Extraordinary claims. Ordinary investigations.

If you thought the fictional Ningen was bizarre, behold the Helicoprion. And this horrifying sea creature is, or actually, was very real, as evidenced by their peculiar lower teeth, fossils of which have been found. It may have grown up to 20 feet long.

As we all know and fear, sharks are indeed killing machines and as such make a lot of use of their teeth. So much so that most species known today are constantly replacing them. They are not attached to their jaw, are placed in several rows, and when a tooth falls, the one behind it takes its place. Somewhat like a conveyor belt. Of very sharp teeth.

But it has not always been this way, and the Helicoprion was a shark-like fish that arose in the oceans of the late Carboniferous 280 million years ago, and eventually went extinct during the early Triassic some 225 million years ago.

You see, the Helicoprion kept growing new teeth throughout its life, but they did not fall. Instead, the teeth grew in spiral fashion, with new, larger ones being added.

It’s actually funny that scientists didn’t know at first how to fit the spirals they found in the fish:

It was not until the discovery of the skull of a relative, Ornithoprion, that it was realized that the tooth-whorl was in the lower jaw. It is difficult to know much about ancient shark-like fish because all that remain from them are usually their teeth. The rest of their body, including their cartilage, is lost to time.

You can see more artistic conceptions of the creature by Gary Staab, in the Field Museum, and the Las Vegas Natural History Museum, though the one at the beginning of this post is clearly the winner. There’s also an illustration of a Helicoprion feeding on ammonites. This may look like a joke – a spiral-toothed fish eating a spiral mollusk –, but as Wikipedia says, this is a serious hypothesis for the spiral-teeth.

Another ancient (and extinct) shark-like fish that did not shed its teeth, but kept growing them, was the Edestus. Scary, but not anything as horrible as the Helicoprion.

I think nobody, even in art, had ever thought of a tooth-whorl jaw for a shark-like fish. Cthulhu probably has one like that, but Lovecraft didn’t describe it. He knew we would go insane.

[via UMAfan]