The word centipede means "100 feet," which is interesting considering that few actually have 100 legs. In fact, some centipedes have as few as 30. Centipedes belong to the class Chilopoda, and have 3,150 species around the globe. Their class is further broken down into five orders: Scutigeromorpha, Scolopendromorpha, Lithobiomorpha, Geophilomorpha and Craterostigmomorpha. All five have unique characteristics that set them apart.
Scutigeromorpha - The Speedy
The Scutigeromorpha order has three families, 16 genera and 80 described species. They have an estimated global fauna of 100 to 150 species. Scutigeromorpha are short-bodied, with 15 pairs of long legs that get longer toward the rear. They're rarely found with all legs intact, however, as they easily shed limbs to avoid predators. Their long, whip-like antennae protrude from their dome-shaped heads. They have two compound eyes, and 15 plates on their belly, known as sterna. These guys are fast and hard to catch.
Scolopendromorpha - The Large
Scolopendromorpha are the most recognized order of centipedes. They consist of three families: Scolopendridae, Scolopocryptopidae and Crypotopidae. They have 33 genera, around 600 species and an estimated global fauna of 800 species. Their last pair of legs are usually longer than the others and seem to at least partially function as graspers. This order has the world's largest centipede, Scolopendra gigantea, found in Venezuela at 11 inches long. There's also an unverified report of one around 16 inches on Curacao.
Lithobiomorpha - The Bristly
Lithobiomorpha consists of short centipedes with 15 pairs of legs and segments in adults and seven in kids. They have tergite heteronomy, meaning that their plates alternate between small and long. They have ocelli, or simple, small, extra eyes. They have two families, which differ in having only setae (little bristly hairs) on their legs (Henicopidae) or setae and spurs (Lithobiidae). There are 95 genera, and around 1,500 species described of an estimated global fauna of 2,000 species.
Geophilomorpha - The Blind
Geophiomorpha are unique from the others if a few ways. First, they're not adapted for speed. They move slowly and like to burrow into substrate. Second, these are the only centipedes that actually have a full set of 100 legs. Also, they have the most diversity of any order, with 14 families, 180 genera and around 1,100 described species of a 4,000 estimated global fauna. They are native to all inhabited continents. Lastly, none of them have eyes.
Craterostigmomorpha - The Lonely
Last and least, the Craterostigmomorpha are the most limited geographically and in diversity. They have only one family, one genus and one species, the Craterostigmus tasmanianus. They are found only in New Zealand and Tasmania. It was thought that they were restricted to the South Island until they had been recently cited on the North Island. They have a pair of ocelli and their head is longer than wide.
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Brian McCracken lives in Portland, Ore., where he writes on pets and animal wildlife as well as a wide array of other topics, ranging from real estate to personal development.