Heterochrony and Early Left-Right Asymmetry in the Development of the Cardiorespiratory System of Snakes
Figure 2
Phylogeny of species used, with our hypothesis of the lung reduction steps mapped on.
Red species were used for lung typification only, blue species for lung and vascular development only, and purple species for both. ‘Lung’ and ‘PA’ give lung type [12] and pulmonary artery type (Fig. 4), respectively. Stem and family branches are based on Refs. [46]–[48], [50]; the branches within families are based on Refs. [12], [49], [50].