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Ferns first appear in the fossil record about 360 million years ago in the late Devonian period. [73] Synapsids such as Dimetrodon were the largest terrestrial vertebrates in the Permian period, 299 to 251 million years ago.
Homininid Era – Period prior to the existence of Hominini; Prehistory – Period between the appearance of Homo ("humans"; first stone tools c. three million years ago) and the invention of writing systems (for the Ancient Near East: c. five thousand years ago). Paleolithic – the earliest period of the Stone Age
The Cambrian (/ ˈ k æ m b r i. ə n, ˈ k eɪ m-/ KAM-bree-ən, KAYM-) is the first geological period of the Paleozoic Era, and the Phanerozoic Eon. [5] The Cambrian lasted 51.95 million years from the end of the preceding Ediacaran period 538.8 Ma (million years ago) to the beginning of the Ordovician Period 486.85 Ma.
The Archean represents the time period from (million years ago). The ... levels only 500 million years after ... 4600–539 million years ago; Timeline of natural ...
The findings challenge the existing theory that the planet was completely covered by ocean four billion years ago. Fresh water present on Earth ‘500 million years earlier than previously thought ...
The Cambrian is the first period of the Paleozoic Era and ran from 539 million to 485 million years ago. The Cambrian sparked a rapid expansion in the diversity of animals, in an event known as the Cambrian explosion , during which the greatest number of animal body plans evolved in a single period in the history of Earth.
A photograph shows a cast of a 560 million-year-old Dickinsonia costata fossil found in South Australia. At more than a meter in length, the creature is the largest known animal from that period.
The last common ancestor of all extant eukaryotes is thought to have lived around 1.8 billion years ago. Around 800 million years ago, there was a notable increase in the complexity and number of eukaryotes species in the fossil record. [133] Before the spike in diversity, eukaryotes are thought to have lived in highly sulfuric environments.