[Taxacom] phylogeny (Monotremata)

[Stephen Thorpe]

increasingly, I get the impression that the basic principles of phylogeny are not well understood
 
look at the first paragraph here: http://www.ucmp.berkeley.edu/mammal/monotremesy.html
 
>Monotremes are mammals. Unlike other mammals monotremes lay eggs, as did the ancestors of the mammals. For this reason, the Monotremata are considered the sister group to all other mammals.<
 
Surely, this is badly expressed, or even just plain wrong? The reason why Monotremata (or at least the extant lineage thereof) are considered to be the sister group to all other mammals is because they are monophyletic (by virtue of having synapomorphies), in addition to being basal to (outside of) the main mammal clade (by virtue of laying eggs - a plesiomorphy) ...