in 1903, at willow creek, montana, several fossil osteoderms were discovered "lying upon the surface of the soil" by john bell hatcher and t.w. stanton. these osteoderms were initially attributed to the ankylosaurid dinosaur "euoplocephalus". excavation at the site, carried out by w.h. utterback, yielded further fossils, including additional osteoderms, as well as vertebrae, ribs, and a pubis. when these specimens were examined, it became clear that they belonged to a large crocodilian and not a dinosaur; upon learning this, hatcher "immediately lost interest" in the material. after hatcher died in 1904, his colleague w.j. holland studied and described the fossils. holland assigned these specimens to a new genus and species, "deinosuchus hatcheri", in 1909. "deinosuchus" comes from the greek δεινός/"deinos", meaning "terrible", and σοῦχος/"suchos", meaning "crocodile".