Edmontosaurus regalis ed-MON-toh-SOR-us

"Edmonton lizard"

Edmontosaurus silhouette
You 1.8 m (5.9 ft) tall
Edmontosaurus 12 m (39 ft) long
7 people holding hands
silhouette · Ivan Iofrida (CC-BY) via PhyloPic
Length
12 m (39 ft) — About 12 m long, ~4 tonnes — one of the largest hadrosaurs.
Period
Late Cretaceous (73–66 Mya)
Place
North America · Alberta, Canada · Montana · Wyoming
Food
Herbivore — Pine needles, conifer twigs, leaves — chewed by a battery of hundreds of teeth.
Clade
Hadrosauridae Dinosauria Ornithischia Cerapoda Ornithopoda Iguanodontia

Edmontosaurus was the cow of the Cretaceous — enormously abundant, found from Alaska to Texas in vast herds. It had no crest, a broad duck-bill snout, and the dental battery typical of hadrosaurs: hundreds of teeth fused into a grinding surface. Edmontosaurus lived alongside Tyrannosaurus and made up a major part of its diet.

What we know

  • One of the last and most abundant hadrosaurs.
  • Mummified specimens preserve skin impressions — bumpy scales, no feathers.
  • Lived alongside T. rex and Triceratops in the final two million years of the Cretaceous.
  • Found in massive bonebeds with hundreds of individuals — possibly migratory herds.

What we guess

  • Whether large fleshy combs grew from the top of the head in life (one specimen suggests yes).
  • Whether herds migrated seasonally between Alaska and the U.S. interior.
  • How fast it ran — most evidence supports moderate (~25 km/h) escape speed.