Complex sentence: Later, Gwangi pursues them to their base camp, where it is able to get the best of them, until they begin to rope it down, however, the "Styracosaurus" reappears and battles Gwangi.
Split into simpler sentences: Later, Gwangi pursues the people to their base camp, where it is able to get the best of them, until they begin to rope it down. Then, the "Styracosaurus" reappears and battles Gwangi.