Research overview: iterative evolution of the sabertooth ecomorph

This overview synthesizes the striking pattern by which a sabertooth body plan evolved repeatedly and independently across unrelated lineages of predatory mammals. True cats (machairodonts), nimravids, barbourofelids, the marsupial-relative Thylacosmilus, and even earlier non-mammalian synapsids such as gorgonopsians and certain creodonts all developed elongated, blade-like canines for dispatching large prey. The survey reviews why this particular solution recurs, examining the biomechanical advantages and constraints of sabre canines, the ecological settings of abundant large herbivores that seem to favour them, and the common features, wide gape, reinforced canines, powerful neck, that convergent sabertooths share. It frames the sabertooth as a classic textbook example of convergent and iterative evolution, repeatedly assembled and repeatedly lost over tens of millions of years.