Paleontologists have uncovered a massive fossil tooth belonging to a fearsome marine predator - a fossil that is the largest of its kind in the United Kingdom, researchers say.

The tooth itself, which has a broken tip and is about 5.5 cm (2.2 inches) long, was discovered near Chesil Beach in Dorset, England. It belonged to a prehistoric relative of modern crocodiles known as Dakosaurus maximus.

This massive creature once swam in the shallow seas that covered Europe some 152 million years ago. It grew up to about 4.5 meters (15 feet) long, and was part of a family of marine animals known as thalattosuchians, which are relatives of today's crocodiles.

By examining the unusual shape of the animal's skull and teeth, scientists determined that it probably ate similar prey to modern-day killer whales. It would have likely used its broad, short jaws to swallow large fish whole and to bite chunks from larger prey.

"Given its size, Dakosaurus had very large teeth," Dr. Mark Young, of the University of Edinburgh's School of Biological Sciences, said in a news release. "However, it wasn't the top marine predator of its time, and would have swum alongside other larger marine reptiles, making the shallow seas of the Late Jurassic period exceptionally dangerous."

The impressive chompers were dredged up from the sea floor, which according to researchers is rather unusual considering most fossils are found on the shore or dug up. It was then bought at an online auction by a fossil collector.

Researchers and curators from the University of Edinburgh and Natural History Museum in London identified the item and placed it in the fossil collection of the Natural History Museum.

The discovery can hopefully provide paleontologists with more information about this prehistoric creature, and the days of early Earth when many such massive animals roamed the land and seas.

The findings are published in the journal Historical Biology.