When They Were Giants
This script will be for prehistoric mammals that currently have modern day relatives. These prehistoric mammals need to be at least twice the size (be it height or weight) for them to make it into the script.
Taken from “The Rise and Reign of The Mammals” by Dr. Steve Brusatte, PhD “This suggests there is some limit to overall land mammal body size, probably dictated by a combination of factors. First is diet: the bulkiest mammals are always herbivores and are generally about ten times heavier than the largest predators they live alongside. To get epically big, you need a steady source of calories, and the best way to do this is to binge on plants, which are much more readily available than meat. Second has to do with temperature: big animals are at risk of overheating, and the problem becomes more acute the bigger you get.”