Mystery of whale bones found in Chilean desert

It's a mystery that's nearly as old as time, but just how did these 75 whales manage to wind up in a desert more than two million years ago.

The bones of these ancient mammals were found just yards apart from each other in one of the world's best preserved graveyards for prehistoric whales, but scientists are still debating exactly how the bones ended up more than 800m inland, the Daily Mail reported.

The relics were found side-by-side near Caldera in the Atacama Desert in Chile back in June 2010, and the whales, many as big as buses, have been taken to the Smithsonian Institution for study.

Scientists are divided on just how they got there though - some believe they became disoriented and beached themselves, while others believe they were trapped in a lagoon after being moved inland by a landslide.

It's not the first time groups of bones have been found, there have been sites in Peru and Egypt, but the large number and relatively preserved nature of the bones makes this one of the more spectacular finds in archaeology.

"I think they died more or less at the same time,’ Nicholas Pyenson, curator of fossil marine mammals at the Smithsonian's National Museum of Natural History, said.

"There are many ways that whales could die, and we're still testing all those different hypotheses."

There's no conclusive evidence that the 75 whales all died approximately at the same time, and different measurements suggest they could have died between two and seven million years ago.

Pyenson said that it would be very hard to conclude when the animals died in the "lagoon-like environment".

The majority of the remains were those of baleen whales, but scientists also found a sperm whale skeleton and a now-extinct dolphin which had two walrus-like tusks.

"We're very excited about that," Pyenson said. "It is a very bizarre animal."

Vertebrae paleontologist Eric Fitzgerald hailed the find as significant.

"The fossils are exceptionally well preserved and quite complete — a rare combination in paleontology and one that will likely shed light on many facets of the ... ecology and evolution of these extinct species," Fitzgerald said.

He said it's possible "these fossilized remains may have accumulated over a relatively long period of time".