The genes of living fungi indicate that their common ancestor lived over a billion years ago.
New fossils were found in the remote Northwest Territories of the Canadian Arctic. The fossils were single-celled organisms. They were much bigger than bacteria, but Mr. Loron couldn’t determine exactly what they were. Dr. Rainbird’s analysis of the rocks showed that these organisms, whatever they were, had fossilized a billion years ago in an estuary, where a river flowed into a sea.
Three fossils produced a pattern that matches that of a substance called chitin. All fungi make chitin to build their tough walls. Only insects and a few other species do the same.
The researchers concluded they had found an ancient fungus, which they named Ourasphaira giraldae. “This is the first evidence that fungi are a billion years old, even though we’ve thought they were for a long time,” said Mary Berbee, a mycologist at the University of British Columbia, who was not involved in the new research.