The Morrison Formation is a historical and scientific site which is primarily located in Morrison CO. However, the geographic range of this site extends to places as far north as Montana all the way down to New Mexico. This location is very famous for its fossils of ancient animals and plant life, It's most well known fossils originate from the Late Jurassic Period which spanned from 165 million years ago until 145 million years ago.  The Most famous fossils that come from the Morrison Formation come from various species of Dinosaurs, from small animals like Stokesosaurus and Dryosaurus, to the larger animals like Stegosaurus, Brachiosaurus, and Allosaurus. 

Morrison Formation

(Image Taken from Wikipedia)

https://en.wikipedia.org/wiki/Morrison_Formation

Allosaurus Restoration (Image created by Fred Wierum)

https://fredthedinosaurman.artstation.com/projects/Qg0WB

During the Late Jurassic, the environment would have looked drastically different from today as grass wasn't present during the Jurassic period and would've been replaced with ferns and conifer trees. The forests and plains of the Morrison formation would've been populated by many species of herbivorous dinosaurs. the more common types of dinosaurs would have been animals like Camptosaurus which were distant cousins to the larger Iguanodon species later on in the Early Cretaceous period. Accompanying the more common Camptosaurus would've been animals like Stegosaurus. A larger armored herbivore dinosaur known for its large plates going down it's vertebrae and large tail spikes called thagomizers. Other much larger animals like many types of Sauropod dinosaurs would've been seen there as well like. Large animals like Camptosaurus, Apatosaurus, and Brachiosaurus would've been the largest type of herbivorous animals in the Morrison formation.

Stegosaurus reconstruction by John ConwayApatosaurus scaring off a Marshosaurus (Art by Fred Wierum)

On the flip side, the various amount of carnivorous animals that lurked around the Morrison were just as interesting. Small carnivores known in the Morrison Formation are animals like Stokesosaurus and Ornitholestes would've been hunting insects, small dinosaurs, and even juvenile animals from larger animals. These animals would've filled a similar role to modern day animals like jackals and vultures of the modern day savannah. Other carnivorous animals like Marshosaurus and Ceratosaurus  would've been in the middle of the carnivore hierarchy in this ancient ecosystem. These predatory animals would've been big enough to take down animals their size like Camptosaurus. These were Medium sized carnivores of the Morrison formation. Small enough to hunt faster animals but large enough to defend themselves from larger predatory animals. The last types of carnivorous dinosaurs, which would've been the apex predators of their time were animals like Torvosaurus and the famous Allosaurus. These were the Lions and bears of their time being big enough to scare away smaller predators from fresh carcasses and big enough to probably hunt the largest animals of the ecosystem. Sadly, these animals would never been seen again for millions of years as their numbers dwindled over time and the animals, big and small, would've become extinct giving an end to the Late Jurassic animals that lived in the Morrison Formation.