Where were the medium-sized Cretaceous carnivores? They were all teenagers

Anyone who made it out of high school alive knows how wild the cliques, gossip and bullies can be. Now imagine going through that as a carnivorous dinosaur.

A teenage theropods may not have had special lunch tables or stolen someone else’s prom date, but there was a “you can’t sit with us” idea when it came to too many predators and not enough prey. There was a gap in the Cretaceous fossil record for a long time – where had the middle carnivores gone? Turns out there was no room for mediocre species when there were already too many young dinosaurs of that size taking other youngsters out into battle to compete with rival species and get to the top of the food chain.

Things could be ugly when there were so few facilities to go around and a hormonal dino teenager (certainly not a tiny bitch, as you can see from the skull above) was swimming over on the first thing that inspired their great nobles.

“We found that the youngsters of large carnivorous dinosaurs may have been using the facilities available to medium-sized species. The juveniles were apparently eating the prey, and taking up the environmental space of a medium-sized theropod, ”said paleontologist Kat Schroeder, who led a study recently published in Nature, told SYFY WIRE.

The teenage T-rex and juvenile versions of another theropod had not grown to be the majority of their wonderful parents. Hatchlings could not weigh more than about 30 pounds as it would have been impossible to lay those eggs. They are thought to have started catching insects, and as they grew, they took on a larger and faster prey that had to be fast on their feet to catch them. While teenagers were rough, they had not yet developed adult bone-crushing jaws, which could be triggered by a slow keratopsian or hadrosaur taking a slow drink and clenching their teeth. to the neck without difficulty.

As Cretaceous megatheropods went through different stages as they grew, juveniles of different ages took over the roles that would have gone to smaller teropods. This did not really happen during Jurassic. Allosaurus, one of the Jurassic’s most horrific threats, didn’t change much when he was a teenager. He was basically born as a small adult who grew up to be a much bigger man. Jurassic megatheropods as it were also grew at a more steady pace and did not experience the more drastic changes that something like T. Rex would have in the Cretaceous. It may have depended on what prey was around.

“Jurassic megatheropods may not have to change as much as they grow, considering the availability of large sauropod dinosaurs as a potential prey – more food available means less competition, ”said Schroeder. “Jurassic megatheropods may be more likely to hunt in groups, or at least accept the presence of smaller members of their species at large carcasses. ”

If there weren’t so many large sauropods around, and Cretaceous sauropods just big enough for an adult T. Rex to make food out of one, he wouldn’t want to share it. This would have led the younger ones to go after things that would suit size no matter what stage of growth they were going through. Meaning, there was no more space in the ecological space that would normally be occupied by mediocre predators. This explains at least part of why dinosaur diversity was so low in the Cretaceous period.

It is also possible that a moderate theropod is missing due to juveniles or smaller dinosaurs of different species (or both) that ended up not fossilizing too well. This remains a mystery. Paleontologists can only understand what really happened by digging deeper (both literally and otherwise). Finding out how dinosaurs changed as they grew, interacted with each other and other animals, and evolved over longer periods of time could reveal any factors. -exciseably caused by onions in particular. Schroeder thinks that seeing how dinosaurs fit into their own communities and their entire ecosystems – and if girls were mediocre in the way – could give us an idea of ​​how who tried these tyrannical teenagers to survive.

“Perhaps the energy available on the planet, and how it was separated, explains more about dinosaur diversity,” she said. “Our research shows that gigantism in dinosaurs had a major impact on their large distribution and community structure, and we are thrilled to see what new research is emerging from this idea. . “

.Source