Coralline alga Spongites yendoi/ Derek Keats (CC BY-SA 3.0 Four hundred and thirty million years ago, according to ScienceDaily:The discovery made by FAU palaeontologists Dr. Sebastian Teichert, Prof. Dr. Axel Munnecke and their Australian colleague Dr. William Woelkerling has far-reaching
Source: Researchers: Coralline red algae existed 300 million years earlier than thought | Uncommon Descent