I.
from “Buried Treasure,” Newsweek, 6/27:
Other researchers have been doing equally remarkable things with [dinosaur] bones. Kent Stevens, a computer scientist at the University of Oregon, became interested in the large long-necked sauropods of the late Jurassic Period, about 150 million years ago. Members of this family, which includes apatosaurus and diplodocus, were assumed to be treetop browsers, usually depicted standing foursquare with their heads high above the ground, like fat, short-legged giraffes…. But when Stevens modeled the bones on his computer, he discovered the vertebrae just don’t seem designed to fit together that way. Instead, their natural position seems to lie almost parallel to the ground, or even below the horizontal, where the animal could browse on low shrubs or aquatic plants. This has been an unwelcome revelation to many laymen, Stevens has found.
II.
Dr. Stevens:I am a curious layman who recently read with great interest the Newsweek article that featured your research so prominently. I was intrigued to read about your computer models and what they suggested about the behavior of long-necked sauropods (since it challenged everything I thought I knew about them, rendering my education more worthless still) but the article left a question unanswered that has bugged me ever since I read it: if diplodocus couldn’t use its long neck to reach tall branches, why did it have such a long neck in the first place? Conventional wisdom holds that an animal with such an unusual feature must have evolved in response to some kind of need or environmental factor. In other words, one does not need a 20-foot neck to eat a shrub.
I realize that computer science is your area of expertise, but given the nature of the project described in Newsweek I thought you would be able to point me in the right direction one way or another. Any insight would be greatly appreciated.
Jim Ski
III.
Mr. Ski:Good questions. Please check out the discussions on my webpage www.cs.uoregon.edu/~kent under DinoMorph. It shows up in several places, including the discussion of Apatosaurus on that link and in the Science article which you can read online or download.
My colleague Michael Parrish and I side with those who have suggested that some dipolodocids, like Apatosaurus and Diplodocus, were potentially feeding along riverways, using their long necks to reach out without getting their forelimbs mired. There’s no proof that this was their lifestyle, but it’s consistent with various clues (dentition ill suited for very hard vegetation but well suited for soft river plants and a center of mass that is back near their hindlimbs).
Also, on dry land, it turns out very economical to swing the neck around and eat a swath of low fodder while standing in one place.*
I appreciate your writing. I hope you enjoy the discussions that I have on my webpages, and I welcome input from all quarters!
Sincerely,
Kent
Moral:
Crazy old shut-ins know what they’re doing: write more random letters to the people in the newspaper. It doesn’t cost anything, and you learn about dinosaur necks.
* Can you even imagine the time it would save if you could reach your Cheerios, your juice, and your toast without using your hands or bending forward? I have to evolve me one of those necks.