Besides the many extinct species, and extinct genera of Mammalia that are enumerated in this list, the occurrence of nine or ten extinct species of fossil Birds in the Eocene period of the tertiary series, forms a striking phenomenon in the history of organic remains.[1]
In this small number of species, we have seven genera; and these afford examples of four, out of the six great Orders into which the existing Class of Birds. is divided, viz. Accipitres, Gallinaceæ, Grallæ, and Palmipedes. Even the eggs of aquatic birds have been preserved in the lacustrine formations of Cournon, in Auvergne.[2]
It appears that the animal kingdom was thus early established, on the same general principles that now prevail; not only did the four present Classes of Vertebrata exist; and among Mammalia, the Orders Pachydermata, Carnivora, Rodentia, and Marsupialia; but many of the genera also, into which living families are distributed, were associated together in the same system of adaptations and relations, which they hold to each other in the actual creation. The Pachydermata and Rodentia were kept in check by the
- ↑ The only remains of Birds yet noticed in strata of the Secondary series are the bones of some Wader, larger than a common Heron, found by Mr, Mantell in the fresh-water formation of Tilgate Forest. The lspnes at Stonesfield, once supposed to be derived from Birds, are now referred to Pterodactyles. A discovery has recently been made in America by Professor Hitchcock, of the footsteps of Birds in the New Red sandstone of the valley of the Connecticut, which he refers to at least seven species, all apparently Waders, having very long legs, and of various dimensions from the size of a Snipe, to twice the size of an Ostrich. (See Pl. 26a. 26b.)
- ↑ In the same Eocene formation with these eggs, there occur also the remains of two species of Anoplotherium, a Lophidon, an Anthracrotherium, a Hippopotamus, a ruminating animal, a Dog, a Martin, a Lagomys, s Rst, one or two Tortoises, a Crocodile, a Serpent or Lizard, and three or four species of Birds. These remains are dispersed singly, as if the animals from which they were derived had decomposed slowly and at different intervals, and thus fragments of their bodies had been lodged irregularly in various parts of the bottom of the ancient lake: these bones are sometimes broken, but never rolled.
