Baryonyx in indeed a tank breaker.
Best use I’ve found is to keep it in reserve against a wall (Anykylosaurus or Nodopatosaurus, for example). He’s useless against all raptors and similar dinosaurs, as they’ll 2-shot him in no time. He’s got a reasonable, though not guaranteed, to down a large theropod like Tyrannosaurus.
Do not swap him in unless in desperation against a tank. Move him in as a new dino. R2C is your first move, followed by the big hit; it usually hits in excess of 3K even at the introductory level of 11, goes through armor, and destroys shields. Also doesn’t tend to last too much longer on the field unless the follow-up opponent is low-damage or even another tank.