1A. An example species of mongosaur. 1B. A mongosaur opening its muzzle to reveal its sharp teeth.
Time period - 100 million A.D.
Habitats - Swamps, Grasslands, Deserts, and Mountainous Reigns
Mongosaur is a descendant of mongooses of the Holocene/Anthropocene, after the extinction of most other large carnivorous mammals during 100 million years time. Unlike most other carnivorous mammals, the early ancestors of mongosaurs (around 85 million years earlier), which resembled meerkats in appearance and locomotion (being able to stand up on hind legs), evolved to be much bigger and evolved to be able to walk and run bipedally, becoming very similar to the Mesozoic non-avian theropod dinosaurs in many ways. Depending on a species, mongosaurs can grow to about the size of a small cat to about the size of a Tyrannosaurus, making the Tyrannosaurus-sized species (which lives in the Bengal Swamp) the biggest ever carnivorous mammals on Earth (big enough to hunt a large juvenile toraton alone, rarely hunting in packs and killing adult toratons), thanks to Earth having higher oxygen than today, and the mongosaurs having hollow bones and bird-like airsacs in their bodies, allowing them to grow bigger than any carnivorous mammal before, even greater than the Andrewsarchus or even the biggest bears.