Original: As the most abundant large predator in the Morrison Formation, Allosaurus was at the top of the food chain, probably preying on contemporaneous large herbivorous dinosaurs and perhaps even other predators (e.g. Ceratosaurus).
Simplified: Allosaurus was at the top of the food chain. It probably preyed on large herbivorous dinosaurs and perhaps even other predators (e.g. Ceratosaurus).