Deepest and most extensive whale graveyard discovered in Indian Ocean

Some remains found in Diamantina fracture zone date back more than 5m years and reveal species and ecosystems unknown to science

The oldest, deepest and most extensive whale graveyard yet discovered has been found in the south-eastern Indian Ocean, with fossils dating back more than 5m years.

Whale falls – the term for dead whales that sink to the ocean floor – are not uncommon, but most have been found at depths of less than 4km (2.5 miles). By contrast, the newly discovered necropolis reaches depths of more than 7km, and extends hundreds of miles across the sea floor.

What’s more, researchers found decaying carcasses teeming with life.

Dr Giovanni Bianucci, a co-author of the study based at the University of Pisa, said: “This discovery demonstrates that these extreme and unexplored environments are home to species and ecosystems still unknown to science, and that we are therefore still far from understanding the true biodiversity of our planet.

“Furthermore, it shows us that life can adapt and evolve even in extreme environments where light is absent and pressure is extremely high.” He added that the study also provided unique information on creatures including the “mysterious and elusive” beaked whales.

In an article accompanying the study, Stephen J Godfrey of the Calvert Marine Museum in the US described the graveyard as “a truly unique discovery”, saying the site could yield many more exciting finds. “[The research] reminded me of a trailer for the first in a series of epic movies,” he wrote.

A team of researchers based in China, Italy and New Zealand used a submersible to explore an area of trenches and ridges in the south-eastern Indian Ocean, known as the Diamantina fracture zone. This formed between 60m and 50m years ago as the Australian and Antarctic continents drew apart.