Neoproterozoic
Geologic time period
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The Neoproterozoic Era is the unit of geologic time from 1 billion to 538.8 million years ago.
It is the last era of the Precambrian Supereon and the Proterozoic Eon; it is subdivided into the Tonian, Cryogenian, and Ediacaran periods. Wikipedia
Eon: Proterozoic
Occurred: 1,000 million years ago - 541 (+/- 1) million years ago
Periods: Tonian, Cryogenian, and Ediacaran
Lower boundary definition: Defined Chronometrically
Lower GSSA ratified: 1991
Proposed subdivisions: Cryogenian Period, 850–630 Ma; Ediacaran Period, 630–541.0 Ma
Upper boundary definition: Appearance of the Ichnofossil Treptichnus pedum