What is the minimum number of clades necessary to partition Vertebrates while maintaining the classical groups of Birds, Mammals, and Amphibians? At school I was taught the Linnaean view of vertebrate life - that vertebrate animals consisted of 5 distinct groups: mammals, birds, reptiles, amphibians, fish. I learned later however that this was phylogenetically inaccurate, with birds being 'closer related' to crocodiles than other reptiles are, for example. As such I am curious - since the idea of these groupings is so strong in popular conceptions of animals: **What is the minimum number of clades we would need in order to partition 'Vertebrates', maintaining 'Mammals', 'Amphibians', and 'Birds' as clades?**

Phylogenetic taxonomy of the Vertebrates (mun.ca) has the following graphic (14 clades total, minimum of 12 collapsing Amphibia):

![enter image description here](

Here, what was preivously 'Fish' (the paraphyletic group of non-tetrapod vertebrates) becomes 6 clades, and 'Reptiles' (the paraphyletic group of non-avian Sauropsids) becomes 3.

It seems the question is equivalent to asking "what is the minimum number of clades necessary to partition Vertebrates while maintaining 'birds' as a clade?".