One of nature’s most intriguing horror stories is that of the fungus that “zombifies” ants to spread its spores. Now, researchers have discovered the oldest known example of this kind of parasite at work, preserved in ancient amber.
Ophiocordyceps unilateralis is not a very fun guy. When its spores infect carpenter ants, it effectively hijacks the unfortunate insect’s nervous system, driving it against its will to climb a tall plant and clamp its jaws tightly to the underside of a leaf. There, the ant dies and grows a fungus stalk out of its head, which eventually releases spores down to the ground to infect the next round of hapless ants.
And it seems this story has been playing out for eons. Researchers at Oregon State University have discovered the oldest known specimen of a fungus parasite preying on an ant, frozen in a 50 million-year old piece of amber.
The victim is a familiar carpenter ant, but the fungus appears to be an unknown genus and species, which the discoverers have named Allocordyceps baltica. The basic process seems the same as the modern fungi, but it seems to include a few new stages of development. Most notably, the ascoma – the fruiting body that releases the spores – isn’t growing out of the ant’s head, but the other end.
“We can see a large, orange, cup-shaped ascoma with developing perithecia – flask-shaped structures that let the spores out – emerging from the rectum of the ant,” says George Poinar Jr, corresponding author of the study. “The vegetative part of the fungus is coming out of the abdomen and the base of the neck. We see freestanding fungal bodies also bearing what look like perithecia, and in addition we see what look like the sacs where spores develop. All of the stages, those attached to the ant and the freestanding ones, are of the same species.”
Amber is a fantastic medium for capturing ancient wonders. Other recent finds include a baby snake, a tailed spider, a tiny lizard skull, giant sperm, mammalian red blood cells and a dinosaur tail complete with feathers.
The new find was described in a paper published in the journal Fungal Biology.
Source: Oregon State University