Brian Switek in Smithsonian Magazine:
Living large isn’t easy. The sauropod dinosaurs—the biggest creatures to ever walk the Earth—required rapid growth rates, skeletons that were both light and strong and copious amounts of food, just for starters.
Now, paleontologists may have cracked one of the remaining mysteries about these giant dinosaurs: How did they pump enough blood up their long necks to feed their brains?
University of Southern California paleontologist Michael Habib was inspired to investigate sauropod necks after seeing bones from a giant titanosaur found in the New Mexico desert. The well-preserved neck bones included spines called cervical ribs that stretch almost six feet long. These rods, Habib says, turned out to be made of a very flexible sort of bone that “made pretty darn good springs.”
As the giant dinosaurs walked, the motion would have created an “inertial problem” for the sauropods. Without something to dampen this effect, Habib says, “the neck is going to start to sway back and forth like a badly mounted crane or tree in a breeze.”
This is where the cervical ribs came in. These springy bones dampened that effect, allowing the dinosaurs to keep their necks relatively steady as they plodded along, Habib told researchers gathered last week at the Society of Vertebrate Paleontology meeting in Dallas, Texas.