|Thorell , 1888|
The palpigradi or switch rotor (Palpigradi) are an order of chelicerata (Chelicerata) in the class of the arachnids (Arachnida). Almost 80 species are known around the world that are only two to three millimeters long. In Europe there are 26 known species (with 34 subspecies).
The body structure of the palm runners is reminiscent of that of the flagellum scorpions , as their abdomen also ends in a multi- segment flagellum . The first pair of legs is also noticeable here, which, like the flagellum spiders and flagellum scorpions, is laid out as long tactile organs with an increased number of leg links. The pedipalps are leg-like and are used as a walking leg. The jaw claws ( chelicerae ) are relatively large and are used to hold prey (small springtails ) in front of the mouth. The palm runners are completely colorless and have no eyes.
Reproduction and development
Almost nothing is known about the reproduction and development of the palpebras. In some species, males appear very rarely, for this reason it is assumed that the palpebras sometimes reproduce parthenogenetically .
The exact position of the palm runners in the arachnid system has not yet been fully clarified. The most common version is compared to the other members of this group within the Apulmonata (lungless arachnids) as a sister group (see jaw-claw bearers ) and justifies this mainly with the missing fan lungs . She presents an alternative to the flagellated spiders , flagellated scorpions and web spiders as a sister group on the basis of several small morphological changes.
The order currently includes the following two families and six genera.
- Family Eukoeneniidae
- Family Prokoeneniidae