In a groundbreaking discovery, scientists have unearthed the oldest known ant fossil, dating back 113 million years, in northeastern Brazil. Published in the journal Current Biology, this finding reveals that ants were already widely distributed and highly diversified early in their evolutionary history.
The ancient specimen, belonging to the extinct subfamily Haidomyrmecinae — commonly known as hell ants — was preserved in limestone from the renowned Crato Formation, famous for its exceptional fossil preservation. This marks the first time a hell ant has been found fossilized in rock, as previous discoveries were preserved in amber from France and Myanmar.
“Our team has discovered a new fossil ant species representing the earliest undisputable geological record of ants,” said Anderson Lepeco of the Museu de Zoologia da Universidade de São Paulo, who led the study.
The discovery challenges previous assumptions about ant evolution and biogeography. What makes this finding even more remarkable is the specialized predatory adaptations already visible in this ancient lineage. Hell ants are known for their bizarre, trap-jaw-like mouthparts designed for hunting, and this specimen displayed sophisticated anatomical features suggesting unique feeding strategies.
Using advanced Micro-computed tomography (Micro-CT) imaging, researchers were able to capture intricate 3D details of the fossil. They found that the newly discovered species shares a close relationship with hell ants previously found in Burmese amber, highlighting a broader and earlier distribution than previously believed.
“While we expected to find hell ant features, we were shocked by the complexity of its feeding apparatus. It suggests that even these early ants had already evolved advanced hunting techniques quite different from those of modern ants,” said the researchers.
This remarkable fossil not only adds to the known diversity of ancient ants but also pushes back the timeline of ant evolution, offering crucial insights into how these resilient insects have adapted and thrived for millions of years.