Note: Man classifying life forms is an attribute given to him by God in the Garden of Eden (see below). However, much classification is based in the evolutionary philosophic framework but this does not need to be the case. Life forms could be collated into clads or other groupings based on common characteristics without any unnecessary assumptions of progenitor relationships between distinctly different life forms. That is, unless procreative activity was demonstrated no direct relationship should be assumed. Only structure/function similarities should be discussed.
Genesis 2
19 "And out of the ground the Lord God formed every beast of the field, and every fowl of the air; and brought them unto Adam to see what he would call them: and whatsoever Adam called every living creature, that was the name thereof.
20 And Adam gave names to all cattle, and to the fowl of the air, and to every beast of the field..." KJV