 Another would be found in the late 1870s and put on display at the Natural History Museum, Berlin in 1881.Other primitive toothed birds were found by Othniel Marsh in Kansas in 1872.Marsh also discovered fossils of several primitive horses in the Western United States that helped trace the evolution of the horse from the small 5-toed "Hyracotherium" of the Eocene to the much larger single-toed modern horses of the genus "Equus".