99-million-year-old 'zombie' fungi found preserved in amber, scientists say
Scientists have discovered two new species of ancient parasitic fungi preserved in amber dating back 99 million years.
The fungi were growing out of the bodies of host insects that became trapped in globs of amber during the mid-Cretaceous period, according to a paper published last month in the Proceedings of the Royal Society B.
"It's fascinating to see some of the strangeness of the natural world that we see today was also present at the height of the age of the dinosaurs," said Edmund Jarzembowski, a paleoentomologist at the Nanjing Institute of Geology and Palaeontology and co-author of the study, in a statement.
The species of fungi that were growing out of the body of a young ant in its cocoon stage was named Paleoophiocordyceps gerontoformicae, while another species found bursting from the body of an ancient fly was named Paleoophiocordyceps ironomyiae.
Entomopathogenic fungi can infect a wide range of insect groups, including ants, flies, spiders, cicadas and beetles, scientists say.
The discovery represents the oldest-known examples of parasitic fungi that infect insects, the researchers said. Throughout their 400 million years of coexistence, fungi have proved to be an important regulator of insect populations.
"As the infections are lethal, Ophiocordyceps likely played an important role in controlling the populations of insects by the Mid-Cretaceous, in a similar way to how their living counterparts do today," Jarzembowski said.
Little is known about ancient entomopathogenic fungi due to the scarcity of fossils that display typical pathogenic structures on their hosts, according to the paper.
The newly discovered species of fungi shared common traits with modern species of Ophiocordyceps, a group of fungi that contains the zombie-ant fungus Ophiocordyceps unilateralis, according to the paper. The groups may have diverged from each other about 130 million years ago, during the early Cretaceous period, the researchers said.
The discovery represents the oldest-known examples of parasitic fungi that infect insects, the researchers said. More than 1,500 species of parasitic fungi are currently found in five of the eight major groups of fungi, according to the Natural History Museum in London.
O. unilateralis is known for infecting the brain of its hosts and manipulating the insect's behavior -- forcing it to seek more favorable conditions so that the fungi can thrive, the researchers said. Once the ant dies, the fungus grows outside of its body and releases millions of spores to infect more ants.
The Zombie-ant fungi was the premise of the post-apocalyptic television series "The Last of Us."
"This discovery shows the impact of tiny organisms on social animals long before humans evolved -- with the comforting thought that these tiny organisms are unlikely to jump to us, unlike in sci-fi films!" Jarzembowski said.
The specimens are being housed at the Nanjing Institute of Geology and Palaeontology at the Chinese Academy of Sciences and Yunnan University.
