Scorpion Identifier

Scorpions are arachnids belonging to the order Scorpiones, with approximately 2,500 described species worldwide. They are among the oldest terrestrial arthropods, with a fossil record extending over 400 million years. Despite their ancient lineage, their basic body plan has remained remarkably consistent, making the general form easily recognizable. Like spiders (see our Spider Identifier tool), scorpions are arachnids with eight legs, but their prominent pincers and curved tail make them unmistakable.

The most distinctive feature is the metasoma, or tail, which curves upward and forward over the body, ending in a bulbous segment called the telson. The telson houses the venom glands and bears a sharp, curved stinger. The tail is composed of five segments and is used for defense and prey capture.

Pedipalps are the large, prominent pincers at the front of the body. Their size and shape vary significantly between species and are among the most useful identification features. Some species have slender, elongated pedipalps, while others have massive, robust claws. Generally, species with smaller, more delicate pedipalps tend to rely more heavily on their tail, while those with large pedipalps use them more for prey capture.

Body structure follows the arachnid plan with two main body sections: the prosoma (cephalothorax) covered by a carapace bearing a pair of median eyes on top and two to five pairs of lateral eyes on the front corners, and the opisthosoma (abdomen) divided into a broad mesosoma and the narrow tail. Scorpions have four pairs of walking legs.

Color provides useful identification clues. Common colors include tan, brown, black, reddish-brown, and yellow. Some species are translucent pale yellow. Under ultraviolet light, most scorpions fluoresce a bright blue-green due to compounds in their exoskeleton, which can help detect them at night.

Size ranges from about 13 mm in the smallest species to over 200 mm in the largest, such as emperor scorpions. Body proportions, including the relative size of the pedipalps, tail thickness, and leg length, help distinguish families and genera.

Habitat preference varies greatly. Some species inhabit arid deserts, others prefer tropical forests, and some live in mountainous regions or caves. Many are burrowing species, while others are found under rocks, bark, or in leaf litter.