Description and Classification

Corythosaurus was a large plant-eating dinosaur, typically reaching lengths of about 9 meters (30 feet) and weighing around 3 to 4 metric tons. It could walk on its strong hind legs but likely also moved on all fours to graze on low-lying plants. The most striking feature of Corythosaurus was its tall, hollow crest, which was shaped somewhat like a dinner plate standing on edge, or an ancient Greek Corinthian helmet. This crest was a hollow structure formed by bones from its snout growing upwards and backwards, and it connected to its nasal passages. Scientists believe the crest may have been larger or shaped differently in males compared to females, and also changed as the dinosaur grew older.

Impressions of its skin found with some fossils show it was covered in small, bumpy scales called tubercles, but without any large armor plates. Corythosaurus belongs to the family Hadrosauridae, commonly known as duck-billed dinosaurs because of their broad, flat snouts. Within this family, it is part of the Lambeosaurinae subfamily. These dinosaurs are known for their elaborate, hollow head crests. Other members of this group include dinosaurs like Parasaurolophus and Lambeosaurus, which also had unique crests and lived around the same time and place as Corythosaurus.

Distinguishing Features

Corythosaurus had several features that helped identify it:

• A large, hollow, plate-like crest on its head, which was unique in its specific rounded shape compared to other crested hadrosaurs like Parasaurolophus.
• A “duck-bill” snout, common to hadrosaurs, which was toothless at the very front but had hundreds of tightly packed cheek teeth in the back of its jaws for grinding tough plants.
• Relatively long and slender forelimbs for a bipedal dinosaur, suggesting it frequently used them for support while feeding or moving quadrupedally.
• A long, stiff tail that helped it to balance when walking or running on its two hind legs.

The hollow passages inside the crest connected to its nasal cavity. This suggests the crest could have been used to make loud, distinctive sounds, perhaps for communicating with other Corythosaurus over distances or warning them of danger. The crest’s size and shape might also have been important for visual display, helping these dinosaurs recognize members of their own species, attract mates, or establish social ranking.

Paleoenvironment and Diet

Corythosaurus lived during the Campanian stage of the Late Cretaceous period. Its fossils are primarily found in the Dinosaur Park Formation of Alberta, Canada. During this time, the area was a warm, wet coastal plain with many rivers, swamps, and forests. This lush environment supported a rich variety of plant life and many different kinds of dinosaurs.

As a hadrosaur, Corythosaurus was a herbivore. Its complex dental batteries, consisting of many small, interlocking teeth that were constantly replaced, were perfectly suited for chewing and grinding tough plant material. It likely ate a variety of plants, including conifers (like pine needles and cones), flowering plants, seeds, twigs, and fruits. Corythosaurus shared its environment with other herbivorous dinosaurs such as the horned Centrosaurus and Styracosaurus, the armored Euoplocephalus, and other hadrosaurs. Predatory theropods like Gorgosaurus and Daspletosaurus also lived in this ecosystem and may have hunted Corythosaurus.

Significance and Ongoing Research

Corythosaurus is a very important dinosaur for scientists because so many well-preserved fossils have been found. These include nearly complete skeletons and even rare impressions of its skin. These discoveries have provided significant insights into the anatomy, growth, and possible behaviors of lambeosaurine hadrosaurs. The wonderfully preserved crests allow paleontologists to study how these unusual structures might have been used for sound production, display, and species recognition.

Ongoing research on Corythosaurus continues to explore the exact functions of its crest. Scientists use modern techniques like CT (computed tomography) scans to examine the internal structure of the fossilized crests without damaging them. Researchers also study variations in crest shape and size among different individuals to better understand differences between males and females (sexual dimorphism) and how the crest changed as a Corythosaurus grew from a juvenile to an adult. By comparing Corythosaurus with related hadrosaurs, scientists aim to learn more about the evolution of these fascinating crested dinosaurs and the complex ancient ecosystems they were part of during the Late Cretaceous period.