Edmontosaurus

Edmontosaurus regalis was one of the largest and most successful hadrosaurid dinosaurs of the Late Cretaceous, a gentle giant that browsed the coastal plains and forests of western North America around 73 million years ago. As a member of the 'flat-headed' hadrosaurines, it lacked the elaborate hollow crests of its lambeosaurine cousins, instead relying on its massive body size and likely complex social behaviors for survival in a world dominated by tyrannosaurs.

This species was named by Lawrence Lambe in 1917 based on fossils discovered in the Horseshoe Canyon Formation near Edmonton, Alberta—hence its name, which means 'Edmonton lizard.' The species name 'regalis' means 'royal,' a fitting title for such an impressive animal. Edmontosaurus regalis represents the earlier-occurring species of the genus, predating its famous relative E. annectens by several million years.

Edmontosaurus regalis possessed a sophisticated dental battery containing hundreds of tightly packed teeth designed for grinding tough vegetation. Its broad, duck-like bill was covered in a keratinous sheath that helped it crop plants efficiently. Evidence suggests these animals lived in large herds, providing safety in numbers against predators like Gorgosaurus and Daspletosaurus that shared their ecosystem.

Remarkably, some E. regalis specimens preserve exquisite skin impressions revealing a pebbly texture of non-overlapping scales. Even more surprisingly, a 2013 study revealed that at least some individuals sported a fleshy comb or 'cock's comb' on top of their heads—a soft tissue structure that would never have been predicted from bones alone, revolutionizing our understanding of hadrosaurid appearance.