ANN ARBOR, Mich., March 31 (UPI) — U.S. paleontologists say they’ve discovered some sauropod dinosaur species’ skull shapes changed drastically during normal growth.
University of Michigan researcher John Whitlock and Assistant Professor Jeffrey Wilson, along with Matthew Lamanna of the Carnegie Museum of Natural History in Pittsburgh, said they made the discovery at the museum while studying the skull of a juvenile Diplodocus, a 150 million-year-old sauropod from western North America.
“Adult sauropod skulls are rare but juvenile skulls are even rarer,” said Whitlock, a doctoral candidate in the university’s Museum of Paleontology. “What we do know about the skulls of sauropods like Diplodocus has been based entirely on adults so far.”
Wilson, an assistant curator at the university’s museum, said Diplodocus had an unusual skull. “Adults had long, square snouts, unlike the rounded or pointed snouts of other sauropods,” he said. “Up until now, we assumed juveniles did, too.”
The scientists, however, said the small Diplodocus suggests major changes occurred in the skull’s shape throughout the animal’s life.
The researchers said those changes might have been tied to feeding behavior, with adults and juveniles eating different foods to avoid competition. Young Diplodocus, with their narrower snouts, may also have been choosier browsers, selecting high-quality plant parts.
The research is detailed in the Journal of Vertebrate Paleontology.
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