Pseudoscorpiones (Pseudoscorpions) is an order of arachnids. There are 3789 species of Pseudoscorpions, in 479 genera and 26 families. This order has been around since the givetian age.
Definition: The number of fossil occurrences in the Paleobiology Database (https://paleobiodb.org) that are identified as belonging to a particular taxon or any of its subtaxa.