TRICERATOPS
The heaviest frontline herbivore on the island: three horns, a shield of bone and enough mass to end a charge.
Triceratops plays forward. The frill absorbs most frontal damage, so the correct answer to an ambush is almost always to turn into it and hold ground rather than to run. Herds of two or more are close to unkillable in open terrain.
The gore attack throws lighter attackers and deals the highest single-hit damage available to a herbivore. It punishes over-commitment: let the carnivore close, then gore on their lunge. Never chase — the stamina pool is short.
Ground growth and low shrubs. It can strip a clearing quickly, which makes it loud and easy to track; move between feeding spots instead of emptying one. Mud wallows reduce parasite build-up during long growth.