Creating a group is simple. Find a dinosaur who is the same as you and when close enough 2 Call. The dinosaur should get a pop up asking them to join the group and to "Friendly Call" or "2 Call" back to accept. If you wish to not join all you need to do is "Threaten" or "3 Call" to decline. Mechanically the game will not let you party with someone not of the same species.

Grouping is a great way to survive the dangers of the Isle. The larger your party the safer you may be but also the less stealthy you are as well. You may also attract more attention overall and get attacked as well. So keeping your ears open and eyes scanning nearby bushes and horizon is a good idea and easier with a group. If you are protecting young dinosaurs you may lose a few along the way to new areas.

Tip: If you see an icon on your navigation that looks like a group of dinosaurs in red. This could indicate an oversized group (going outside of the group limits set by the game) or large gathering of dinosaurs.