mya

Units & Measurements abbreviation · Time

mya
Stands forMillion years ago
CategoriesUnits & Measurements

mya stands for Million years ago, a time abbreviation.

Informal abbreviation common in popular science, museum labels, textbooks and documentaries. The first animals with hard skeletons appeared in the Cambrian, roughly 540 mya, and the earliest members of the genus Homo about 2.8 mya.

Example: The central Atlantic Ocean began opening roughly 200 mya as Pangaea broke apart.

Usage notes

Also written MYA, m.y.a. or Mya. Scientific journals usually prefer Ma. Related forms include kya (thousand years ago) and bya (billion years ago); Earth formed about 4.54 bya. Note that "mya" gives a point in the past, not a length of time.

More time abbreviations

  • MM – Month (two-digit, in date formats)
  • MM/DD/YYYY – Month/day/year (US date format)
  • mo – Month
  • MoM – Month over month
  • ms – Millisecond
  • MTD – Month to date
  • ns – Nanosecond
  • p.m. – Post meridiem (after midday)
  • Q1 – First quarter
  • Q2 – Second quarter
  • Q3 – Third quarter
  • Q4 – Fourth quarter

See all 51 time abbreviations →