North America: Cope, [128]; Hatcher, [314]; Lambe, [365], [366]; Williston, [611].
Tertiary:
Europe: Beyrich, [36]; Bieber, [37]; Cuvier, [197]; Fraas, [246], [247]; Günther, [301]; Laube, [367-370]; von Meyer, [424], [430], [444], [446], [447]; Portis, [525]; Scheuchzer, [535]; Tschudi, [574-575]; Walterstorff, [585-586].
Pleistocene:
North America: Brown, [76]; Wheatley, [598].
South America: Lydekker, [393].
Asia: Clark, [103]; Lydekker, [393]; Owen, [506].
Europe: Lydekker, [393].
II. Phylogeny of Amphibia.
Arldt, [10]; Baur, [22-25], [31]; Boulenger, [44]; Branson, [49]; Budgett, [79]; Cope, [153], [166], [173]; Davison, [198]; Dollo, [228]; Gadow, [256]; Gaudry, [280], [282]; Gregory, [299], [300], [300a]; Haeckel, [312]; Huxley, [337]; Kingsley, [358]; Moodie, [489b]; Owen, [512]; Pollard, [524]; Quenstedt, [527]; Thevenin, [567-568]; Versluys, [578]; Vogt, [581]; Wiedersheim, [601].