Wikipedia:Today's featured article/June 28, 2015

Edmontosaurus, a genus with the species E. regalis and E. annectens, was one of the largest duck-billed dinosaurs, up to 12 m long and weighing around 4.0 MT. Widely distributed across western North America, especially in the coasts and coastal plains, it was a herbivore with small crests that walked on two legs or four, and probably lived in groups. It was named after Edmonton, Alberta; the first fossils were discovered in Alberta's Horseshoe Canyon Formation. Abundant fossils have allowed researchers to study its brain, feeding habits, pathologies, and even injuries, including in one case from a tyrannosaur attack. Fossils of E. regalis have been found in rocks that date from 73 million years ago, while those of E. annectens (reconstruction pictured) are around 66 million years old, both in the Cretaceous Period. Edmontosaurus was one of the last non-avian dinosaurs, living alongside Triceratops and Tyrannosaurus shortly before the Cretaceous–Paleogene extinction.