Opiliones (Harvestmen) is an order of arachnids. There are 1625 species of Harvestmen, in 888 genera and 49 families. This order has been around since the pragian 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.
Definition: The institution that holds a type specimen for a given species. The recommended best practice is to use the identifier in a collections registry such as the Biodiversity Collections Index (http://www.biodiversitycollectionsindex.org/).