The Last of Us zombie fungus hijacked minds even as early as dinosaur era, scientists find

Fungal fossils trapped in amber reveal insights about parasite’s early host shifts

The mind-controlling “zombie” fungus, which served as the inspiration for the video game and post-apocalyptic TV show The Last of Us, emerged about 133 million years ago when dinosaurs roamed Earth, a new study has found.

In the real world, fungi belonging to the Ophiocordyceps genus infect ants and cause them to behave strangely.

The fungi force their ant hosts to scale a plant to one of its tallest branches and clamp their jaws tightly onto a leaf.

As the ant remains locked onto the leaf, the fungus slowly consumes the insect’s tissues, growing and finally scattering spores down onto the forest floor from the height to restart the cycle afresh with new ant victims.

The fungus is known to reprogramme the instincts of its insect hosts for climbing, gripping, and walking to seek ideal conditions for its own reproduction.

Now, researchers have found remains of early species of this genus trapped in nearly 100-million-year-old fossilised plant sap.

Fungi growing out of the head of an insect encased in 99-million-year-old amber (Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, NIGPAS)

The study, published in the journal Proceedings of the Royal Society B: Biological Sciences, reveals early changes and host shifts undergone by the fungi that shaped their evolution.

These findings are some of the oldest direct evidence of parasitic relationships between fungi and insects, say researchers, including those from Chinese Academy of Sciences.

The origins of such parasitic behaviour have been difficult to trace since the soft nature of fungal tissues causes them to rarely fossilise.

Researchers have now identified two fungal species preserved in 99-million-year-old amber from northern Myanmar.

“Here, we report two new fungi, Paleoophiocordyceps gerontoformicae and Paleoophiocordyceps ironomyiae from mid-Cretaceous Kachin amber (approx. 99 million years old),” scientists wrote in the study.

One of these species, named P. gerontoformicae, occurred along with an infected ant pupa encased in amber dated to about 99 million years ago.

Scientists found that the structural features of this ancient parasitic fungus match those of modern-day Ophiocordyceps species.

By comparing the traits of this ancient fungus to those of other known extinct fungi, researchers say Ophiocordyceps likely emerged about 133.25 million years ago, earlier than previously proposed estimates of about 100 million years.

This was during the Early Cretaceous when dinosaurs roamed the Earth, scientists say.

“These fossils are among the oldest fossil records of animal-pathogenic fungi,” they wrote.

Researchers suspect the fungal genus initially parasitised beetles before undergoing host shifts to infect ants.

This shift was likely related to the increase in diversity and abundance of moths and ants during this period, scientists say.

The latest findings not only document some of the oldest evidence of insect-pathogenic fungi, but also provide new insights into the coevolution between fungi and host insects.