Monday, July 13, 2009

Burrowing Dinosaurs?- Fossil Evidence Shows that some small Ornithischians Burrowed to Escape Polar Winters

Interestingly enough, Naveed of Naveed's Realm, sent me an article from News Scientist, an on-line science magazine (Well, that was obvious! Now forgive me for wasting your time with this obvious information.) about findings of small Hypsilophodontids in burrows in Australia (And even in Canada, mainly Alberta.)...sound familiar? It should because this was covered in my First Fossil Fact and even a Paleo Fact by Traumador the Tyrannosaur over at the Tyrannosaur Chronicles. Well, despite the fact that I was only correct in describing the Cretaceous world and, basically regurgitating what I'd heard in a Walking with Dinosaurs episode (which is exactly what I did! Thankfully, Traum was kind of enough to give me some help and kindly correct me about this information. Hopefully he'll read this post, because I, personally, think he would be interested to see this new research and see that BBC and I may have been correct after all. Huh....Who knew?). Orginally, my first Fossil Fact was basically to supplement Traumador's well-researched, knowledgeable and well-written Paleo Fact. Now, there is actually fossil evidence to suggest such a thing, though the behavior of the Leaellynasaura as organized as they were is still speculation. Anywho, it's about time I stop here with this Introduction and begin with the details of the finds.

Did they actually Burrow?

Well....that's what the fossil record seems to tell us. In the Polar regions of the Earth (In Alberta, Canada, and as far south as Australia), several remains of small Ornithischian Dinosaurs ("Bird-hipped," mainly referring to the majority of herbiverous dinosaurs) have been found in what looked to be burrows. The scientists who played a prominent role in the research of Dinosaur migratory patterns of the Polar regions, Eric Snively and Now, the Hypsilophodont, Leaellynasaura was only known from fragmentary bones from that region, but, now, we seem to have a more complete picture of life at the Polar regions during the Cretaceous.

Measurements of burrows from Alberta, Montana, USA, and Australia suggest their occupants, though possibly temporary, were small Hypsilophodontids roughly around the same size as Leaellynasaura (and the same size as their contemporaries.) Of course, what does this mean?

Eric Snively, of the University of Alberta in Edmonton, with David Varrichio of Montana State University in Bozeman, theorize that, though they were selectively adapted to wait out the chilling Polar, Cretaceous winters, they couldn't stay their year round because, as evidence also suggests, the burrows were made in soil that was deposited by flood waters, indicating the risk of flood.

As new evidence comes to light, more insight into the life and behavior of the Dinosaurs becomes available. That's the beauty of Paleontology. One day, perhaps, we'll find complete vertebrate fossils in Oceania and Antarctica and gain MORE insights into their behavior.

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