Hypacrosaurus

Name:

Hypacrosaurus (Greek for "almost the highest lizard"); pronounced hi-PACK-roe-SORE-us

Habitat:

Woodlands of North America

Historical Period:

Late Cretaceous (70-65 million years ago)

Size and Weight:

About 30 feet long and 4 tons

Diet:

Plants

Distinguishing Characteristics:

Pointed crest; spines growing out from backbone

About Hypacrosaurus

Hypacrosaurus received its odd name ("almost the highest lizard") because, when it was discovered in 1910, this duck-billed dinosaur was considered second only to Tyrannosaurus Rex in size. Needless to say, it has since been outclassed by numerous other dinosaurs, both herbivorous and carnivorous, but the name has stuck.

What sets Hypacrosaurus apart from most other hadrosaurs is the discovery of a complete nesting ground, complete with fossilized eggs and hatchlings (similar evidence has been found for another North American duck-billed dinosaur, Maiasaura). This has allowed paleontologists to piece together a fair amount of information about Hypacrosaurus' growth patterns and family life: for instance, we know that Hypacrosaurus hatchlings attained adult size in 10 or 12 years, far sooner than the 20 or 30 years of the typical tyrannosaur.

Like most other hadrosaurs, Hypacrosaurus was distinguished by the prominent crest on its snout (which didn't quite attain the baroque shape and size of, say, the crest of Parasaurolophus). The current thinking is that this crest was a resonating device for funneling blasts of air, allowing males to signal females (or vice-versa) about their sexual availability, or to warn the herd about approaching predators.