Hadrosaurs were a large family of ornithischian dinosaurs from the Cretaceous Period. Related to Iguanodons, they are known primarily for their "duck-bills" which are in fact elongated rostral bone structures that give the appearance of a beak, but actually housed hundreds of small teeth that allowed these giant herbivores to grind through all manner of plant material, including rotten wood.

This specimen is a slice of Hadrosaur bone from an Edmontosaurus, recovered on private land in South Dakota from the Lance Formation. The specimen comes inside a classic, glass-topped riker display case measuring 4 1/2" x 3 1/2". A small information card is also enclosed.

More About Hadrosaurs

"Hadrosaurs grew rapidly, and quantifying their growth is key to understanding life-history interactions between predators and prey during the Late Cretaceous."

~ Lisa Noelle Cooper, "Relative growth rates of predator and prey dinosaurs reflect effects of predation." Proceedings of the Royal Society B: Biological Sciences 275.1651 (2008)

Hadrosaur fossils have been found on all continents. Evidence of their migratory nature has been recovered, but recent studies suggest that some species, those in polar regions, may have settled in place year-round.

These large herbivores ate twigs, berries and coarse plant matter. Much is known about their diet as fossilized stomach contents have been identified. They foraged on low-level foliage from conifers and deciduous shrubs and trees.

Recent studies suggest that Hadrosaurs, which could reach the size of a Tyrannosaurus rex, grew at phenomenal speeds, in part to avoid predation by therapods. Compare this with T. rex, which took three times that long to grow to full size.

As noted above, this specimen is a fragment of Hadrosaur bone recovered on private land in South Dakota from the Lance Formation. Once a coastal plain threaded with streams along the Western Interior Seaway, the Lance Formation is one of the most productive locations for Late Cretaceous Period fossils all the way up to the end of the Cretaceous. Studies indicate rainfall amounts increased dramatically after the K-Pg boundary event, with an influx of sediments and widespread swamps.