June 13, 2012
Apatosaurus means “deceptive lizard.” It’s really the perfect name for the bulky Jurassic sauropod. “Brontosaurus“—a dinosaurian fan favorite whose memory lives on even after being relegated to the taxonomic dustbin—turned out to be a species of Apatosaurus, and for decades, paleontologists assigned the wrong head to Apatosaurus because of a confused view of who the dinosaur was most closely related to. Apatosaurus continues to play tricks. The sauropod tracks placed behind the American Museum of Natural History’s Apatosaurus skeleton were actually made by much different sauropods that lived millions of years later.
The cartoon series “I’m a Dinosaur” presents a different interpretation of the sauropod’s name. A grey, blunt-headed Apatosaurus—who sounds like the Jurassic precursor to Mortimer Snerd—tells the tale, while delivering a few basic facts along the way.
Apatosaurus isn’t the only dinosaur to present a short cartoon autobiography. The same series also features a regal Tyrannosaurus, a Baryonyx suffering ennui, and an anxious Beipiaosaurus who dreams of flying. The educational content is pretty thin—generally how big the dinosaurs were, where they lived and what they ate—but this is cartoon kid’s stuff, after all.
Then again, if Apatosaurus is such a deceptive dinosaur, why should we believe anything he says?
June 6, 2012
Today’s Dinosaur Sighting comes to us from friend of the blog Sarah Zielinski. While visiting the 10th floor of the Artomatic festival in Crystal City, Virginia, where she is an exhibitor, Sarah spotted the wire dinosaur creations of Roger Cutler. Along with an Allosaurus and a tiny Tyrannosaurus, Cutler created an eight-foot-high model of Apatosaurus—a scaled-down outline of the massive Jurassic herbivore.
Have you seen a dinosaur or other prehistoric creature in an unusual place? Please send a photo to email@example.com.
April 12, 2012
You can’t understand dinosaurs without a sense of time. We need to know when a dinosaur lived to comprehend how it fits into what paleontologist William Diller Matthew called “life’s splendid drama.” But we throw around Deep Time estimates, framed in millions of years, so often that it’s easy to become inured to the wider context of life’s history.
The Mesozoic Era, which lasted from about 250 million to 66 million years ago, is often called the Age of Dinosaurs. As a kid, this brought to mind one endless summer when dinosaurs flourished. And many of the books I read picked one environment from three different periods within the era to represent dinosaur life. Little Coelophysis was the canonical Triassic dinosaur; the huge sauropods and theropods of the Morrison Formation represented the Jurassic, and a Cretaceous Tyrannosaurus versus Triceratops face-off ultimately capped off the succession. With the periods juxtaposed this way, millions of years didn’t seem so very long.
But let’s unpack some of that scenery. Diplodocus, Apatosaurus, Allosaurus, Stegosaurus and their neighbors roamed western North America about 150 million years ago. This slice of time falls in the latter portion of the Jurassic. The traditional representatives of the latest Cretaceous scene—Tyrannosaurus and Triceratops—did not evolve until about 67 million years ago. By themselves, these dates are just labels, but think of them falling along evolution’s timeline. About 83 million years separated Apatosaurus from Tyrannosaurus and Allosaurus from Triceratops. The so-called Age of Mammals—which began when the non-avian dinosaurs were wiped out—has been going on for about 66 million years. Less time separates us from Tyrannosaurus rex than separated T. rex from Stegosaurus.
Consider how much life has changed in the past 66 million years. Archaic mammals flourished and ultimately went extinct long before anything like the world’s modern fauna appeared. Saber-fanged, knobbly-headed herbivores such as Uintatherium, lemur-like primates called adapiforms, razor-jawed carnivores known as creodonts and many other strange forms proliferated and disappeared. Even lineages familiar to us today, such as horses, rhinos and elephants, evolved and diversified and are now represented by just remnants of what once existed.
The time between the last Triceratops and now has seen radical evolutionary changes. Now think of the 83 million years between the Jurassic and Cretaceous titans. During that time, the first flowering plants bloomed; the fish-like ichthyosaurs disappeared as plesiosaurs and mosasaurs became the predominant predators of the seas; vast herds of hadrosaurs and ceratopsids occupied places once dominated by sauropods; tiny tyrant dinosaurs transformed into apex predators, and early birds established themselves in ever-greater variety alongside their dinosaurian kin. These are just a few highlights, and that is part of the wonder and frustration of tracking the history of life on earth. We are offered only glimpses of an ever-changing picture, and when viewed separately, it’s easy to forget how those snippets relate to each other. But when we can step back, and consider how all those snippets run together, the long and ever-changing history of life on our planet seems all the more fantastic.
April 10, 2012
“Brontosaurus” will always be special to me. The shuffling, swamp-dwelling dinosaur never really existed, yet, for my younger self, the Jurassic behemoth was an icon of everything dinosaurs were supposed to be. The skeleton mounted at the American Museum of Natural History is what really hooked me on the sauropod. When I first visited the skeleton in the late 1980s—before the museum’s dinosaur halls were renovated in the late 1990s—I was astonished. I had seen illustrations of Brontosaurus before, but seeing the animal’s actual bones was a transcendent experience for me. I already liked dinosaurs, but after standing in the shadow of those column-like limbs and intricate vertebral column, I loved dinosaurs.
Today we know that the specimens once assigned to Brontosaurus excelsus really belonged within the genus Apatosaurus. That issue was settled decades before I was even born, although museums and paleontologists themselves were slow to adopt the change. (It wasn’t until the proper head of Apatosaurus was rediscovered—the specimen was excavated at Dinosaur National Monument in 1909 but confused for a Diplodocus skull for decades—that the move to publicly shun Brontosaurus started in earnest.) Indeed, in 1903 paleontologist Elmer Riggs recognized that Brontosaurus excelsus was extraordinarily similar to the skeleton of another sauropod, named Apatosaurus ajax. Both had been named by Yale paleontologist O.C. Marsh at the height of the Bone Wars era, when many dinosaur specimens, no matter how subtle their differences, were given a new genus or species designation. In this particular case, the fact that the Apatosaurus ajax specimen came from a relatively young animal and the Brontosaurus excelsus specimen was an older animal led Marsh astray. Both forms, Riggs concluded, belonged to the same genus, and Apatosaurus had priority since it was named first.
The American Museum of Natural History mount went up in 1905. The dinosaur was promoted as Brontosaurus, not Apatosaurus. Even though Riggs’ case would eventually win out, AMNH paleontologists Henry Fairfield Osborn and William Diller Matthew didn’t agree with the name change. Exactly why Brontosaurus was allowed to live on—much to Riggs’ frustration—is unclear. But all these little quirks of nomenclature and procedure had a major influence on the popularity of Brontosaurus over Apatosaurus. The AMNH mount was the first reconstruction of this dinosaur ever attempted, and in 1905, it was one of a kind. (The original material Marsh used to describe Brontosaurus was held at Yale, but Marsh never made an effort to publicly display the partial skeleton his crew found at Como Bluff, Wyoming. The specimen, carrying a Brontosaurus name plate and the wrong head, was not reconstructed at Yale until 1931.) The AMNH Brontosaurus mount was the introduction of sauropods to the fascinated public.
William Diller Matthew recounted the process of mounting his museum’s Brontosaurus in an American Museum Journal article and a news item for the Independent. The skeleton was a Frankenstein. The principal part of the mount was an incomplete skeleton found near the Nine Mile Crossing of the Little Medicine Bow River in Wyoming. This one site yielded most of the vertebral column, all the ribs, elements of the shoulders and hips, and a few portions of the limbs from the single sauropod. But quite a few parts were missing, so AMNH paleontologists turned to other specimens. The AMNH Brontosaurus also included various elements from specimens found at Como Bluff and Bone Cabin Quarry, Wyoming, as well as plaster casts made from the Yale Brontosaurus material and other bones already in the AMNH collections.
And, of course, there was a question of the head. No one had ever discovered a Brontosaurus skull articulated or even associated with the rest of the skeleton. (And Earl Douglass’ discovery at Dinosaur National Monument was still four years away.) A skull had to be specially designed for the AMNH mount, and the New York museum followed Yale’s lead.
While all the bones from Marsh’s original Brontosaurus specimen came from Quarry 10 at Como Bluff, there was no skull among the lot. Rather than let the dinosaur go decapitated, however, Marsh identified two skull portions from a more diverse bonebed nearby, known as Quarry 13, as belonging to Brontosaurus. The sections of upper and lower jaws were set with spoon-shaped teeth, and these are the skull portions which make up the head of the famous 1883 reconstruction of the dinosaur Marsh commissioned.
The Como Bluff jaws outlined what the front of the dinosaur’s jaws might have looked like and, assuming that Marsh was correct, indicated that the skull of Brontosaurus was very different from that of Diplodocus. Fortuitously, the same AMNH expeditions to Bone Cabin Quarry which turned up Brontosaurus parts also brought back a complete Camarasaurus skull. Prior to this discovery, no one knew exactly what the head of Camarasaurus looked like. The fact that it seemed to share the spoon-shaped teeth assigned to Brontosaurus meant that the skull was a good model for reconstructing the rest of the missing “thunder lizard” skull. As far as I’m aware, the paleontologists did not consider that the supposed Brontosaurus skull parts, found in a different quarry than Marsh’s original specimen, really belonged to Camarasaurus.
Of course, accumulating all the right bones is just the first step in preparing a mount. Today, huge dinosaur skeletons are the stars of many museums. In 1905, though, such an effort had never been attempted before, and the AMNH paleontologists were not entirely sure how the brontosaur bones should be articulated. Matthew, along with colleague Walter Granger, dissected lizards and crocodiles to investigate how their muscles attached to their limb bones, and used these distant modern analogs to give their Brontosaurus a slightly bow-legged posture.
Mounted an a raised platform, the AMNH Brontosaurus looked like an impressive terrestrial titan. Yet during his study of the bones, Matthew concluded that Brontosaurus was a great amphibious dinosaur. Drawing from the authority of anatomist Richard Owen and paleontologist E.D. Cope, Matthew pointed out that the anatomy of Brontosaurus was so well-suited to life in water that you could tell the approximate depth at which the animal submerged. While the dense, heavy limbs of the dinosaurs acted like the heavy boots of deep-sea divers, Matthew pointed out, the sauropod’s light vertebral column would have been more buoyant. The dinosaur’s back therefore represented a sort of high water line which indicated the depth at which Brontosaurus wallowed in swamps, arcing its long neck to slurp up soft water plants.
Brontosaurus, in Matthew’s estimation, spent life slogging through a warm Jurassic bath. That seemed just as well—the dinosaur’s brain was comically small for its size. This sauropod was not an intelligent, behaviorally complex creature, Matthew argued, but a dim-witted leviathan devoted to a lazy lifestyle. “Hence we can best regard the Brontosaurus as a great, slow-moving animal automaton,” Matthew wrote, “a vast storehouse of organized matter directed chiefly or solely by instinct and to a very limited degree, if at all, by conscious intelligence.”
I am glad that dinosaurs have changed dramatically since Matthew characterized them as idiotic, clumsy piles of flesh. Apatosaurus and the whole rest of the dinosaurian ensemble are far more fascinating now than they were when bound to short and savage lives in steaming jungles and marshes. The true identity of “Brontosaurus” was eventually made clear, sauropods were ushered out of the swamps, butt-brains have been refuted, and paleontologists are able to extract more information about dinosaur lives from old bones than ever thought possible before.
And yet, I still feel some affection for Brontosaurus. This isn’t because I would prefer to see dumb, blunt-headed dinosaurs sloshing through algae-filled ponds, but because the old thunder lizard represented the epitome of true dinosaur-ness when I was a child. The mountain of muscle and bone was a wonderful icon which, in memory, reminds me just how much dinosaurs have changed during the twenty four years since I first saw the sauropod’s bones. I am thrilled that paleontologists sunk Brontosaurus, and the story of the icon’s demise reflects how paleontology has matured from a contest to see who could collect the biggest skeletons to a discipline that is carefully teasing out the secrets of prehistoric lives.
Matthew, W.D. 1905. The mounted skeleton of Brontosaurus. American Museum Journal.V (2), 63-70
Osborn, H.F. 1906. The skeleton of Brontosaurus and the skull of Morosaurus. Nature. 1890 (73), 282-284
Parsons, K. 2001. Drawing Out Leviathan: Dinosaurs and the Science Wars. Bloomington: Indiana University Press. pp.1-21
March 12, 2012
In the American Museum of Natural History’s Hall of Saurischian Dinosaurs, there is a great fossil mismatch. You can find the deceptive pairing in the Apatosaurus exhibit. Set in the floor behind the enormous dinosaur is a set of trackways—the Apatosaurus is posed as if the skeletal sauropod has just left the tracks behind. But there is no way that Apatosaurus left those tracks. The footprints and the long-necked dinosaur on display were separated by tens of millions of years.
Apatosaurus is an iconic Morrison Formation dinosaur. The hefty sauropod trod across prehistoric floodplains of America’s Jurassic West around 150 million years ago. But the footprints on display at the AMNH comes from a different time. The slab is part of a roughly 113-million-year-old trackway found along the Paluxy River near Glen Rose, Texas. Apatosaurus was long gone by the time the Texas tracks were created, and the shape of the footprints indicate that a very different kind of sauropod, probably belonging to the subgroup called titanosaurs, actually created the tracks.
Regardless of the inappropriate juxtaposition, though, getting those tracks out of the ground and set up at the AMNH was a massive paleontological undertaking. A YouTube video—posted above—shows actual footage of the 1938 excavation.
Although dinosaur tracks were known to local people since at least the beginning of the 20th century, it wasn’t until the late 1930s that the footprints garnered broad attention from paleontologists. Roland T. Bird, a fossil collector working with the AMNH, was roving the Southwest in 1937 when he got word of dinosaur tracks in the vicinity of the Paluxy River. When he got there, he found that the tracks supported a small local industry—everyone seemed to know about them, and many people had quarried tracks to sell for rock gardens. Fortunately for Bird, there were still plenty of tracks in the ground, including impressive trackways of multiple dinosaurs moving together.
The slab at the AMNH is one section of a large trackway that Bird had divided into three pieces. (The other two parts are at the University of Texas and the Smithsonian Institution.) Getting the tracks out was arduous, destructive work, made all the more complicated by the fact that at least some of the trackway went under the river. Bird and members of the local Works Progress Administration crew diverted the river to access and remove the tracks.
Bird’s tracks didn’t immediately go up on display. The broken pieces of excavated trackway just sat in the museum’s yard, and Bird’s health rapidly declined due to unknown causes and he was forced into an early retirement. When the AMNH decided to renovate its dinosaur halls in the 1940s, however, paleontologist Edwin Colbert asked Bird to come back to oversee the reconstruction of the trackway behind the museum’s “Brontosaurus” mount. Without Bird, the project would have been impossible—the broken trackway pieces were becoming exposed to the elements in the museum’s storage yard, and many of the fossil pieces were not labeled. The project was scheduled to take six weeks. Bird took six months, but, nonetheless, Bird and his collaborators were able to restore the steps of a Cretaceous giant.