by Aaron G. Filler, MD, PhD
Figure 8-3 Evolution of the Lung
A - The air sac used for ballast is exploited for land breathing in Polypterus.B - More lung surface area from internal branching in early land vertebrates.
C - Amphibians use a throat pouch to push air into the lung.
D – Archosaurs (alligator) use a liver-based suction pump to add to rib based suction.
E – Birds have continuous forward air flow through their parabronchii.
F – Undulation of the body during running interferes with coordinated rib breathing.
A & B – From: Dean, B. (1895). Fishes, Living and Fossil. An Outline of their Forms and Probable Relationships. New York, London, Macmillan and Co.
C – Redrawn, modified by AGF after: Schmidt-Nielsen, K. (1979). Animal Physiology : Adaptation and Environment. Cambridge England; New York, Cambridge University Press.
D – Redrawn, modified by AGF after: Randall, D. J., W. W. Burggren, A. P. Farrell, et al. (1981). The Evolution of Air Breathing in Vertebrates. Cambridge England; New York, Cambridge University Press.
E – Redrawn, modified by AGF after: Alexander, R. M. (1981). The Chordates. Cambridge England; New York, Cambridge University Press.
F - Redrawn, modifed by M. Rivera after: Gambaryan, P. P. (1974). How Mammals Run: Anatomical Adaptations. New York, Wiley and "Beg Mlekopitayushchikh - Prispobitel'nye," Izdatel'stvo Nauka, Leningradskoe Otdelenie 1972.