Which order is wingless hexapods characterized by two long tails (cerci) on the abdomen and monocondylic mandibles?

Which order is wingless hexapods characterized by two long tails (cerci) on the abdomen and monocondylic mandibles?

• A. Diplura
• B. Protura
• C. Collembola
• D. Ephemeroptera

Answer: (A)

Two long tails (cerci) at the end of the abdomen are a hallmark of Diplura, a primitive group of wingless hexapods. Along with monocondylic mandibles, where the jaw attaches to the head by a single articulation, this combination uniquely identifies Diplura among the wingless hexapods. The other groups lack this exact pairing: Protura lack prominent tails and have highly simplified mouthparts; Collembola have a springing organ and different head-mouth part structure; Ephemeroptera are not wingless in their adult stage and have a different jaw articulation. So the two cerci plus monocondylic mandibles point to Diplura.

Two long tails (cerci) at the end of the abdomen are a hallmark of Diplura, a primitive group of wingless hexapods. Along with monocondylic mandibles, where the jaw attaches to the head by a single articulation, this combination uniquely identifies Diplura among the wingless hexapods. The other groups lack this exact pairing: Protura lack prominent tails and have highly simplified mouthparts; Collembola have a springing organ and different head-mouth part structure; Ephemeroptera are not wingless in their adult stage and have a different jaw articulation. So the two cerci plus monocondylic mandibles point to Diplura.