Late Cretaceous

Campanian 83 - 74 mya

Judith River

The Two Medicine Formation in northwest Montana was deposited during the Campanian. It irepresents an environment of floodbasin ponds and lakes on an alluvial plain with shallow streams and a seasonal climate. A variety of fossils have been found, including clams, snails, turtles, champsosaurs and dinosaurs, but is particularly noted for the preservation of eggs, nests and colonial nesting grounds, and has several bone beds dominated by one species of hadrosaur or ceratopsian.Maiasaura, Orodromeus, Troodon and other indeterminate dinosaurs have been described.

updated 112014

Much like the original Carnegie Safari Maiasaura, the green Faro figure from Italy is sitting on the eggs. It seems unlikely that this was practical given the weight of Maiasaura. The Troodon are from the National Geographic MicroMachine series, and in the center is a Battat figure with a JP 3 nest and egg from the mold kit. Last is the current Carnegie Safari Maiasaura with nest.

Maiasaura (the good mother dinosaur) was the first dinosaur given a female name ending.  Jack Horner found giant nesting areas for this species of solid crested hadrosaur.  It is estimated the site is from a colony of over 10,000 Maiasaura

The original Carnegie Safari Maiasauralacked the solid crest and is improbably sitting on the nest of eggs. It is still a good representative of the crestless hadrosaurs. The Maiasaura hatching is from the series 3 Dino Tales by Kaiyodo. The Battat Edmontonia is often imitated as a vinyl figure and seen in toy bins.The nests seem separated by about the body length of an adult Maiasaura, and it is suggested that the eggs were incubated by covering them with rotting vegetation, like some current day birds. There is evidence that the young remained in the nests and were cared for until they reached a certain size.

Carnegie Safari Albertosaurus, Wild Safari Hypacrosaurus, Battat Euplocephalus and Schliech AlbertosaurusEuoplocephalus was an about twenty-foot long ankylosaur characterized by a tail club. 

Repainted ChinasaurTroodon was a small hunter with steak-knife teeth, two long slim legs and short narrow 4-toed feet unlike those of any other dinosaur. It had a large brain and eyes, and could hunt by day or night. Recent studies on the teeth indicate Troodon may have been omnivorous.Egg Mountain is a locality in the Willow Creek Anticline of Two Medicine Formation in western Montana. It was discovered and named in 1979 by members of a team led by Horner, and hundreds of eggs have since been discovered, along with skeletal remains of dinosaurs, lizards and mammals. Examination of the embryos demonstrated were Troodon eggs and embryos.



CollectA Popular AchelousaurusAchelousaurus was a robust centrosaurine with relatively small, pitted nasal boss and relatively large high-ridged bosses over eyes (rather than horns). It had a single pair of spikes pointing backwards from rear of frill, but curved outwards as well.