Dinosaurs are often depicted as voracious animals with extremely loud voices, but a group of researchers from various universities in the United States has identified that there were some species of birds capable of closed-mouth vocalizations.
More often than not, dinosaurs are portrayed in films as loud animals that roamed the Earth some hundreds of million years ago. But a new study suggests that there were actually 52 species of dinosaurs capable of creating sounds with their beaks or mouth closed.
In order to test the hypothesis, scientists from the University of Texas in Austin, Midwestern University in Arizona, Memorial University of Newfoundland, and the University of Utah collaborated on a study funded by the Gordon Betty and Moore Foundation. A primer of the study, which will be published in the next print of the science journal Evolution, was published electronically this week.
The group, which studied around 208 species of birds, used statistical analysis to investigate closed-mouth vocalization among birds, a behavior possessed by still-existing birds such as pigeons. Since birds are direct descendants of dinosaurs, researchers believe that studying their vocalization behavior could yield information on the evolution of dinosaurs’ vocalization behavior.
According to the study, birds create different sounds for different purposes. First, birds vocalize to attract their mate or warn other birds that they own the territory. Different birds create sounds differently, and the majority of birds creates sounds or vocalize with their mouths open.
In a statement, Professor Tobias Riede, a physiology professor from the Midwestern University, said that there’s a rational explanation why some birds are able to generate sounds with their mouths closed. Riede turned to physics to explain such occurrence.
“The inflation of an elastic cavity could present a size-dependent challenge. The lung pressure required to inflate a cavity depends on the tension in the wall of the cavity, and this tension increases for smaller body sizes. A cool thing about this work is the demonstration that closed-mouth behavior evolved many times,” Riede said.
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