113-million-year-old ant found in Brazil oldest ever discovered

By Stephen Beech

A 113-million-year-old fossilized ant is the oldest ever discovered.

The “remarkably well-preserved" hell ant was found in limestone in Brazil.

Scientists say it is a member of Haidomyrmecinae - an extinct group that only lived during the Cretaceous period.

They had highly specialized, "scythe-like" jaws that they probably used to pin or impale prey, according to a study published in the journal Current Biology.

Study author Anderson Lepeco said: “Our team has discovered a new fossil ant species representing the earliest undisputable geological record of ants.

“What makes this discovery particularly interesting is that it belongs to the extinct ‘hell ant’ - known for their bizarre predatory adaptations.

"Despite being part of an ancient lineage, this species already displayed highly specialized anatomical features, suggesting unique hunting behaviors.”

He said the ant's discovery challenges present understanding of ant evolution and biogeography through time.

The previous oldest ants were found in France and Burma and were preserved in amber instead of limestone.

The researchers say the existence of a hell ant in Brazil shows that ants were already widely distributed and diversified early in their evolution, says the team.

Lepeco, of the Museum of Zoology of the University of São Paulo, Brazil, said: “Even though there have been hell ants described from amber, this was the first time we could visualize this in a rock fossil."

The research team discovered the ant specimen while systematically examining one of the world’s largest collections of fossil insects from the Crato Formation, a deposit renowned for its exceptional fossil preservation.

Lepeco said: “When I encountered this extraordinary specimen, we immediately recognized its significance, not only as a new species but as potentially the definitive evidence of ants in the Crato Formation.

“This finding highlights the importance of thorough examination of existing collections - private or in museums - and brings a spotlight to Brazilian paleontology and the underexplored fossil insect fauna of the country.”

Micro-computed tomography imaging - a 3D imaging technique that uses X-rays to view the inside of an object - showed that the newly discovered ant was closely related to hell ants previously known only from specimens preserved in Burmese amber, a type of amber found in Myanmar.

The researchers say it shows that the ants were widely distributed around the globe and must have crossed Cretaceous landmasses repeatedly.

But what surprised them most was the hell ant’s specialized features.

Lepeco said: “While we expected to find hell ant features, we were shocked by the characteristics of its feeding apparatus."

Unlike modern ants with laterally moving mandibles, the research team noted that the species possessed mandibles that ran forward parallel to the head and facial projection anterior to the eyes.

Lepeco said: “Finding such an anatomically specialized ant from 113 million years ago challenges our assumptions about how quickly these insects developed complex adaptations."

He added: "The intricate morphology suggests that even these earliest ants had already evolved sophisticated predatory strategies significantly different from their modern counterparts.”