Lutonsotherium (name meaning Luton's beast), formerly known as Mustelirhynchus (name meaning weasel jaw), is one of the direct descendants of cetofelis that started to evolve the ability to walk on their hind legs (although still preferred to only stand, in a similar fashion to modern day meerkats) and becoming more omnivorous. It was the ancestors of Homodon (name meaning man teeth) and modern dylanuses. It lived in North America's grasslands and forests. It probably became extinct due to competition from newly evolving wild dogs (including the ancestors of gray wolves).