Previously believed to be plant or fungi, these giant organisms may have been a now-extinct fourth type of life.

Prototaxites, an extinct organism from the Devonian period, has been thought to be a fungus since its first fossil was ...

The Paleozoic era's Silurian period saw animals and plants finally emerge on land. But first there was a period of biological regrouping following the disastrous climax to the Ordovician.

The most formidable of them were the armored placoderms, a group that first appeared during the Silurian with powerful ... The fossils of these remarkable animals come from the red rocks of ...