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