In one sense every organism is an intermediate form but it is also true that all living species are the current endpoint of an unbroken chain going back to the origin of life. Nonetheless, many species do share characteristics of two distinctly different groups, and in that sense can be thought of as intermediates. A commonly cited example is Peripatus, which has characteristics of both worms and arthropods. However, this does not mean that Peripatus itself is changing from a worm to an arthropod, but is is descended from a group of organisms some of which gave rise to modern arthropods