Solifugae many species also are used for stridulation. Unlike scorpions, solifugids do not have a third tagma that forms a "tail". Most species of Solifugae live in dry climates and feed opportunistically on ground-dwelling arthropods and other small animals. The largest species grow to a length of , including legs. A number of urban legends exaggerate the size and speed of the Solifugae, and their potential danger to humans, which is negligible. Solifugae are moderately small to large arachnids (a few millimeters to several centimeters in body length), with the larger species reaching in length, including legs. In practice, the respective
Diania Diania Diania is an extinct genus of animal found in the Lower Cambrian Maotianshan shale of China, represented by a single species D. cactiformis. Known during its investigation by the nickname "walking cactus", this organism belongs to a group known as the armoured lobopodians and has a simple worm-like body with robust, spiny, and apparently jointed legs. Its significance is that jointed legs are the defining character of the arthropods and "Diania" may thus be very close to the origins of the most diverse group of animals on the planet. Fossils of these animals were discovered independently by Jianni Liu