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Invertebrate Fossils

Invertabrate Fossils At GPDMWhen dinosaurs roamed North America during the Cretaceous period, high water levels on Earth caused flooding on the low lands of the Midwest. Stretching from the Arctic down to the Gulf of Mexico, this shallow yet wide seaway split the continent in two. Present-day Montana sat on the western coast of this vast Western Interior Seaway.

Therefore, it’s no surprise that in addition to finding dinosaurs in the area’s sandy soils, fossilized marine animals are also found. Most abundant are remains of shelled cephalopods (related to squids and octopus), lobsters, and crabs. 

The Great Plains Dinosaur Museum is very proud to exhibit the invertebrate collections of the Eichhorn family of Montana. The Eichhorns have been responsible for discovering countless marine fossils including three new species of crab which now bear their name.

Eichhorn Collection