A reconsideration of the phylogeny of the tetrapod heart
Article first published online: 6 FEB 2005
Copyright © 1975 Wiley-Liss, Inc.
Journal of Morphology
Volume 147, Issue 2, pages 209–228, October 1975
How to Cite
Holmes, E. B. (1975), A reconsideration of the phylogeny of the tetrapod heart. J. Morphol., 147: 209–228. doi: 10.1002/jmor.1051470207
- Issue published online: 6 FEB 2005
- Article first published online: 6 FEB 2005
After dissecting a variety of vertebrate hearts and extensively reviewing the literature, I have drawn some conclusions concerning the phylogeny of the tetrapod heart that differ from commonly expressed viewpoints in the literature. It is probable that the absence of an interventricular septum in amphibians is a primitive feature (rather than representing a loss). The complete interventricular septum of crocodilians and birds probably evolved primarily from the major horizontal septum of the typical (noncrocodilian) reptilian heart, with a smaller part representing a new development. The interventricular septum of mammals probably also evolved primarily from the reptilian horizontal septum. There is no reason to assume that the mammalian heart and aortic arches evolved directly from a pre-reptilian stage, as is often assumed. The evidence upon which these conclusions are based is given.