No one on earth has heard the roar of dinosaurs. But that hasn’t stopped scientists and filmmakers from wondering: what did dinosaurs sound like?
The most famous answer probably comes from a movie Jurassic Parkwhich contains a dinosaur roar that sounds like this:
It’s a horrible noise, but it’s probably not realistic.Dinosaurs are reptiles, but when Jurassic Park Sound designers created their roars, building them mostly from mammal sounds – from recordings of tigers, lions, koalas(!), donkeys, dolphins and elephants.
Tyrannosaurus rex sounds like a donkey with no scientific basis.Instead, the filmmakers tried to evoke that feeling in front of dinosaurs. (Jurassic Park Sound designer Gary Rydstrom once laughed in response to a scientist’s critical question about the film, saying, “It’s a movie.”)
Figuring out what dinosaurs actually sounded like was a near-impossible task because scientists couldn’t unearth the fossil’s roar with precision. “Most vocal structures are soft tissue or less elastic hard tissue,” says paleontologist Michael Habib can not explain, Vox’s science podcast on unanswered questions. “It’s muscle and cartilage, which tend not to be fossilized.”
Still, scientists think it’s an important question. Figuring out what dinosaurs sounded like means a better understanding of the world they lived in, and is key to understanding how they behaved.
First, the shape of the dinosaur bones does provide some hints.A dinosaur called parasaurolophus (aka Ducky from land before time), which has a long chamber in its skull, which allowed scientists to estimate the general frequencies that might resonate in its head. But the room doesn’t tell us the real dinosaur sounds.
Still, all hope is not lost. To figure out what real dinosaur sounds might have sounded like, scientists can look for living dinosaur relatives.
“We have to do what we can,” Khabib said, using clues the scientists had. These are the most promising leads.
The crocodile made a low rumbling sound. Maybe Tyrannosaurus rex too.
Scientists can look for living relatives of dinosaurs to reconstruct their sounds. If they share a common ancestor, they may also share similar properties, such as how they vocalize.
One related group is the crocodiles (crocodiles, alligators, caimans), which share a common ancestor with dinosaurs that lived around 250 million years ago.
if you look Jurassic Parkyou’ll see T. rex growling with its mouth open, but if the T. rex were more like a crocodile, they might have made more of a low, closed-mouth rumble.
“They rumble so intensely that you can see ripples around them on the water,” Khabib said of the crocodiles. “They’re basically shaking the pond.”
Larger animals tend to make lower-pitched sounds than smaller animals. So imagine a huge dinosaur, many times bigger than the average crocodile; this dinosaur probably made a very low, closed-mouthed crocodile rumble.
Paleontologist Julia Clark actually did a demo with the BBC, placing the voice of a crocodile far away to simulate the voice of a Tyrannosaurus rex:
As the pitch drops further, it approaches a range known as infrasound. Just as the wavelengths of infrared light are too long for humans to generally see, infrasound waves vibrate so slowly that they are difficult for humans to hear. So if a dinosaur does sound like a subwoofer alligator, a lot of their voices might be hard to hear. Because of this sound, the ear hairs are too small to vibrate, but larger parts of the body may.
If a person is sent back in time, they may actually feel a leg or chest sound. horrible!
Birds are close relatives of dinosaurs, so did dinosaurs sing?
Crocodiles are a good starting point for imagining what dinosaurs might sound like, but they’re not close relatives of dinosaurs.
This honor belongs to birds, direct descendants of dinosaurs. “I used to have a roast chicken on the document viewer in the classroom,” Clark said. “You can see the assembly of those structures in your roast chicken in the fossil record.”
So how could birds possibly teach us about dinosaur sounds? One clue: Birds have a unique vocal organ. Most vertebrates make sounds using their larynx, a vocal organ located in the throat, but birds use the syrinx, a vocal organ located deep in the chest, near the heart. Clark likes to joke: “The bird sings from the heart.”
Because the syringe is located deep in the chest, it can make sounds more efficiently, which is why the bird can make such a loud noise. Also, unlike the larynx, the syrinx actually has two openings, so birds can make multiple tones simultaneously. “They can sing a duet with themselves,” Khabib said. The Thrush, for example, does just that, singing two notes at the same time.
But if birds are actually small dinosaurs, why bother with crocodile sounds? The problem is that scientists aren’t sure when the syringes first appeared. Clark found a 67-million-year-old syrinx (about a million years before the big dinosaurs went extinct), but this syrinx came from an ancient duck relative, not a giant dinosaur. She has yet to find concrete evidence of a giant dinosaur.
But because syrinxes are soft structures, it’s hard to find evidence for them. (Clark’s syrinx is an extremely rare find.) So there may be other, older syrinxes waiting to be unearthed.
Dinosaurs duet with themselves?
If scientists were to confirm that dinosaurs had syrinxes, it would open up a world of sound possibilities. Dinosaurs may sound similar to large flightless birds such as ostriches or emus, which emit a variety of whistles, guttations and hoarse clicks.
But the bigger the dinosaur, the weirder it sounds. Habib describes a potentially huge dinosaur whistle as a “trumpet trumpet”. “It’s like a pulse,” he said. “Very low voice. Woo woo woo woo woo woo.” Habib actually made this sound to me over the phone:
But wait. It can get even weirder. A single syrinx can make a dinosaur make two sounds at once, so Khabib really can let his imagination run wild: “Take two tubas. And make them play different notes as loud as possible. That’s the war rumbling. Voice.”
It’s also possible that dinosaurs sounded like a cross between a bird and a crocodile. They might be able to make both a bird’s mouth opening and a crocodile’s closing sound, Habib said.
Here’s what he imagined:
They may make an open mouth sound with two different tones, and then they can also make a rumble closing mouth sound. They can switch between the two, which means they can rumble, and while your body is still shaking from the rumble, they can open their mouth and bombard with two non-infrasonic but still low notes You, while things are still well shaken from the rumble. It can get really interesting.
Habib is quick to warn that this is all speculative since we don’t know whether large dinosaurs had syrinxes. “A more conservative estimate is to use crocodile-based sounds” to imagine dinosaurs, he said. “But the best is probably a careful combination of all of the above.”
in this week’s show can not explain, Vox sound designer Cristian Ayala tries to create some scientifically sound dinosaur sounds based on these dialogues. Here’s how he assembled a new T. rex sound based on what we’ve learned from paleontologists.
He starts with the chicken ‘b’caw, pushes it down, then adds the snipe sound (and can not explain Producer Mandy Nguyen’s pigeon Sunny) superimposes noises of different frequencies. A little tuba influence, and some ostrich, emu and crocodile sounds.
Is this really the voice of a Tyrannosaurus rex? no one knows!
but it may be more accurate than what you hear Jurassic Park. The scientists I spoke with emphasized that this work is more than trivial.Sound is important because it shows how ancient animals communicated, how they moved, how they lived. Scientists may never know exactly what the world sounded like, but in trying to recreate the sounds of dinosaurs, they can imagine the world these creatures lived in, if only slightly better.