Egg Mountain

In the mid-1970s Jack Horner, a Montana paleontologist, along with fellow paleontologist Bob Makela discovered what appeared to be a large number of dinosaur nests containing the fossils of a duckbilled dinosaur in north-central Montana.

Egg Mountain and the area surrounding it were filled with fossilized eggs, babies and adult dinosaurs from approximately 80 million years ago.

Horner and Makela named the new dinosaur Maiasaura, which means "good mother lizards," after examining the nests and the remains of eggs they found inside. It was the first proof that some dinosaurs took care of their young in much the same way birds do now.

Horner observed a number of interesting characteristics about the nests. The even spacing between the nests and trampled eggshells within suggested that the nests were part of a colony, not the result of nesting in a different spot each year. He also determined that there would have been a lack of vegetation in the area of the nests. Using this clue, Horner theorized that the mother dinosaurs found food elsewhere and brought it back to their young while they cared for them in the nest, also that they may have left enough room to lie down next to the eggs to protect and shelter them - the first evidence of parental care by dinosaurs.

Their round nests were six or seven feet wide and could hold 25 eggs. The hatched babies weighed about as much as a phonebook and were about one foot long. Adult Maiasaurs weighed almost 6,000 pounds and were almost 30 feet long.

Egg Mountain is 12 miles west of Choteau. Today it is the site that has yielded more information about dinosaur biology during the Cretaceous period than any other paleontology dig in the world. Paleontology programs are available for adults and children.