Keywords: Origin of Vertebrates Fig 051.png Fig 51 ”Skull of Adult Dog-fish Side View From Parker cr cranium; Br branchial arches; Mn + Hy mandibular and hyoid arches 1908 The Origin of Vertebrates https //archive org/details/originofvertebra1908gask Walter Holbrook Gaskell PD-old-auto-1923 1914 Origin of Vertebrates book Fish skulls |