A name associated with several animals in four different orders of living mammals (see table). They are so named because they are insectivorous, having a diet of ants and termites which they detect mainly by smell. These animals provide a good example of the evolutionary concept of convergence, in which similar adaptations are made by organisms of different groups. The animal most frequently associated with this name is the giant anteater (Myrmecophaga tridactyla), a ground-dwelling member of the family Myrmecophagidae in the order Xenarthra (see illustration). Three arboreal species—the northern tamandua (Tamandua mexicana), southern tamandua (T. tetradactyla), and the silky, or pygmy, anteater (Cyclopes didactylus)—are also classified in this family. They are found in Central and South America from Mexico to northern Argentina. Although they share membership in Xenarthra with sloths and armadillos, anteaters are the only toothless members of the order. Tamanduas and silky anteaters do possess either distinct tooth sockets or vestiges, which indicate that the teeth have been lost in the course of phylogenetic development. All members of the order Xenarthra differ from all other mammals by having xenarthrous vertebrae, lumbar vertebrae that have additional articulations (xenarthrales) to provide reinforcement for digging.