Oryctodromeus

Phylogeny: Dinosauria > Ornithischia > Genasauria > Neornithischia > Thescelosauridae > Orodrominae

Overview: Growing to be about two meters long, Oryctodromeus wasn’t a large dinosaur by any means, or exciting from a first glance. It was a bipedal herbivore that probably subsisted mainly on low-level shrubbery and ferns. What is unique about it was its potential lifestyle. The holotype of Oryctodromeus is one of the first known examples of evidence for burrowing behavior among the Dinosauria. Skeletal remains of the animal were actually found within their burrows, closely packed together and smothered with infilled sediments. The anatomy of the bones themselves also supports such a lifestyle. Its forelimbs and shoulders were modified to allow for prolonged digging, in a somewhat similar fashion to that of some modern burrowing animals.

Living in burrows would’ve granted a few key advantages to Oryctodromeus. It gave it a place to flee from larger predators and a place to more safely raise its young. As with other dinosaurs, it would’ve laid clutches of eggs, so multiple hatchlings probably lived together with their parents inside these burrows. We can assume, however, that some predators may’ve adapted in turn to this behavior, as there are some predators in our own time that specialize in pursuing burrowers. Described in 2007, the generic name of Oryctodromeus means “digging runner”, which refers to both its lifestyle and to its smaller, more agile form. The genus belonged to a family of mainly small-bodied ornithischians called the Thescelosauridae, Orodromeus being a close relative.