Fig. 7
From: Developmental changes and novelties in ceratophryid frogs
The prehallux is modified to support a keratinized spade for digging in ceratophryids. Cleared and stained specimens showing the spade on the foot in dorsal view of a Ceratophrys cranwelli, adult female; b Chacophrys pierottii, adult male; c Lepidobatrachus laevis, adult male; and d Lepidobatrachus llanensis, recently metamorphosed individual. Keratinization occurs earlier in L. llanensis, i.e., when digits become completely separated and the internal metatarsal tubercle is well differentiated. The same process occurs at the beginning of metamorphosis in L. laevis and C. pierottii, and after metamorphosis in Ce. cranwelli. dpha distal prehallical element, pph proximal prehallical element. Bar equals 2Â mm