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. 2021 Nov 23;305(7):1563–1591. doi: 10.1002/ar.24820

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© 2021 The Authors. The Anatomical Record published by Wiley Periodicals LLC on behalf of American Association for Anatomy.

This is an open access article under the terms of the http://creativecommons.org/licenses/by-nc-nd/4.0/ License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non‐commercial and no modifications or adaptations are made.

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Beaks of wing‐propelled divers in lateral view showing the slit‐like external nares (n): (a) Cinclus mexicanus (Cinclidae, American Dipper; USNM 530549) and (b) Fratercula cirrhata (Alcidae, Tufted Puffin; USNM 589729)