Oldest-ever fossil mushroom found, aged 115 million years

US-based scientists have unearthed the oldest known mushroom fossil dating back 115 million years, from the dinosaur-era when ancient supercontinent Gondwana was breaking apart. The mushroom fossilised in a limestone in Brazil was an "extraordinarily rare event", scientists said. They believe the mushroom was mineralised after it fell into a salty lake being covered layer-by-layer with sediments.