Even before Charles Darwin published his theory of evolution by natural selection in 1859, scientists had long pondered the Earth's rich biodiversity.

Source: https://phys.org/news/2023-01-rosy-finches-colorado-high-alpine-specialists.html

With its combination of reptile and bird features, the Archaeopteryx proved to be the "missing link" that illustrated Charles Darwin's then-recently published theory of evolution.

Source: https://rapidcityjournal.com/news/nation-world/archaeologists-in-louisiana-save-artifacts-12-000-years-old-from-natural-disasters-and-looters/article_390de877-f66c-5f8d-bab5-c5661df9dfc6.html