Why in News:

• Microfossils of a globular spore connected to a T-shaped filament excavated in an Arctic region of north-western Canada represent the oldest-known fungus, a discovery that sheds light on the origins of an important branch in earth’s tree of life.

Background: / Ourasphaira Giraldae:

• 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. Fungi play a crucial role in global ecosystems such as in the organic decomposition process. Fungi belong to a broad group of organisms, called eukaryotes, that possesses a clearly defined nucleus and also includes animals and plants. A fundamental difference between fungi and plants is that fungi are incapable of photosynthesis, harnessing sunlight to synthesize nutrients.
• Because of a close evolutionary relationship between fungi and animals, the researchers suspect that early forms of microscopic animal life may have lived at the same time as Ourasphaira. The earliest fossils of rudimentary animals are about 635 million years old. The microscopic fossils, contained in shale rock from the Northwest Territories of Canada, dated to the Proterozoic era before the advent of complex life forms.
• In determining that the fossils were of fungi, the researchers identified the presence of a fibrous substance called chitin in Ourasphaira’s cell walls, a key fungal characteristic.