The Tyrannosaurus Rex's roar is often taken as a given. 

But would you think less of the mighty creature if it quacked like a duck instead? 

An article published in Nature earlier this week has raised the possibility that dinosaurs made noises more akin to the cooing of a bird or a duck's quack than the gigantic roars so often heard in Hollywood films. 

Palaeontologists led by Julia Clarke analysed the oldest fossilised avian vocal organ known to man, and came up with a surprising hypothesis. 

“What we see in the fossil is totally consistent with the variety of sounds produced by ducks or ostriches,” Clarke said in an interview with the Christian Science Monitor.

While humans make the sounds they do thanks to their larynx, birds have an altogether different instrument, called a syrinx. 

The larynx is used to produce sound but also has other functions, such as blocking objects from entering the lungs: the syrinx, on the other hand, is solely used for sound production. 

Paleontologists had previously found dinosaur larynx fragments, but given the larynx's various functions, this was not definitive proof that dinosaurs roared. 

Clarke's team has now found fossilised evidence that at least some dinosaurs had a syrinx, raising the possibility that these creatures emitted sounds more akin to those of birds than humans. 

As for dinosaur species with no syrinx, Clarke's team has hypothesised that they made noises similar to the low-frequency booms emitted by crocodiles - dinosaurs' closest living relatives.