Lacerta agilis, cranium of a 47 mm long embryo in ventral view, modified from Gaupp (1906: fig. 383). Dermal bones have been removed from the specimen’s left side to show the chondrocranium (gray).

  Part of: Wible JR (2022) The history and homology of the os paradoxum or dumb-bell-shaped bone of the platypus Ornithorhynchus anatinus (Mammalia, Monotremata). Vertebrate Zoology 72: 143-158.