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Robert Bakker, curator of paleontology for the Houston Museum of Natural Science, helps out at the dig. "If you want to understand the late Jurassic, you need to understand the common animals, which means Apatosaurus," he says. "This is the original Apatosaurus quarry, and it's a ‘triple-decker'—the only one in the world with three dead Apatosaurus buried one on top of each other."
Most people know Apatosaurus as Brontosaurus because of a mistake made by Marsh. In 1879, two years after he named the first Apatosaurus, one of his workers discovered a more complete specimen in Wyoming. Marsh mistook it to be a new animal and named it Brontosaurus. Though the error was soon discovered, scientific nomenclature required keeping the first name. But in the meantime the "Brontosaurus" misnomer had made its way into popular culture.
For almost 100 years, Apatosaurus was portrayed as a swamp-bound animal whose immense body was buoyed by water. In the 1960s, Bakker joined a handful of paleontologists who argued that the massive beasts were really more like elephants: all-terrain animals that could roam over the flood plain, through river channels and anywhere else they wanted to go.
Bakker, then an undergraduate at Yale, went to Morrison to see if Apatosaurus' habitat supported his idea that the beasts were mobile. But he and two students spent two years unsuccessfully hunting for Quarry 10, which aside from being partially filled in, as Bakker finally discovered, was also obscured by bullet cartridges, beer cans and other remnants of teenage outings.
Today, Bakker is sifting through Lakes' spoil pile—lumps of clay stone that the 1870s crew tossed aside—when someone in the pit excitedly calls for him. He scrambles down into the hole, where his bearded face lights up under his straw cowboy hat. The museum crew has uncovered what appear to be Jurassic-era castings of a small tree's root system. "This is a big deal," says Bakker, using a finely bristled brush to baste the knobby fossils with glue. "In ‘CSI' terms, that's the crime scene floor. Victim number one"—the Apatosaurus found in 1877—"lay buried just above."
The clue adds to evidence that Apatosaurus did not live in water. The team has found layers of sediment consistent with a small pond, but none of the crocodile or tortoise fossils typically found in swamps from the Jurassic Period more than 200 million years ago. This spot may have attracted generations of Apatosaurus, Bakker says, because it provided a watering hole on a dry wooded plain. "If there was a forest, there would be a lot more wood—and there isn't—and a lot more fossilized leaves—and there ain't. So it was a woodland but probably a lot like Uganda—hot tropical woodland that was dry for most of the year."
The most significant recent discoveries at the Morrison quarries have been dinosaur tracks. Early dinosaur hunters overlooked them. In Quarry 10 and another Lakes quarry less than a mile away, museum staff have recovered 16 Stegosaurus tracks. They include ten hatchling tracks—the first ever discovered. One rock appears to show four or five baby Stegosauri all heading in the same direction. Another boulder includes a partial juvenile Stegosaurus hind paw track that was stepped on by an adult Stegosaurus. "It suggests that Stegosaurus moved in multiple-age herds," says Mossbrucker, and adults may have cared for hatchlings.
The researchers have also found the world's first baby Apatosaurus tracks. They could change paleontologists' view yet again: the tracks are from the rear legs only, and they are spaced far apart. "What's really cool about these tracks is that the baby animal is functionally running—but it's doing this just on its back legs. We had no idea a Bronto could run, let alone scoot along on its hind legs like a basilisk," Mossbrucker says, referring to the "Jesus lizard" that appears to walk on water.
Related topics: Dinosaurs Fossils Jurassic Period 19th Century Colorado
Additional Sources
"The Sauropod Chronicles," by Richard A. Kissel, Natural History, April 2007
Historic Dinosaur Quarries of the Dinosaur Ridge Area by Adrian Hunt et al., Friends of Dinosaur Ridge and the University of Colorado at Denver, 2002


Comments
I thought "Where Dinosaurs Roamed" from your May 2008 issue was a great article by Ms. Rajewski; a fascinating read about "battling" paleontologists. It's amazing how uncivilized acedemics can be to each other. I thought this was a well-researched piece that didn't get lost in facts: the writer wove a lively narrative that made the most of the limited word count. I enjoy reading Smithsonian whenever I pick it up, but felt compelled to offer kudos for this story because it left me wanting to learn more. I am curious to know, however, why the writer was given such limited space for such a compelling story? (Is she working on a book on this topic? If so, I will keep a look out for it.) Perhaps I am a "dinomaniac," like the writer, but I thoroughly enjoyed this story and look forward to reading more of Ms. Rajewski's fine journalism. Well done. Smithsonian.
Posted by George Corsiglia on April 25,2008 | 06:40PM
Where are the Morrison Quarries? My Microsoft Streets & Trips does not yield the site the article discusses. Is it in or near Dinosaur National Monument?
Posted by Philip Neal on April 26,2008 | 07:01PM
The Morrison quarries are known as Dinosaur Ridge. The Friends of Dinosaur Ridge (http://www.dinoridge.org/) offer tours, and paleontologists at the Morrison Natural History Museum (http://www.mnhm.org/) dig there.
Posted by Sarah on April 30,2008 | 08:55AM
This is wrong, this isn't the 'first' time 'Apatosaurus' i.e. sauropod junile tracks were found of them walking bipedally. In fact the first one that I know of was in 1996. Ferrusquia-Villafranca, I., Jimenez-Hiadalgo, E., and Bravo-Cuvas, V. M., 1996, Footprints of Small Sauropods from the Middle Jurassic of Oaxaca, Southeastern Mexico: In: The Continental Jurassic, edited by Morales, M., 1996, Museum of Northern Arizona Bulletin, n. 60, p. 119-126. I even did a drawing of an Apatosaurus (adult) walking bipedally through a termite mound 'field in 2000. Tracy
Posted by Tracy Ford on April 30,2008 | 10:45PM
In response to Tracy Ford: The article is correct. I'm pretty sure that the tracks you are referring to are from the Middle Jurassic, far too old to be from Apatosaurus proper. Regardless, these footprints are from a site were Apatosaurus was found. I have seen these tiny sauropod tracks at the Morrison Museum, and they show distinct claw impressions that link them to Apatosaurus. The article references not just bipedal tracks but “functionally running” tracks. This too would distinguish these footprints from the Mexican tracks. I hope this adds clarity. Great article.
Posted by Tim Mulvey on May 2,2008 | 03:27PM
You left out the "insult" that Marsh saddled his rival Cope with for all time. I was told that after finding fossilized poop, Marsh, in honor of his rival named it coprolite, so that Cope would be associated in perputuity.
Posted by Christian Edwards on May 13,2008 | 07:53AM
William Buckland, an English geologist, coined the term "coprolite" in the early 1800s. It is derived from the greek words kopros, meaning "dung", and lithos, meaning "stone".
Posted by Sarah on May 16,2008 | 01:19PM
Hi, my name is amber i am 13 years old and i have a therory for this type of stuff, archaeology is something more than just digging up fossils and finding bones it gives us an idea about how wedo stuff to save the planet or find out how others lived there lives. you compare and contrast, there are so many things you can figure out. I know that ur thinking that this is wrong accepting this from a young girl but its the truth. I have learned alot. sincerly, amber mock
Posted by amber mock on March 19,2009 | 08:49AM