Digging Up The Ancestors

The Naked Scientists spoke to Professor Jim Clark, George Washington University
26 February 2006

Interview with 

Professor Jim Clark, George Washington University


Chris - Now you've been out in China looking at some interesting things to do with dinosaurs. Tell us about your work.

Jim - For the last five years I've been working with Dr Xu Xing of the Institute of Vertebrate Palaeontology in Beijing, and we've been going out to Xinjiang in the Gobi Desert of far western China. Our most recent discovery is a kind of ancestor of T. rex, a thing we call Guanlong.

Chris - It's a nice name, but what does it actually mean?

Jim - It means crested dragon.

Chris - And was it a crested dragon?

Jim - Yes, well it has a big crest running down the top of its head which we were surprised to find once we'd dug the skeleton out.

Chris - Why is this so important?

Jim - For one thing, it's very very old. T. rex was about 65 million years old and we're at about 160 million years old. So we're older in the other direction from T. rex than T. rex was from us.

Chris - That's a significant difference isn't it because 60 million years ago is roughly when the dinosaurs were thinking about being hit by a meteorite and disappearing for good. 160 million years must be way back in the really early origins of T. rex.

Jim - It is. It's really when the dinosaurs first started growing, and when the first big dinosaurs appeared.

Chris - So what big unknowns does this fill in in the field?

Jim - Mainly it helps us verify that T. rex and the Tyrannosaurs were relatives of the kinds of dinosaurs that were giving rise to birds and the timing of all that is really back there at the beginning of the surge of dinosaur evolution in the Jurassic.

Chris - So given that this early dinosaur is a stepping stone from other dinosaurs into what became the T. rex lineage, can you just set the scene? What would he have looked like?

Jim - Well it would be a fairly gracile animal. Unlike T. rex it had long forelimbs, which is one of the things that's placing it with theropods which gave rise to birds. Guanlong wasn't terribly big but it wasn't terribly small, so it was about twelve feet long from the toe down to the end of its tail. And we're guessing that it's a fast agile animal but of course that's something that you don't have a good handle on with fossils.

Chris - One view is that Tyrannosaurus rex wasn't agile and quite lumbering. Is that a reasonable thing for people to assume?

Jim - There is some very good work that was done based on how big the muscles would have to be on an animal as big as T. rex to move it quickly. Basically they couldn't find any way to put enough muscles on T. rex to move it very quickly. That's not the case with our finding because it's smaller. So ours could have been faster but again, this is all fairly speculative.

Chris - It's very early and not before seen. It's come from a region of China that's not been looked at very closely for dinosaurs, hasn't it?

Jim - Well there was some really interesting earlier work done by a joint Canadian - Chinese group in the late 1980s. They found some intriguing things but that was right at the end of their expedition. Phil Curry, on eof the leaders, has told me that it's one of the places he'd really like to go back to and explore in China.

Chris - And where will you be taking this research next?

Jim - We're continuing to study the fossils we've found. There's a huge area still out there too. It's the same area in which Crouching Tiger, Hidden Dragon was filmed. The badlands go on for a hundred kilometres or more, so there's a huge area to look in.

Chris - And presumably you want to fill in the gap between 160 million years and the 60 million years to the modern Tyrannosaurs.

Jim - Well you'd like to. Of course we're committed to these beds right now at 160 million years. I've worked in some younger beds before but I really like these older beds. We're really getting down to the base of some interesting lineages.


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