biostratigraphy: Meaning and Definition of

bi•o•stra•tig•ra•phy

Pronunciation: (bī"ō-stru-tig'ru-fē), [key]
— n.
  1. a branch of geology dealing with the differentiation of sedimentary rock units on the basis of the fossils they contain.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.