April 3, 2012
In 1941, Czech paleo-artist Zdeněk Burian created one of the most iconic dinosaur images ever. I saw it four decades later, in one of my childhood science books, and the illustration amazed me as soon as I saw it. I still love it. Not because it’s correct, but because the painting so beautifully captures an obviously incorrect idea.
The painting, in careful detail, shows a trio of Brachiosaurus neck-deep in a prehistoric lake. Two poke their grinning heads above the surface, while a third plucks a gob of soft aquatic plants from the silty lake bottom. It was reproduced in a TIME/LIFE young readers nature library book on evolution, and I fondly remember opening the book to that page and taking in the Jurassic scene.
I am surprised this strange sauropod imagery was cherished by so many for so long. Brachiosaurus was a little more streamlined than an office building, and if the dinosaur led a watery life, it looked capable only of sticking its pylon-like legs into the muck and waving its head around to strain algae. And then there was the Goldilocks problem—an aquatic Brachiosaurus would require rivers and lakes of just the right size and depth to survive. To make matters worse, Brachiosaurus would have needed to haul themselves out and go looking for mates in other hot tubs if the species was to continue. Despite recent suggestions that these huge dinosaurs were capable of amorous aqua-acrobatics, I’m not convinced the exceptionally air-filled, buoyant sauropods could have pulled off the required underwater maneuvers. Brachiosaurus, and its counterpart Giraffatitan from the Jurassic of Tanzania, were creatures of the terrestrial realm, just like all other sauropods.
In fact, with the exception of feathery dinosaurs that took to the air, all dinosaurs were land-dwellers. This fact has been amply documented by studies of dinosaur anatomy and trackways and by attempts to reconstruct the habitats where dinosaurs actually lived. After all, paleontology relies on a combination of anatomy and geology, and by pulling at those two threads paleontologists have been able to investigate how dinosaurs interacted with the various habitats they called home—be they fern-covered floodplains, dense forests, or sandy deserts. To pick just one example, paleontologists Chris Noto and Ari Grossman recently reviewed the pattern of global ecology during the Jurassic dinosaur heyday and found that aridity—which affected vegetation in prehistoric forests—influenced the abundance and variety of herbivorous dinosaurs present in different parts of the world. As paleontologists keep digging and poring over what has already been found, the ecology of the dinosaurs is coming into clearer and clearer focus.
All of which is to say that I was dumbfounded when the BBC’s Today program ran a sensationalist story about a so-called dinosaur debate that isn’t really a debate at all. You can listen to the brief story yourself here, presented by journalist Tom Feilden. (I have clashed with him about dinosaur journalism before.) The upshot is that dinosaurs should be shown wading through prehistoric lakes, not walking along the edges of prehistoric forests.
Feilden talks to Brian J. Ford—identified as a cell biologist and with no apparent expertise in paleontology—about why dinosaurs seem to be all wrong. Ford is given relatively little time to explain himself, but insists that dinosaurs were simply too big to have walked on land. “The tail of a dinosaur could weigh ten, twenty tons,” Ford says, which isn’t a precise statement or one that seems to be derived from evidence. Let’s assume that “a dinosaur”—which dinosaur is unclear—had a 20 ton tail. To put this in perspective, in his revision of Brachiosaurus, sauropod expert Mike Taylor estimated the huge Giraffatitan to be about 23 tons in life. Ford is suggesting that some dinosaurs had tails about as heavy as an absolutely huge sauropod, but not surprisingly, where he is drawing this information from isn’t mentioned. Things don’t get better from there.
To Ford, dinosaurs must have lived in perpetually flooded habitats. His whole argument boils down to “Dinosaurs look big!” A popular-audience article in Laboratory News gives Ford some additional space to spell out his ideas, though this does the reader little good. Dinosaurs were big and had heavy tails, Ford tells his audience, ergo, they make no sense on land. That’s it—that’s the whole basis for his speculation. Ford does not appear to have reviewed any of the literature on dinosaur biomechanics or body mass. He just flatly says that dinosaurs, as often depicted, aren’t right. Or as Ford succinctly frames his idea in the final paragraph, “Dinosaurs look more convincing in water.”
I would be remiss if I didn’t point out that Ford isn’t just talking about sauropods. He applies his idea to all large, multi-ton dinosaurs, and goes so far as to suggest one of the strangest ideas I have ever heard for the relatively small forelimbs of tyrannosaurs. Again, Ford uses an aquatic environment as an answer. “The fact that the limbs [of Tyrannosaurus] became foreshortened is entirely reasonable,” he wrote, since “animals like to inspect their food as they eat, and holding it closer to the face is normal behaviour.” Imagine a submerged Tyrannosaurus, trying to peer down at a fish in its arms. If you have ever looked at a tyrannosaur skeleton at all, you can see how downright silly this is. Tyrannosaurus would have to strain its neck pretty hard to get even a glance at whatever it might try to hold in its two-fingered hands. This is the sure sign of a rather crummy idea—the idea is not only unscientific, but it attempts to answer almost every question about dinosaur evolution, biology and extinction.
And there’s an important fact Ford totally missed in his position piece. While he criticizes interpretations of the dinosaur track record, Ford doesn’t mention that there are actually rare traces of dinosaur swim tracks. The majority of dinosaur tracks indicate that the animals primarily lived on land, but some dinosaurs, primarily medium-sized carnivores, sometimes went into the water. If dinosaurs really did live in water, we’d expect to see many more swim tracks in the fossil record, but these trace fossils are a rarity. We know the kind of tracks dinosaurs left on land, and we know what kind of tracks at least some made in water. Based on the track evidence, Ford’s idea immediately sinks.
Ford’s ideas are zany. That’s not a crime. There are plenty of weird ideas about prehistoric life around the web—the idea that tyrannosaurs hugged trees to hide from prospective prey is probably my favorite nonsense idea. But Feilden did not do his due diligence as a journalist. He reported this story as if there actually was a shred of merit to it, when all that was behind the story was a cell biologist who entirely ignored paleontology. Ford’s comments seem to stem from watching Walking With Dinosaurs—there’s no indication that he has carefully researched the subject he pontificates upon. (In searching for depictions of dinosaurs to criticize, Ford takes an image created for a creationist website as the best science can offer. Oops.) As paleontologists Mike Taylor and Dave Hone have already pointed out on their blogs, there’s not even really a discussion worth having here. Ford presents no actual evidence for his claims, and Feilden uncritically ran with the unsupported assertions.
To his credit, Feilden spoke to dinosaur expert Paul Barrett at the Natural History Museum for a second opinion, but that’s small consolation in a story that didn’t deserve the attention it received in the first place. If there is a story here, it’s about how a cell biologist arrogantly ignored the evidence collected over decades in a different field in an attempt to foist his own just-so stories on dinosaurs to ease his own discomfort at seeing landlubber Diplodocus. Even worse, Feilden makes a connection between the dissenting Ford and Galileo—Galileo, for crying out loud—to hint that Ford’s idiosyncratic views, unfettered by the problem of actually looking at the evidence, may turn out to be right. No. Just no. The accumulated tonnage of evidence places dinosaurs as primarily terrestrial beings, and simply ignoring all of that for the sake of controversial isn’t amazing news. It’s bad science communicated by bad journalism.
March 15, 2012
Brachiosaurus used to hold the title of biggest dinosaur ever. I remember when, as a young dinosaur fanatic, books and documentaries told me that this long-necked dinosaur was the ultimate prehistoric titan. Then Supersaurus, Argentinosaurus and other super-sized dinosaurs came along and ruined all the fun. Even worse, paleontologists recently realized that we actually know very little about what Brachiosaurus really looked like.
In 1903, paleontologist Elmer Riggs described Brachiosaurus altithorax from fossils discovered in the 150-million-year-old Late Jurassic strata of western Colorado. The dinosaur, which Riggs believed to be the largest known, was represented by a huge humerus and assorted elements of the shoulder girdle, hips, hindlimbs, vertebrae, ribs and a few other miscellaneous parts. Despite the relative smattering of material, though, the proportions of the bones led Riggs to conclude that he had found a previously unknown dinosaur that was significantly larger than Apatosaurus, Diplodocus and other giants which lived at the same time.
Fossils discovered by German expeditions to Tanzania seemed to fill out the form of Brachiosaurus. At the beginning of the 20th century, the Late Jurassic deposits of Africa were believed to be roughly equivalent to those of western North America, and so dinosaurs discovered in Tanzania’s Tendaguru Formation were often assigned to genera known from the Morrison Formation of Colorado, Utah and Wyoming. As a result, paleontologist Werner Janesch described partial skeletons and skulls of a large sauropod dinosaur from Tanzania under the name Brachiosaurus brancai. The fact that the material from Africa was more complete allowed paleontologists to get a better idea of just how big the dinosaur was—Brachiosaurus brancai reached over 80 feet long and may have weighed more than 25 tons.
But there’s a major problem with this approach. Paleontologists recently determined that the brachiosaurs from Africa and North America don’t actually belong to the same genus after all. Artist Gregory S. Paul noted differences between the two brachiosaurs in 1988, and in 2009 sauropod expert Mike Taylor confirmed that the two dinosaurs were different enough to warrant placement in separate genera. Furthermore, a skull fragment tentatively assigned to Brachiosaurus hints that the traditional picture of the dinosaur may have been skewed by reliance on fossils from Tanzania. While the North American form has retained its name, Brachiosaurus altithorax, the dinosaur from Tanzania is now called Giraffatitan brancai. Thanks to a name change, we know significantly less about Brachiosaurus than we thought we did.
Then again, a reevaluation of another Jurassic dinosaur skeleton may provide a rough idea of what Brachiosaurus looked like as a baby. In 2007, Daniela Schwarz-Wings and colleagues described a juvenile sauropod skeleton found in Wyoming’s Howe Stephens Quarry. This Late Jurassic specimen was designated SMA 0009, and was initially thought to be a young diplodocid dinosaur. But in a new paper published in Palaeontology, Schwarz-Wings, José Carballido and colleagues have amended their diagnosis. Additional preparation of the partial skeleton revealed that the dinosaur was not a close relative of Diplodocus and Apatosaurus at all, but was more closely related to Brachiosaurus.
Schwarz-Wings and co-authors refrained from assigning SMA 0009 to a particular dinosaur species. The fact that the animal is a juvenile confounds precise identification attempts—dinosaurs changed significantly as they grew up, and the traits seen in adult dinosaurs may not have been present in juveniles. Likewise, the revised idea that SMA 0009 is a brachiosaur makes comparisons difficult since paleontologists have yet to assemble a complete picture of an adult Brachiosaurus. Still, since the young dinosaur is grouped closely with Brachiosaurus, and Brachiosaurus was the only dinosaur of its kind present in the Morrison Formation, there is a good possibility that SMA 0009 is a young Brachiosaurus. Until someone finds more complete remains of this rare and enigmatic dinosaur, however, Brachiosaurus will remain a dinosaurian enigma.
CARBALLIDO, J., MARPMANN, J., SCHWARZ-WINGS, D., & PABST, B. (2012). New information on a juvenile sauropod specimen from the Morrison Formation and the reassessment of its systematic position Palaeontology DOI: 10.1111/j.1475-4983.2012.01139.x
RIGGS, E.S. (1903). “Brachiosaurus altithorax, the largest known dinosaur.” American Journal of Science (series 4) 15(88): 299-306.
TAYLOR, M.P. (2009). “A Re-evaluation of Brachiosaurus altithorax Riggs 1903 (Dinosauria, Sauropod) and its generic separation from Giraffatitan brancai (Janensh 1914).” Journal of Vertebrate Paleontology, 29(3): 787-806
December 9, 2010
I have never been particularly good at sending out Christmas cards. By the time I get into the holiday spirit and remember, it is usually December 24th. This year, however, the Etsy member FrankNBones has given me a good excuse to do things right with a unique set of dinosaur holiday cards!
Featuring the dinosaur celebrities Tyrannosaurus, Triceratops, Velociraptor, Brachiosaurus, Dilophosaurus and Parasaurolophus, each card depicts a dinosaur skull with a holiday flourish. (I especially like the Dilophosaurus skull with the jingle bells.) Each one is unique. As their creator explains on the store page:
These original, hand-pulled linocut carvings are printed on 5×7 inch cards. The linoleum blocks were cut by hand, inked, and printed individually. Due to the printing process, there are variations and imperfections from print to print, and no two cards are the same.
Now all I have to do is figure out what to write inside them. (“RAWR”?)
September 9, 2010
Since the time of their discovery in the early 19th century, dinosaurs have been pop-culture superstars. Beyond their scientific identities, they have a celebrity that has remained strong from decade to decade, and given their notoriety it is no wonder that they have been so often used as metaphors and symbols.
More often than not, dinosaurs have been used as icons of stagnation. They were creatures that seemed “too big to fail”—only to have their gargantuan size turned against them. This belief stemmed from uncertainty about the extinction of the dinosaurs. At the beginning of the 20th century, many naturalists thought that dinosaurs were either out-competed by mammals or became so big and grotesque that they could no longer adapt to changing environmental conditions. Either way, they ultimately failed because they were too large and ponderous to react appropriately in the face of new challenges, and so they became the perfect icons of big business. Jay S. Miller, in a 1913 issue of the Business Philosopher, put it this way:
But why was the dinosaurs, with all its size and strength, finally compelled to succumb to its weak and apparently helpless rivals [the mammals]?
The answer is easy. It was their degree of adaptability to changed conditions.
In spite of its seeming advantages, the dinosaur possessed little ability to respond to changed conditions. Just so long as its environment was favorable and congenial it continued to flourish. But when its surroundings began to change and become less favorable it failed to adapt itself to these changes and was necessarily slowly but surely exterminated.
The lesson behind all this was that, to survive in business, being able to swiftly adapt to new conditions was key. Better to be like the small mammals than the powerful dinosaurs. A May 1919 issue of The Shoeworkers’ Journal similarly admonished cordwainers to be more like mammals and less like dinosaurs. Of dinosaurs, the article’s author, Victor McCone, said:
They planned nothing. They were contented.
They produced nothing. They were contented.
They achieved nothing. They were contented.
They voted “no” on life above the dead line.
Once again, mammals showed the potential of mental agility and innovation, leading McCone to offer his readers a choice:
Will you be a man or a dinosaur? Are you going to be chained down by beef and boneheadedness? Or will you cultivate every personal excellence, all the skill you have no matter what you are doing, and rise out of the cellar of life? It is up to you.
A century later, these disparaging perspectives of dinosaurs seem rather silly. Dinosaurs were not a homogeneous group of large, lazy, and stupid creatures that died out one by one. They were a very diverse group of organisms, one lineage of which left living descendants, and they were done-in by a cataclysmic event that wiped out a variety of organisms (including some groups of mammals). If we look back even further, we can see that the kin of the first mammals were pared back by an even worse extinction, yet it would be ludicrous to say that the origin of mammals was delayed because their ancestors were so short-sighted and slothful that they ceded ground to the more agile dinosaurs. Ultimately, any use of dinosaurs as a metaphor or symbol for human endeavor tells us more about the way we view dinosaurs than what they were actually like.
August 19, 2010
On my way back from Montana, I had a layover in Chicago’s O’Hare International Airport, and it was there that I spotted this impressive mount of Brachiosaurus altithorax. Another skeletal restoration of the immense dinosaur stands outside the city’s famed Field Museum. I have to say that seeing this one near my departure terminal made me think about heading right back out into the field.