My Beloved Brontosaurus

by Brian Switek

  And then I heard the bad news.

  * * *

  “Brontosaurus” was dead to begin with. My favorite dinosaur wasn’t real, but only a misconstrued amalgamation that had been borne and slaughtered by science. The dinosaur’s true name was Apatosaurus—a creature that paleontologists envisioned as vastly different from my brontosaur. Apatosaurus was not a waterlogged grubber of algae and water lilies, but in fact was a taut, active animal that trod Jurassic floodplains with its neck and extended whiplash tail held high off the ground. “Brontosaurus” as I knew the beast—a hulking pile of flesh and bone that bathed in Jurassic swamps—never actually existed. Almost everything about the monstrous creature—its lifestyle, its skull, and, most regrettably, its name—were human inventions drawn from prehistoric skeletons that actually supported a different form. I had been fooled! The dinosaur I met was a petrified museum zombie, shuffling on even though scientists had shot it down decades before.

  You see, the dinosaur’s major makeover wasn’t easy, and it wasn’t fast. I had encountered the brontosaur only as it was slowly fading from books and museum halls. A few years before I made my first museum visit, a groundswell of scientific interest in sauropods, stegosaurs, tyrannosaurs, and their varied kin—given the dramatic title “The Dinosaur Renaissance”—had crushed the image of dinosaurs as stupid, abominable reptiles and recast them as animals that had more in common with birds than with any lizard or crocodylian (a term for the group encompassing alligators, crocodiles, and gharials). The fossil bones were the same as they ever were, but paleontologists saw the petrified remnants in a new light. And in the special case of “Brontosaurus,” the dinosaur’s name, skull shape, and cultural identity are all bound together in a complicated knot where science and imagination meet.

  The story started over a century ago during one of the most fruitful times in the history of paleontological discovery. In 1877, the Yale paleontologist Othniel Charles Marsh applied the name Apatosaurus ajax to the partial skeleton of a juvenile sauropod that Arthur Lakes, later one of Marsh’s field assistants, had discovered in Colorado. Two years later, Marsh coined Brontosaurus excelsus on the basis of a more complete skeleton his men had found, this time at Como Bluff, Wyoming.

  The dinosaurs were only subtly different, but in Marsh’s day, paleontologists interpreted even the slightest of skeletal differences as indicators of previously unknown genera and species. After all, Marsh and his contemporaries were among the first to scientifically catalog a prehistoric lost world full of creatures no one had ever seen before. Who could say how many different forms there were?

  In 1896, the paleontologist O. C. Marsh published this reconstruction of “Brontosaurus” excelsus in his major monograph The Dinosaurs of North America. (Image from Wikimedia Commons: en.wikipedia.org/wiki/File:Brontosaurus_skeleton_1880s.jpg)

  In this case, though, what Marsh thought were two different dinosaur genera were merged into one. In 1903, the paleontologist Elmer Riggs argued that Marsh’s “Brontosaurus” wasn’t distinct enough from Apatosaurus to justify a new genus name. The “Brontosaurus,” Riggs reasoned, was only a new species of Apatosaurus, and since Apatosaurus was named first, it had priority of title. Thus “Brontosaurus” excelsus became Apatosaurus excelsus. The trouble was that the name change didn’t filter from technical journals to pop culture (or, clearly, to museum displays). As institutions such as the AMNH erected Apatosaurus skeletons, they slapped the mounts with the old “Brontosaurus” label for reasons that have never been resolved. Maybe they thought the old name sounded better, or were unsure about rebranding one of the most famous dinosaurs in their halls. Whatever the reason, “Brontosaurus” was given a second life.

  For the moment, let’s follow the lead of Riggs’s stubborn contemporaries and call the animal “Brontosaurus.” In general form, the “Brontosaurus” skeletons museums so proudly displayed weren’t very different from other huge sauropods, such as Diplodocus. These two dinosaurs—who lived alongside each other in western North America about 150 million years ago—shared the same body plan, with “Brontosaurus” being a bit bulkier than its more slender counterpart. What made “Brontosaurus” different, and seemed to characterize the dinosaur’s personality, was its skull.

  When I met the skeletal “Brontosaurus” in 1988, the dinosaur’s neck was capped with a skull that made it look about as dumb as early-twentieth-century scientists insisted the animal must have been. As the AMNH paleontologist William Diller Matthew wrote, “We can best regard the Brontosaurus as a great, slow-moving animal automaton, a vast storehouse of organized matter directed chiefly or solely by instinct, and to a very limited degree, if at all, by conscious intelligence.” To my mind, this man, who oversaw the construction of the mount I was so fascinated by, viewed the dinosaur as a bad evolutionary joke, a heavyweight that was all brawn and no brain.

  Unbeknownst to me at the time of my first museum trip, this reptile’s skull was a conglomeration of bone fragments and speculation.

  * * *

  When Marsh’s field crew discovered the original “Brontosaurus” material at Como Bluff, they were frustrated that the specimen lacked a cranium. (Sauropods had a habit of losing their heads between their death and burial.) So, when it came time for Marsh to commission an illustration of what the animal’s skeleton would have looked like, he drew on several skull bones found at another Como Bluff quarry. These pieces actually came from a different animal—a short-snouted, high-skulled sauropod called Camarasaurus that lived at the same time—but Marsh didn’t know that. He assumed that the skull and skeleton belonged to the same animal, and so he used the fragments to re-create a “Brontosaurus” skull. Other museums followed suit. It was years before anyone found the dinosaur’s true skull.

  * * *

  The beginning of the end for “Brontosaurus” goes back to Dinosaur National Monument, one of the richest boneyards ever found. You know you’re getting close to the park when goofy, tourist-trap dinosaurs start appearing along Highway 40 in Vernal, Utah. You can’t miss them. Some of them snarl, others pose outside hotels, and my favorite—a rendition of the town’s long-necked mascot Dinah—wears a polka-dot bikini and stands above a sign that reads: “Let’s swim!” Dinosaurs didn’t have mammary glands, so I’m not sure what good a bikini top would do. Maybe that’s just the Utah sense of modesty at work.

  Vernal’s dinosaurs have a gleefully outdated feel. They’re mostly holdouts from an earlier era, from a tourism boom after a glass-walled museum was erected over Dinosaur National Monument’s quarry of bones in 1957. The protected excavation was the dream of Earl Douglass—the man who struck a rich vein of fossils among the area’s rocky hills in 1909, and extensively quarried the site under the employ of Pittsburgh’s Carnegie Museum of Natural History. Even though Douglass shipped tons of bones back east, he wanted the enormous bonebed to become a living museum where visitors could come and see paleontology in action. Some of his dreams—such as an airstrip on the site and fine dining for high-class clientele—didn’t come to pass, but the heart of his vision was realized and continues to show visitors that prehistory can seem as alien as another world.

  Cruise past decaying rock shops, a few more cracked and faded dinosaurs, and emerald swaths of farmland that spring from the banks of the Green River, and you’ll finally arrive at the park. A dopey Diplodocus grins sheepishly at visitors from a parking lot just outside the park limits. And if you know your geology, the winding drive to the recently renovated museum is a literal trip through time. Millions of years of deposition, uplift, and erosion cracked the depths of the earth into a series of sharp slices, each sliver older than the last. Remnants of ancient oceans transition into traces of fern-covered floodplains, divided from the vestiges of dune-filled deserts by the incursion of another vanished sea, and so on down through time. Even if you’re not well versed in the paleontological particulars, you can follow the changes by color. Each formation is set off from the others by its own range of hues, from mint
green to rust red. I could never dream of a more wondrous landscape. This is one of the most beautiful places on Earth.

  The road leading up to the quarry wall is a mixture of maroon slices interspersed through grayish-purple stacks. This is the classic color scheme of the Morrison Formation, the roughly 150-million-year-old deposits that herald the presence of dinosaur giants. This was the era of Stegosaurus, Allosaurus, Diplodocus, Brachiosaurus, Ceratosaurus, and many other favorites, including—of course—the dinosaur formerly known as “Brontosaurus.”

  Picking out each species on the sheltered quarry wall isn’t easy for anyone who doesn’t have an encyclopedic knowledge of dinosaur anatomy. The exposed rock face is a logjam of bones created by an unfortunate twist of Mesozoic fate. Dozens of dinosaurs died in a Jurassic drought, and when the rainy season finally broke the dry spell, the bodies of the poor dinosaurs were washed together into this one place. Disembodied limbs and segments of tail are interspersed with isolated skeletal elements in a slurry of tan-shaded bone. Bad luck for the dinosaurs, but a bonanza for Earl Douglass and other paleontologists that followed him.

  The quarry was bigger a century ago. The slanted bonebed extended another one hundred feet upward, and another hundred feet to either side. Those portions were uncovered, excavated, and shipped to museums long ago. And while most dinosaurs in the quarry wound up as isolated bones and body parts, Douglass also exhumed a few complete skeletons. In September of 1909, not long after he stumbled on the string of dinosaur vertebrae that first called his attention to this place, Douglass excitedly picked away at what appeared to be a complete “Brontosaurus” skeleton. “We evidently have the most complete of the huge Dinosaurs that ever was found, at least I haven’t heard of any other so complete as this appears to be,” Douglass wrote back to the Carnegie staff. There was even the possibility that the dinosaur’s long-lost skull might be at the end of the neck. “I am not sure,” Douglass confided, “but believe now that we will get the head.”

  The arc of the dead dinosaur’s body pointed the way for Douglass. After two more months of excavating the skeleton, he found that the dinosaur’s neck was thrown backward over the rest of the spinal column—the classic dinosaur death pose. If the skull was there, surely it would have been at the end of the arched neck. Douglass and his crew carefully uncovered the remainder of the neck “with beating hearts,” and as he recounted to his boss William Holland, “I could almost see the skull I was so sure of it for was there not a series of 8 cervicals undisturbed and in natural position.” But the neck stopped at the third or fourth neck vertebra. There was nothing else. “How disappointing and sickening,” Douglass sighed.

  Douglass pushed forward regardless, continuing his work through the coming seasons. He even set up a permanent residence among the colorful outcrops, toiling through the brutal summer heat and enduring the winter chills that annually closed his field operations. And while no skull was ever found attached to a “Brontosaurus” neck, Douglass turned up a few isolated skulls of the hefty, long-necked sauropod dinosaurs. Most of these resembled the profile of Diplodocus. Instead of having blunt heads with spoon-shaped teeth, like Camarasaurus, Diplodocus had elongated, shallow skulls tipped with a squared muzzle of pencil-shaped teeth.

  But Douglass wasn’t entirely sure all the skulls really belonged to Diplodocus. Perhaps some of the craniums in his collection truly belonged to “Brontosaurus”—still a headless dinosaur at the time. “Can we be positively certain that the supposed skull of Diplodocus is not that of Brontosaurus?” he wondered. Specifically, in 1910 Douglass discovered a puzzling skull very close to the neck of a second “Brontosaurus” specimen simply titled No. 40. Douglass believed that the fossilized cranium was a Diplodocus head that had rolled away from its owner after death, “though I would be glad to give a fellow [a] crown of glory if he’d convince me otherwise.” He wasn’t quite ready to go out on a limb and say that he had found—at long last!—the head of “Brontosaurus.”

  William Holland didn’t think Douglass had found another Diplodocus noggin. He believed that his man in the Jurassic had indeed found the long-lost “Brontosaurus” head. The skull was similar to that of Diplodocus, so it was no surprise that Douglass’s doubts threw him off the trail, but the “Brontosaurus” cranium looked a little wider and bulkier, befitting the heavier stature of the dinosaur. Holland argued that the established “Brontosaurus” skull form—assembled by Marsh from only a few fossil scraps—was totally wrong. The stout skull Douglass had found near dinosaur No. 40, Holland thought, truly did belong to the “deceptive lizard,” properly called Apatosaurus.

  Scientific uncertainties and paleontological politics continued to complicate the legacy of Apatosaurus. Despite arguing that Douglass had finally found the dinosaur’s skull, Holland decided to leave his museum’s mount of the dinosaur headless, and the reconstruction stood that way for twenty years. Only in 1934, two years after Holland passed away, did the Carnegie Apatosaurus get a head, and it was a blunt Camarasaurus-like stand-in. No one seems to know who made the decision, but the choice reflected the consensus of the time—similar to Marsh’s view—that Apatosaurus was a close relative of Camarasaurus. Due to their presumed affinity, the two dinosaurs would be expected to have similar skulls. The Carnegie dinosaur, along with its counterparts at Yale and the AMNH, smiled at visiting masses with a substitute head for years. And that peculiar skull Douglass had found next to skeleton No. 40 was placed in the collections of the Carnegie with Diplodocus on its label.

  Eventually, Douglass’s tentative hunch and Holland’s assertions were proven correct. In 1975, a physicist turned self-trained sauropod expert by the name of John McIntosh reviewed the various letters, notes, and quarry maps Douglass had composed and confirmed that Douglass’s strange “Diplodocus” head was found right up against an Apatosaurus skeleton. McIntosh described the skull in a paper outlining the fossil’s distinct anatomy, and finally put the last, essential piece of Apatosaurus in place. On October 20, 1979, the Carnegie officially replaced the incorrect skull with a cast of the rediscovered Apatosaurus fossil. Other museums took a little bit longer to fix their mounts. Yale’s Peabody Museum exchanged skulls in 1981 (“This is the first head transplant that I’ve ever performed,” the paleontologist John Ostrom quipped as he put the new skull on the skeleton), and the AMNH fixed theirs much later on, during the mid-nineties revamp.

  Sure, paleontologists already knew that Apatosaurus was the proper name for the dinosaur when the skull switches happened. Riggs had settled that issue in 1903, and various papers cemented the technicality, but even though Riggs made it crystal clear, “Brontosaurus” lived on. Tyrannosaurus rex might be the undisputed favorite now, but “Brontosaurus” ruled the early days of cinema and has left a sizable imprint on the cultural landscape. Gertie the Dinosaur, one of the first animated features, starred a frisky dinosaur based on the American Museum of Natural History’s “Brontosaurus.” More monstrous brontosaurs would later threaten humans in 1925’s The Lost World and the 1933 classic King Kong. (Not to mention Cary Grant’s frustrated search for the dinosaur’s “intercostal clavicle”—a bone that doesn’t actually exist—in 1938’s Bringing Up Baby.) And that galumphing, sometimes aggressive personality was encapsulated by that fabricated skull. When the proper skull was placed on the dinosaur’s body—just as paleontologists were revising the essence of what dinosaurs were—the animal’s entire demeanor changed.

  Apatosaurus excelsus as we know the dinosaur today. (Illustration by Scott Hartman)

  By now, we know that Apatosaurus is the dinosaur’s proper name. If you note the wrong term in front of a young fossil fan, you’ll get a swift correction. But you can’t keep a brontosaur down. Everyone knows the dinosaur’s name and we want “Brontosaurus” to exist. Even though some of my paleontologist friends have tried to match the name’s popularity by spreading the name of a previously unknown sauropod, Brontomerus—or “thunder thighs”—there isn’t going to be another dinosaur that c
an fill the cultural gap “Brontosaurus” left behind, which is funny, since it’s not like there’s some “Brontosaurus”-shaped hole in prehistory. Just look at Google’s Ngram Viewer—a service that tracks word use in books through time. We started using “Apatosaurus” and “Brontosaurus” at about the same time, but the Ngram reveals that “Brontosaurus” has always been the victor. Even from the 1970s on, when we knew that the dinosaur wasn’t real, the name still beats Apatosaurus in frequency. Whenever we mention Apatosaurus, we feel compelled to remind everyone that the dinosaur used to be called “Brontosaurus,” and so the discarded name persists. (I’m certainly compounding the problem here.) We can’t conjure Apatosaurus without the memory of “Brontosaurus” trailing close behind.

  The torturous episode reminds me of when Pluto was demoted from planet status to the dwarf planet level. The cosmic body is still out there—scientists didn’t destroy it with a Death Star or other interplanetary weapon—but the outcry over the change was intense. Even many die-hard science fans loathed the technical decision. Why should a mundane label change matter so much? As the astronomer Mike Brown, whose work contributed to Pluto’s fall from interstellar grace, put it:

  In the days that followed [Pluto’s demotion], I would hear from many people who were sad about Pluto. And I understood. Pluto was part of their mental landscape, the one they had constructed to organize their thinking about the solar system and their own place within it. Pluto seemed like the edge of existence. Ripping Pluto out of that landscape caused what felt like an inconceivably empty hole.

  The Jurassic herbivore was a touchstone that put the rest of the archosaurian horde in context and helped us revive lost worlds in our imaginations. And the sauropod’s apparition remains a cultural baseline against the ever-shifting image of what dinosaurs are. To my mind, we didn’t lose a dinosaur so much as gain a much clearer view of a real Jurassic giant. The contrast between old “Brontosaurus” and dinosaurs as we know them now shows us just how much we have learned about dinosaur biology.