Final answer:
The top predator at Dinosaur Monument during the Jurassic period was c. Allosaurus, a theropod dinosaur at the apex of the ecosystem's food chain. Sauropods were herbivores, while the therapsids.
Step-by-step explanation:
The top predator in the Jurassic fossil bone bed at Dinosaur Monument was c. Allosaurus. Allosaurus was a large carnivorous dinosaur that lived during the late Jurassic period. It was part of the group known as the theropods, which later gave rise to birds. This dinosaur was at the top of the food chain in its ecosystem, preying on a variety of other dinosaurs, including sauropods.
Although sauropods were massive and formidable herbivorous dinosaurs, and therapsids were mammal-like reptiles that lived millions of years before the Jurassic, neither were the apex predators in the Jurassic ecosystems. Archosaurs like Allosaurus were fearsome predators of their time, while brachiopods are a group of marine invertebrates and not dinosaurs at all. Furthermore, therapsids had largely been replaced by dinosaurs and other groups of reptiles by the Jurassic period, with the final evolution of mammals still forthcoming.