Ricinulei (Hooded Tickspiders) is an order of arachnids. There are 74 species of Hooded Tickspiders, in 7 genera and 3 families. This order has been around since the pennsylvanian sub-period.
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.