Scientist's Dino Findings Making Waves

There is something about dinosaurs that captures the imagination - giant, mysterious animals that roamed the Earth for millions of years, now gone forever.

All they've left us are their fossils, the dried-out mineral remnants of the creatures they once were, with the organic material that gave them life long gone. Or so everyone always thought.

Until B. "Rex," a 68 million year old Tyrannosaurus Rex, who was dug up and named by a paleontologist from Montana State University whose unorthodox approach to dinosaurs may be changing the whole dino ballgame.

When thinking of dinosaurs, most of us think "Jurassic Park," the 1993 classic film about a dinosaur resurrection experiment gone wrong, and its embattled hero, famed paleontologist Alan Grant.

Web Extra: Dino Chicken
Web Extra: Evo Devo
Book: How to Build a Dinosaur
Montana State University: Museum of the Rockies
North Carolina State University: Dr. Mary Schweitzer
Sean Carroll

60 Minutes correspondent Lesley Stahl met Jack Horner, the real-life Alan Grant who consulted on all of the "Jurassic Park" movies.

Fortunately for him, Horner joked, Grant didn't get eaten.

Jack Horner is one of the most prominent and controversial paleontologists in the country - a dyslexic MacArthur Foundation genius who never finished college, and who says he doesn't care why dinosaurs went extinct.

To him, the important part is how they lived. "I'm trying to figure out the biology of dinosaurs and what they were like as living creatures," he told Stahl.

"You wanna know what their behavior was, how they treated their young," Stahl asked.

"I wanna know everything we can know about them and make one if we can," he replied with a smile.

Make a dinosaur? The things Horner says make him a maverick, but the finds he has made, including more T. Rexes than anyone else in the world, make him a legend.

One of his finds include the teeth of the oldest T. Rex ever found, which Horner pulled out of a drawer in the Collections area of his Museum of the Rockies in Bozeman, Mont., and showed Stahl.

"This little pocket right here in the teeth is where the next tooth sits. Dinosaurs replace their teeth throughout their life. And T. Rex replaced all of their teeth every year," Horner explained.

But Horner is most famous for discovering a kinder, gentler side of dinosaurs.

In the badlands of Montana, he and his team uncovered the first dinosaur nesting ground in the world - a vast landscape full of eggs, nests, and babies that helped change our image of dinosaurs.

Thanks to Horner's influence, "Jurassic Park" showed that most dinosaurs were social animals who lived in colonies, and he has found evidence they actually cared for their young.

"So, this is the tibia, the shin bone. And this is a little less than a month old. And here, here is the same bone," he told Stahl, showing her a much bigger bone.

Stahl assumed the larger bone belonged to an adult, but Horner corrected her: though much larger, this specimen belonged to a one-year-old.

Horner figured out that such rapidly growing baby dinosaurs couldn't walk at first, meaning their parents were bringing food back to them in the nest, like birds. His discoveries lent support to a then-controversial but now widely accepted theory that dinosaurs actually gave rise to modern birds.

"If a little kid today who studies all this in school and they look up in the sky and see a bird and turn to mom and say, 'You know, that's a dinosaur'…," Stahl remarked.

"They're right," Horner replied.

"Horner told us that birds are dinosaurs. Do you agree with that?" Stahl asked Sean Carroll, a professor of molecular biology and genetics at the University of Wisconsin.

"Absolutely," he replied. "So, really, dinosaurs never went extinct."

"Dinosaurs never went extinct. But we all think they did," Stahl said.

"There was an asteroid event that took out a lot of life on Earth, including T. Rex and all the most famous dinosaurs. But this other group, what we call birds, made it through and of course, there's thousands of species of birds still around today," Carroll explained.

The dinosaur-bird connection is largely settled now, but that hasn't stopped Horner from using unusual means to make unusual discoveries, and he has found the perfect partner in his protégé Mary Schweitzer. She's a professor at North Carolina State who studies the internal makeup of ancient bone.

She let us in on the paleontologists' trick for telling dinosaur bone from rock.

Instead of looking at it, you're supposed to lick it, and she encouraged Stahl to participate in the experiment.

"It's supposed to stick like Velcro. Does it stick?" Schweitzer asked, as Stahl put the dinosaur bone to her tongue.

"Ah, ew. It did," Stahl replied.

Asked how this works, Schweitzer said, "Because the bone's filled with little capillaries. And when you put your tongue on it, the moisture from your tongue sucks out the capillaries. … Rocks don't do that."

The tricky thing about Schweitzer's work is that she needs to get her hands on the insides of dinosaur bones, which means literally breaking the bones apart and sometimes dissolving pieces of them in acid. Most paleontologists won't let her near their precious finds.

"Jack [Horner] is the only paleontologist out there who lets me dissolve his dinosaurs," she told Stahl.

It means ruining the bones.

"Isn't that considered a little sacrilegious to…take one of these precious artifacts, fossils that have been in the ground for 68 million years and crack it in half?" Stahl asked Horner.

"We found the first dinosaur embryos, the first babies inside of eggs. And it was just from breaking eggs open and looking inside. I mean, people had always thought that eggs were so precious, they didn't wanna break them and look inside. And yet, they're like presents. You know, I mean, it's like having a Christmas present and never unwrapping it," he replied.

"Did you ever, though, have a moment where it was kinda heartbreaking? You know…'I'm destroying.' Never?" Stahl asked.

"No," Horner said. "Glue is cheap."

Horner's practice of breaking dinosaur bones apart and sending the insides to Schweitzer has landed the two of them at the center of one of the biggest controversies paleontology has seen in years.

It started back in 2000, with a series of coincidences. A member of Horner's team, Bob Harmon, wandered away from a dig site one day to eat lunch, and noticed a small piece of bone sticking out of the side of a 50-foot cliff.

"I could tell pretty much what it was from where I was sitting. It was a T. Rex metatarsal," Harmon recalled.

Horner named the T. Rex "B. Rex" in Bob's honor, and made the decision to dig it out.

"This was under 50 feet of rock. I mean, this was in a terrible place. There was no road to it. There was no access to it. And so for the next three summers, we sent out climbing crews, people that could repel down cliffs with jackhammers. I mean, it was a horrendous undertaking," Horner remembered.

The site was so remote, the bones had to be lifted out by helicopter. But the giant cast containing B. Rex's thigh bones was too heavy; the chopper couldn't get it off the ground.

So after all that excavating, Horner gave the order to cut one of B. Rex's femurs in two pieces.

"Now, that was heartbreaking!" Stahl remarked.

"Well... not really. I mean, you get a chance to see inside," he said with a smile.

Horner shipped the bone fragments that fell out to Mary Schweitzer.

"So the first piece I pulled out, I picked it up and I looked at it. And I said, 'It's a girl and it's pregnant,'" Schweitzer remembered.

It was the first time anybody had ever been able to identify gender in any dinosaur.

Schweitzer recognized a specific type of bone called medullary bone, which female birds produce when they're about to lay eggs. No one had ever found it before in a dinosaur.

It was yet another link to birds, and it meant that B. Rex was definitely no Bob.

"She calls up and says, 'We have medullary bone,'" Horner remembered.

And that wasn't all.

What happened next happened by mistake. Schweitzer put some fragments of the bone in acid to dissolve away the outermost layer of mineral. But the acid worked too fast, and all the mineral dissolved away.

Being a fossil, there should have been nothing left. But there was. It was elastic, like living tissue.

She showed us video she took under the microscope. It looked like the soft tissue she would have expected to find if it had been modern bone.

This was impossible. This bone was 68 million years old.

Asked what she thought at the time, Schweitzer said she didn't want to tell anyone for fear of being ridiculed.

"And so I said to my technician, 'Okay, do it again. I don't believe it,'" she recalled.

And yet in sample after sample, they were there - things that looked suspiciously like flexible, transparent blood vessels. She finally mustered the courage to tell Horner.

"She said she dissolved the bone away and there were blood vessels. And, you know, I was like shocked," Horner remembered. "How could that be?"

The things Schweitzer was finding inside dinosaur bones - blood vessels, and even what seemed to be intact cells - pose a radical challenge to the existing rules of science: that organic material can't possibly survive even one million years, let alone 68 million.

Schweitzer, Horner and their team published their B. Rex findings in a series of papers in the journal "Science" and were promptly attacked.

Critics said their samples might have been contaminated, or that the supposed blood vessels were actually something called "biofilm," a type of slime.

But as Schweitzer showed Stahl, she has been able to replicate her findings.

She dissolved away pieces of an even older dinosaur - a well-preserved 80-million-year-old duckbill - in acid, and again, as she showed Stahl, found what appear to be blood vessels.

"It's so consistent, over and over and over again. We do this bone and it comes out and I get excited every time. I can't help it. I mean, 80 million years old," Schweitzer told Stahl.

She published her new results last spring. And while some of her critics have been swayed, the controversy still rages.

And the stakes are high: if blood vessels can survive 80 million years, what about DNA? Jack Horner is looking. His crews are now wearing surgical gloves - unheard of in the world of paleontology where no one used to worry about getting skin cells, sweat, or even an occasional spilled beer on fossils.

Horner is skeptical that the full dinosaur DNA sequence will ever be found, but that hasn't stopped him. He has come up with a whole new idea for his dream of making a dinosaur.

"The best way is just to use a modern dinosaur. The chicken," he told Stahl. "Because evolution works, birds are actually carrying ancestral DNA."

Horner has written a new book proposing a plan to mine that ancestral DNA as a way to reverse-engineer a chicken into what he calls a "dino-chicken."

It may seem improbable that a common chicken is carrying dino DNA, but when you think about it, birds, like the dinosaurs they evolved from, still walk on hind legs, most have three toes pointing forward with one in the back, and they even all have wish bones.

As for dinosaur features you don't see in modern chickens, like long tails, Horner's contention is they can be brought back, since you can still see them in embryos as little chicks grow.

"As the chicken embryo develops, it does develop a fairly long tail before a gene kicks on and destroys it. So if we can stop that gene, we theoretically can get a chicken to hatch out with a relatively long tail," he explained.

"So you're not saying actually change the gene?" Stahl asked.

"Just switching a gene on or switching a gene off," Horner said.

He says picture a chicken with a long tail, teeth, and little claw-like hands instead of wings.

"It's reversing evolution?" Stahl asked Sean Carroll.

"That's right," he said. "Going backwards. It's changing the chicken back to something like the way that its ancestor looked."

Asked if there may be a dino chicken one day, Horner said, "I am sure there will be a dino chicken. …I think we'll be able to make a dino chicken within the next five years."

"Boy, I see a new movie coming out of this," Stahl remarked.

"This time I could get eaten," Horner joked.

Produced by Shari Finkelstein and Meghan Frank