Phanerozoic

The Phanerozoic is the current and the latest of the four geologic eons in the Earth's geologic time scale, covering the time period from 538.8 ± 0.6 million years ago to the present. It is the eon during which abundant animal and plant life has proliferated, diversified and colonised various niches on the Earth's surface, beginning with the Cambrian period when animals first developed hard shells that can be clearly preserved in the fossil record. The time before the Phanerozoic, collectively called the Precambrian, is now divided into the Hadean, Archaean and Proterozoic eons. The time span of the Phanerozoic starts with the sudden appearance of fossilised evidence of a number of animal phyla; the evolution of those phyla into diverse forms; the evolution of plants; the evolution of fish, arthropods and molluscs; the terrestrial colonisation and evolution of insects, chelicerates, myriapods and tetrapods; and the development of modern flora dominated by vascular plants. During this interval, plate tectonic processes assembled the continents into Pangaea, the most recent supercontinent, before its later fragmentation into the present-day continental landmasses.