Long-Necked Dinosaurs: Heads Up!

"Long-Necked Dinosaurs Held Heads High"
LiveScience (June 1, 2010)

"The long necks of the largest dinosaurs that ever lived might have been raised high after all, a new study now suggests.

"The sauropod dinosaurs, which included titans such as Brachiosaurus, Diplodocus, and Apatosaurus (once known as Brontosaurus), are well-known for the very long necks they usually sported. The lengthy neck extended the animal's reach for grabbing food.

"However, it has recently proven controversial as to whether sauropods actually ever held their heads up high to dine on hard-to-reach leaves because of all the energy needed to pump blood to such heights. Most researchers, for instance, do agree that Apatosaurus and Diplodocus likely kept their necks low while grazing.

"Now, at least for some of these sauropods, research suggests the goliaths did indeed hold their heads up high...."

For example, Euhelopus zdanskyi weighed in the neighborhood of 8,400 pounds and was about 36 to 39 feet long, nose-to-tail-tip. Bones let the University of Flensburg, Germany's functional morphologist Andreas Christian run numbers on what sort of stresses the neck and head would have experienced when the animal was alive.

Turns out, a giraffe-like posture with the neck held straight at about a 45 degree angle would not have been too hard to hold aloft. For a few minutes at least.

More number crunching showed that holding the neck up like that would pay off in added energy, if the dinosaur had moved just its neck around to get at high leaves, instead of shifting its entire body to get at food.

I doubt that this is the last word on the habits of long-necked dinosaurs: particularly since we currently lack any live specimens. Even if (when?) someone manages to reconstruct dinosaur DNA and coax it into growing a dinosaur for study, the animal's behavior will be debatable, since it can't be observed in its natural habitat, and - perhaps more to the point - wasn't raised in the wild.

Sort-of-related post:

• "Bringing Back the Dinosaurs: Not a Crazy Idea Any More"
  (June 29, 2009)