What Sharks Attacked 5 Million Years Ago

Why It Matters

The discovery documents ancient shark‑whale interactions and signals long‑term loss of large predatory sharks in northern European waters, informing modern marine ecosystem and conservation studies.

Key Takeaways

• Fossil whale skulls show 5‑million‑year shark bites
• Carcharodon plicatilis likely tried removing whale’s head
• Hexanchus griseus scavenged dead right‑whale carcass
• Great‑white relatives present in ancient North Sea ecosystem
• Findings indicate historic loss of large predatory sharks

Pulse Analysis

Researchers from the Institute of Natural Sciences in Brussels have turned two accidental whale‑skull finds into a window on Miocene marine life. Using high‑resolution micro‑CT scans, the team identified embedded shark teeth and distinctive bite patterns in a *Casatia* skull and a *Balaenella brachyrhynus* skull recovered from Belgian beaches. The marks point to an aggressive encounter with *Carcharodon plicatilis*, an extinct great‑white ancestor, and a scavenging episode by the blunt‑nose six‑gill shark *Hexanchus griseus*. These fossils provide the first direct evidence of shark‑whale interactions five million years ago.

The bite locations reveal contrasting behaviors: *C. plicatilis* appears to have targeted the whale’s forehead, possibly attempting to decapitate the animal, while *H. griseus* left marks on the upper skull of a belly‑up carcass, indicating opportunistic scavenging. Such dual evidence suggests that the ancient North Sea supported a complex food web where apex predators and opportunistic feeders coexisted. Neither of these shark species inhabits modern northern European waters, highlighting a long‑term contraction of large predatory shark ranges likely driven by climatic cooling and changing ocean productivity.

Understanding these prehistoric interactions helps scientists model how marine ecosystems respond to the loss of top predators. The disappearance of *C. plicatilis* and the retreat of six‑gill sharks mirror today’s declines in great‑white and other large shark populations, which can trigger trophic cascades affecting fish stocks and coastal economies. By linking fossil evidence with modern conservation concerns, the study underscores the importance of preserving remaining apex sharks to maintain ecosystem resilience. Future research may expand the geographic scope, revealing whether similar predator‑prey dynamics existed in other ancient seas.