]> The geologic time scale is a chronologic schema (or idealized model) relating stratigraphy to time that is used by geologists, paleontologists and other earth scientists to describe the timing and relationships between events that have occurred during the history of the Earth. [Wikipedia] 1000 0 0 0.0117 0.126 0.781 1.806 2.588 3.600 5.332 7.246 11.608 13.82 15.97 20.43 23.03 28.4 0.1 33.9 0.1 37.2 0.1 40.4 0.2 48.6 0.2 55.8 0.2 58.7 0.2 61.1 65.5 0.3 70.6 0.6 83.5 0.7 85.8 0.7 88.6 93.6 0.8 99.6 0.9 112.0 1.0 125.0 1.0 130.0 1.6 133.9 140.2 3.0 145.5 4.0 150.8 4.0 155.6 161.2 4.0 164.7 4.0 167.7 3.5 171.6 3.0 175.6 2.0 183.0 1.5 189.6 1.5 196.5 1.0 199.6 0.6 203.6 1.5 203.6 1.5 216.5 2.0 228.7 237.0 2.0 245.9 249.5 251.0 0.4 253.8 0.7 260.4 0.7 265.8 0.7 268.0 0.7 270.6 0.7 275.6 0.7 284.4 0.7 294.6 0.8 299.0 0.8 303.4 0.9 307.2 1.0 311.7 1.1 318.1 1.3 328.3 1.6 345.3 2.1 359.2 2.5 374.5 2.6 385.3 2.6 391.8 2.7 397.5 2.7 407.0 2.8 411.2 2.8 416.0 2.8 418.7 2.7 421.3 2.6 422.9 2.5 426.2 2.4 428.2 2.3 436.0 1.9 439.0 1.8 443.7 1.5 445.6 1.5 455.8 1.6 460.9 1.6 468.1 1.6 471.8 1.6 478.6 1.7 488.3 1.7 492 496 499 503 506.5 510 515 521 528 542 1.0 635 850 1000 1200 1400 1600 1800 2050 2300 2500 2800 3200 3600 4000 4600 Epochs are divided into ages [millions of years] [Wikipedia] Periods are divided into epochs [tens of millions of years] [Wikipedia] Eras are divided into periods. [Wikipedia] Eons are divided into eras [several hundred million years] [Wikipedia] Supereons are divided into eons. [billions of years] [Wikipedia] The largest defined unit of time is the supereon, composed of eons.] [Wikipedia] The subdivisions of geologic time. The table of geologic time spans are dates and nomenclature defined by the International Commission on Stratigraphy. [Wikipedia]