why were birds and butterflies placed into different groups within the biological classification system

see explanation

Explanation:

Even though birds and butterflies do fly, the mechanisms of flight in the bodies of butterflies and birds are significantly different.

Organisms are placed in groups on the basis of similarities in anatomical patterns was well as a common ancestry.

Butterflies  and birds possess different anatomical patterns hence they ought to be placed in different groups alongside other organisms with which they share a greater similarity.

i think it was   tsar alexander ii