Gross morphological features of the non-pigmented roof (Nr) of the oropharynx. a: D. novaehollandiae. b: S. camelus. Choana (C), rictus (R) and paired pharyngeal folds (Pf). The black dotted line on the pharyngeal folds denotes the border between the free (red star) and attached regions of the folds. The infundibular cleft (black arrow) is more obvious in S. camelus than in D. novaehollandiae. Caudo-lateral extensions of the pharyngeal folds (white arrows) are obvious in D. novaehollandiae. The retropharyngeal position of the underlying pharyngeal tonsil in S. camelus is indicated (grey shaded area). Insets show the openly displayed oropharynx of D. novaehollandiae and S. camelus.