| Order Saurischia Seeley. | |
| Suborder Coelurosauria von Huene (=Compsognatha Huxley, Symphypoda Cope.) | |
| Fam. Podokesauridæ | Triassic, Connecticut. |
| " Hallopodidæ | Jurassic, Colorado. |
| " Coeluridæ | Jurassic and Comanchic, North America. |
| " Compsognathidæ | Jurassic, Europe. |
| Suborder Pachypodosauria von Huene. | |
| Fam. Anchisauridæ | Triassic, North America and Europe. |
| " Zanclodontidæ | Triassic, Europe.* |
| " Plateosauridæ | |
| Suborder Theropoda Marsh (=Goniopoda Cope) | |
| Fam. Megalosauridæ | Jurassic and Comanchic. |
| " Deinodontidæ | Cretacic. |
| " Ornithomimidæ | Cretacic, North America. |
| Suborder Sauropoda Marsh (=Opisthocoelia Owen, Cetiosauria Seeley.) | |
| Fam. Cetiosauridæ | Jurassic and Comanchic. |
| " Morosauridæ | |
| " Diplodocidæ | |
| Order Ornithischia Seeley (=Orthopoda Cope, Predentata Marsh.) | |
| Suborder Ornithopoda Marsh (Iguanodontia Dollo) | |
| Fam. Nanosauridæ | Jurassic, Colorado. |
| " Camptosauridæ | Jurassic and Comanchic. |
| " Iguanodontidæ | |
| " Trachodontidæ | (=Hadrosauridæ), Cretacic. |
| Suborder Stegosauria Marsh. | |
| Fam. Scelidosauridæ | Jurassic and Comanchic. |
| " Stegosauridæ | |
| " Ankylosauridæ | (=Nodosauridæ), Cretacic. |
| Suborder Ceratopsia Marsh. | |
| Fam. Ceratopsidæ | Cretacic. |
| * Regarded by Dr. von Huene as ancestral respectively to the Theropodaand Sauropoda. | |
FOOTNOTES:
[2] If some vast catastrophe should today blot out all the mammalian races including man, and the birds, but leave the lizards and other reptiles still surviving, with the lower animals and plants, we might well expect the lizards in the course of geologic periods to evolve into a great and varied land fauna like the Dinosaurs of the Mesozoic Era.
[3] The ancestral types have four complete toes, but in the true Theropoda the inner digit is reduced to a small incomplete remnant, its claw reversed and projecting at the back of the foot, as in birds.