Paraphyletic Group

The term paraphyly was first used by the German biologist and zoologist, will Henning in the early 1960s. Paraphyletic groups are beneficial in analyzing significant traits causing a subclade to take an evolutionary divergent trait. A paraphyletic group is a collection of organisms based on ancestral similarities as opposed to similarities among the individual group. The use of paraphyletic groups in cladistic taxonomy is only applied when the application of paraphyletic taxon is reasonable for taxonomic study and when incorporating comprehensive classification of the extinct groups because every species originated from the parts of another species. 

We can look at the class Reptilia as a paraphyletic group because it excludes its two descendant groups, the class Mammalia and class Aves.