Ornitholites of the Caverns.—Many limestone districts abound in fissures and caves, which vary in extent from more superficial hollows to deep excavations and caverns of considerable magnitude (Wond. p. 175, &c.) Beneath the stalagmitic or sparry floors of some of these caverns, the bones of extinct species of Cats, Bears, and Hyænas, occur in immense quantities; but the full consideration of these phenomena will be reserved for the next chapter. The skeletons and detached bones of several kinds of Birds are often found imbedded with these remains; and under circumstances which seem to indicate that they were brought into these caverns as prey by the carnivora, with whose relics they are now associated. Some examples show that the birds had fallen into the fissure; others, that their bones had been transported to their present situation by the action of water.
In the Cave of Kirkdale, in Yorkshire (Wond. p. 179), Dr. Buckland found bones of the Raven, Lark, Pigeon, Duck, and others; and as almost all the specimens were the remains of wing-bones, it is considered probable that they are the relics of dead birds, which had been brought into the cave by the hyænas, whose den it is supposed to have been for a considerable period (Reliquiæ Diluvianæ, p. 34).
Similar remains have been discovered in the Kent’s Hole cavern, and in that at Berry Head, Torbay; from the latter Professor Owen has obtained the wing-bones of a Falcon (Brit. Fos. Mam. and Birds, p. 558).
In France, the Lunel-Viel caverns have yielded a few bird-bones; and many such remains occur in the caves of Brazil, described by M. Lund.
The so-called "bone-breccia" of the coasts and islands of the Mediterranean (Wond. p. 185) contains frequent remains of birds: they have been especially noticed at Cette, Nice, Sardinia, and Gibraltar.
In the deposits especially referred to the northern drift or Boulder-clay period, fossil birds appear to be very rare, although the remains of vertebrate terrestrial animals are locally abundant. Dr. Buckland states that some bones, apparently of a species of goose, found at Lawford, with the remains of Hyæna, Elephant, Rhinoceros, &c., is the only instance he has met with of fossil birds in the drift of England (Reliq. Diluv. p. 27).
On the Continent, bird-bones have been found, at Quedlingbourg, Meissen, and in the Lahn Valley, in deposits said to be of this age.
Ornitholites of the older Tertiary Deposits. (Lign. 246.)—The very rich pliocene deposits at Œningen (p. 559) have afforded a few fragments of birds’ bones.
Three or four species of Ornitholites (Duck, Heron, Flamingo, &c.), and several examples of the eggs of birds, have been discovered in the lacustrine strata of Auvergne. Birds’ bones also occur in the fresh-water limestone near Issoire, in the Buy de Dôme, associated with the remains of eocene mammalia. In Germany, bird-bones have been found in tertiary deposits at Wiesbaden, Wiesnau, and Mornbach. In the Siwalik Hills the remains of birds are associated with the fossil reptilia and mammalia, to which reference has already been made (p. 731).
From the quarries of gypseous limestone of Montmartre, near Paris, Baron Cuvier obtained many bones, and some connected portions of the skeletons of several birds related to the Pelican, Sea-lark, Curlew, Woodcock, Owl, Buzzard, and Quail.[723] In several of these examples there are the imprints and remains of the quills and feathers; in some the skeleton has perished, and a pellicle of dark-brown substance, with the configuration of the original, alone remains (see [Lign. 246]). These Ornitholites are associated with the bones of the Palæotheria, and other extinct mammalia of the eocene period. Two or three Ornitholites have been discovered at Montmartre, in which almost the entire skeleton is preserved. In one example, described by Cuvier, the remains of a bird are displayed in such a manner as to render it probable that the animal had fallen on its belly, and become partially impacted in the surface of the soft gypsum, which is now become solid stone; and that, previously to its being completely enveloped, the principal part of its head and the left leg were removed either by some voracious animal, or by the action of the water. In addition to the other parts of the skeleton, the under side of the bill is very distinctly impressed on the stone, and the left branch is entire; there are also the remains of the cellular basis of the skull; and both the wings are well preserved. Nine or ten species of fossil birds were identified by Cuvier from the Paris eocene strata.