Community Research and Development Information Service - CORDIS

Trending Science: Dinosaurs may have cooed, not roared

A new paper has raised the possibility that dinosaurs sounded more like their descendants, the birds. Rather than the stereotypical roar, they suggest that the ‘terrible lizards’ of prehistory would rather have cooed, mumbled or hooted.
Trending Science: Dinosaurs may have cooed, not roared
If asked to picture a mighty Tyrannosaurus Rex or fearsome Velociraptor, arguably the most prominent stars of the ‘Jurassic Park’ franchise, you will probably also automatically recall the fearsome roars emitted from the mouths of these ruthless predators as they pursued their human prey across four blockbuster films. What many do not know is that the roar of the ‘Jurassic Park’ Tyrannosaur was a remix of baby elephant cries, tiger chuffs and a gargling alligator, whilst the Velociraptor’s signature blood-curdling shrieks were a mixture of dolphin screams, walrus bellowing, hissing geese, an African crane’s mating call, mating tortoises and human rasps.

In short, the ‘Jurassic Park’ filmmakers allowed themselves a high level of creative licence when imagining how dinosaurs sounded. Moreover, many of the depictions of dinosaurs still prominent in Hollywood are now thought to be outdated. For example, it is commonly accepted amongst palaeontologists that a large number of dinosaurs - including the Tyrannosaurus Rex - were covered in feathers, rather than scales. Now a team of researchers from the United States and Canada are arguing that dinosaurs most likely made sounds closer to the coo of a pigeon or the mumble of an ostrich, indeed a far cry from mammalian screams.

They reached this conclusion by first collecting vocal data on many living archosaurs, a group which includes both birds and crocodiles. Many extinct species, including dinosaurs are also classified as being members of the archosaur family. They then divided the type of sounds into various groups, including closed-mouth noises. Small birds, like sparrows and finches, do not make these noises but birds with proportionally larger body types, such as doves, ostriches and the New Zealand cassowary, do. This, argue the research, could suggest that large-bodied dinosaurs may have had similar vocal abilities.

However, as not all birds have this trait, the research team say that it evolved separately in different groups of animals. Specifically, it appeared in 16 distinct animal lineages, including crocodiles and birds, and as such, it is perfectly reasonably to theorise that it could have evolved in dinosaurs as well. ‘A cool thing about this work is the demonstration that closed-mouth behaviour evolved many times. This suggests it can emerge fairly easily and be incorporated into mating displays,’ commented Tobias Riede, Midwestern University physiology expert and lead author of the paper that has been published in the journal ‘Evolution’.

Of course the researchers were handicapped by the fact that vocal organs, made of soft tissue, do not fossilise, unlike bones. But based on what is known about birds, dinosaurs likely did not have vocal chords, but rather air sacs and possibly a birdlike syrinx (similar to the human larynx but two-pronged and lower in the chest). Consequently, if a dinosaur whooshed like a bird, the scientists suggest it may have sounded like the most intimidating large-bodied birds that exist today, namely ostriches and cassowaries. Disappointingly for Hollywood filmmakers, the ostrich mating call though is a low buzz, rather than a ferocious roar.

Though for the fans of the ‘Jurassic Park’ films, they can take relief from the fact that the filmmakers may not have got it all wrong when giving voices to their reptilian stars. If you find yourself watching the iconic first instalment of the franchise, pay close attention to the noises emitted by the Velociraptors just before they ambush game warden Robert Muldoon in the jungle - it’s the sound of a hissing, rasping goose. According to this study, this depiction may not actually be so far from the truth.

Source: Based on media reports

Related information

Countries

  • Canada, United States
Record Number: 125819 / Last updated on: 2016-07-14
Category: Trending Science
Provider: EC