28" Hadrosaur (Maiasaur) Ischium with Stand - Montana

 
 
 
 
 
This is a 28" long Hadrosaur ischium (pelvic bone) from the Two Medicine Formation of Montana. The proximal end of the bone is 5.8 wide and the distal end is 1.7" wide. On the custom metal display stand, this specimen is 26" tall. It was collected this summer from one of our partners private quarries in Pondera County and prepared from the hard sandstone matrix.

This bone was found in pieces within the rock, requiring crack repair in several locations. Some of the cracks required gap fill restoration, however the restoration to this bone is quite minimal. The proximal end of the bone required the most crack repair for it was found fragmented. About 6-7" away from the distal end of this bone, there are two circular impressions, possible bite marks.

Maiasaura meaning "good mother reptile" or "good mother lizard" is a large herbivorous hadrosaur ("duck-billed") dinosaur that lived in the area currently covered by the state of Montana in the Upper Cretaceous Period. The first fossils of Maiasaura were discovered in 1978. The name refers to the find of nests with eggs, embryos and young animals, in a nesting colony. These showed that Maiasaura fed its young while they were in the nest, the first time such evidence was obtained for a dinosaur. Maiasaura reached lengths of around 30 feet long, making it a fairly large Hadrosaur. Young animals walked on their hind legs, adults on all fours.

Maiasaura peeblesorum, a hadrosaur from the Late cretaceous of Montana.  By Nobu Tamura (http://spinops.blogspot.com) Creative Commons License
Maiasaura peeblesorum, a hadrosaur from the Late cretaceous of Montana. By Nobu Tamura (http://spinops.blogspot.com) Creative Commons License

The Two Medicine Formation is a geographical formation in Central Montana and Southern Alberta, Canada. The formation is predominantly sandstone laid down by rivers and deltas during the Campanian Age of the Cretaceous about 80-75 million years ago. Approximately two thousand feet thick on the western edge, it lies on top of the Virgelle Sandstone formation and under the Bearpaw Shale. It is located between the Front Range of the Rocky Mountains and the Sweetgrass Arch, a tectonic fold feature 40-90 miles east of the Front Range.

The Two Medicine is the same age as the Judith River Formation found further east. It was laid down further inland from the Western Interior Seaway, while the Judith River Formation was deposited along the coast. The Two Medicine contains much of the same dinosaur fauna, but fewer reptiles, amphibians and aquatic fossils.

A view of the Two Medicine Formation quarry operated by Northwest Montana Fossils where much of our Two Medicine dinosaur material has been found.
A view of the Two Medicine Formation quarry operated by Northwest Montana Fossils where much of our Two Medicine dinosaur material has been found.

DETAILS
SPECIES
Maiasaur
LOCATION
Pondera County, Montana
FORMATION
Two Medicine Formation
SIZE
28" long, 26" tall on stand
CATEGORY
SUB CATEGORY
ITEM
#148786
GUARANTEE
We guarantee the authenticity of all of our
specimens. Read more about our
Authenticity Guarantee.