Schizaeales is an order of fern (class Pteridopsida). The ferns in this order were once all lumped into the family Schizaeaceae in the old order Filicales. However, although they are demonstrably related, these ferns differ markedly, and so three groups have now been elevated to family status: At one time some workers believed the water ferns (order Salviniales) to be allied to this order because of certain structural similarities, but modern cladistic studies have ruled out any special alliance.