THE ORNITHOMORPHA
The Ornithomorpha arranged in this way show that the three middle groups—carnivorous Saurischia, Aristosuchia, herbivorous Ornithischia—which are usually united as Dinosauria, intervene between Birds and Ornithosaurs; and that the Crocodilia and Ornithosauria are parallel groups which are connected with Birds, by the group of Dinosaurs, which resembles Birds most closely.
The Ornithomorpha is only one of a series of large natural groups of animals into which living and extinct terrestrial vertebrata may be arranged. And the succeeding diagram may contribute to make evident the relations of Ornithosauria to the other terrestrial vertebrata (see [p. 191]).
Herein it is seen that while the Ornithomorpha approach towards Mammalia through the Ornithosauria, and less distinctly through the Crocodilia, they approach more directly to the Sauromorpha, through the Plesiosaurs and Hatteria; while that group also approaches more directly to the Mammals through the Plesiosaurs and Anomodonts.
Diagram of the Affinities of the Orders of Animals comprised in the Ornithomorpha.
After a diagram in the Philosophical Transactions of the Royal Society, 1892.
The Aristosuchia is imperfectly known, and therefore to some extent a provisional group. It is a small group of animals.