A fossilised ‘hell ant’ from Brazil is shaking up our understanding of ant evolution, revealing that these ancient predators evolved their nightmarish hunting tools far earlier than anyone thought.
Key Points at a Glance
- New fossil from Brazil dates back 113 million years, the oldest undisputed ant fossil.
- The species, Vulcanidris cratensis, belonged to the extinct hell ant subfamily.
- It had forward-facing, scythe-like jaws adapted for impaling prey.
- The fossil reveals complex hunting strategies already evolved in early ants.
- This discovery came from rock, not amber—unprecedented for hell ants.
Before ants became the ubiquitous ecosystem engineers we know today—burrowing, foraging, and dominating landscapes from jungles to sidewalks—they were terrifying, efficient predators. A new discovery from the Crato Formation in northeastern Brazil reveals just how far back their dark legacy stretches.
Scientists have uncovered a 113-million-year-old fossil of a previously unknown ant species, Vulcanidris cratensis, which now holds the title of the oldest undisputable geological ant record. But more than its age, it’s the identity of this insect that has researchers buzzing: it belonged to the extinct subfamily Haidomyrmecinae, better known as the “hell ants.”
Described in the journal Current Biology, the fossil is astonishing in its preservation and anatomical detail. Using high-resolution micro-CT scanning, researchers reconstructed its body and feeding structures, revealing a gruesome evolutionary design. Unlike modern ants with sideways-moving mandibles, this ancient predator had scythe-like jaws that extended forward, slicing and pinning its prey like a natural guillotine.
“Despite being part of an ancient lineage, this species already displayed highly specialised anatomical features,” says Anderson Lepeco of the Museum of Zoology at the University of São Paulo. “This suggests unique hunting behaviours and a level of predatory sophistication unexpected for its time.”
Previous discoveries of hell ants have mostly come from amber, particularly in Burma and France, dating back around 100 million years. However, this fossil, preserved in limestone rather than tree resin, pushes their confirmed existence back by at least 13 million years and expands the environments in which they’ve been found. It is the first time a hell ant has been visualized in such detail from a rock fossil, opening new possibilities for understanding ancient insect diversity.
Even more surprising was the configuration of the new species’ mouthparts. While hell ants were already known for their unusual jaw structures, Vulcanidris cratensis exhibited feeding adaptations never before seen in this group. Its jaws moved ventrally—downward and forward—allowing it to grasp prey in a way completely different from modern ants. This radical morphology implies that ant predation strategies diversified much earlier than once believed.
The implications are profound. Not only does this fossil rewrite the timeline of ant evolution, but it also highlights how quickly some ant lineages evolved extreme anatomical specialisations. During the Cretaceous period—an era of dinosaurs, primitive birds, and flowering plants—the hell ant was already carving out its niche with deadly efficiency.
This extraordinary find underscores how much remains to be discovered about Earth’s earliest terrestrial ecosystems and the hidden evolutionary experiments that once roamed them. It also reminds us that today’s ants, though mighty in number, owe their legacy to a group of ancient ancestors who, for a time, ruled their microscopic kingdoms with jaws worthy of nightmares.
Source: Museum of Zoology of the University of São Paulo in Brazil
