What is "paleo-"

Paleo- \Pa"le*o-\ [Gr. palaio`s, adj.] A combining form meaning old, ancient; as, palearctic, paleontology, paleothere, paleography. [Written also pal[ae]o-.]

before vowels pale- word-forming element used in scientific combinations (mostly since c.1870) meaning "ancient, early, prehistoric, primitive," from Greek palaio-, comb. form of palaios "old, ancient," from palai "long ago, far back," related to palin "again, backwards," tele- "far off, at a distance," from PIE root *kwel- (2) "far" in space and time" (see tele-).

pre. 1 old. 2 ancient. 3 prehistoric. 4 primitive. 5 Related to paleontology.