Nobody ever cranks out a masterpiece in one sitting. Not even Mother Nature gets it right the first time. If she did, then the prehistoric ages wouldn't have been filled with stupid and bizarre-looking prototypes of modern species that seemed doomed to fail from the start. Some of evolution's laughable early drafts include ...
7Platybelodons, aka Elephants With Giant Trunk-Mouths
Who knew that the quickest way to strip an elephant of all its majesty was to replace that dick it carries around on its face with a duck bill? About 10 million years ago, back when evolution was still throwing everything at the wall to see what stuck, there were actually several different trial-and-error elephants wandering around. But Platybelodon was the only one with a long rat tail and a dustpan for a mouth.
Paleontologists apparently have long-winded arguments on why nature would intentionally make an animal look like that. Some suspect that the shovel tusk was useful for gobbling up aquatic vegetation, but others are adamant that Platybelodon grabbed onto tree branches with its mouth and then sawed into them with those hillbilly teeth on the bottom. But regardless of the actual function, Platybelodon seems to have sacrificed all aesthetic to achieve it, because these elephants are an embarrassment.
American Museum of Natural History
This comparison, showing its jawbone, illustrates just how well it could keep snow off of its driveway.
The shortened tusks aren't doing it any favors either. It's the one menacing weapon modern elephants have, and nature decided, "What if I try making them so short that they're completely useless and then use them as decoration on either side of a permanent guffaw?" The only reason these animals lived as long as they did was because predators could only laugh and move on in search of something less absurd to eat.
6Helicoprion, aka the WTF-Mouthed Shark
Helicoprion is essentially a shark from 250 million years ago with a buzz saw for a lower jaw. If you're having a hard time wrapping your head around the logistics of that, then congratulations, you and science are in the same boat. Unfortunately, since a shark's skeletal structure is made almost exclusively of cartilage, no one has ever found more significant remains of the Helicoprion than these serrated jaws that look like they were pulled from a Tim Burton set. In fact, paleontologists originally thought the Helicoprion mouth they discovered was just an ammonite. It wasn't until later on that researchers realized that what they had found was an important example of Mother Nature testing the boundaries of the crazy shit she could get away with.
Paleontologists are still trying to figure out how this shark even fed itself with such an absurd mouth. The leading theory is that Helicoprion would have used its flexible jaw like a whip, lashing what was essentially a spiked tentacle into schools of fish and then pulling in whatever it managed to stab. But experts can't even agree on where Helicoprion would have stored its lower jaw when it wasn't using it to devastate swarms of prehistoric fish -- that's why different artists' renditions don't even look like the same animal:
"We're just pretty much guessing here."
Bruce Wendorff via National Geographic
"Oh yeah? Well, we can guess much stupider than you."
Originally they assumed that the teeth just rolled back under the jaw, but the most recent hypothesis is that the shark would keep them tucked neatly away in its throat, because obviously that's always the best place to keep a deadly coil of razors.