Millions of fossil whale bones found in deep-ocean ‘necropolis’

Researchers piloting a crewed submersible to a depth of 7 kilometres discovered millions of whale bones accumulated on the ocean floor, creating what scientists describe as a "necropolis" spanning vast stretches of seafloor. The collection includes fossils up to 5 million years old and represents previously unknown whale species.

The discovery reveals how whale carcasses sink to the deepest parts of the ocean over geological time. As whales die and descend through the water column, their bodies accumulate on the abyssal plain, where cold temperatures, high pressure, and low oxygen preserve bone material for millions of years. This process, called a "whale fall," creates unique ecosystems that sustain specialized organisms.

The submersible expedition allowed researchers to observe the accumulation in unprecedented detail rather than relying on scattered dredged samples. The depth and location remain unreported in available sources, though deep-ocean research typically focuses on trenches and abyssal zones where such fossils remain undisturbed by surface activity.

The fossils catalogued during the dives include skeletal remains that paleontologists can use to reconstruct evolutionary patterns in whale species. Some bones belong to species previously unknown to science, expanding the known diversity of extinct cetaceans. The age range spanning millions of years provides a temporal cross-section of whale evolution during periods when ocean conditions, food availability, and whale migration patterns differed substantially from today.

Whale-fall ecosystems support specialized communities of bacteria, fungi, and invertebrates that consume bone collagen and other organic material. Understanding ancient whale falls contributes to broader knowledge of deep-ocean food webs and how marine megafauna deaths have shaped abyssal communities throughout Earth's history.

This research demonstrates the value of deep-submergence vehicles for paleontological fieldwork. Direct observation in situ preserves context impossible to obtain from sampling alone.