Hypacrosaurus Characteristics

Hypacrosaurus measured around 30 feet (9 metres) in length and would have weighed more than 4 - 5 tons. Like other duck-billed dinosaurs, Hypacrosaurus was bipedal who moved around on its hind legs and probably only went on all 4 legs to forage low-lying vegetation. Its forelimbs were shorter than the hind limbs and it had a heavy, long, stiff tail which was used to counter-balance was the dinosaur darted from side to side evading an attack from predators. Hypacrosaurus was a relatively fast runner. Hypacrosaurus had quite large eyes for a dinosaur which were probably used to detect predators.

Hypacrosaurus had a hollow crest that resembled a helmet located on top of its head that most likely had a social function such as a visual signal to indicate gender or species or used as a cooling device. This dinosaurs nostrils went up through the crest so it could also have been used as a smell enhancer. The crests also made loud horn sounds that could be heard from a reasonable distance.

Hypacrosaurus had a short toothless beak and almost 40 rows of self-sharpening cheek teeth. The teeth were able to self-sharpen as the dinosaurs top teeth were set at an angle to the bottom teeth which caused them to grind against each other. Hypacrosaurus had a row of short spines that extended its vertebrae forming a ridge along its back.

Hypacrosaurus was a herbivore and would have eaten a variety of plant material that it found in the humid forests where it lived including pine needles, seeds, fruit, twigs and magnolia leaves. Plants would have been cropped by its broad beak and held in the jaws by a cheek-like organ. Hypacrosaurus may have lived in herds who would migrate to higher ground from shorelines to reproduce.

A nest that may have belonged to Hypacrosaurus was found in Devil's Coulee, near Alberta, Canada. Eight large eggs were present in the nest along with duck-bill embryos. Hypacrosaurus was an ornithopod, whose intelligence (as measured by its relative brain to body weight, or EQ) was midway among the dinosaurs.

The type remains of Hypacrosaurus remains were collected in 1910 by Barnum Brown for the American Museum of Natural History. The remains, a partial postcranial skeleton consisting of several vertebrae and a partial pelvis, came from along the Red Deer River near Tolman Ferry, Alberta, Canada, from rocks of what is now known as the Horseshoe Canyon Formation (early Maastrichtian, Upper Cretaceous). Hypacrosaurus was named by Brown in 1913.