows.
Once again, we have a member of the paleoavifauna from Agate which is representative of a greater, worldwide avifauna still in existence at the end of the Oligocene and into the early Miocene. The fossil birds of the Agate Fossil Beds National Monument are very interesting at several levels. First, they are interesting at an alpha taxonomic level as new genera and species. Secondly, birds are frequently used as environmental indicators of certain habitats and to evaluate the health of the environment. The birds from the Monument support Hunt's interpretation of the paleoenvironment as an area with ephemeral stream channels, open plains, but with riparian areas along the streams.