mya

1. million years ago: megayears ago.

   1 more example

   The first (oldest) unit of time is the Precambrian Supereon, which covers much of Earth's history from its origins roughly 4.55 bya to 545 mya. Very primitive, one-celled life-forms arose as early as 4.0 bya and near the end of the era (570 mya) the oldest known fossils of multi-celled organisms appear.

   2015, Joyce A. Quinn, Susan L. Woodward, “Introduction”, in Earth's Landscape: An Encyclopedia of the World's Geographic Features, volumes I: A–L, Santa Barbara, CA: ABC-CLIO, →ISBN, page xxxi

1. million years ago: megayears ago.

1. A female given name from Latin.

plural Myas

1. A surname.

1. million years ago: megayears ago.

   Both tabulates and rugosans evolved independently as part of the Ordovician Radiation; the tabulates appeared first in the Early Ordovician (~488 Mya), followed by rugosans about 20 My later.

   2013, Walter M. Goldberg, “A Brief History of Reefs and Corals”, in The Biology of Reefs and Reef Organisms, Chicago, Ill.; London: University of Chicago Press, →ISBN, section 13-2 (An Introduction to Paleozoic Corals), page 272, column 2