Research overview: the major tribes of the Machairodontinae

This overview surveys the internal classification of the Machairodontinae, the true sabertooth cats within the family Felidae. Researchers commonly divide the subfamily into several tribes: the Smilodontini, including the dirk-toothed Megantereon and Smilodon; the Homotherini, encompassing scimitar-toothed forms such as Machairodus, Amphimachairodus, and Homotherium; and the Metailurini, a group of smaller, less extreme sabertooths like Metailurus and Dinofelis whose placement is debated. The survey reviews the diagnostic features used to define these tribes, the evolutionary trends toward canine elongation within each, and ongoing controversy over whether the Metailurini belong with the sabertooths at all. It frames how this tribal structure organizes more than ten million years of machairodont evolution across the Old and New Worlds.