Timeline of Evolution: Standard Secular Model of Life's Development

Based on standard secular models, the following chart depicts a timeline of the evolutionary development of life on earth.

Life Forms¹This chart was adapted from an insert called the “Tower of Time” by John Gurche as reproduced in The Thread of Life: The Smithsonian Looks at Evolution, by Roger Lewin, Smithsonian Books, Washington, D.C., Distributed by W.W. Norton & Company, New York, N.Y. 1982.	Millions of Years Ago	Period	Era
Humans	0	Quaternary	Cenozoic
Mammals arrive	50	Tertiary	Cenozoic
Dinosaurs flourish, Tyrannosaurus rex, Triceratops, etc	100	Cretaceous	Mesozoic
Reptiles, pre-bird, archaeopteryx	150-175	Jurassic
Proliferation of land plant life	200	Triassic
Reptile branches, pre-mammalian forms. Dinosaurs arrive.	250	Permian	Paleozoic
Amphibians and first reptiles on land	300	Carboniferous
plants from the sea began to colonize the land.	350	Devonian
Vertebrate fish, jawless,	425	Silurian
Marine Invertebrates, trilobites, cephalopods…	450-500	Ordovician
Trilobites, snails, brachiopods	500-575	Cambrian
Multicellular life forms. Soft-bodied animals, worms, jellyfish, etc.	600-650	Algonkian	PreCambrian
Life begins 3.5 billion years ago

References[+]

References
1↑	This chart was adapted from an insert called the “Tower of Time” by John Gurche as reproduced in The Thread of Life: The Smithsonian Looks at Evolution, by Roger Lewin, Smithsonian Books, Washington, D.C., Distributed by W.W. Norton & Company, New York, N.Y. 1982.