primordium

plural primordia

1. anatomyAn aggregation of cells that is the first stage in the development of an organ.

   In tomato, for example, the first sepal primordium is formed as an outgrowth at the periphery of the apex and the subsequent sepal primordia are initiated in a helical fashion at an angle of approximately 137° from the previous one.

   2017, Taylor A. Steeves, Vipen K. Sawhney, Essentials of Developmental Plant Anatomy, Oxford University Press, page 29

   Synonyms: anlage, proton

2. historyA primordial, original condition or event.

   It is thus vain to hope that the history of the primordia can be reduced to the progress of archeological investigation.

   1997 [1991], Alexandre Grandazzi, translated by Jane Marie Todd, The Foundation of Rome: Myth and History, →ISBN, page 33

   2 more examples

   Attempts have been made by historians of religion to distinguish between mythic orientations in time concerned with the repetition of a primordium and those concerned with the anticipation of an eschaton.

   2003, David Chidester, Salvation and Suicide: Jim Jones, the Peoples Temple, and Jonestown, 2nd edition, →ISBN, page 106

   [Joseph Smith] did not think of himself as going back to a primordium of true Christianity, as the Puritans did. In his view, there never was a golden age when religion flourished to perfection.

   2008, Richard L. Bushman, Mormonism: A Very Short Introduction, →ISBN, page 5