Footprint Sheds More Light On Prehistoric Alaska

Photo courtesy of Anthony Fiorillo

A recent discovery of an enormous, ancient footprint in Denali National Park is being seen as another indication of how busy the Alaskan landscape was with prehistoric animals coming and going for seasonal food hunting. Anthony Fiorillo is the curator of earth sciences at the Perot Museum of Nature and Science in Dallas. He says the first dinosaur print in Denali was found in 2005. He says that discovery, now on display at the Murie Science & Learning Center was the tip of the iceberg in terms of realizing how much dinosaur activity Denali once contained.

“Every year we’ve been going up there and every year we’ve been documenting dozens or hundreds of new localities. So at this point it’s safe to say that Denali national park actually has thousands of dinosaur foot prints throughout part of the park,” Fiorillo said.

Fiorillo says the new find, a Therizinosaur track was beyond Fang Mountain.

“Once you cross the sanctuary river and looked to the south side of the road, you would be looking all the way out to Toklat camp and even a little bit beyond that, you would be driving through some of the best dinosaur country, anywhere,” Fiorillo said.

Fiorillo says the feathered Therizinosaur was related to both Tyranasaurus rex and the chickadee, with four forward facing toes and peg like teeth suited for chomping vegetation.

FIORILLO- Another feature of the Therizinosaurs is that they had off their hands these very long claws. So if you put all that together, you have four forward facing toes, these almost knuckle dragging long claws on the hands and a mouth that seems to be adapted to eating vegetation. Also a very wide body, almost cow like if you will. And so you think of a pot bellied, bipedal knuckle dragging plant eating dinosaur and you’ve got it. Not exactly a flattering image but that’s what we think we’re talking about. TOWNSEND- How much would a Therizinosaur have weighed? FIORILLO- Certainly the big ones would have weighed what a Tyrannosaur would weigh which is on the order of a few tons. TOWNSEND- T-Rex had little tiny arms, but these guys had tiny arms? FIORILLO- With big long claws..right. TOWNSEND- How long ago where they in Alaska? FIORILLO- Well the track that we described in our paper is now even better supported because the discovery this summer was that we found several more tracks that we can attribute to this animal. So it’s not just one Therizinosaur being a pogo stick landing once and we never see it again, we in fact actually have several of these tracks now. In Alaska, we have, our best evidence suggest that these dinosaurs lived between 69 and 70 million years ago.”

Fiorillo says the Therizinosaur track will be on display with other Alaska dinosaur finds in the fossil hall at the new Perot Museum of Nature and Science in Dallas. The opening is slated for January 2013.

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Lori Townsend is the news director and senior host for Alaska Public Media. You can send her news tips and program ideas for Talk of Alaska and Alaska Insight at or call 907-550-8452.

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