Complex sentence: As they flee to safety, a "Tyrannosaurus" feasting on a carcass appears, and the "Spinosaurus" returns, but the humans escape while the two dinosaurs are distracted and fight each other.
Split into simpler sentences: As they flee to safety, a "Tyrannosaurus" feasting on a carcass appears. The "Spinosaurus" returns, but the humans escape while the two dinosaurs are distracted by fighting each other.