Deep Sea Whale Necropolis Is Five Million Years Old

In the south-eastern Indian Ocean, at depths where pressure would collapse an unprotected human in milliseconds, researchers have found the oldest, deepest and most extensive whale graveyard on Earth. It stretches roughly 1,200 kilometers (745 miles) across the sea floor. Some of the bones have been there since before our genus existed.

Whale falls, the term for carcasses that sink to the seabed, create biodiversity oases, but most sit at less than 4 kilometers (2.5 miles) down. The newly documented necropolis in the Diamantina fracture zone reaches depths of more than 7 kilometers, extending some 1,200 kilometers along the southeastern Indian Ocean floor, far beyond anything previously described.

A team from China, Italy and New Zealand used a submersible to conduct 32 dives, documenting five modern whale-fall communities and 485 fossil cetacean sites. The oldest recoverable fossil, a skull belonging to an extinct beaked whale (Pterocetus benguelae), dates to 5.3 million years ago. A second skull represented something new to science entirely: a species the team named Pterocetus diamantinae.

The sedimentation rate near the Diamantina zone is extraordinarily low, meaning skeletal remains could be exposed for hundreds of thousands of years on the flat bottom and millions of years on slopes or uplifted sections. The zone is not just a graveyard. It is an archive.

The modern carcasses were far from inert. Communities of brittle stars, bone-boring worms and chemosynthesis-based bivalves were found living on the decaying remains, many of them potentially new to science. Researchers suggest the corridor may function as a migration route for filter-feeding species and a productive deep-diving ground for beaked whales, possibly pushing some individuals to the outer edge of what their physiology can survive.

Pterocetus diamantinae has been waiting in the deep dark for five million years. It can wait a little longer while we figure out what else lurks down there with it.

Read the full story at The Guardian, June 10, 2026

Hot Take: Beaked whales already rank among the deepest-diving vertebrates. Learning they've hunted in the same crevice in the seafloor for millions of years suggests we've wildly overestimated our map of their natural history. The real answer: barely at all.