The Collaborative International Dictionary of English v.0.48:

Paleolith \Pa"le*o*lith\ (p[=a]"l[-e]*[-o]*l[i^]th), n. [Paleo-
   + -lith.] (Geol.)
   A relic of the Paleolithic era.
   [1913 Webster]

WordNet (r) 3.0 (2006):

paleolith
    n 1: a stone tool from the Paleolithic age

Moby Thesaurus II by Grady Ward, 1.0:

23 Moby Thesaurus words for "paleolith":
   ancient manuscript, antique, antiquity, archaism, artifact,
   cave painting, eolith, fossil, mezzolith, microlith, neolith,
   petrification, petrified forest, petrified wood, petroglyph,
   plateaulith, relic, reliquiae, remains, ruin, ruins, survival,
   vestige