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2 Witmer, Nature, 28 July 2011, “An icon knocked off its perch”, pages 458-9, http://www.nature.com/nature/journal/v475/n7357/full/475458a.html
4 Xu et al., Nature, 28 July 2011, “An Archaeopteryx-like theropod from China and the origin of Avialae”, pages 465-470, http://www.nature.com/nature/journal/v475/n7357/full/nature10288.html
5 Witmer, Nature, 28 July 2011, “An icon knocked off its perch”, pages 458-9, http://www.nature.com/nature/journal/v475/n7357/full/475458a.html