They will wonder into water wih no reason and die.
U can climb on it and harvest it but when it is gone beware of megs or other dinos in water.
Brontosaurus
The Brontosaurus is a behemoth of a dinosaur with a powerful tail 'tail sweep' attack that can smash all nearby enemies. This method is also one of the most efficient ways to gather berries and thatch, and the Brontosaurus' ability to carry large quantities of items make it even more useful for gathering. With its ability to carry a Platform Saddle, the Brontosaurus is often considered a must-have dinosaur for nomadic tribes looking for a mobile base.
How to survive, fight, and kill a wild Brontosaurus, from players who have done it.