News:2009 dinosaur burrows discovery



In 2009, a journal article in Cretaceous Research highlighted the recent find of dinosaur burrows in Victoria, Australia. The research paper indicates that various dinosaur species exhibited digging and burrowing behavior.

In 2006, Anthony Martin, along with colleagues from Montana State University and Japan, described the 95-million-year-old dinosaur species Oryctodromeus cubicularis (meaning "digging runner of the lair"). The genus is based on a small adult dinosaur and two juveniles in a fossilized burrow in southwestern Montana.

The researchers hypothesized that dinosaurs may have utilized burrows for caring for their young, as well as allowing them to survive extreme temperatures and harsh environments. During a hike to a remote site known as Knowledge Creek, west of Melbourne, Anthony Martin uncovered the trace fossil of what appeared to be a burrow almost identical to the one he had identified in Montana. The burrow was from an Early Cretaceous (Albian) outcrop, and is about six-feet long and one-foot in diameter, and is in the shape of a semi-spiral, ending in an enlarged chamber. Martin later found two similar trace fossils in the same area. Martin described the trace fossil as being made by small ornithopod dinosaurs.

The trace fossils dare to around 100 million years ago, roughly the same time that the Australia continent split withh Antarctica. During the polar winters at that time, temperatures would easily have been near or below freezing. Previously, researchers had theorized that the small dinosaurs in this region had survived the harsh weather by sheltering beneath vegetation. This recent find, however, indicates that small dinosaurs may have burrowed into the soft mud banks near rivers.

The age, size and shape of the likely burrows led Martin to hypothesize that they – herbivores that were prevalent in the region. These ornithopods stood upright on their hind legs and were about the size of a large, modern-day iguana.

"It's fascinating to find evidence connecting a type of behavior between dinosaurs that are probably unrelated, and lived in different hemispheres during different times," Martin says. "It fills in another gap in our understanding of the evolution of dinosaurs, and ways they may have survived extreme environments."