Here is the full list of all 12 Saurian achievements.
Advance to Adult for the first time
Advance to Juvenile for the first time
Successfully hunt your first prey
Find Bone Butte
Advance to Sub-Adult for the first time
Advance to super-adult for the first time
Die of old age
Reach the highest elevation on the map
Travel 100km
Successfully kill a Borealosuchus
As a juvenile, successfully kill an Acheroraptor
Eat flesh from another of your own species