One of the three multicellular kingdoms, along with the Plantae (plants) and Animalia (animals). Although resembling plants, Fungi feed by ingesting organic matter, whereas plants are autotrophic and require only inorganic substances as nutrients. As fungi generally lack hard parts they are rarely found as fossils, but thread-like representatives have been found in Precambrian rocks. Fungi probably left the sea about 400 million years ago, when the first plants colonized the land.