RE: Blood pressure in Sauropoda

-----Original Message-----
From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu]On Behalf Of Buckaroobwana@aol.com
Sent: Monday, December 31, 2001 11:33 AM
To: dinosaur@usc.edu
Subject: Re: Blood pressure in Sauropoda

Greetings,
I hope everybody on-list had a Merry Christmas or Happy Hanukkah(I know I butchered the spelling of that, sorry...) Now on to the questions, Is there a consensus among the paleontology community about the horizontal posture of sauropod necks? As Bakker once asked, "Why evolove a 30 foot neck if all feeding is to be done on the ground?" It always seemed odd to me that such long necks would be used at a horizontal level. Is there any advantage to horizontal feeding with such a long neck? It seems to me that such a feature would have to evolve under selective pressures conductive to arboreal feeding. Also, what was the exact curvature of the diplodocid neck? I've seen it illustrated with the s-curve typical of theropods, and also coming straight out from the chest region and curving upward toward the head. What way do the neck vertebrae articulate?
Thanks to whoever responds,
Brian Buck

What needs to be looked at and is often over looked is the actually vertebrae! How they articulated is VERY IMPORTANT! I did an article for Prehistoric Times after reading;

Stevens, K. A., and Parrish J. M., 1996, Articulating three-dimensional computer models of Sauropod cervical vertebrae: Journal of Vertebrate Paleontology, v. 16, supplement to n. 3, Abstracts of Papers, Fifty-sixth Annual Meeting, Society of Vertebrate Paleontology, American Museum of Natural History, New York, New York, October 16-19, p. 67A.

Stevens, K. A., and Parrish J. M., 1997, Comparisons of neck form and function in the Diplodocidae: Journal of Vertebrate Paleontology, v. 17, supplement to n. 3, Abstracts of Papers, Fifty-seventh Annual Meeting Society of Vertebrate Paleontology, Field Museum, Chicago, Illinois, October 8-11, p. 79a.

Stevens, K. A., and Parrish J. M., 1999, Neck Posture and Feeding Habits of Two Jurassic Sauropod Dinosaurs: Science, v. 284, p. 798-800.

I wanted to check and see if they were right. I used Gilmore’s Apatosaurus monograph and drew each individual cervical and lined it up with the next, and guess what, the front of the neck turns DOWN!!! So they are right. Just because WE perceive something as being wrong, doesn’t mean it was. We see a long neck and automatically think the animal HAD to be eating from a high tree, not so.

>>David M wrote

I've got the opportunity to read this interesting paper. It concerns only Giraffatitan brancai and no other sauropods, about which it only includes cautionary notes about diversity. It arrives at the conclusion that G. held its neck vertically by measuring the areas of the intervertebral disks and calculating stresses. Unlike the paper that concludes that all sauropod necks were horizontal (ref later if needed), it considers the cervical ribs resistant against tension -- so that the head didn't fall on the back -- rather than as resistant against compression and providing the ventral bracing of a beam.<<

Whats the paper? And what intervertebral disks? I didn’t know anywhere preserved. In order to have a vertical neck you need to have a complete set of vertebrae to show the ‘last two?” cervical vertebrae were beveled to hold the neck like a Giraffe’s. I’ve seen a Giraffe’s neck vertebrae, actually played with them, and I’ve jet to see a sauropod quite like that (maybe Mamenchiosaurus). Now back to aquatic dinosaurs…

Tracy L. Ford

P. O. Box 1171

Poway Ca 92074