zygotomerehttp://www.oed.com/dictionary/zygotomere_n%3Ftab%3Dmeaning_and_usezygotomere, n.
First published 1921; not fully revised

zygotomerenoun

Biology.
  1. 1899–
    One of a number of cells formed by segmentation of a zygote in the malaria parasite or other Sporozoa.
    Stressed as zyˈgotomere.
    1. 1899
      Nucleus and protoplasm divide into a number of zygotomeres, which become blastophores, each bearing on its surface..a large number of filamentous zygotoblasts.
      T. C. Allbutt et al., System of Medicine vol. VIII. 945

Originally published as part of the entry for zygote, n.

zygote, n. was first published in 1921; not fully revised.