Edmontosaurus regalis
Large, flat-skulled saurolophine hadrosaurid from late Cretaceous North America.
Edmontosaurus regalis is a species of saurolophine hadrosaurid dinosaur from the late Campanian age of the Cretaceous Period, approximately 73 million years ago, with possible survival into the early Maastrichtian. It was one of the largest hadrosaurids, reaching up to 12 meters in length and weighing around 4.0 metric tons. Known from numerous fossils in western North America, it is a key species for understanding hadrosaurid paleobiology.
Quick Facts
- Genus
- Edmontosaurus
- Species
- regalis
Facts from the source article.
Lore & Background
The species is known from several bone beds, suggesting it lived in large groups. Its skull was triangular and flat, lacking a crest. The beak was toothless and covered in keratin, while teeth were present in the upper and lower jaws in columns. The front legs were shorter than the hind legs, and the hands had four fingers, with the second and third bearing hoof-like claws hidden within skin. The feet had three toes with keratinous hoof tips. A 2011 study showed that skull shape changed dramatically with growth, leading to past classification errors; for example, Thespesius edmontoni is now considered a junior synonym of E. regalis, based on adult material.
Reader's Guide
Edmontosaurus regalis holds significance as one of the largest and most completely known hadrosaurids, providing insight into the biology and behavior of duck-billed dinosaurs. Its fossils, including multiple bone beds, indicate gregarious, herd-living behavior. The wealth of specimens has allowed detailed study of its brain, feeding mechanics, and pathologies. The species also illustrates the challenges of dinosaur taxonomy, as several earlier names (Trachodon cavatus, Agathaumas milo) have been synonymized with it, and growth-related changes in skull shape have led to misclassification of smaller specimens as separate species. Its remains are primarily from the Horseshoe Canyon Formation of Alberta, Canada, and the species lends its name to the genus Edmontosaurus, derived from the Edmonton Formation.
Did You Know?
- Edmontosaurus regalis was one of the largest hadrosaurids, measuring up to 12–13 meters (39–43 ft) long and weighing about 4.0 metric tons.
- The type specimen, NMC 2288, was discovered in 1912 by Levi Sternberg in the Horseshoe Canyon Formation of Alberta.
- A 2011 study found that skull shape in E. regalis changed dramatically with growth, leading to past misclassification of adult specimens as separate species, such as Thespesius edmontoni.
Frequently Asked Questions
What is Edmontosaurus regalis?
Edmontosaurus regalis is a large duck-billed dinosaur from the saurolophine hadrosaurid group that lived in western North America. It is one of the most well-documented hadrosaurids and a cornerstone species for studying how these dinosaurs grew, fed, and moved.
How big was Edmontosaurus regalis?
It could reach roughly 12 to 13 meters (about 39–43 feet) from snout to tail and weighed around 4 metric tons. That placed it among the heaviest members of the hadrosaurid family.
What did Edmontosaurus regalis eat?
It was a strict herbivore that used its broad, flat skull and rows of tightly packed teeth to grind down tough vegetation. Its wide, duck-bill-like beak would have let it crop plants efficiently near the ground.
When did Edmontosaurus regalis live?
It is primarily known from late Campanian-age deposits, putting it at roughly 73 million years ago. Some evidence hints it may have lingered briefly into the early Maastrichtian, making it one of the last non-avian dinosaurs before the end-Cretaceous mass extinction.
Could Edmontosaurus regalis walk on two legs?
Yes; like other hadrosaurids it was facultatively bipedal, meaning it could shift between walking on all fours and rearing up on its hind legs. It probably switched gaits depending on how fast it needed to move or what terrain it was crossing.
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