Why having a T. rex as a pet isn’t as bad an idea as you might think

Big dinosaurs like Tyrannosaurus rex have been extinct for 66 million years, but it’s still fun to think about how they might interact with humans.

So, which dinosaur would make a good pet? Honestly, there are many decent options, but how can you look past the king, T. rex?

The obvious problem with have a pet T. rex (let’s call it Rex, for no particular reason), is the dozens of serrated, banana-sized teeth inside the most powerful jaws of all time. Rex is built for chomping through solid bone, taking chunks of meat down its gullet – not licking its owner.

While this may all be true, the image of T. rex as a cold-blooded monster, perpetuated in popular media, is likely inaccurate.

Cosmos recently spoke to world-famous palaeontologist Jack Horner – the inspiration behind Dr Alan Grant in Steven Spielberg’s 1993 classic film Jurassic Park. As a researcher from the University of Montana, Horner has spent a lot of time studying some of North America’s most famous dinosaurs like T. rex.

Horner says that certain biases in how we imagine dinosaurs lived and behaved aren’t quite up to date when it comes to the science. Rex, for example, probably wasn’t as much a hunter as we might like to believe.

“We have a lot of T. rex skeletons,” says Horner. “But we still argue about how they got their meat. I’m still a strong advocate of T. rex being an opportunist. The people that think that it’s an apex predator – I think we have to think that this just based on their own biases, because there’s no evidence for it.”

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Read more: How many T. rexes ever lived? Billions

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Even fossils showing animals maimed by T. rex teeth isn’t enough to convince Horner that the animals were apex predators.

“There are people that say there’s a broken off tooth in an animal it survived afterwards,” Horner adds. “But show me exactly how the T. rex had to bite this animal in order for a tooth to be lodged in the centrum vertebrae and not alter the neural spine, which is the most fragile part. It just doesn’t make any sense, unless, of course, the animal was sitting or laying down on the ground already.”

Horner adds: “Lots of scientists just want T rex to be an apex predator and so they’re going to do science the opposite way it’s supposed to be done, they’re going to look for evidence to support their theory.”

So, Rex may not quite be about to go on a rampage.

“Dinosaurs probably weren’t as exciting as we’d like to make them,” Horner explains. “They were just normal animals. People trying to sell something, whether it be a TV show or a movie, are going to over-sensationalise the behaviours of animals.”

In fact, some palaeontologists believe that T. rex would have functioned rather like a crocodile – eating one large meal (up to half its body weight) every few months. It’s relatively low metabolism probably meant T. rex were more on the slow, sluggish side. I’d still keep the family dog away, though, as you never know when Rex is going to need a snack.

But Rex probably won’t be all that interested in you or your pooch. See, mammals like us were little more than glorified shrews when T. rex evolved meaning that our scent wouldn’t trigger much of a response from your dino pal.

In fact, Rex’s sense of smell may be a source of benefit. Studies of the olfactory bulbs in T. rex fossils show that the massive carnivores had the best sense of smell of any dinosaur. Maybe Rex could be a truffle hunter if they’re not going to be hunting anything else!

One small catch, however, is that scientists estimate an adult animal like Rex would need a lot of space – around 100 square kilometres. That would mean you could fit about 30 individual T. rex in the Adelaide metropolitan area.