The age of lichens
Before there were trees, the tallest things on land were fungal and algal crusts.
- When
- Known to
- ± 15 million years
- Era
- Silurian, Paleozoic
Lichenised and free-living fungi, cyanobacteria and algae form extensive crusts on rock and soil through the Ordovician and Silurian — a terrestrial biosphere with no plants in the modern sense. Enigmatic tube-like nematophytes, some over a metre tall, are the largest organisms on land. These communities weather rock, build the first soils, and create the conditions in which vascular plants can later take hold.