Dinosaurs After ‘Jurassic Park’: Paleontologists on What’s Changed, 25 Years Later

Monday, June 18, 2018

Yutyrannus huali, a feathered tyrannosaur discovered in China, at the American Museum of Natural History in New York. EDEN, JANINE AND JEN UNDER ATTRIBUTION 2.0 GENERIC (CC BY 2.0)

25 years ago, on June 11, 1993, Jurassic Park premiered in theaters across the United States. The film was indomitable from release, its financial success and enduring place in the culture assured. Princess Diana attended the London premiere. A thousand products made by a hundred companies—video games, figures, sleeping bags, fanny packs—were timed to the release, at the time the second widest ever, with only Batman Returns shipping more prints to theaters.

Despite opening like a monster movie—an armored crate emerges from the fog, the mysterious monster inside screeching and snorting—Jurassic Park was conceived, from its origins as the latest in a long line of Michael Crichton technothrillers (“I was writing the most expensive movie ever made,” Crichton would jokingly tell people before Steven Spielberg bought the movie rights for $1.5 million), with scientific fidelity in mind. Spielberg wanted to show people real dinosaurs, as they lived in the Mesozoic Era.

“This isn’t The Beast from 20,000 Fathoms, you know?” Spielberg said from the London premiere red carpet, referencing a 1953 movie about a city-stomping lizard awoken by an atomic bomb test. “This is really a movie that I think is really happening as I’m watching it.”

He wasn’t alone. A whole generation of paleontologists can describe just where they were when they first saw Jurassic Park and just what it meant to them.

Kristi Curry Rogers Ph.D., Professor in the Biology & Geology Departments of Macalester College, was an undergraduate at Montana State University in 1993. Her advisor: Jack Horner, a paleontologist who discovered the duck-billed Maiasaura and described its nurturing nesting habits, part of a wave of revisionist research that dramatically recharacterized animals once seen as slow, dumb lizards. A technical advisor on Jurassic Park, Horner secured a Bozeman premiere for the movie. “It was some of Jack’s discoveries of dinosaur nesting sites in Montana that really prompted my first interest in paleontology as a kid,” Rogers told Newsweek.

“I was a first-year college student,” Rogers said. “I got to see the movie with Jack.” That same summer, Rogers began fieldwork at Egg Mountain, the bonebed where Horner made some of his most consequential discoveries. The dig site became the basis for Snakewater, Montana, where Jurassic Park founder John Hammond (Richard Attenborough, who Spielberg convinced to take up acting again after a 15-year hiatus) first invites Dr. Alan Grant (Sam Neill) and Dr. Ellie Sattler (Laura Dern) to inspect his “biological preserve” and “maybe even pen a wee testimony.”

“It was the first time in a long time a pop culture venue actually seemed to take the science seriously and take the animals seriously. And they accomplished that with very little embellishment,” Thomas Carr Ph.D., Associate Professor of Biology and Director of the Carthage Institute of Paleontology told Newsweek.

When Jurassic Park came out, Carr was working on a senior thesis focused on Tyrannosaurus growth, a subject that continues to animate his work. He remembered one shot in particular—the escaped T.rex stepping in front of a Jeep, its immense body visible through the windshield—as a “magical moment.”

“It carried me away,” Carr said. “It does the animals justice.”

“I think most of us felt our hearts flutter when we saw the scene with the Ornithomimus running across the field,” said Karen Chin Ph.D., Associate Professor and Curator of Paleontology at University of Colorado, Boulder. “We’ve been working on dinosaurs for so long and we’ll never see them in their natural habitat. That’s a scene you would expect to see if you were transported back in time by a time machine: a herd of dinosaurs, perhaps startled by something.”

Others were still a bit too young. “I was not liking the scary dinosaurs,” Caleb Brown Ph.D., a postdoctoral researcher at Canada’s Royal Tyrrell Museum of Paleontology in Drumheller, Alberta, recalls of his first viewing. “A lot of people in paleontology who are my age or slightly older were almost all influenced to get into the field because of Jurassic Park. I’m kind of the opposite. I liked dinosaurs before that, but it almost put me off them because it was so scary.”

And Jurassic Park didn’t get everything right. The Brachiosaurus was too big. So were the Velociraptors (that annoying kid who compares the predator to “a six-foot turkey” would be closer to the real scale, if only he dropped the “six-foot”). It’s not true that T.rex “visual acuity is based on movement,” as Grant says. (“That poor kid,” one paleontologist commented. “If that were a real T.rex that kid would have been sensed and eaten instantaneously.”)

Even that pile of poop was too big.

“When I first saw that scene I just burst out laughing, I think what they meant was they had kind of shoveled it all together?” Chin said. An expert in coprolites, or fossilized feces, the largest dung mass Chin has seen was between 7-9 liters in volume, just enough to overflow a dutch oven. “It’s quite possible the sauropods produce a larger fecal mass,” she said.

But Jurassic Park wasn’t going for perfect realism, nor would perfect realism have been possible. Technical advisers like Horner and Robert T. Bakker, an early proponent of swift, warm-blooded dinosaurs, were able to offer the most up-to-date science, but there’s a limit to our understanding. There was no way to get everything right, and in some ways it wasn’t supposed to, something Spielberg knew. “There’s a mystery about dinosaurs. I think that’s why the uncovering of bones in Montana or in Canada or wherever they find dinosaur bones today, is like a great mystery. What we did with this was, we sort of fleshed them out,” Spielberg said at the London premiere. At a certain point, choices become more about storytelling than scientific extrapolation.

“The sauropod eyes look like cow eyes and the Velociraptor eyes look like lizard eyes. And T. rex eyes kind of look like the eyes of a lion,” Rogers said. “There are all of these subtle things, if you’ve seen Jurassic Park as many times as I have, there are all these subtle hints of how we are supposed to feel.” (Rogers said she’s seen Jurassic Park 10 times, but after some reflection upgraded to “12, maybe more.”)

Where some dinosaurs were designed to remind us of more familiar animals with anthropomorphic associations, others were tweaked to feel more alien, particularly the Dilophosaurus that kills Dennis Nedry (Wayne Knight).

“A little hopping creature that spits venom and has a big neck frill: that was created for the movie,” John Scannella Ph.D., the John R. Horner Curator of Paleontology at the Museum of the Rockies in Bozeman said. “It’s so fantastical, but that helps raise questions about what possible things could these animals have going on that we wouldn’t necessarily know about? How would we find evidence of that in a fossil?”

“I love the film, I’m not going to sit and nitpick about it,” Stephen Brusatte Ph.D., an Associate Professor in the School of GeoSciences at the University of Edinburgh and author of the recently released The Rise and Fall of the Dinosaurs told Newsweek. "Jurassic Park is probably the best thing that ever happened to paleontology.”

But while Jurassic Park depicted dinosaurs as close to the true state of paleontological understanding in 1993, the field has changed a lot in the intervening 25 years. New technology, new research and new discoveries have expanded our understanding of not just individual dinosaur species, but an entire ancient ecosystem of astounding diversity and complexity.

Feathers

Though feathers have yet to infiltrate the Jurassic Park sequels, the connection between dinosaur and birds was in the series from the very beginning. When Grant speculates, “maybe dinosaurs have more in common with present-day birds than they do with reptiles,” he was voicing a growing consensus in the field, Jurassic Park once again situating itself right on the frontier of the science. And though a narrow clade of feathered species, including Archaeopteryx, pointed to the evolutionary continuity between dinosaur and birds, widespread dinosaur feathers were still just a supposition.

That changed in 1996, when Li Yumin, a farmer and amateur fossil hunter, uncovered Sinosauropteryx in China’s Liaoning Province, where volcanic ash from Mesozoic eruptions preserved spectacular fossils. Sinosauropteryx was a bipedal predator and close relative of the Compsognathus (seen in Jurassic Park sequel The Lost World killing Peter Stormare), smaller than a house cat, believed to feed on small lizards and mammals. It was also covered in short feathers, close to the thickness of fur, but likely coarser. We even have an idea what color it was: reddish-brown, its tail striped with chestnut and rust.

Sinosauropteryx was just the beginning. Further discoveries made in Liaoning’s Yixian Formation included dinosaurs with not just feathers, but wings. “They probably couldn’t fly, but instead used them for display,” Brusatte said. What had once been theoretical now has extensive fossil evidence. New research even pointed to feathered, fully-plumed Velociraptor.

“Now it’s almost a common occurence to find feathers on dinosaurs and it further strengthens the link between non-avian dinosaurs and birds,” Scannella said.

“Meateaters, by and large, had feathers, but not all of them,” Carr said. “Things like T.rex were actually scaly, not feathery. And that was normal for dinosaurs. The big theropods (bipedal predators, including the raptors), StegosaurusAnkylosaurus.” But while not all dinosaurs were feathered, Carr pointed out an essential difference in our new understanding: unfeathered dinosaurs likely represent evolutionary reversals from their feathered predecessors. Carr pointed to the discovery of a feathered tyrannosaurid, once again in Liaoning Province—not Tyrannosaurus rex, but Yutyrannus huali, which was “only” 30 feet long and 3,000 pounds—as evidence toward large, featherless predators having reversed from feathered forebears.

The conversation has essentially flipped, with dinosaurs now often discussed as presumptively feathered, with a deepening fossil record pointing to the evolution of feathers in a common ancestor to pterosaurs (winged reptiles) and dinosaurs. Which means, as much as Jurassic Park sequels may not want to embrace the feathers, the fuzzy, plumed dinosaur isn’t going away. Instead, they’ve become as central to our modern understanding of dinosaurs as was the warm-blooded, nurturing animals of Bakker, Horner and John Ostrom’s “Dinosaur Renaissance” in the decades leading up to Jurassic Park.

“Why not show accurate dinosaurs?” Carr asked. “Hell, I’d say a feathery Velociraptor that could do a short glide, that’s a scary animal. Why not?”

Dinosaurs are like Birds

Dinosaurs are like Crocodiles

Dinosaurs are like Dinosaurs

While modern-day birds are dinosaurs, there’s another category of living vertebrates that also bear comparative similarities to dinosaurs: the crocodilians. Rather than evolving from dinosaurs, like birds, the evolution of crocodilians split off early in the Triassic, to form a clade known as Pseudosuchia.

“They were doing a greater range of body sizes and behaviors. There were crocodiles the size of buses, some that ate plants, some covered in armor and spikes and some that walked on two legs,” Brusatte said. “The dinosaurs were playing second fiddle to them.”

But 200 million years ago, at the end of the Triassic, there was another mass extinction event—probably a combination of factors, including supervolcanoes, the resulting runaway global warming and the breakup of the supercontinent Pangaea—that wiped out the Psuedosuchia, all except a narrow group of crocodilians.

The close evolutionary lineage of the crocodiles makes them a useful comparison point for understanding dinosaurs. Modern techniques, like high-resolution CT-scanning, have enabled paleontologists to reach astoundingly specific behavioral conclusions.

“Tyrannosaur facial skin is highly innervated, and we know that because the entire snout is shot through with really tiny holes that allowed nerves through to skin to bring the sensation of touch back to the brain,” Carr said, comparing the complex weave of nerve canals running from its brain to facial skin to the snouts of alligators, crocodiles and caimans.

With facial skin more sensitive than human fingertips, Tyrannosaurus likely used its head for far more than scent and a powerful bite. Like crocodiles, high facial sensitivity would have made them sensual animals, prone to communicating by touch. “It’s not hard to imagine that tyrannosaurs would have used their snouts in the same way,” Carr said. “They will be rubbing snouts with each other, they will be monitoring their nest, they will be touching carcasses they’re feeding on.”

With birds in their direct lineage and crocodilians as close cousins, a diagnostic practice known as “extant phylogenetic bracketing” has deepened our understanding of dinosaurs since Jurassic Park. In extant phylogenetic bracketing, an extinct taxon is compared to, and bracketed by, its nearest living relatives. The method, introduced in 1995 by Lawrence Witmer, Professor of Paleontology at Ohio University, allows researchers to infer traits to an extinct species, by looking for traits common to the living relatives that bracket it. Extant phylogenetic bracketing provides a common framework and set of standards for paleontologists extrapolating from the present for insight into these distant past. These inferences can be scaled to various confidence-levels based on the strength of bone or soft tissue evidence available and whether a proposed trait, such as warm-bloodedness, matches with one or both bracket taxons.

“We always try and frame our arguments, especially about things that aren’t so easy to preserve in the fossil record, using this comparative model,” Rogers said. “Sometimes dinosaurs are more like crocodiles than they are like birds, and sometimes more like birds. We really need to think about dinosaurs as dinosaurs.”

Rogers offered dinosaur growth rates as an example. “All dinosaurs grow faster than living reptiles, some of them grow more than 50 times faster than living reptiles,” she said. Yet, no dinosaur growth rate has been discovered that matches the much-faster growth rate found in birds. The slower and faster growth rates on either side of a dinosaur’s phylogenetic bracketing form theoretical bounds.

“Comparative method helps us find the places where they are uniquely dinosaur,” Rogers said. “Dinosaurs are different, they’re doing their own thing.”

Which means there’s always room for the unexpected.

CAT Scans and the Rise of Molecular Paleontology

Jurassic Park had its own vision of the future of paleontological fieldwork. “A few more years development and we won’t even have to dig anymore,” a technician says in the film, excited at the prospect of sonar imaging in the field. But that never really came to pass.

“It’s still pretty basic, it’s still jackhammers, we don’t use any fancy sonar,” Rogers said. “But mapping techniques have gotten more specific. GPS is really important to people in the field.”

But if digging up dinosaur bones remains low-tech, the same can’t be said of lab analysis techniques developed since 1993. CT scans, which computer-process multiple X-ray measurements into virtual “slices” of a 3D object, like a dinosaur skull, have become a major driver of new discoveries.

"If we CAT scan the skulls of dinosaurs we can build digital models of the brain, of the ear, of the blood vessels and all the things that are hidden in the head,” explained Brusatte.

From dinosaur cochlea, paleontologists can extrapolate the sound-space in which individual dinosaur species existed. Their immense olfactory bulbs have granted researchers insight into the primacy of smell in the lives of raptors and tyrannosaurs.

In 2007, Prof. Mary Higby Schweitzer and her colleagues announced the discovery of proteins recovered from the fossilized femur of a Tyrannosaur rex. Paleontologists had previously believed fossilization didn’t preserve cellular structures. Now a variety of biochemical markers can be extracted from dinosaur fossils, including protein fragments called peptides, amino acids and nucleotides.

“We are learning things about dinosaurs we thought we would never be able to tell for certain,” Schweitzer told Newsweek. “We have learned a lot about how things preserve, what kinds of information fossils can yield at the molecular level, and new ways to analyze dinosaur tissues.”

“It’s opened up a whole new field of, basically, biochemistry for dinosaurs,” Carr said. “She just thought about fossils in a different way.”

A Quick Aside About Cloning

The Jurassic Park scenario—recovering dinosaur DNA from mosquitoes trapped in amber—no longer seems viable. The blossoming of molecular-scale paleontological research has lead to a disappointing conclusion: DNA and RNA strands simply don’t survive for millions of years.

Horner’s 2009 book How to Build a Dinosaur proposes an alternate strategy: awakening dormant genes in modern birds and reversing evolution, trait-by-trait. In 2015, scientists identified and activated a gene in chickens that matched “ ancestral fossil forms,” creating a chicken embryo with a dinosaur-like snout instead of a beak—the first step toward a “chickenosaurus.” It’s still uncertain whether enough of these atavistic genes can be found and activated within the chicken genome to fully recreate an extinct species.

Growing up Dinosaur

Studying microscopic structures in dinosaur bones, known as histology, has become a commonplace paleontological practice, a change from the more anatomical and taxonomic focus of generations preceding Jurassic Park. One particularly promising new technique is microscopic examination of what Brown described as “lines of arrested growth,” where minute variations in the cellular structure of a dinosaur bone seem to correlate to annual growth cycles, giving deeper insights into how dinosaurs grew and what they looked like at various life-stages.

“There’s been a lot more research looking inside bones to examine the microstructures and see how bones are remodeling and transforming as these animals grew,” Scannella said. “Now it’s clear dinosaurs underwent very dramatic transformations as they grew from babies to adults. A baby T.rex probably looked very different than the adult.”

Combine this refinement in research with an ever-deepening fossil record and you’ll find the basis of the several headline cases of multiple dinosaur species collapsed into a narrower grouping, most famously Triceratops and Torosaurus, now believed to be younger and older examples of the same genus.

The International Dinosaur

Headline-grabbing finds in Liaoning Province have made China the epicenter of global paleontology. “China is the place where the most and the most exciting discoveries are happening right now, probably half, if not more. But people are finding dinosaurs all over the world now,” Brusatte said. “One species a week, which is just nuts. It’s a crazy pace.”

Major finds in Mongolia, Argentina, Brazil, even north of the Arctic Circle have made paleontology more international, resulting in both a widespread collaborative network of researchers and a large enough data set to better understand the total Mesozoic ecosystem, which could provide insight into some of the biggest unanswered questions in paleontology.

For example, was the boloid that struck Mexico’s Yucatán peninsula solely responsible for the death of the dinosaurs? While an asteroid or meteor striking the Earth at the same time the dinosaurs went extinct seems like more than coincidence, there are many different possible interpretations of the catastrophic event. “Were they already on the way out? Or were they moving along just fine and then KABAM, they’re done?” Brown asked, characterizing the open questions that remain.

“There are still so many things to do and so many things to discover. The field is far from finished,” Rogers said. “I’m constantly struck by how many exciting, new things we learn every time we ask a new question or use a new tool.”

Paleontology Survived “Jurassic Park”

In a 1993 issue of The New York Review of Books, Stephen Jay Gould, the paleontologist and popular science writer, fretted over the potential downsides of over-popularizing a scientific field. He writes:

“For paleontologists, Jurassic Park is both our greatest opportunity and our most oppressive incubus—a spur for unparalleled general interest in our subject, and the source of a commercial flood that may truly extinguish dinosaurs by turning them from sources of awe into clichés and commodities. Will we have strength to stand up in this deluge?”

Gould’s concern was not entirely unfounded. There have been downsides, notably a sprawling black market for dinosaur fossils. In 1997, the largest and best preserved Tyrannosaurus rex ever discovered, nicknamed Sue, was auctioned by Sotheby’s and sold for $8.3 million to Chicago’s Field Museum of Natural History. However, many specimens wind up in private hands and inaccessible to researchers.

“Dinosaur fossils on private land in the United States do not have any legal protection,” Carr said, “oftentimes they make it to market.”

Despite dedicated efforts by countries like Mongolia to repatriate fossils smuggled out of the country and sold in black markets, there’s only so much paleontologists can accomplish against buyers who have transformed dinosaurs into luxury market items.

“Fossils are information and when they buy fossils they’re depriving humanity from learning about dinosaurs. Because we don’t know everything!” Carr added. “I can get 11,000 data points from a singleTyrannosaurus skull. So there’s a dozen privately-owned T.rex, so I lose 132,000 data points because those fossils aren’t in real museums.”

While Jurassic Park has helped transform dinosaurs into objects of private desire, Gould’s more spiritual concerns—that our awe will fade—now seem unfounded. A generation later, paleontology is more vibrant than ever, thanks in part to the influx of new scientists whose imaginations were set aflame by the movie.

“More jobs, more funding, that came from Jurassic Park,” Brusatte said. “I don’t think we can overstate how important that was to paleontology. I probably wouldn’t have my job and a lot of my colleagues wouldn’t either.”

And though they’ve been extinct for tens of millions of years, understanding dinosaurs could help us understand ourselves. “They were enormously successful. They survived periods of global warming and global cooling, changing CO2 levels, continental shifts, changing food sources and changing habitats. They adapted to a range of conditions humans have not yet seen,” Schweitzer pointed out. “It behooves us to use every method and tool and source of information at our disposal to see just exactly how they rose to these challenges."

Source: www.newsweek.com