Old mold - Fossil of world's earliest fungus unearthed in Canada

A microscopic multicellular fungus named Ourasphaira giraldae, which lived in an estuary environment roughly 900 million to 1 billion years ago and was unearthed in the Northern Territories of Canada, is shown in this photograph from the University of Liege, Belgium released May 22, 2019. Corentin Loron/University of Liege/Handout via REUTERS.

WASHINGTON (Reuters) - Microfossils of a globular spore connected to a T-shaped filament excavated in an Arctic region of northwestern Canada represent the oldest-known fungus, a discovery that sheds light on the origins of an important branch in Earth's tree of life.

Scientists said on Wednesday the multicellular fungus that they named Ourasphaira giraldae - forerunner to an immensely diverse group that today includes the likes of mushrooms, yeasts and molds - lived in an estuary environment about 900 million to 1 billion years ago. Until now, the oldest-known fungus fossil was one about 410 million years old from Scotland.