Massive Whale Graveyard Found 7,000 Meters Deep in Indian Ocean, Dating Back 5 Million Years

Scientists have announced the discovery of the largest and deepest whale graveyard ever recorded, located in a submarine valley in the southeastern Indian Ocean. Hundreds of whale carcasses and fossils were found spread across approximately 1,200 kilometers of the seabed at depths exceeding 7,000 meters. The findings were published on June 10, 2026, in the journal Nature. The site, known as the Diamantina Fracture Zone, was first surveyed in early 2023 using a manned submersible. The research team conducted 32 dives and discovered 476 whale carcasses and fossils, including five individuals that had recently died. Although the surveyed area was only about 0.065 square kilometers, researchers estimate that the density of whale remains at this location could reach up to 2,000 individuals per square kilometer, making it the largest known cetacean necropolis. Fossilized skulls of various beaked whale species were found in the Diamantina Fracture Zone. Among them are two species still alive today, Mesoplodon bowdoini and Mesoplodon layardii, as well as a newly described species, Pterocetus diamantinae. Fossils of Pterocetus benguelae, dating back 5.3 million years, and Izikoziphius rossi were also identified. The oldest fossil found belongs to Pterocetus benguelae, which lived around 5.3 million years ago, indicating that whale carcasses have been accumulating at this site since the early Pliocene epoch. The team also discovered fossilized skulls of the new species, named Pterocetus diamantinae, which researchers believe will help complete the understanding of the evolutionary history of beaked whales. While the exact reasons for such a large accumulation of whale carcasses at this specific deep-sea location are not yet fully understood, scientists speculate that unique deep-sea depositional environments and past oceanographic conditions may have played a role.