"Kya" redirects here. For other uses, see Kya (disambiguation).

In astronomy, geology, and paleontology, tya, sometimes also kya, is an acronym for thousand years ago and is used as a unit of time to denote length of time before the present. The popular term 'kya' is replaced in scientific literature with ka (kilo annum).

See also

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• annum
• Before Present
• Gya
• bya
• mya (unit)

Units of time