Eumastacinae

Eumastacidae are a family of grasshoppers sometimes known as monkey- or matchstick grasshoppers. They usually have thin legs that are held at right angles to the body, sometimes close to the horizontal plane. Many species are wingless. Their heads are held at an angle with the top of the head often jutting above the line of the thorax and abdomen. They have three segmented tarsi and have a short antenna with a knobby organ at the tip. They do not have a prosternal spine or tympanum. Most species inhabit the tropics, with a greater diversity in the neotropics. They are considered primitive within the Orthoptera and feed on algae, ferns, and gymnosperms, the more ancient plant groups.

The families Chorotypidae and Morabidae were formerly included in this group as subfamilies but are now considered as separate families within the Eumastacoidea. With the exception of the central Asian Gomphomastacinae, all other subfamilies are restricted to South America.