The secrets of a five million year-old whale graveyard have finally come into plain sight.

Scientists examining the fossilised remains of more than 40 whales in Chile's Atacama Desert have published the findings of a two year investigation.

Since 2010, the find beside the Pan-American highway has been the focus of much attention from the scientific community.

The reason why so many whales came to die in the same place has baffled researchers - until now.

In a report published in the Royal Society Journal, it is claimed the mammals died as the result of FOUR mass strandings after ingesting toxic algae.

After death, the carcasses were washed into an estuary and covered in sand over time, which then preserved them as fossils.

The researchers believe the shape of the Cerro Ballena coastline in the late Miocene Epoch period funnelled the carcasses into an area where high tides lifted them onto sand flats.

The area has become known as "Whale Hill" because huge skeletal remains protruded out of white sands like blades made of bone for centuries.

When a construction project for the highway was announced four years ago, the fossils of dozens of whales were unearthed, the BBC said.

Whale Graveyard
Whale graveyard: The site in Chile's Atacama Desert is five million years old

Paleontologists from America and Chile were given just two weeks to investigate the site before work reconvened to complete expansion of the road.

A Smithsonian National Museum of Natural History team and their South American colleagues created 3D models of the skeletal remains in situ.

Some bones were removed from the ancient burial site to be studied later in a laboratory.

Remains of other species of marine life were also unearthed, including an extinct walrus-like whale and dolphins with a walrus-like face.

The bones of billfishes, seals and aquatic sloths were also found in the sands of the ancient whale graveyard.

And, the scientists noted, that all the skeletons were preserved intact on four separate levels which indicated a similar cause of death.

Incredibly, the scientists have ascertained the layers of fossils mean the deaths happened on various episodes over a period of several thousand years.

Nicholas Pyenson, a paleontologist at the Smithsonian's National Museum of Natural History, told the BBC: To me, it's amazing that in 240m of road-cut, we managed to sample all the superstars of the fossil marine-mammal world in South America in the Late Miocene.

"Just an incredibly dense accumulation of species.


"We can't say whether those were the killer algae.
