Title | Cardio-Pulmonary Anatomy in Theropod Dinosaurs: Implications From Extant Archosaurs |
Publication Type | Journal Article |
Year of Publication | 2009 |
Authors | Quick, DE, Ruben, J |
Journal | Journal of Morphology |
Volume | 270 |
Pagination | 1232-1246 |
Type of Article | Journal Article |
ISSN | 0362-2525 |
Abstract | Although crocodilian lung and cardiovascular organs are markedly less specialized than the avian heart and lung air-sac system, all living archosaurs possess four-chambered hearts and heterogeneously vascularized, faveolar lungs. In birds, normal lung function requires extensive, dorsally situated nonvaseularized abdominal air-sacs ventilated by an expansive sternum and specially hinged costal ribs. The thin walled and voluminous abdominal air-sacs are supported laterally and caudally to prevent inward (paradoxical) collapse during generation of negative (inhalatory) pressure: the synsacrum, posteriorly directed, laterally open pubes and specialized femoral-thigh complex provide requisite support and largely prevent inhalatory collapse. In comparison, theropod dinosaurs probably lacked similarly enlarged abdominal air-sacs, and skeleto-muscular modifications consistent with their ventilation. In the absence of enlarged, functional abdominal air-sacs, theropods were unlikely to have possessed a specialized bird-like, air-sac lung. The likely absence of bird-like pulmonary function in theropods is inconsistent with suggestions of cardiovascular anatomy more sophisticated than that of modern crocodilians. J. Morphol. 270:1232-1246, 2009. (C) 2009 Wiley-Liss, Inc. |
URL | <Go to ISI>://WOS:000270423600005 |
DOI | 10.1002/jmor.10752 |