Figure 5 in Morphological evolution in Ceratophryinae frogs (Anura, Neobatrachia): the effects of heterochronic changes during larval development and metamorphosis

Figure 5. Cross sections of the skin of the dorsum in selected tadpoles at larval stage 37. A, Odontophrynus lavillai. The epidermis is double layered with cells organized in an internal layer of columnar cells and an external layer of flattened cells. Melanocytes are in the epidermis. The dermis is a single layer, with a compact stratum composed of collagenous fibres. B, Telmatobius atacamensis. The thick epidermis is composed of an inner layer of tall and large cells, and at least three external layers of flattened cells. Melanocytes are in the epidermis. The dermis is thin and has only a compact stratum. C, Chacophrys pierottii. The epidermis is double layered. Melanocytes are in the epidermis. The dermis is single and thin. D, Ceratophrys cranwelli. Five layers of cells form the epidermis. Melanocytes are in the epidermis and dermis. Two layers form the dermis: the outer stratum spongiosum that has mucous glands, and the underlying stratum compactum. E, Lepidobatrachus llanensis. The epidermis is composed of three or four layers of flat cells. The dermis has the stratum spongiosum with glands and the stratum compactum. There are scarce melanocytes in the dermis. F, Lepidobatrachus laevis. Three layers of cells form the epidermis. The dermis consists of stratum spongiosum and compactum. The stratum spongiosum has small glands and melanocytes. In C. cranwelli, L. llanensis, and L. laevis the dermis thickness is greater than twice the epidermis thickness. Abbreviations: cs, compactum stratum of the dermis layer; d, dermis; e, epidermis; ss, spongiosum stratum of the dermis layer. Symbols: arrowheads point to melanocytes; stars indicate mucous glands. Scale bars: 0.1 mm.