Fig. 3.

Fossil amphibian soft tissues. a–c Frogs from Libros (Miocene, Spain) (a MNCN 63776, Museu Nacional de Ciencias Naturales, Madrid), Bechlejovice (Oligocene, Czech Republic) (b NMP 39449, National Museum Prague), and Messel (Eocene, Germany) (c SMF-ME-00978, Forschungsinstitut und Naturmuseum Senckenberg, Frankfurt). Torsos show dark patches of non-integumentary melanosomes. Inset in b shows melanosomes from the torso. d, e Tadpoles from Libros. Lungs are dark patches in the torso (d MNCN 63848); the notochord, two closely spaced parallel lines (d, e NHM 49999, Natural History Museum, London, UK). f Salamander from Daohuguo (Middle Jurassic; CNU-V-1264, Capital Normal University, Beijing, China). Torso shows conspicuous dark patches. g–j Scanning electron micrographs of melanosomes in frogs (g–i) and tadpoles (j) from Libros. g Non-integumentary melanosomes. h Integumentary melanosomes. i, j Size-specific layers of melanosomes. i Integumentary melanosomes (top right) overlying non-integumentary melanosomes (lower left). j Size-specific layers of non-integumentary melanosomes, reflecting vertical superposition of different internal tissues in vivo. Scale bars, 60 mm (a), 50 mm (b), 20 mm (c), 10 mm (d, f), 2 µm (g–j)