The Geographical Distribution of Animals, Volume 1 / With a study of the relations of living and extinct faunas as elucidating the past changes of the Earth's surface

by Alfred Russel Wallace

Aquatic and wading birds were abundant, including numerous rails, bustards, herons, sandpipers, gulls, divers, and pelicans. There were also many ducks, some allied to the genus Dendrocygna; the Oriental genus of storks, Leptoptilus; Ibidipodia, a remarkable form allied to Ibis and Ciconia; Elornis, near Limosa; Pelagornis, a large bird allied to gannets and pelicans; Hydrornis, allied to the ducks and petrels; Dolichopterus, allied to plovers. Perhaps the most interesting of these extinct birds are, however, the flamingoes, represented by forms hardly distinguishable from living species, and by one extinct genus Palælodus, which had very long toes, and probably walked on aquatic plants like the tropical jacanas.

The Miocene beds of North India have furnished few birds; the only one of geographical interest being an extinct species of ostrich, not very different from that now inhabiting Arabia.

On the whole, the birds of Europe at this period were very like those now living, with the addition of a few tropical forms. These latter were, however, perhaps more numerous and important than they appear to be, as they belong to inland and forest-haunting types, which would not be so frequently preserved as the marsh and lake-dwelling species. Taking this into consideration, the assemblage of Miocene birds accords well with what we know of the mammalian fauna. We have the same indications of a luxuriant vegetation and subtropical climate, and the same appearance of Oriental and especially of African types. Trogon is perhaps the most interesting of all the forms yet discovered, since it furnishes us with a central point whence the living trogons of Asia, Africa, and South America might have diverged.

In the Eocene we find ourselves almost wholly among extinct forms of birds. The earliest known Passerine bird is here met with, in Protornis, somewhat similar to a lark, found in the Lower Eocene of Switzerland; while another Passerine form, Palægithalus, and one allied to the nuthatch (Sitta), have been discovered in the Upper Eocene of Paris. Picariæ of equal antiquity are found. Cryptornis, from the Paris Eocene, and Halcyornis from the Lower Eocene of the Isle of Sheppey, were both allied to kingfishers; while a form allied to Centropus a genus of cuckoos, or, as Milne-Edwards thinks, to the Madagascar Leptosomus, has been found in the Upper Eocene of France. Several Accipitres of somewhat doubtful affinities have been found in the same country; while Lithornis, from the Lower Eocene of the Isle of Sheppey, was a small vulturine bird supposed to be allied to the American group, Cathartes. Among the waders, some extinct forms of plovers have been found, and a genus (Agnopterus), allied to the flamingoes; while there are many swimming birds, such as pelicans, divers, and several extinct types of doubtful affinities. Most intersting of all is a portion of a cranium discovered in the Lower Eocene of Sheppey, and lately pronounced by Professor Owen to belong to a large Struthious bird, allied to the New Zealand Dinornis and also perhaps to the ostrich. Another gigantic bird is the Gastornis, from the Lower Eocene of Paris, which was as large as an ostrich, but which is believed to have been a generalised type, allied to wading and swimming birds as well as to the Struthiones.

Beyond this epoch we have no remains of birds in European strata till we come to the wonderful Archæopteryx from the Upper Oolite of Bavaria; a bird of a totally new type, with a bony tail, longer than the body, each vertebra of which carried a pair of diverging feathers.

North America.—A number of bird-remains have lately been found in the rich Tertiary and Cretaceous deposits of the United States; but here, too, comparatively few are terrestrial forms. No Passerine bird has yet been found. The Picariæ are represented by Uintornis, an extinct form allied to woodpeckers, from the Eocene of Wyoming. Species of turkey (Meleagris) occur in the Post-Pliocene and as far back as the Miocene strata, showing that this interesting type is a true denizen of temperate North America. The other birds are, Accipitres; waders and aquatics of existing genera; and a number of extinct forms of the two latter orders—such as, Aletornis an Eocene wader; Palæotringa, allied to the sandpipers, and Telmatobius to the rails, both Cretaceous; with Graculavus, allied to Graculus; Laornis allied to the swans; Hesperornis a gigantic diver; and Icthyornis a very low form, with biconcave vertebra, such as are only found in fishes and some reptiles—also from Cretaceous deposits.

South America.—The caverns of Brazil produced thirty-four species of birds, most of them referable to Brazilian genera, and many to still existing species. The most interesting were two species of American ostrich (Rhea), one larger than either of the living species; a large turkey-buzzard (Cathartes); a new species of the very isolated South American genus Opisthocomus; and a Cariama, or allied new genus.

Madagascar and the Mascarene Islands.—We have here only evidence of birds that have become extinct in the historical period or very little earlier. First we have a group of birds incapable of flight, allied to pigeons, but forming a separate family, Dididæ; and which, so far as we yet know, inhabited Mauritius, Rodriguez, and probably Bourbon. Aphanapteryx, an extinct genus of rails, inhabited Mauritius; and another genus, (Erythromachus), Rodriguez. A large parrot, said by Prof. Milne Edwards to be allied to Ara and Microglossus, also inhabited Mauritius; and another allied to Eclectus, the island of Rodriguez. None of these have been found in Madagascar; but a gigantic Struthious bird, Æpyornis, forming a peculiar family distinct both from the ostriches of Africa and the Dinornis of New Zealand inhabited that island; and there is reason to believe that this may have lived less than 200 years ago.

New Zealand.—A number of extinct Struthious birds, forming two families, Dinornithidæ and Palapterygidæ, have been found in New Zealand. Some were of gigantic size. They seem allied both to the living Apteryx of New Zealand and the emu of Australia. They are quite recent, and some of them have probably lived within the last few centuries. Remains of Dinornis have also been found in a Post-Pliocene deposit in Queensland, N. E. Australia[^[5]]—a very important discovery, as it gives support to the theory of a great eastward extension of Australia in Tertiary times.

Extinct Tertiary Reptiles.