Dear Cecil: What happened to the brontosaurus? Number-one son (preliterate) recently acquired a major case of dinosaur love, so I've been spending a lot of time lately reading about prehistoric life in books with large type, lotsa pictures, and a sketchy sense of detail. In the course of this I've noticed there's something cooking with my favorite sauropod. There seem to be three possibilities: (1) The brontosaurus has been renamed the apatosaurus. (2) The brontosaurus was never really called the brontosaurus; that was just its popular name, and the dinosaur establishment for unspecified reasons is now cracking down and insisting on the scientific name Apatosaurus ajax. (3) There was never any such thing as a brontosaurus; there was only the apatosaurus, but nobody knew it until recently. What's the truth? Does this have anything to do with the story I heard that all the heads on all the brontos in all the museums everywhere had to be knocked off some years ago and changed? Clint P., Chicago

Cecil replies:

This is going to be a world-class bummer for all you Dino the Dinosaur fans out there, but it seems there’s been a little mistake. A couple mistakes, actually. First, Othniel Charles Marsh, the distinguished paleontologist who discovered the so-called brontosaurus, somehow managed to get the heads mixed up. Second, what he thought was a new species in reality was just another specimen of a previously discovered lizard called the apatosaurus. Since the name that comes first gets priority, apatosaurus stayed, and brontosaurus got the hook. Thus, officially speaking, there is no such thing as a brontosaurus, and what’s worse, what you thought was a brontosaurus actually doesn’t look like what you thought it looked like.

Now, admittedly, I’m exaggerating things a bit here. The apatosaurus really isn’t that much different from the brontosaurus. Basically, it has a longer snout, with more delicate teeth. It also has similar habits, including a moral commitment to vegetarianism. And no doubt the name brontosaurus will continue to be used by laymen. For we purists, though, it just won’t be the same.

Here’s what happened. In the late 1800s, O.C. Marsh was feverishly scouring the American West looking for new dinosaur species, lest he be beaten to the punch by his archrival, Edward Drinker Cope. Between the two of them, Cope and Marsh discovered half the vertebrate fossils known as of 1900. Unfortunately, what was popularly known as the “Dinosaur Wars” occasionally resulted in slipshod work. In 1879 O.C. dug up the skeleton of a jumbo-sized critter that was complete in every respect except one — it didn’t have a head. Never one to get hung up on details, O.C. rummaged around in the veld until he found a couple skulls that looked like they might fill the bill. Voila, the brontosaurus.

There was just one problem: one head was found four miles away from the main skeleton, the other one 400 miles away. Moreover, the skulls were found near the skeletons of another type of dinosaur called the camarasaurus, and in fact looked an awful lot like camarasaurus skulls. O.C. was thus asking the world to believe, in essence, that a whole passel of camarasauruses came along, spied Mr. Bronto, noticed how much he looked like themselves, slipped him a mickey, sawed off his noodle, and dragged it along with them until such time as they too departed this vale of tears. Needless to say, O.C. kept mum about this in his scientific paper on the subject. His colleagues bought his story, and the paleontological equivalent of the unicorn was born.

Questions about the brontosaurus began to surface fairly early on. The problem with the name got straightened out in 1903, at least for scientists, when it was pretty firmly established that the brontosaurus was the same species as the apatosaurus, which Marsh had discovered in 1877. The term brontosaurus thus lost its official standing. Nonetheless, the name has always stuck in people’s minds, and chances are it’ll survive in popular usage for a long time.

The business with the head was a bit more complicated. In 1909 researchers for the Carnegie Museum of Natural History began digging up what turned out to be a pair of apatosauruses in Utah. Near the neck of one, but detached from it, was a skull. It was not, however, a camarasaurus-type skull, but rather looked like that of another big lizard, the diplodocus. In a 1915 paper, Carnegie Museum director William Holland hinted that perhaps O.C. Marsh had messed up and given the apatosaurus the wrong skull. But nobody believed him, since Marsh was still held in high esteem. In 1936 another paleontologist named Charles Gilmore reviewed Holland’s claim. Unfortunately, by this time the original diplodocus-type had gotten mixed up with a smaller skull that probably belonged to an actual diplodocus. (Paleontologists seem to have a real problem with skulls.) Since the second skull was obviously too small, Gilmore dismissed the idea that it belonged to the apatosaurus.

It wasn’t until the 1970s that two researchers, Wesleyan University physicist John McIntosh and Carnegie Museum associate curator David Berman, were finally able to get all the heads straightened out. They assembled enough evidence to convince the scientific community to accept the real (we hope) story, namely, that the apatosaurus had a diplodocus-type head rather than a camarasaurus-type head. Museums around the country subsequently began modifying their skeletons accordingly — although I’m told that the apatosaurus at Yale’s museum still has camarasaurus feet. But let’s take one thing at a time.

Cecil Adams

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