Paleontological observations date back to at least the 6th century BC.
Notes on verification
Confirmed by Wikipedia's paleontology and history of paleontology articles, as well as independent academic sources (Internet Encyclopedia of Philosophy, New World Encyclopedia) that corroborate Xenophanes' 6th century BC observations of marine fossils as early paleontological reasoning. [tier=silver indep_score=0.875 clusters=2 claim_tier=notable]
Sources
- Paleontology (wikipedia)
- https://iep.utm.edu/xenoph/ (corroboration)
- https://www.newworldencyclopedia.org/entry/Xenophanes (corroboration)