Maiasaura

Maiasaura peeblesorum

Maiasaura is a large herbivorous saurolophine hadrosaurid ("duck-billed") dinosaur genus that lived in the area currently covered by the state of Montana and the Canadian province of Alberta, in the Upper Cretaceous (mid to late Campanian), from 86.3 to 70.6 million years ago. Maiasaura is the state fossil of Montana. The first remains of Maiasaura were discovered in the Two Medicine Formation near Choteau, Montana in 1978 by Bynum, Montana resident Laurie Trexler. This holotype specimen was later described by Horner and Makela in 1979 as the new genus and species Maiasaura peeblesorum