A building that allows cheap access to a small pool of fossils depending on map location.
You could have it so that you assign scientists to continuously produce fossils/minerals, consuming a staff action every few minutes.
The chance of fossils/minerals would get worse as more is taken.
Having 3-4 species obtainable in this way seems like it'd be balanced
The yielded species being semi-random would be good, maybe generally just based on continent, seeing most map locales don't have many species actually from them.
For challenge mode it could be interesting to possibly get species you can't research.