What Kingdom was a saber-toothed tiger?

Saber-toothed tigers were not part of the Kingdom Animalia. They were mammals, which are part of the Kingdom Animalia.

Within the Animal Kingdom, saber-toothed tigers belonged to the following classifications:

* Phylum: Chordata

* Class: Mammalia

* Order: Carnivora

* Family: Felidae (cat family)

While they are often called "saber-toothed tigers," they are actually not closely related to modern tigers. They were part of a distinct group of extinct saber-toothed cats, known as Machairodontinae.