Mya (unit)

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In astronomy, geology, and paleontology, mya or "m.y.a." is an acronym for million years ago. This abbreviation is commonly used as a unit of time to denote length of time before the present or "B.P." (before AD 1950). Specifically, one mya is equal to 10⁶ years ago. The popular term 'mya' is replaced in scientific literature with Ma (megaannum).

Like the related unit bya or "b.y.a.," ("billion years ago"), mya is traditionally written in lowercase. The common term bya is replaced in scientific literature with Ga (gigaannum).

[edit] Events around 1 mya:

[edit] Astronomical deep time:

• The light we see now from the Andromeda Galaxy started 2.5 mya
• The light we (do not) see now from the centre of the Milky Way started 0.026 mya

[edit] Geologic periods (Neogene):

• Pliocene 5.3 to 1.8 mya
  • The last geomagnetic reversal was 0.78 mya
  • The (Eemian interglacial) Ice Age started 0.13 mya
• Holocene started 0.01 mya

[edit] Prehistoric Paleontology:

• the permian-triassic mass extinction happend 248 mya killing off 99% of all species.
• flowering plants appear 135 mya
• dinosaurs are extinct 65 million mya
• the first primates appear 90-55 mya
• humans and chimpanzees diverge from a commen ancestor toumai around 7 mya.
• The Stone Age started 3 mya
• Homo erectus existed from 1.8 to 0.07 mya
  • and learns to control fire from 1.5 to 0.5 mya
  • and colonized Asia from 0.5 to 0.3 mya
• Homo sapiens separated from Neanderthal lineage 0.6 mya
  • and emerges out of Africa from 0.076 mya
  • and enters Australasia from 0.07 mya
  • and colonized all of Eurasia 0.04 mya
  • and forms cultures since the Upper Paleolithic Revolution 0.04 mya
  • and colonized all of America 0.015 mya

[edit] See also

• annum
• Before Present
• bya
• tyade:Mya (Einheit)

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