Xenarthra

**Definition:** A superorder of New World mammals characterized by the absence of incisors and canines from among their teeth, and comprising the ARMADILLOS and the SLOTHS. The superorder is distinguished from all others by what are known as xenarthrous vertebrae (xenos, strange; arthron, joint): there are secondary, and sometimes even more, articulations between the vertebrae of the lumbar series. The superorder in part was formerly called Edentata. (From Random House Unabridged Dictionary, 2d ed; Walker's Mammals of the World, 5th ed, vol. I, p515)

**Tree numbers:** - B01.050.150.900.649.313.999