Nathan Myhrvold, the Microsoft millionaire who went on to found Intellectual Ventures, is a huge dinosaur geek. But not just any dinosaur geek: He funds paleontological digs, gets heavily involved in research and keeps a life-size T. rex skeleton in his living room. Now he and other scientists have built a quarter-scale dinosaur tail to show that giant sauropods really could snap their tails at supersonic speeds.
Myhrvold and University of Alberta paleontologist Philip Currie first made that claim 18 years ago, based on computer modeling. But their hand-operated contraption – a 44-pound tail section that’s assembled from 3D-printed vertebrae and tipped with a bullwhip popper – provides an ear-splitting demonstration of the effect.
“Personally, I think one of the most interesting aspects of this is the process of using physical simulations to try to ascertain the behavior of extinct animals,” Dhileep Sivam, a bioinformatics specialist who works at Intellectual Ventures, told GeekWire in an email.
Sivam, Myhrvold and Currie are the authors of a poster about the research, which was presented Thursday at the Society of Vertebrate Paleontology’s annual meeting in Dallas. The long-running study addresses an even longer-running mystery about diplodocids, a class of plant-eating sauropods that includes Apatosaurus and the recently re-recognized Brontosaurus.
Here’s a video showing how the robo-tail was created.
“Despite the massive size of these animals, they had tiny vertebrae towards the end of their tails, and it’s hard to see what good such a small structure could do them,” Sivam said.
Modern-day monitor lizards are known to whip their tails to strike back at intruders – in fact, there’s at least one case in which a monitor delivered a stinging blow to a researcher’s eye. But Myhrvold and his colleagues say the vertebrae of a sauropod would have been too small to do much damage to an attacker. “Indeed, a hit of sufficient force to cause serious damage to such a hypothetical predator would likely cause more damage to the tail than to the assailant,” they write.
They propose instead that the dinosaurs whipped their tails to produce a sonic boom, similar to the crack of a bullwhip. The objective wouldn’t be to hurt their foes, but to scare them off.
The physical simulation suggests that the sauropod known as Apatosaurus louisae, which lived about 152 million years ago, could swing the tip of its tail at speeds of up to 370 meters per second (828 mph), producing a whip-crack as loud as the report of a naval gun.
“This indicates that it might have been a form of communication – either scaring off other animals, attracting mates, communicating otherwise,” Sivam said. “I’m not sure if any other species in the world uses supersonic tail-based communication. So if this were true, it represents a novel behavior. Of course, this experiment just suggests the possibility of supersonic movement, and the rest is conjecture, but it’s fun to think about.”
And you’ve got to admit it’d make for a cool sound effect in the “Jurassic World” sequel that we all know is coming.
