The animal with exactly 21 pairs of legs, not just 21 legs, is the Scolopendromorpha. Specifically, some species of centipedes belonging to the Scolopendromorpha group have 21 pairs of legs.
Scolopendromorpha Centipedes
Scolopendromorpha, also known as tropical centipedes, are a distinct group of centipedes. They are known for their relatively large size and fast movement.
- Leg Count: They possess exactly 21 pairs of legs (42 legs total).
- Appearance: Typically reddish-brown in color.
- Movement: These centipedes are known for their speed and agility.
- Habitat: These centipedes are often found in tropical regions.
- Comparison to Geophilomorpha: Unlike the Geophilomorpha (earth centipedes) which have many more legs pairs, ranging from 35 to 101, Scolopendromorpha have a consistent 21 pairs.
Table Summary
| Feature | Scolopendromorpha | Geophilomorpha |
|---|---|---|
| Common Name | Tropical Centipedes | Earth Centipedes or Wire-centipedes |
| Leg Pairs | 21 | 35 - 101 |
| Color | Reddish-brown | Yellowish or pale (sometimes reddish-brown) |
| Movement | Fast Moving | Varies |
Why the Confusion?
It is important to note the difference between leg pairs and individual legs. The question asked about an animal with 21 legs which, literally, is only 10 pairs and a single leg. Many centipedes have numerous legs and legs come in pairs. The group of centipedes known as Scolopendromorpha is the only one from the reference that has precisely 21 pairs of legs.
