| Named By: | Steven C. Wallace & Richard C. Hulbert Jr in 2013 |
| Time Period: | Early Pliocene |
| Location: | USA, Florida - Upper Bone Valley Formation |
| Size: | Uncertain due to lack of remains, but analysis of fore limbs leads to an estimated weight of between 55.7-58.3 kg for one individual, and 76.6-85 kg for another |
| Diet: | Carnivore |
| Fossil(s): | Partial mandible (lower jaw) with teeth, as well as a complete left tibia and proximal right tibia, left humerus and distal end of the right humerus. Remains are of at least two individuals |
| Classification: | | Chordata | Mammalia | Carvnivora | Felidae | Machairodontinae | Smilodontini | |
Rhizosmilodon is an extinct genus of saber-tooth cat of the subfamily Machairodontinae that lived during the Early Pliocene and was discovered in the U.S. state of Florida. Comparable in size to a medium-sized modern jaguar at about 165 lb. in weight, Rhizosmilodon is known only from Florida (though it likely inhabited other areas of North America). The best specimens for this species are its lower jaw and teeth, which carry intermediate characteristics between advanced forms such as Smilodon and primitive forms such as Paramachairodus. It was likely an ambush predator, preying on animals such as deer, tapirs and horses.