Fungi are older than literal roots. The first land plants relied on them for nutrient exchange before evolving a radical system. My mind was blown away during a presentation by Dr. Toby Kiers about the latest research on mycorrhizal networks. They directly imaged nutrients moving both ways through those narrow filaments! Which is impressive on its own, but completely mind-fucked me when I noticed they were in real-time. https://www.spun.earth/networks/mycorrhizal-fungi

Fungi are much older. Source

Plants are older than thought: 500 million years old. Source

The earliest fungi started to develop 1.5 billion years ago, with other types 635 to 400 million years ago. Source

In fact, both flora and fauna can't survive without fungi. Source