Bird fossils
(a) Archaeopteryx lived in the late Jurassic Period around 150 million years ago. It had teeth like a dinosaur, but had (b) flight feathers like modern birds, which can be seen in this fossil.
Source
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"OpenStax College, Birds. October 17, 2013."
http://cnx.org/content/m44694/latest/Figure_29_05_04ab.jpg
OpenStax CNX
CC BY 3.0.
