Opilioacarida is an order of mites. There are 25 species of Opilioacarida, in 8 genera and 1 family. This order has been around since the priabonian age.
Definition: overall repetitive or reflective pattern in the body of one individual of this taxon. eg: bilateral symmetry, rotational symmetry, radial symmetry
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.