Ancestral Plains
Overview
Ancestral Plains is the largest map currently functional in the game. It features a large ocean and a variety of different terrains and landmarks able to be explored. Currently the map is the most widely used on servers both official and community-run, making it important to know where you're headed. If you are new to the game and this map, it is recommended you use a Pteranodon to fly around and get a feel for the landscape before you begin a journey as a terrestrial or aquatic creature.
Notable Features/Landmarks
Rivers
Ancestral Plains is currently the only map (besides Caldera) to feature one or more rivers. There are two on the map in total, one draining into a mid-sized lake and the other draining into the inland sea. Both feature varying strengths of current, able to pull and drag young creatures and poor swimmers with it. If a current exercises a strong enough effect on one's creature, there is a possibility of drowning. Be careful!
A well-equipped aquatic creature such as a Mosasaurus with speed talents or an Elasmosaurus may be able to swim up either of the rivers.