any of 70 species of the arthropod class Arachnida that are similar in appearance to whip scorpions (order Uropygi) but lack a telson, or tail. They occur in hot parts of both North and South America, Asia, and Africa, where, by day, they hide under bark or stones. They often enter houses. An example is the 11-mm (0.4-inch) Tarantula marginemaculata of Florida.