113-Million-Year-Old Hell Ant Fossil Found in Brazil

The discovery of a 113-million-year-old hell ant fossil in Brazil rewrites ant evolutionary history. It’s the oldest known ant fossil, offering rare insight into ancient hunting behaviors and global dispersal patterns.

What is the significance of the 113-million-year-old hell ant fossil discovery in Brazil?
On April 24, 2025, scientists from the University of São Paulo announced the discovery of the oldest ant fossil ever, dating back 113 million years. Unearthed from the Crato Formation in northeastern Brazil, this fossil predates all known ant fossils by 13 million years. It belongs to the extinct Haidomyrmecinae subfamily and provides the earliest known evidence of ant evolution in the Southern Hemisphere’s ancient Gondwana landmass.

How does the fossil reveal the hunting behavior of early ants?
CT scans of the Brazilian hell ant fossil revealed scythe-like mandibles paired with a horn, which likely helped impale and trap prey. This hunting mechanism was unique among Cretaceous insects and represents a highly specialized predatory adaptation. One previously discovered fossil from Myanmar even shows prey caught between the jaws and horn. These anatomical traits suggest early ants developed niche-specific strategies for survival in prehistoric ecosystems.

What evolutionary insights does this fossil offer about ant diversification?
This fossil highlights that ants had already begun evolving specialized anatomical traits and global dispersal by the mid-Cretaceous period. With over 17,000 modern species, this discovery bridges a 13-million-year evolutionary gap. It confirms that hell ants thrived across Laurasia and Gondwana for over 20 million years, diversifying rapidly before their extinction, likely due to ecological shifts and narrow dietary habits during the Cretaceous.

Did hell ants go extinct during the K-Pg extinction event?
Although hell ants vanished from the fossil record 78 million years ago, long before the K-Pg extinction 66 million years ago, their specialized hunting might have led to their demise. Experts theorize that ecological changes during the late Cretaceous rendered their prey scarce, ultimately reducing their ability to adapt. This reinforces how evolutionary specialization, while advantageous short-term, can limit long-term species survival.

What makes this story a must-read?
This discovery not only sets a new record in paleontology but reshapes our understanding of insect evolution and prehistoric ecosystems. It underscores how even small creatures like ants played crucial roles in Earth’s biodiversity during the dinosaur era. The research blends technology, evolutionary biology, and geology to craft a richer picture of life 113 million years ago—reminding us that groundbreaking science often lies in the smallest fossils.