Ancient Parasitic Fungi Documented in 99-Million-Year-Old Amber

Ancient Parasitic Fungi Discovered in 99-Million-Year-Old Amber

Fossilized insects preserved in 99-million-year-old amber have provided direct evidence of parasitic fungi infecting insect hosts during the Cretaceous period. The discovery, detailed in Proceedings of the Royal Society B, documents the oldest known instances of such fungal behavior.

The fossils, an ant and a fly, were found in amber deposits from northern Myanmar. Researchers utilized microscopic and 3D imaging techniques to analyze the specimens, identifying fungal growths protruding from the insects' heads and bodies. Yuhui Zhuang, a paleontology researcher at Yunnan University and lead author, noted the infrequent occurrence of such preserved symbiotic relationships among amber specimens.

The analysis led to the identification and description of two previously unknown fungal species:

• Paleoophiocordyceps ironomyiae: Observed growing from the head of the fossilized fly.
• Paleoophiocordyceps gerontoformicae: Observed on the body of the fossilized ant.

These growths represent the fruiting bodies of the fungi, which are structures involved in spore dispersal post-host death.

The morphology and growth patterns of these ancient fungi suggest parasitic tactics similar to modern Ophiocordyceps fungi, also known as "zombie-ant fungi." This indicates that the behavioral alteration of hosts prior to fungal reproduction existed nearly 100 million years ago. Conrad Labandeira, a scientist at the Smithsonian Museum of Natural History, commented that ants appear to have been consistently targeted by this type of parasitoid fungus.

João Araújo, a co-author of the study, posited that these fossilized fungi are likely ancient relatives of contemporary zombie-ant fungi. The preservation within amber offered a detailed view of the fungal takeover, suggesting the insects were infected and died just before becoming encased in tree resin. This discovery contributes to understanding the role of parasitism in prehistoric ecosystems.