Edmontosaurus Chicks & Juveniles

Sort of like a penguin chick, after hatching edmontosaur chicks stayed in the nest with their dozen or so siblings while their parents brought them food and protected them from being eaten by predators or trampled by adults. They had lots of company because they were born in a colony with other nests.

Photo by Christopher Michel

 

Edmontosaurus is one of the largest members of the herbivorous hadrosaur (“thick or stout lizard”) family. However, hadrosaur babies were tiny in comparison to their parents. Evidence suggests hadrosaurs nested in colonies, most likely to protect themselves from predators. Edmontosaurus is named for the rock formation near Edmonton in Alberta, Canada where the genus was first discovered.

Identification level: Genus
Since adult Edmontosaurus body fossils have been found on Alaska’s North Slope and the foot characteristics and rock ages are very similar, both the adult and juvenile hadrosaur prints in Denali are attributed to the same genus.

 

Photo by Tony Fiorillo

What is for dinner?
Edmontosaur chicks were probably fed by their parents until they could safely leave the nest. It is difficult to know what the chicks ate, but it may have been plants, regurgitated plants, a milk-like substance similar to what pigeons produce in their throats, or a combination of these.

How do we know I lived in Denali?
Numerous footprints of juvenile Edmontosaurus have been found in Denali in close proximity to adults walking in the same direction at the same time. This is excellent evidence that Edmontosaurus bred and raised young in Denali.

 

Edmontosaurus chicks started their lives relatively small at only 20 inches long and 8–10 inches tall at birth, smaller in size than a modern caribou calf. It seems likely that trampling would be a concern for the protective parents. 

Fun Fact
Fossils trackways featuring adult and juvenile Edmontosaurus walking side-by-side have been found in Denali, reinforcing the well-established idea that hadrosaurs actively cared for their young.