Figure 2 in Morphological evolution in Ceratophryinae frogs (Anura, Neobatrachia): the effects of heterochronic changes during larval development and metamorphosis

Figure 2. Anal tube morphology in anuran tadpoles. A, Telmatobius atacamensis (stage 36), ventral view of the funnel-shaped anal tube. B, Odontophrynus lavillai (stage 36), lateral view of the funnel-shaped anal tube. C, Chacophrys pierottii (stage 35), ventral view of the anal tube, which is short and cylindrical. D, Ceratophrys cranwelli (stage 36), the anal tube is cylindrical and smaller than the anal tube of C. pierottii. E, Lepidobatrachus llanensis (stage 34), lateral view of the anal tube. The anal tube is funnel shaped and short. F, Lepidobatrachus llanensis (stage 36), ventral view. The anal tube is short and its opening is wide. After this stage the anal tube disappears. Scale bars: 2 mm.