One thing that marks a therizino’s presence is if there’s virtually not a single carnivore (excluding rexes and gigas and allosauruses or any other big carnivore and the sea obviously). At that very moment use your camera to pan around you, count your remaining shotgun shells and your sword and shield’s durability. A therizinosaur, most likely a high level one...is nearby. A high enough level might even be able to take put the whole cave of the strong by itself.