9.4" Juvenile Hadrosaur (Hypacrosaur) Humerus w/ Metal Stand - Montana

This is a beautifully preserved, 9.4" long juvenile Hadrosaur (Hypacrosaurus sp.) humerus bone from the left arm, collected from the Two Medicine Formation of Montana. It was collected this summer from one of our partners quarries in Pondera County. It comes from a hard sandstone layer and the bone quality is excellent and very dense. It comes with a custom metal display stand for display.

It was found broken into several pieces, requiring crack repair and gap fill restoration in spots. Both the proximal and distal ends are weathered, however there is no restoration to either end. Each of the repaired cracks through middle of the bone required some restoration where the bone crumbled away, with the most notable restoration at the point of repair just over 3 1/2" from the distal end of the humerus.

Hypacrosaurus is a very large, Lambeosaurini Hadrsosaur that would have been almost as large as the Tyrannosaurs that it lived alongside. Like Corythosaurus, it had a tall, hollow, rounded crest, although not as large and straight. It is known from the remains of two species that spanned 75 to 67 million years ago in the Late Cretaceous of Alberta, Canada, and Montana, United States, and is the latest hollow-crested duckbill known from good remains in North America. It is estimated to have been around 9.1 meters (30 feet) long and to have weighed up to 4-5 tons.

 Hypacrosaurus drawing by Wikipedia user debivort. Creative Commons License
Hypacrosaurus drawing by Wikipedia user debivort. 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.

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DETAILS
SPECIES
Hypacrosaurus sp.
LOCATION
Pondera County, Montana
FORMATION
Two Medicine Formation
SIZE
9.4 x 2.2", 9.6" tall on stand
CATEGORY
SUB CATEGORY
ITEM
#159682
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