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

Fine 0.45 inch baby Hadrosaur tooth! Unusual!

Edmontosaurus was one of the largest of the “duckbilled” dinosaurs.  It lived during the last few million years of the Cretaceous.  When I was a kid, scientists called it “Trachodon” and then they thought the genus was “Anatosaurus.”  A few other names have been given to this dinosaur but Edmontosaurus was the one deemed to be the senior synonym, the first proposed and best-supported name.