We have some leftover bones of these things. Everything else is just comparison to modern animals. Dinosaur with carnivorous features would likely have some sort of roar, because well modern carnivores do. The MGM intro doesn't start with the soothing coo of a lion. For all we actually know they communicated by flashing lights on their forehead with some sort of code. So you compare what you observe to what you do know.
The one in the middle is right, they are making up unfounded shit for attention.
We have some leftover bones of these things. Everything else is just comparison to modern animals. Dinosaur with carnivorous features would likely have some sort of roar, because well modern carnivores do. The MGM intro doesn't start with the soothing coo of a lion. For all we actually know they communicated by flashing lights on their forehead with some sort of code. So you compare what you observe to what you do know.
The one in the middle is right, they are making up unfounded shit for attention.
Considering the size of dinosaurs noses, like that t-rex, I'd bet it didn't so much as roar, as may have had a rather violent honk.
Gators also don't roar, but they rumble and vibrate which is terrifying in it's own right.
They can roar. Though it is wasting precious energy when their rumbling cost way less energy and scares the crap out of intruders