Here is the full list of all 20 Prehistoric Tales achievements.
For starting trade relationships with neighboring tribes.
For making friends with a little greenskin.
For finding the arena of ancient battles.
For rescuing the valley from the invasion of greenskins.
For reaching level 10.
For reaching level 15.
For reaching level 25.
For eliminating 250 dinosaurs.
For winning 7 battles.
For winning 20 battles.
For winning 40 battles.
For 70 exchanges with traders.
For 200 exchanges with traders.
For building 15 constructions in your settlement.
For building 40 constructions in your settlement.
For collecting 120 plants.
For using 30 spells in battles.
For using 70 spells in battles.
For finding 15 artifacts and rare items.
For finding 25 artifacts and rare items.