for National Geographic News
The bony crests that straddled the heads of some duck-billed dinosaurs may have been used to produce deep, haunting bellows, according to new research.
Medical scans of the dinos' nasal passages suggest that—like human teenagers—the animals' voices may have changed as they aged, and that the dinos had the ability to recognize individuals based on their voices alone.
Duck-billed dinosaurs known as lambeosaurs lived 85 to 65 million years ago during the late Cretaceous period.
(Related: "Giant Duck-Billed Dino Discovered in Mexico" [February 12, 2008].)
Their often elaborate bony head crests contained long and looping nasal passages whose functions have been debated for decades.
For example, the crests have been proposed to act as communication tools, brain coolers, smelling enhancers—and even snorkels.
The new study, presented this week at the annual meeting of the Society of Vertebrate Paleontology in Cleveland, Ohio, supports the theory that the dinos used their crests to communicate via low-frequency calls.
"More and more evidence is mounting for this kind of behavior," noted Terry Gates, a paleontologist at the Utah Museum of Natural History who was not involved in the study.
But until now evidence for whether the lambeosaurs could hear such calls remained a missing part of the picture.
"It doesn't matter if they could make the calls if [their ears] couldn't pick them up," Gates said.
Unique as Fingerprints
In the new study, scientists from three U.S. and Canadian universities used medical CT scans to create digital reconstructions from fossils of the brains and crest cavities of four different lambeosaur species.
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