Abstract
Birds and crocodylians, the only living archosaurs, are generally believed to employ pelvic girdle movements as a component of their respiratory mechanism. This in turn provides a phylogenetic basis for inferring that extinct archosaurs, including dinosaurs, also used pelvic girdle breathing. I examined lung ventilation through cineradiography (high-speed X-ray filming) and observed that alligators indeed rotate the pubis to increase tidal volume, but did not observe pelvic girdle movement contributing to lung ventilation in guinea fowl, emus or tinamous, despite extensive soft-tissue motion. Re-examination of fossil archosaurs reveals that pubic rotation evolved in basal crocodyliforms and that pelvic girdle breathing is not a general archosaurian mechanism. The appearance of pelvic aspiration in crocodyliforms is a striking example of the ability of amniotes to increase gas exchange or circumvent constraints on respiration through the evolution of novel accessory breathing mechanisms.
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Selected References
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- Baumel J. J., Wilson J. A., Bergren D. R. The ventilatory movements of the avian pelvis and tail: function of the muscles of the tail region of the pigeon (Columba livia). J Exp Biol. 1990 Jul;151:263–277. doi: 10.1242/jeb.151.1.263. [DOI] [PubMed] [Google Scholar]
- Boggs D, Jenkins F, Dial K. The effects of the wingbeat cycle on respiration in black-billed magpies (Pica pica) J Exp Biol. 1997;200(Pt 9):1403–1412. doi: 10.1242/jeb.200.9.1403. [DOI] [PubMed] [Google Scholar]
- Boggs Dona F. Interactions between locomotion and ventilation in tetrapods. Comp Biochem Physiol A Mol Integr Physiol. 2002 Oct;133(2):269–288. doi: 10.1016/s1095-6433(02)00160-5. [DOI] [PubMed] [Google Scholar]
- Duncker H. R. Coelom-Gliederung der Wirbeltiere--Funktionelle Aspekte. Verh Anat Ges. 1978;(72):91–112. [PubMed] [Google Scholar]
- Farmer C. G., Carrier D. R. Pelvic aspiration in the American alligator (Alligator mississippiensis). J Exp Biol. 2000 Jun;203(Pt 11):1679–1687. doi: 10.1242/jeb.203.11.1679. [DOI] [PubMed] [Google Scholar]
- Gans C., Clark B. Studies on ventilation of Caiman crocodilus (Crocodilia: Reptilia). Respir Physiol. 1976 May;26(3):285–301. doi: 10.1016/0034-5687(76)90001-3. [DOI] [PubMed] [Google Scholar]
- Owerkowicz T., Farmer C. G., Hicks J. W., Brainerd E. L. Contribution of gular pumping to lung ventilation in monitor lizards. Science. 1999 Jun 4;284(5420):1661–1663. doi: 10.1126/science.284.5420.1661. [DOI] [PubMed] [Google Scholar]
- Ruben John A., Jones Terry D., Geist Nicholas R. Respiratory and reproductive paleophysiology of dinosaurs and early birds. Physiol Biochem Zool. 2003 Mar-Apr;76(2):141–164. doi: 10.1086/375425. [DOI] [PubMed] [Google Scholar]
- Wang N., Banzett R. B., Nations C. S., Jenkins F. A., Jr An aerodynamic valve in the avian primary bronchus. J Exp Zool. 1992 Jul 1;262(4):441–445. doi: 10.1002/jez.1402620411. [DOI] [PubMed] [Google Scholar]
- Wang T., Warburton S. J. Breathing pattern and cost of ventilation in the American alligator. Respir Physiol. 1995 Oct;102(1):29–37. doi: 10.1016/0034-5687(95)00043-d. [DOI] [PubMed] [Google Scholar]