I rate the article four stars for insight, because the article presents a major advance in our understanding of pterosaur respiration. Although the idea that pterosaurs had air sacs and potentially an avian-like respiratory system is not a new one (e.g., Bonde and Christiansen 2003; O'Connor, 2006), the detail of (and support for) the reconstruction of the respiratory system presented here is. Similarly, the detail of the analysis of fossils, integrated with the neontological data, warrants five stars for reliability. Finally, I also give five stars for "style," given the comprehensive presentation and multi-pronged evidence provided for the conclusions.