the english word "fish" does not fit neatly into cladistics, which is the scientific way to put living things into groups. so scientists call it a paraphyletic word. this means that the animals called "fish" in english do not fit into just one phylum. some fish are more closely related to land animals than they are to other fish. for example, lobe-finned fish were the first animals with bones to come live on land, and all land animals are their descendants. lobe-finned fish are more closely related to humans than to ray-finned fish.