feathers of birds
... that the feathers of birds are considered the most complex integumentary structures found in vertebrates, and a premier example of a complex evolutionary novelty?
... that the <b id="mwAkw"><a href="./Glossary_of_bird_terms#feather" id="mwAk0" rel="mw:WikiLink" title="Glossary of bird terms">feathers of birds</a></b> are considered the most complex <a href="./Integumentary_system" id="mwAk4" rel="mw:WikiLink" title="Integumentary system">integumentary</a> structures found in <a href="./Vertebrate" id="mwAk8" rel="mw:WikiLink" title="Vertebrate">vertebrates</a>, and a premier example of a complex evolutionary novelty?