Edmontosaurus sp.
Late Cretaceous
Hell Creek Formation
Harding County, SD, USA

Good 0.3 inch juvenile Hadrosaur shed tooth!  Unusual!

Dinosaur, Hadrosaur.

Edmontosaurus was one of the largest of the “duckbilled” dinosaurs and it lived during the last few million years of the Cretaceous.  When I was a kid, scientists called it “Trachodon.”  Some time later, they thought the genus was “Anatosaurus.”  A few other names have been given to material that turned out to be the same genus and Edmontosaurus was the one deemed to be the senior synonym, the first, best-supported name.