Hell ants have previously been found preserved in amber in Myanmar, Canada and France. Named 'hell ants’ because of their peculiar and slightly scary-looking headgear, they have scythe-like mouthparts – known as mandibles – that look a bit like upward-pointing tusks, and a 'horn’ on their heads.
Until now, the oldest hell ants were dated at 100 million years old. But a new paper in Current Biology describes an even older ant. Found in a museum collection, a fossil from northeastern Brazil has been dated at 113 million years old, meaning ants are much older, and specialised much sooner, than we thought.
Do insects have brains?
What are the smelliest insects?
Why were prehistoric insects so large?
Ant CT-Scan reconstruction
CT-Scan reconstruction of the hell ant specimen found in Brazilian museum. Credit: Odair M. Meira
"It's like finding a diamond": 16-million-year-old animal found encased in amber on Caribbean island
Scientists know it is a hell ant because, using a method called ‘computed tomography’ (essentially, very detailed 3D scans), it is clear that the fossilised ant has the classic hell ant headgear.
But what was this strange headgear used for?
“The most accepted hypothesis suggests that hell ants were specialised predators, which used their mandibles to grab extinct insects,” Dr Lepeco, lead author of the study, tells BBC Wildlife. “There are fossil hell ants grabbing prey with their mandibles, which supports this theory.”
However, an alternative hypothesis – and a bit less fitting with the name ‘hell ant’ – is that the ants used their headgear to carry droplets of nectar or honeydew, sugary liquids that many modern ants feed on.
Whatever the headgear was used for, it obviously provided a foraging strategy that was effective in very different environments. In northeastern Brazil, the ants would have been living in a dry and barren environment. In Myanmar, on the other hand, they would have lived in a forested, tropical environment.
Deadliest insects in the world
A paleoartistic reconstruction of the ant
Artistic reconstruction of the hell ant. Credit: Diego Matiello
Not only does the discovery of a Brazilian hell ant improve our understanding of the range of habitats they lived in, it also more fundamentally changes our understanding of ant evolution. While it was thought that ants existed 100-million-years-ago, we now know that they have been on Earth for at least 113 million years.
Not only that, but hell ant headgear suggests specialist foraging behaviour. Given that such specialised ants existed 113 million years ago, this means diversification and specialisation happened in ants much faster than scientists previously thought.
The newly discovered hell ant fossil may be small, but in terms of scientific insight, it is mighty.
More amazing wildlife stories from around the world
Ancient creatures found encased in amber in remote forests of Myanmar
“Utterly spectacular”: incredibly rare 'pack ice' killer whale filmed swimming in Antarctic snow
Underwater vehicle stumbles across never-seen-alive 'glass' animal in Antarctic abyss
Colossal squid filmed alive in deep ocean for the first time ever
Beki Hooper
Writer
Beki has a PhD in cognitive evolution and a double master's degree in evolutionary biology. She writes about human and animal evolutionary biology, genetics and genomics, psychology, cognition, conservation and animal ethics.