So everyone asks, "CoUlD SPiNo bEAT T.rEX?!?!?!?" but no one ever asks how they would do if they worked together. I have decided to create a little battle royal royal with one prehistoric animal from each major class. These creatures are: Paracetherium for mammals, Purrusaurus for reptiles, Argentavis for birds, Prionosuchus for amphibians, Edustus for fish, and 5 meganura for arthropods.
The battlefield is simple, two temperate forests, one closely packed, the other quite open. These forests are separated by a river, where Edustus while lurk.
So I guess its up to you to decide if they can beat spino and rex. (: