See these fearsome fangs? They just won the record for sharpest teeth of all time. Funny thing is, they’re invisible (without a microscope).

PHOTOS: Sea Monsters Real and Imagined

With tips only one-twentieth the width of a human hair, these minute munchers belonged to an ancient, eel-like animal known as a conodont, which died out about the time dinosaurs began their reign, 200 million years ago.

Each tiny conodont, only about two inches long, had a paired set of these precise pincers but neither the bony jaws nor the strong jaw muscles most blunter-toothed beings use to bite down on bits of food. So, how did they eat?

ANALYSIS: Pre-Dino Toothy Marine Animals Revealed

Paleontologist David Jones of the University of Bristol in the U.K. says the unbeatable sharpness of conodont teeth is precisely what made them so effective.

“In most big animals with teeth embedded in bony jaws, sharp teeth would quickly break and wear down under the pounding they would suffer under those large forces,” Jones told Discovery News. “In small animals by contrast, especially those without jaws, only tiny forces could be brought to bear on food, so it seems teeth must be very sharp to concentrate these forces efficiently.”

In a report published today in Proceedings of the Royal Society B, Jones and his colleagues describe how they used x-rays to create virtual models of conodont teeth. Combined with an engineering technique (finite element analysis) they used to analyze the stress on individual teeth of the conodont species Wurmiella excavata, the team was also able to discover how the paired sets of teeth worked together.

Palaeontologists often use finite elment analysis to look at stress and strain in structures like dinosaur skulls, but rarely in small objects like the conodont teeth, Jones said.

ANALYSIS: Earth’s Biggest Doomsday Event, Death by CO2

IMAGE: Scanning electron micrograph of the ultra-sharp teeth of the conondont Wurmiella excavata. (Courtesy David Jones, University of Bristol)