The dinosaur diplodocus lived 150 million years ago. Adults could reach 170 feet in length, making them the biggest animals ever to walk the planet. These plant-eating creatures with lizard-like bodies could weigh more than 12 tons.
Artists often render the creatures stretching their snake-like necks to graze upon treetops.
But then what? Did they nibble the leaves? Or did they strip the leaves off tree branches with their mouths and swallow?
The dinosaur’s eating method has been uncertain since the first diplodocus skeleton was unearthed more than 130 years ago. But a team of scientists from several museums and universities, including the University of Missouri, may now have the answer. Their findings were reported this summer in the natural science journal Naturwissenschaften.
Using data from a CT scan, the team of researchers designed a three-dimensional computer model of a 2.5-foot-long diplodocus skull and tested it using finite element analysis (FEA), which is used to aid in mechanical engineering and design.
The process revealed the stresses on the dinosaur skull from three different eating behaviors: a normal bite, branch stripping and bark stripping.
“Originally, some scientists in the early 1900s thought that diplodocus would strip bark off of trees using its jaws to close down on the bark,” said Casey Holliday, MU assistant professor of pathology and anatomical sciences. “However, we found that this process places a lot of stress and strain on the dinosaur’s teeth and skull, which could result in bone damage or breaking of teeth.”
Were they leaf biters? Holliday said no because the anatomy of their skull and teeth would make them poor chewers. “They were swallowers,” Holliday said.
Analysis of CT scans of the skull suggested that branch stripping — when the dinosaur places its mouth on a branch and pulls the leaves off — was most likely. The technique “placed little or no stress on the teeth and skull,” Holliday said.
The information helps scientists better understand today’s large animals.
“Sauropods tell us about the evolution of gigantism, or giant body size, because they enable us to understand how much range or space giant animals really need to get around, and how much food they need to survive,” Holliday said.
“The findings on sauropods also help us understand today’s giant herbivores, such as elephants and giraffes, and how they interact with their environments.”