T-rex gets a lot of flak for his tiny baby arms, but he’s got nothing on the South American carnotaurus, a smaller cousin that had a short skull adorned with horns and a pair of stubby vestigial forelimbs with completely immobile elbows. That means the only thing they could do with their minuscule arms is flap them about uselessly. Imagine trying to decide whether to run in terror or point and laugh.
An elephant’s tusks are a powerful tool, used for self-defense, digging, object manipulation and protecting the elephant’s sensitive trunk. Which is why deinotherium is so baffling, as its tusks protruded backward from its chin and could probably serve no function except scratching that irritating neck itch.
You might think this curious beast from 270 million years ago is a reptile, like the monitor lizard it rather resembles in build. It’s actually a synapsid, an egg-laying proto-mammal, which means it’s more closely related to us than it is to dinosaurs. It was an apex predator of its time, reaching as much as 15 feet in length. What the dimetrodon used its giant sail for is a matter of debate, with some scientists arguing it was used to regulate body heat and others thinking it was used in courtship displays.
This bizarre prehistoric mammal looks like a mix between a sabretooth tiger, a rhino and a giraffe, but is related to none of those animals. Beyond the strange knob-like “horns” on its skull and the giant fangs that are rather atypical of browsing herbivores, its most striking feature is the shape of its skull, which is both concave and flat.
Is this Sesame Street? Because that is one big bird. Quetzalcoatlus, named after the legendary flying snake of Aztec myth, was a pterosaur with a wingspan as long as 36 feet, which would make it about the size of a fighter plane. On the ground, it would tower to the height of 16-18 feet, about the same size of a giraffe.
A cousin of modern-day armadillos, doedicurus rather looks like a mammalian version of ankylosaurus, a dinosaur that had a tough armor and a club tail it used for defense from predators. However, scientists currently think doedicurus couldn’t use the spiked end of its tail in such a manner, as its limited field of vision wouldn’t allow it to look behind to effectively aim the tail, due to its far-too-bulky armor.
Is it a dolphin? Is it a swordfish? Neither. This smooth-skinned, long-snouted marine animal was a reptile that returned to the ocean in much the same way that the ancestor of whales and dolphins had. The striking similarity to dolphins and some large carnivorous fish is the result of what is called convergent evolution, a process by which completely unrelated organisms evolve similar traits in order to fill a similar ecological niche.