Are you a ferocious T. rex — or just chicken?

By David Ewing Duncan

updated 12:36 p.m. ET March 20, 2008

Here is a metaphorical query for everyone — Wall Street traders, venture capitalists, writers, politicians, farmers, mechanics, and editors. Are you a T. rex or a chicken?

Turns out we may be a bit of both — as I discovered during a recent trip to Bozeman, Montana, where I had come to find out if I share a genetic sequence with a tyrannosaurus rex that died 68 million years ago in Hell Creek, an isolated spot near the Canadian border.

In the basement of Bozeman's Museum of the Rockies, I'm running my fingertips over a stump of the T. rex's cool, hard femur bone, or what's left after scientists sliced up and pulverized most of it in search of microspecks of soft tissue that should have decayed eons ago.

Instead, paleontologists discovered fragments of a protein with apparent similarity to Type I collagen, a building block of both skin and bone. In bone, it both holds the bone together and keeps it flexible. In human skin, collagen is the single largest component (after water). Collagen is found in most creatures with bones — including humans.

In a basement lab at the museum, dinosaur hunter Jack Horner is showing me the truncated femur. All around him teams of paleontologists study heaps of bones using everything from tiny brushes and magnifying glasses to C.T. scanners and an electron microscope.

Horner is the real-life scientist on which Michael Crichton based the central character in his novel Jurassic Park. Horner also advised Steven Spielberg on the Jurassic Park films.

He disagrees, however, with the central scientific conceit of both book and movie: that dinosaurs could be reborn using dinosaur DNA in the bellies of Jurassic-era mosquitoes that had bitten dinosaurs and then been trapped in amber. "It's unlikely that could happen," he says.

But Horner — a genial man whose unruly gray beard makes him more of a rustic Santa Claus than an Indiana Jones — says it could be possible to re-create dinosaurs another way. So anyone out there with an interest in starting a theme park with real dinosaurs and potentially raking in the cash, listen up!

As Horner explains, dinosaurs are still with us. They're now called  birds. As pretty much any nine-year-old fascinated with terrible lizards can also tell you, many dinosaurs shared bone structures and other features — including, on some species, feathers — with modern avians. This strongly suggests that dinosaurs, including the ferocious T. rex, evolved into birds.

The short protein fragments recovered from the T. rex bone found in Hell Creek confirms this, matching most closely to chicken collagen. (This analysis was organized by a former student of Horner's, Mary Schweitzer of North Carolina State University, and was written up in Science magazine last year.

In fact, Horner will tell you that chickens retain dormant sequences of DNA that would, if activated by bioengineering, cause a chicken to grow teeth and a dino-tail, and to grow little T. rex arms instead of wings.

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