The original mount had three claws on each of those curiously short front arms; when paleontologists concluded that the T. rex had only two claws, one was plucked off each arm. In the early nineteen-nineties, more changes were made. The pose was altered. Its head and neck were lowered, so that it now looks more like a magnificent, giant, running chicken. Today, the T. rex stands only twelve feet above the ground at its highest point.
By one estimate, a new extinct species is discovered nearly every week. In part out of nostalgia for elementary-school trips to what was nicknamed the “dinosaur museum”—now the Sam Noble Museum of Natural History, in Norman, Oklahoma—I called up a curator, Jacqueline Lungmus. She thought that she would become a veterinarian until, she said, “I realized I didn’t like soft-tissue anatomy.” She is part of the new generation of paleontologists; she received her Ph.D. from the University of Chicago in 2020. She said that, in her eyes, a superbloom in paleontological knowledge occurred “in the nineties, with histology, the study of microscopic tissue.” By cutting open bones and looking at them through a microscope, scientists “could figure out how fast-growing a creature was, how long-living it was,” she said. “This revolutionized how we thought about their life histories.” The rapid growth of dinosaurs suggested that they were warm-blooded, because cold-blooded reptiles necessarily grow more slowly. Though there is a long history of connecting birds to dinosaurs, the link only recently began to be seen as scientific fact (by most experts), and to make its way into the popular imagination.
The paleontologist Gregory Erickson, a professor at Florida State University, tells the thousands of students in his course Living with Dinosaurs: The Rise, Reign, and “Demise” of the Fearfully Great Reptiles to recognize that they live in Jurassic Park, with eleven thousand species of dinosaurs—birds—around them. “I think we looked at them as dead animals for a long time, but now see them as formerly living animals,” Erickson said, of dinosaurs. With that shift in perspective comes more interest in behavior. As an example, he spoke about how some dinosaurs are now understood to most likely have been “gregarious”—a term that refers to living in social groups. “We’ll find cases where we have trackways of sometimes hundreds of skeletons that died at the same time,” Erickson said. Reptiles are rarely gregarious; birds almost always are. “You don’t see, like, two hundred lizards crossing the street.”
Most of us have few ideas about what a Dunkleosteus or a gorgonopsid or a terror bird might have looked like, or of how they might have behaved—but paleontologists now have plenty. Early in the making of “Life on Our Planet,” while thinking about how to depict animals whose appearances and behaviors would have to be deduced from an increasing but still mysterious set of fossil clues, the creators invited scientific consultants from Yale, Bristol University, and the University of London to the London office of I.L.M. “We started with ‘King Kong,’ ”—in which the protagonist fights a T. rex—“and went on forward, through to ‘Jurassic Park,’ to ‘Walking with Dinosaurs,’ ” Tapster said. The experts were asked to share what they thought about the different depictions of dinosaurs. I asked if the scientists liked any of them. Tapster laughed: “Mostly it was no, no, no.”
Even within the scientific community, there are often profound disagreements about how to interpret the fossil record. T. rex, one of the dinosaurs about which the most is known, is a great example of this. Some scientists say that it moved like a roadrunner from Hell (a moniker first used by Robert Bakker), but others argue that T. rex’s legs would not have been able to bear the body’s enormous weight while running. Some say T. rex was mostly a hunter, and others assure you that it was really a scavenger. Some say that the king of the dinosaurs was covered with feathers, and others that only the young had feathers, or that, among adults, probably only the males had a few decorative feathers. My generation, for the most part, can’t picture T. rex with any feathers at all. “One thing I learned at that conference was the damned-if-you-do, damned-if-you-don’t concept,” Tapster said. Among the few details that the scientists agreed on was that dinosaurs shouldn’t look “shrink-wrapped.” Tapster explained, “Dinosaurs in films are often very muscly, as if they’ve just come from the gym. Except for human bodybuilders, animals don’t look like that.” Fletcher, the scientific consultant, said, “We decided the T. rexes needed to be . . . hefty. To have those chunky legs.”
How do you tell a story that spans four billion years? Estimating that there are eight million or so species alive today, and nearly a hundred times more across time, and also the companion stories of the evolution of plants, and eight episodes, each of them less than an hour—the math just gets silly. “We had two geologists in the basement—they really were in the basement—giving us information about the planet’s history,” Tapster said. Then the writers had to solve the challenge of making unfathomable scales of time and change feel intelligible, at least a bit. “We used Post-it notes in five different colors,” Tapster said. “I know . . . Post-it notes.” One color for prehistoric creatures with an important story to tell—learning to swim, or eggs that can survive out of water. Another color for prehistoric creatures that are iconic—viewers need their dinosaurs. A third for modern-day animals in which exceptional evolutionary traits are apparent. A fourth for key events on Earth. And a fifth for potential cliffhanger moments. Then the team would discuss what would be included and what wouldn’t make the cut.
Tapster said, “One of our researchers, Ida-May Jones, kept pushing for Lystrosaurus,” a proto-mammal that she found very cute. “We were, like, It has to be more than just cute.” The Lystrosaurus was herbivorous, about the size of a pig, with small tusks and a kind of beak. Because its front legs are so much stronger than its back legs, it is believed to have dug and lived in burrows. It existed both before the Permian extinction (in relatively small numbers) and then also after—it survived. “She brought it up again, she had really fallen for it, but what essential story was it telling?” Tapster said. Then Jones uncovered an unexpected detail about Lystrosaurus: at one point, after the Permian extinction, the species represented seventy-five per cent of all the vertebrates on Earth. It was, briefly, king. “So Lystrosaurus made it in,” Tapster said. A startled Lystrosaurus in its burrow appears early in Episode 4.
Tapster and his writing team also wanted the show to highlight less well-known aspects of the history of life on Earth: creatures other than dinosaurs, the mesmerizing progression of plant life, momentous environmental events. “I remember getting the note of ‘So you’re beginning Episode 2 with plankton? And Episode 3 with lichen?’ ” Tapster said. But who knew (other than paleontologists) that there was a time in Earth’s history when it rained for a million years? Or about the forty million years when moss dominated the planet? Or about how plankton, by inventing photosynthesis and thereby giving off oxygen in the course of some two billion years, transformed Earth’s yellow methane-filled atmosphere into blue skies, and the lifeless landscape into forests of green? In William Steig’s book “Rotten Island,” illustrations show erupting volcanoes and creepy sea creatures and thorny plants and vicious land animals. One day, a jealous battle starts over a new life-form: a flower. Violence, destruction, giant insects, and ice and fire ensue, and lead to a mass extinction. I used to think that “Rotten Island” was about the disastrous pettiness of human wants and behaviors, and about how much better life might be without us. Now I see it as a reasonably accurate visual history of our planet, with extra polka dots and stripes, in watercolor.
Even if you haven’t visited it in person, there’s a good chance you’ve seen Cheatham Grove. An ecological park in Northern California, it’s where the famous chase scene in “Return of the Jedi” was filmed. Walking a few minutes with Tapster and Fletcher along a trail strewn with redwood needles, and sheltered by trees several hundred feet tall, I met Jonathan Privett, the visual-effects supervisor from Industrial Light & Magic; Jolyon Sutcliffe, a producer and a director with an extensive background in natural-history documentaries; and Katy Fraser, a camera operator whose additional skills as a deep-sea diver were essential for many of “Life on Our Planet” ’s underwater scenes. They were snacking on grapes and chatting while waiting for the sun to come out from behind the clouds, so that they could shoot footage that would match that of previous days. “Nature documentary is often hours and hours of waiting and then a few moments of intensity,” Sutcliffe told me. He had stayed up for many nights in the Sonoran Desert to capture the moment when a kangaroo rat leaps out to karate kick an attacking rattlesnake in midair; he had sat for hours waiting for the tiny scuffle of dust that signifies a trapdoor spider popping out from its burrow to seize its prey. During the pandemic, he spent weeks filming lichen growing; thousands of those images had to be “stacked” for the sequence in “Life on Our Planet” that shows lichen spreading across the land.
The team had their equipment on hand, including a special three-hundred-and-sixty-degree camera that is essential for making the lighting of the landscape convincingly correspond to the lighting on the extinct creatures—in this case an Anchiornis, a small gliding dinosaur speeding among the trees. “The natural-history people tend to be reactive” when it comes to lighting and other details, Fraser explained. “The visual-effects people have to be methodical.”
Privett is fifty-four, with a friendly, relaxed, slightly mischievous vibe. He showed me on a laptop the method he and other I.L.M. artists use to build a creature. “It’s like making a real puppet,” he said. He pulled up files on Anchiornis. “We first build the skeleton. The audience never sees the skeleton, but, if you get that right, a lot follows.” The skeleton could be animated, “and, see, we realized the wings couldn’t fold completely away, like a pigeon’s”—so Anchiornis, with his wings only partially tucked in, looks a bit like he’s wearing a cape. “And then we can add the muscles, then the skin—it’s like a sculpture.” Some remarkably intact Anchiornis specimens have been found, so there’s a lot of information to work with. “Then we add the feathers.” In recent years, scientists have even deduced the color of the species’ feathers, by a microscopic examination of melanosomes, a kind of pigment cell. Parameters can be put in for how stiff the various feathers are, and for how many barbs they have. “It’s the same with fur—you can decide how clumpy it is,” he added. Wind and turbulence variables can be added, too. Privett went on, “He doesn’t fly so much. It’s more like what Buzz Lightyear says: he falls with style. He’s sort of part bird, part flying squirrel.”
Privett’s background is in mechanical engineering. After graduating from college, in 1991, he took a job in Detroit modelling cars with software that was new at the time. The software allowed car designers to work digitally, instead of having to build a model by hand. Soon, Privett was offered a position at a visual-effects company, and he has spent more than twenty years doing work he would never have foreseen, and that he loves. “This is kind of embarrassing, but I was never a fiction person—I read the dictionary and the encyclopedia,” he told me. The scientific information that went into building creatures naturally appealed to him, even though “it’s a leap of faith, too,” he said. Fur and feathers are the toughest. “The snow blowing through the woolly mammoth’s fur—that was a lot of work,” he said, with a little shudder.
Tom Fletcher’s Ph.D. was on the hydrodynamics of ancient fish and sharks, and he lights up when talking about geologic formations, fossilized skin impressions, the movement patterns of early amphibians. In becoming a paleontologist, Fletcher, who’s thirty-six, didn’t so much follow his dreams as follow his fears. “The room of dioramas of dinosaurs in the natural-history museum in Liverpool—they’re outdated now, but it looked like a sinister aquarium with ichthyosaurs and giant squids, and I would have nightmares about them,” he said. “They were terrifying, but also awesome.” His parents sometimes drove him to the coast, where he searched for fossils, deciding pretty early on that that was what he wanted to do with his life.
One of Fletcher’s jobs in “Life on Our Planet” was to give feedback on each draft of extinct creatures. Once I.L.M. artists had visuals, they would send a collection of images, almost always including one of the creature posed next to a fountain topped with a statue of Yoda which sits in front of I.L.M.’s San Francisco office. Revisions would then be suggested, to improve on both the “feel” of what Tapster and others thought would work best artistically and, for Fletcher, the scientific accuracy. A producer might want to put something “characterful” on a creature, such as a crest, and Fletcher would have to explain that, owing to fossil evidence, it wasn’t possible. “Pretty much all the accuracy changes suggested we were into—but there was disappointment about having to put lips on the Tyrannosaurus rex,” Tapster said. Lips are likely rare on the T. rexes of the popular imagination. “But the science was pretty strong,” Fletcher said. With T. rex’s feathers, there was disagreement among experts about how many there would have been. An early draft of the T. rex “looked like he had a mullet and was headed to a Metallica concert,” Tapster said. “We asked them to pluck some of the feathers.”
More often, Tapster said, I.L.M. saved the show from mistaking an inexact science for an exact one—from failing to take advantage of the special insights of art. He gave the example of the terror bird, a ten-foot-tall apex predator that lived after the dinosaurs. In “Life on Our Planet,” we see one terror bird in a territorial dispute, and another as it hunts a group of cute llama-like creatures. There is limited fossil evidence of the terror bird, so in designing one the production team tried to Frankenstein it from modern-day descendants. “We said to I.L.M. to give it the legs of a secretary bird and the beak of its closest living relative, a seriema,” a much smaller leggy bird that often sports a bright beak with a fanciful plume at its base. What resulted “looked like a giant chicken with lipstick,” Tapster said. They asked the artists to come up with a version that looked like it belonged in the sandy landscape and was suitably terrifying—as per the ambush predator’s name. They “came up with something so much better,” Tapster said. The terror bird now looks more like an ostrich on steroids, but with a killer hooked beak.
So many astounding creatures now gone! One theme across the episodes is that of the dominant species not surviving the next extinction; it tends to be the smaller, more adaptable ones that make it to the far side. Another through line is that of chance: not only how a random mutation can end up being useful to a creature’s survival but also, for example, the chance arrival of the dinosaur-killing asteroid. On our drive back to San Francisco from Cheatham Grove, Tapster said, “That meteorite is thought to have been stuck in the asteroid belt, before maybe a collision kicked it out onto its thirty-five-million-year trajectory to crash into Earth.” The precise place where the asteroid hit exacerbated the calamity: it landed in an area full of gypsum, which vaporizes into sulfur, which in turn blocks sunlight. “If that journey had ended two hours earlier, or two hours later”—so that its impact was elsewhere—“that would have made a difference.”
Italo Calvino’s short story “The Dinosaurs,” from 1965, is narrated by a dinosaur that has survived the extinction. Feeling himself to be the last of his kind, he’s lonely. He joins a community of New Ones, who don’t recognize him as a dinosaur, or really know anything about dinosaurs, but who tell frightening stories about them. The New Ones’ fear changes to over-the-top admiration, then eventually to telling stories of dinosaurs that position them as laughable, as “terrible monsters” playing “ridiculous roles.” They use stories of dinosaurs, unknowingly, for their own shifting emotional and psychological ends. Late in the story, after a dinosaur fossil is found by the New Ones, the dinosaur sees “everything we had been and were no longer, our majesty, our faults, our ruin.” When the New Ones move on to “the idea of the Dinosaurs” as “bound to the idea of a sad end,” he gets fed up, and leaves. Calvino’s story, written when the extinction of the dinosaurs was still a mystery, now reads as a parable about our own possible extinction, even as its causes are not cloaked but visible.
We are the New Ones now, telling a shifting set of stories, often heedless of their accuracy. The dramatizations of the extinctions in “Life on Our Planet” were difficult to watch, though they were, in a way, magnificent. As sea life froze, or suffocated, or the land transformed into an oven, I admit that I often turned away, as it looked all too real. ♦