Megalosauridae Jurassic and Comanchic.
" Deinodontidae Cretacic.
" Ornithomimidae Cretacic, North America.
Suborder _Sauropoda_ Marsh (=Opisthocoelia Owen, Cetiosauria Seeley.) Fam.

Cetiosauridae } " Morosauridae } Jurassic and Comanchic.
" Diplodocidae } Order ORNITHISCHIA Seeley (=Orthopoda Cope, Predentata Marsh.) Suborder _Ornithopoda_ Marsh (Iguanodontia Dollo) Fam.

Nanosauridae Jurassic, Colorado.
" Camptosauridae } " Iguanodontidae } Jurassic and Comanchic.
" Trachodontidae (=Hadrosauridae), Cretacic.
Suborder _Stegosauria_ Marsh.
Fam.

Scelidosauridae } Jurassic and Comanchic.
" Stegosauridae } " Ankylosauridae (=Nodosauridae), Cretacic.
Suborder _Ceratopsia_ Marsh.
Fam.

Ceratopsidae Cretacic.
* Regarded by Dr.von Huene as ancestral respectively to the Theropoda and Sauropoda.
FOOTNOTES: [Footnote 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.] [Footnote 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.].