Bull Ants: Living Fossils and the Dinosaur Ant

Nov 3

2 min read

Updated: 1 day ago

Bull ants are often described as one of the oldest-looking groups of ants alive today. They hunt alone, rely on their eyes and have workers that can reproduce: traits that many scientists see as typical of early ants. Here is what we know about the deep history of bull ants and their only living relative, the dinosaur ant.

Myrmecia brevinoda bull ant — Myrmecia brevinoda, a member of an ancient group of ants.

An ancient lineage

Bull ants belong to the subfamily Myrmeciinae. Genetic studies suggest that this lineage split off from other ants roughly 100 million years ago, when dinosaurs still walked the earth. Today, the subfamily is found only in Australia and New Caledonia.

Fossils far from Australia

That was not always the case. Fossils of extinct relatives have been found in the Northern Hemisphere, including species from around 50 million years ago described from Denmark, Canada and Washington State in the United States. Another fossil genus, Prionomyrmex, is known from Baltic amber. Bull ants were once much more widespread than they are today.

The dinosaur ant

Bull ants have one living relative in their subfamily: Nothomyrmecia macrops, nicknamed the dinosaur ant. It was first collected in 1931 in Western Australia and then disappeared for decades, despite many searches. In October 1977, a team led by Robert Taylor finally found a single worker at Poochera in South Australia, around 1,300 km from the original site. It is seen as one of the most primitive ants alive.

An ant that loves the cold

The dinosaur ant is strictly nocturnal and most active at cool temperatures, around 5 to 10 degrees. That may help it, because at those temperatures there are fewer competitors and predators around, and prey is slower.

Where bull ants live today

Today, bull ants are found throughout Australia and on its coastal islands. Myrmecia apicalis is the only species outside Australia, on the Isle of Pines in New Caledonia. Myrmecia brevinoda was first found in New Zealand in 1940, but has not been found there since 1981 and is thought to have been eradicated.