May
28
2009

The Dinosaur Mystique

I was like you once, suffering under the misguided notion that sauropods, like Brachiosaurus or Apatosaurus, held their heads low to the ground and their necks horizontally. Turns out, that was just another body myth perpetuated by Hollywood and the mainstream media. And museums, and public television. Scientists now think that these giant creatures held their heads high. And rightly so. I would be proud if I weighed twenty tons. That is quite the feat.

New evidence suggests that these dinosaurs held their necks vertically like giraffes. That means that they would have been up to 49 feet tall. Which is really, really tall, in case you were wondering.

Scientists studied x-rays of vertebrae from ten different groups of vertebrates, or animals with backbones, and found that animals with the same upright leg posture as these dinosaurs, like mammals and birds, have vertical vertebrae.

This means that, in the words of Dr. Mike Taylor, who was instrumental to this research, “Unless sauropods carried their heads and necks differently from every living vertebrate, we have to assume that the base of their neck was curved strongly upwards. In some sauropods this would have meant a graceful swan-like S-curve to the neck, and a look quite different from the recreations we are used to seeing today.”

The research also showed that sauropods would have had a much greater range of movement than previously thought. By observing the structure of neck vertebrae in animals like ostriches and giraffes, researchers discovered that the ball and socket joint structure of sauropods was probably more flexible than scientists believed.

The next step in this research is to determine, through engineering studies, whether holding the neck vertically or horizontally is more efficient. Imagine having a thousand pound neck to support! Oy. I can't even bench press the bar! Of course, sauropods have a little bit of a weight advantage, I mean, I only weigh half a ton. But still.
an extremely realistic apatosaurus
an extremely realistic apatosaurusCourtesy Mykl Roventine

Your Comments, Thoughts, Questions, Ideas

Thor's picture
Thor says:

I've seen a lot of coverage of this in the media in recent days. Yet I'm conflicted. Working in dinos exhibits here at the museum, I've passed along to visitors the old line of thinking that sauropods kept their heads down. One of the main arguments for that was that they wouldn't have a heart large and strong enough to pump blood all the way to the top of their heads in a vertical position. Yet, none of the new stories on this topic reference that old concern. What have I been missing?

posted on Fri, 05/29/2009 - 2:32pm
JGordon's picture
JGordon says:

You know, I've been thinking about this too, but I bet it's not as big a deal as it's sometimes made out to be. Or it is a big deal, but not something nature couldn't find a way around.

It makes me think of the example of pterosaurs, where some biologists have insisted that there's a size limit beyond which wing bones couldn't support their own weight... but then there are these pterosaurs that, like it or not, have mind-bogglingly huge wingspans. So it (their bodies, that is) worked, just not under whatever rules or analogy the naysayers were operating under. That's not to say that whatever potential physical trait I think is awesome about an extinct reptile could necessarily work (the Dinosaur Heresies might fall into this trap on occasion), only that it probably doesn't serve us well to get stuck to a particular train of thought just because giraffes have stupid little hearts. (Or something.)

I remember someone telling me once about how horses have sort of spongy tissue in their feet that helps maintain blood pressure in their legs just by being walked on. I'm not saying that sauropods had this feature, but I don't think it's unreasonable to assume that they might have had something similar to help with the high head thing. Some feature in their neck muscles maybe? (I'm just pulling this out of the air, so don't judge.)

posted on Fri, 05/29/2009 - 3:04pm
mdr's picture
mdr says:

Wild newspaper depiction of brontosaurus c. 1890
Wild newspaper depiction of brontosaurus c. 1890Courtesy Public domain
Speculation regarding sauropod posture has been going back and forth for at least a hundred and thirty years – ever since the creatures were first discovered. Over that time, depictions of sauropods such as Diplodocus and Brontosaurus (Apatosaurus) have shown their necks going up and down like an elevator. Brontosaurus excelsus: Paleontologist O. C. Marsh's figure for his 1883 monograph on sauropod.
Brontosaurus excelsus: Paleontologist O. C. Marsh's figure for his 1883 monograph on sauropod.Courtesy Public domain
Pioneer American paleontologist, O.C. Marsh’s 1883 figure of the brontosaur shows it with a near horizontal, slightly downward “S” curve.

Charles R. Knight illustration c. 1900
Charles R. Knight illustration c. 1900Courtesy Public domain
But artists and scientists weren’t against showing sauropod necks raised in near 90-degree angles to the body. Even famed artist Charles R. Knight’s illustrations waffled between positions.
For several decades a more lofty neck position seemed to dominate scientific thinking. But in the later part of the 20th century, a more downward trend became popular again. Apatosaurus. More horizontal: Geological Museum at the University of Wyoming in Laramie, c. 2006 The skeleton was remounted in 2008.
Apatosaurus. More horizontal: Geological Museum at the University of Wyoming in Laramie, c. 2006 The skeleton was remounted in 2008.Courtesy Mark Ryan
This certainly influenced conceptions in both scientific and popular cultures.

Diplodocus, Science Museum of Minnesota: Evidently the SMM mount has been ahead of its time with a raised head and neck since at least 1999 (and maybe even prior to that).
Diplodocus, Science Museum of Minnesota: Evidently the SMM mount has been ahead of its time with a raised head and neck since at least 1999 (and maybe even prior to that).Courtesy Mark Ryan
I don’t think the latest theory puts an end of the controversy. It reminds me of how hemlines seem to rise and fall over the years. I wonder if there’s a correllation?

posted on Fri, 05/29/2009 - 4:27pm
Matt Wedel's picture
Matt Wedel says:

Hi, I'm one of the authors on the new study. Thor asked about blood pressure, and pointed out that it hadn't come up much in the news coverage on this. Partly that's because this paper is mainly about the posture living animals, and extending that to sauropods and other dinosaurs. It's also partly because we have a paper in the works on blood pressure but it's not ready to go yet. We do feel that the blood pressure problem has been overstated, and hopefully soon we'll have some published results to back that up. Stay tuned!

posted on Tue, 06/02/2009 - 1:16pm

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