Brocklehurst_Figure_01

Figure 1 — Top, Air sacs of a duck, and pneumatic features (including pneumatic foramina) of duck vertebrae. Bottom, Reconstructed air sacs of the theropod dinosaur Majungsaurus, based on pneumatic features preserved in the fossil bones. Abbreviations: Abd, abdominal air sac; Cdth, caudal thoracic air sac, CeP, central pneumatic foramen; Cl, clavicular air sac; Crth, cranial thoracic air sac; Cv, cervical air sac; Fu, furcula; Hu, humerus; Lu, lung; Lvd, lateral vertebral diverticula; NaP, neural arch pneumatic foramen; Nc, neural canal; Ns, neural spine; Pp, parapophysis. Pv, pelvis; Tr, trachea. From O’Connor and Claessens (2005).