CHAPTER XIX.

OSTEOLOGY OF BIRDS.

I.Osteological Characters.—The skull in adult birds presents this remarkable feature, that it is composed of but one bone without any trace of suture: the osseous tissue is very compact; the bone is white, and very smooth externally. The lower jaw is formed, as in reptiles, of several bones, namely, articular, angular, supra-angular, and dental; it is united to the skull by the intervention of a bone (os quadratum), as in certain reptiles. Both jaws are destitute of teeth, and are protected by dense horny sheaths, which form powerful dentary organs. The vertebral column of the neck is exceedingly flexible, and is composed of a greater number of bones than in any other living animals; for the cervical vertebæ, which in the mammalia amount to seven, in birds vary from ten to twenty-four, as in the Swan. To admit of this extreme mobility of the neck without injury to the enclosed spinal cord, the annular part, or neural arch, of each cervical vertebra is enlarged at the extremities that form a junction with the corresponding bones; thus presentinga modification of vertebral development directly the reverse of that possessed by the extinct saurian of the Magnesian conglomerate (see p. 714). The dorsal and sacra vertebral, on the contrary, are firmly interlocked, and often anchylosed together, and constitute a strong, inflexible pillar to afford a fixed point of support to the powerful locomotive organs of flight. There are nolumbar, or rib-less vertebræ. The sacrum often consists of eighteen, twenty, or more vertebræ, anchylosed into a solid bone. In the young Ostrich the vertebræ may be found separate and distinct; and the neural arch is shifted to the union of two vertebræ, as in theMegalosaurus. The sacral spinal cord is almost as large as the brain; to supply the large muscles. The foramina for the passage of the nerves are double, one for the sensitive, and the other for the motive root, which pass out separately and unite in. a ganglion externally. The ribs are formed so as to combine strength with lightness in the construction of the walls of the chest, for each rib has arecurrent apophysis, or process, that extends backwards, and glides over the contiguous bone; this is a very peculiar and obvious character.[719]The ribs are united in front to the sternum by bony processes, analogous to thecostal-arcsof the Plesiosaurus. The pectoral arch is distinguished by the prominent longitudinal keel or crest of the sternum; a structure designed to give attachment to the powerful pectoral muscles which move the wings, and which presents characteristic modifications in the different orders; and by the peculiar bone, termed thefurcula, or merry-thought, which connects the clavicles. The clavicles are strongest and most open in birds of strongest flight. The coracoids (in birds) relate to respiration, and serve to admit of contraction and expansion of the sternum and abdomen. The bones of the anterior extremities are modifiedto adapt these instruments for the purposes of flight, and those of the fore-arm (radiusandulna) are very long, and firmly united together; the ulna has a row of slight eminences for the attachment of the quills of the secondary feathers. The wrist, orcarpus, is composed of but two bones, articulated to the radius and ulna, and which admit only of alateralmovement, by which the wings are folded close to the body. The bones of the hinder extremities consist of the thigh orfemur;[720]the leg-bones,tibia[721]andfibula, the latter very small and anchylosed to the former; and of a single shank-bone, which supplies the place of the tarsal and metatarsal bones of other animals. This bone is articulated at its upper extremity to the tibia, and terminates at the lower end in distinct processes, which correspond in number with the toes; each process having a groove for the pulley-like tendon that moves the corresponding toe. This construction is peculiar to birds; for although in some quadrupeds, as the horse for example, the metatarsus consists of but one piece, the tarsus is composed of several bones.

[719]In very old crocodiles an analogous apophysis, which is generally cartilaginous, is sometimes found, ossified (Owen).[720]The acetabulum, or socket for the head of the thigh-bone, is always perforated. The femur has a surface for the articulation of the fibula; and by this character the femur of all birds may be distinguished. There is always apatella.[721]The lower end of the tibia is very like that of the femur.

[719]In very old crocodiles an analogous apophysis, which is generally cartilaginous, is sometimes found, ossified (Owen).

[720]The acetabulum, or socket for the head of the thigh-bone, is always perforated. The femur has a surface for the articulation of the fibula; and by this character the femur of all birds may be distinguished. There is always apatella.

[721]The lower end of the tibia is very like that of the femur.

The toes of birds present deviations equally recognisable; for the number of the articulations (orphalangealpieces of bone) in each toe is different. Thus the thumb, or short toe, hastwobones; the first toe on the inner sidethree; the the middle toefour; and the outer toefive. In general, three toes are directed forwards, and one backwards. In some species, the thumb or opposable toe is altogether wanting; in others, as in the swallow, it is directed forwards; in climbing birds, both the outer and the back toe are situated behind. The position of the hind toe, therefore,affords an important indication of the habits of the bird (seeWond.p. 146,Lign.23), and from a fragment of the lower extremity of the shank or tarso-metatarsal bone, with any trace of this articulation, we may determine whether the individual to which it belonged was a climber, wader, &c. In the toes of Crocodiles alone, the number of joints is the same as in birds; but in these reptiles, each toe is supported by a distinct metatarsal bone. The osteological peculiarities above enumerated may assist the collector in arriving at some general inferences as to the nature of any fossil remains of birds.

FOSSIL BIRDS.

II.Ornitholites, or Fossil Birds.—The fossil remains of birds consist in general of their osseous skeletons, and of detached bones, and rarely of the feathers and eggs.

Pleistocene Epoch.—Bones of theDodo[722](seeWond.p. 131), a bird which appears to have become extinct by human agency within the last two centuries, have been found, associated with the remains of a recent species of Tortoise, beneath a bed of lava in the Isle of France. And in some caverns in the island of Rodriguez, the bones of one or more large birds allied to the Dodo have also been discovered.

[722]See Penny Cyclopædia,Art.Dodo, and the beautiful work on the natural history of the Dodo and its Kindred, by the late lamented Mr. Strickland and Dr. Melville, 4to.

Dinornis(fearfully great bird).Pict. Atlas, frontispiece, and p. 172—Numerous bones of large extinct birds have been obtained in New Zealand by Mr. Rule, the Rev. W. Williams, Col. Wakefield, Mr. Walter Mantell, and others. These have been referred by Professor Owen to tridactylous struthious birds (one of which was one-third larger than the African ostrich), resembling the livingApteryxof New Zealand (Wond.p. 128,Petrif.p. 106) in the proportions of the tibia to the metatarsus, and also in the rudimentalstate of the wings. The bones are found in the recent alluvium, but probably in some cases at least they have been washed by the streams from older alluvial deposits.

An account of the history of the discovery of the gigantic Moa’s bones in New Zealand (Wond.p. 129) is given in full inPetrif.p. 93,et seq.; and the scientific description of the various parts of the skeleton of theDinornisandPalapteryx, chiefly collected from Professor Owen’s elaborate and finely illustrated memoirs in the Transactions of the Zoological Society, should be consulted,Petrif.p. 108, &c. OfDinornisProfessor Owen discriminates seven or eight species; ofPalapteryx, three species; and indications of a species of a third associated genus,Aptornis.

Fragments of egg-shell accompany these interesting relics of birds from New Zealand. From Madagascar also bird-bones and eggs have been obtained in a fossil state, that indicate the original bird (Æpyornis) to have been even of a greater size than the Dinornis.

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 (seeLign.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.

[723]Ossemens Fossiles, tom. iii. p. 302, plates lxxii.—lxxv.

FOSSIL VULTURE.

Lign. 246. Fossil Bird.Eocene.Montmartre.(Cuvier,Oss. Foss.vol. iii. p. 318, pl. lxxiii.fig.2.)The remains of this individual consist only of a thin brown pellicle, indicating the form and proportions of the head, body, and limbs.

Lithornis vulturinus.Geol. Trans.2d series, vol. vi. p. 206, pl. xxi. figs. 5 and 6.—Under the name of Lithornis (petrified-bird), Professor Owen has described the fossil remains of a bird, consisting of two most characteristic bones,—the sternum and sacrum,—and fragments of other bones, obtained from the London Clay of the Isle of Sheppey. These relics present a close agreement with the corresponding bones of the Vulture tribe, but indicate a smaller species of Vulture than any now known to exist.

In his "History of British Fossil Mammalia and Birds," 1846, Professor Owen has also described another sacrum from the Sheppey Clay, asternumfrom Primrose Hill, and thecraniumof a bird, probably of theHalcyonidæfamily,from the same eocene deposit at Sheppey. This has also yielded a portion of shank-bone, which, according to Mr. Bowerbank, indicates a bird of the size of a full-grown albatross. Brit. Assoc. 1851.

Some few specimens of cylindrical bones from the Chalk and the Wealden[724]have been previously referred to Birds, and described as remains of species of that family. These fossils, however, have lately been reexamined in comparison with more perfect bones of similar character; and, with the exception of a few, the structure of which decidedly has the characters belonging to bird’s bone, the result of this investigation has assigned them to Pterodactyles.[725]The long thin cylindrical bones from the Stonesfield Oolite are probably all Pterodactylian also, as suggested by the late Mr. Miller.

[724]One fragment of a bone, apparently of anulna, retained a row of small eminences, probably the points of attachment for the quills of the secondary feathers of the wings. This specimen would appear to have a decided reference to ornithic structure, but it was transferred to the British Museum, and is not now to be seen.[725]SeeQuart. Geol. Journ.vol. ii. p. 96, &c.; and Owen’sMonograph on Chalk Reptiles, 1851, p. 80,et seq.It is to be hoped that the eminent microscopists, Mr. Bowerbank and Professor Quekett, may be enabled before long to elucidate the intimate structure of pterodactylian bone; which, although of an essentially reptilian type, has characters of its own, offering some resemblances to bird-structure, that have not yet been fully described. Some specimens of bones from the Wealden (for instance, the specimen figured inGeol. Trans.2d ser. vol. v. pl. xiii.fig.6, andGeol. Journ.vol. iv. pl. i.fig.9,) exhibit under the microscope an intimate structure resembling that seen in bird-bone, in contradistinction to that characteristic of reptilian bone. But until we are better acquainted with the microscopic structure of the osseous tissue of the Pterosaurians, and are in possession of more perfect specimens of bones, it cannot be satisfactorily determined to what extent the class of Birds existed in the country of the Iguanodon.

[725]SeeQuart. Geol. Journ.vol. ii. p. 96, &c.; and Owen’sMonograph on Chalk Reptiles, 1851, p. 80,et seq.It is to be hoped that the eminent microscopists, Mr. Bowerbank and Professor Quekett, may be enabled before long to elucidate the intimate structure of pterodactylian bone; which, although of an essentially reptilian type, has characters of its own, offering some resemblances to bird-structure, that have not yet been fully described. Some specimens of bones from the Wealden (for instance, the specimen figured inGeol. Trans.2d ser. vol. v. pl. xiii.fig.6, andGeol. Journ.vol. iv. pl. i.fig.9,) exhibit under the microscope an intimate structure resembling that seen in bird-bone, in contradistinction to that characteristic of reptilian bone. But until we are better acquainted with the microscopic structure of the osseous tissue of the Pterosaurians, and are in possession of more perfect specimens of bones, it cannot be satisfactorily determined to what extent the class of Birds existed in the country of the Iguanodon.

ORNITHOIDICHNITES.

III.Ornithoidichnites.(Bird-like foot-prints.)Ligns.247,248.Bd.pl. xxvi.a, xxvi.b.—The palæontological historyof the class of birds, as evidenced by the foregoing pages, is carried back but to a comparatively recent era in the earth’s history: and indeed, in the present state of our knowledge, it may be said that all positive evidence of the former existence of this highly organized class of vertebrated animals is confined to the Tertiary and Wealden deposits. A most interesting discovery, however, by Dr. James Deane,[726]of Greenfield, U. S. seems to prove that numerous bird-like bipeds, and some of gigantic size, existed at the period when the Triassic orNew Redstrata were in the progress of formation; that period, as the reader will remember, in which the Labyrinthodonts and other extraordinary reptiles flourished.Rep. Brit. Assoc.1841, p. 230, note.

[726]See "Illustrations of Fossil Foot-prints of the Valley of the Connecticut," 1849, 4to. with nine plates.

In certain localities of the New Red sandstone in the valley of the Connecticut, numerous tridactyle markings had been occasionally observed on the surfaces of the slabs of stone when split asunder, in like manner as the ripple-marks appear on the successive layers of sandstone in Corncockle Muir, Tilgate Forest, &c. Some remarkable distinct impressions of this kind at Turner’s Falls (Massachusetts) happening to attract the attention of Dr. Deane, that sagacious observer was struck with their resemblance to the foot-marks left on the mud-banks of the adjacent river by the aquatic birds which had recently frequented the spot. The conviction that the imprints on the stone were referable to a similar origin with those on the mud was so strongly impressed on his mind, that he immediately collected a series of specimens, and communicated his discovery and opinion to Professor E. Hitchcock, who followed up the inquiry with a zeal and success that have led to the most interesting results. No reasonable doubt now exists that the imprints in question have been produced by thetracks of bipeds, impressed on the stone when in a soft state. The announcement of this extraordinary phenomenon was first made by Professor Hitchcock, in the American Journal of Science (January, 1836); and that eminent geologist has subsequently published full descriptions of the different species of imprints which he has detected, with excellent lithographs, in his "Geology of Massachusetts." (SeePetrif.pp. 64-73.)

Three highly interesting specimens of the Ornithoidichnites of North America, collected and developed by Dr. James Deane, have been lately added to the collection of organic remains in the British Museum. They exhibit several varieties of the foot-prints, and are in a very fine state of preservation. The surface of the largest slab is eight feet by six, and bears upwards of seventy distinct impressions, disposed in several tracks, as shown in theLign.247. The direction and disposition of the foot-tracks are rendered more distinct by the lines drawn from one imprint to another in the consecutive series.

The principal tracks on this slab,Lign.247, are as follow;

Fig.1 to 1,directed from below upwards, is a track consisting of six large footsteps.2 to 2,from above downwards; a track of four foot-prints, disposed almost in a right line, and very far apart.3 to 3,a track of five foot-prints, from above downwards, of a large, heavy animal, like fig. 1.4 to 4,from above downwards, four foot-prints likefig.2, disposed in a nearly straight track, and far apart.5,a track of five heavy foot-prints, directed obliquely upwards.6 to 6,five foot-prints of a large biped, in a track from below upwards.7,a series of five delicate foot-prints.8 to 8,a track of eleven very small foot-prints, disposed in zigzag, and extending obliquely from the right extremity to the upper edge of the slab.9 to 9,a track of four large and distant foot-prints, passing obliquely across the stone from left to right.

Fig.

directed from below upwards, is a track consisting of six large footsteps.

2 to 2,

from above downwards; a track of four foot-prints, disposed almost in a right line, and very far apart.

3 to 3,

a track of five foot-prints, from above downwards, of a large, heavy animal, like fig. 1.

4 to 4,

from above downwards, four foot-prints likefig.2, disposed in a nearly straight track, and far apart.

a track of five heavy foot-prints, directed obliquely upwards.

6 to 6,

five foot-prints of a large biped, in a track from below upwards.

a series of five delicate foot-prints.

8 to 8,

a track of eleven very small foot-prints, disposed in zigzag, and extending obliquely from the right extremity to the upper edge of the slab.

9 to 9,

a track of four large and distant foot-prints, passing obliquely across the stone from left to right.

I subjoin also a representation of one of the smaller foot-prints, of the natural size, the surface of the stone being sprinkled also with hemispherical markings produced by drops of rain. (Lign.248.)

A Slab ofNew Red Sandstone(eight feet by six), from Turner’s Falls, Massachusetts, United States, covered with numerous Foot-marks ofBipeds; indicating the Tracks of ten or twelve individuals, of various sizes. Discovered byDr. James Deane, of Greenfield, Massachusetts. This Specimen is now in the British Museum.—(From the American Journal of Science, vol. xlvi. p. 73.)

Lign. 247. Ornithoidichnites, or Imprints of the Footsteps of Bipeds with Bird-like Feet, on Sandstone.To facep. 770.Click on image to view larger sized.

ORNITHOIDICHNITES.

The above will suffice to give the reader a general idea of the nature of these extraordinary impressions. A few shapeless fragments of bones are the only vestiges of the skeletons of any animals, with the exception of fishes, that have been found in the strata which have furnished the slabs of Ornithoidichnites. Some Coprolites also have been discovered.

Lign. 248. Bird-like Footprint, and impressions of Rain-drops, on Sandstone(nat.).New Red Formation; Massachusetts.[Amer. Journ. of Science, (1843,) vol. xlvi. p. 73.]

The enormous size of some of the foot-marks is calculated to excite great surprise. I have in my possession (through the kindness of Dr. Deane) imprints that prove the size of the foot to have been fifteen inches in length, and ten inches in width, exclusive of the hind claw, which is presentin some species, and is here two inches long. The foot-prints of this biped when in a consecutive series of five or six, are from four to six feet apart; which, of course, must have been the length of the stride; the longest stride was probably made by the animal when running; the shortest, when walking at a moderate pace. These footsteps indicate proportions so far exceeding those of all known living bipeds,—for the foot of the African ostrich is but ten inches long,—that the geologist may be pardoned for having hesitated to adopt the opinions of the American savans, in the absence of any relics of the osseous structure of the supposed birds; although sanctioned by the high authority of Dr. Buckland, who, from the first, concurred in the views of Professor Hitchcock (Bd.ii. p. 39): but this objection has been in a great measure removed by the discovery of the remains of the gigantic Moa or Dinornis of New Zealand, with feet equal in magnitude to the largest of the Connecticut foot-prints. See p. 763, andPict. Atlas, frontispiece. Professor Hitchcock is of opinion that upwards of forty species of these biped foot-prints may be distinguished. Foot-prints referable to chelonians, batrachians, and lizards are associated with the above.[727]

[727]Trans. Amer. Phil. Soc. n. s. vol. x. pt. ii. p. 312.

In the New Red Sandstone of Stourton Hill, near Liverpool, Mr. Cunningham has observed tridactylous, webbed foot-prints,[728]21/2inches long, which he refers to a bird; Mr.Hawkshaw also noticed some bird-like tracks at Lymm; and Professor Harkness met with a trace of a biped at Weston Point, near Runcorn. These appear to be the only indications of ornithoidichnites in the Trias of England; and these are very obscure.

[728]These are accompanied by cheirotherian prints, and by the cast of an impression quite similar to that made on the sands of the sea-beach of to day, by the Medusa (sea-nettle or jelly-fish) left by the reflux of the tide and exposed to a few hours of sunshine. Mr. Cunningham and Mr. Pidgeon have furnished a figure of this interesting impression of the "jelly-fish," which has left "the solid memorial of its evanescent existence en the ancient strand" of the Triassic sea, showing that the physical conditions of land, water, and atmosphere were the same then as those that now obtain.—Liverpool Lit. Phil. Soc. Proc.1848, p. 128,fig.1. A similar imprint on a Jurassic rock in Germany is referred to at p. 280.

In the Wealden of Hastings and the Isle of Wight, the natural casts of large tridactylous foot-prints have been observed by Mr. Taggart and Mr. Beckles (seeQuart. Journ. Geol. Soc.vol. ii. p. 267, vol. vii. p. 117, vol. viii. p. 396, andGeol. Isle of Wight, p. 328), but as yet no solution of the mystery at present enwrapping these gigantic, tridactylous, biped (?) ichnolites has presented itself: we only know that the creature that left them traversed the borders of the mighty river which floated down the bulky carcases of the Hylæosaur and Iguanodon.

ON COLLECTING FOSSIL BIRDS.

On Collecting the Fossil Remains of Birds.—Notwithstanding the extreme rarity of fossils of this class, the student should not be discouraged in his search for the remains of Birds in the secondary rocks. That far more instructive specimens than any that have fallen under my observation may be discovered in the Wealden strata by diligent research, there can be no reasonable doubt. It is also very probable that the Stonesfield slate, which abounds in remains of terrestrial plants and animals, will be found to contain Ornitholites. It is important for the collector to bear in mind, that when only a fragment of the shaft of a bone remains imbedded in the stone, if the imprint of the other portions be preserved, he may obtain a knowledge of the form of the extremities; in the same manner as the external markings of the surface of a shell may be ascertained, when the shell itself is lost or destroyed, and a smooth stony cast of the internal cavity only is left. The same remark will apply to the bones of reptiles and other animals; for example, a perfect leg-bone may be imbeddedin a block of limestone; but, when exposed by breaking the stone, a portion of the shaft may alone remain attached, and both extremities be shattered to pieces by the concussion of the blow; yet, if the impression remains, the entire form of the original may be determined.

Thefoot-prints, not only of birds, but of reptiles and other animals, should be diligently sought for on the surfaces of laminated strata of sand and clay, and especially where the presence of ripple-marks, and the impressions of rain-drops, indicate that the beds were deposited in shallow water. The forest-marble flags at Castle Comb, north of Bath, the Stonesfield slates, and the sandstones around Horsham (in Sussex), and particularly at Stammerham (seeGeol. S. E.p. 213), are often rippled, and it is therefore probable that the foot-prints of some of the Oolitic and Wealden quadrupeds and bipeds, if such existed, will sooner or later be discovered.

FOSSIL MAMMALIA.

The remains ofMammaliadiscovered in a fossil state include an immense number of species, and furnish examples of almost every living genus, and of numerous genera, and even orders, of which no existing species are known. Yet amidst the vast accumulations of the skeletons of the higher orders of vertebrata contained in the tertiary deposits, and in the superficial drift, belonging to species which have successively appeared on the surface of our planet, flourished for indefinite periods of time, and then become annihilated, no vestiges ofMan, or of his works, have been detected. Human skeletons, naturally imbedded, have hitherto only been observed in the silt of modern alluvial plains,[729]in peat-bogs (Wond.p. 64), and in conglomerates of recent date, such as are in the progress of formation on the sea-shores, particularly where the water is loaded with the detritus of shells and corals, and the waves transport the calcareous matter along the margins of creeks and bays, or deposit it in the shallows along the coast (seeWond.p. 87, andPetrif.p. 483).

[729]There seems, however, reason to believe that the human skulls and bones found with elephantine and other remains in the Alps of Swabia, are of contemporaneous origin with these extinct mammals. (SeeLiterary Gazette, 1853, p. 1027.)

The geological distribution of fossil mammalia,[730]—the occurrence of the entire carcases of extinct species of Elephantand Rhinoceros in blocks of ice (Wond.p. 151),—of recent species in the superficial alluvial clay and silt,—of recent and extinct forms in the Drift or Pleistocene deposits (Wond.p. 147),—of the gradual preponderance of unknown species and genera, in proportion as we carry back our retrospect to the most ancient Tertiary strata (Wond.p. 254), —the sudden disappearance of all vestiges of the entire Class of Mammalia, with the last bed of the Eocene deposits,—with the exception of a few minute jaws in one set of beds of the Oolite in England (Wond.p. 510), and of a few teeth in the Trias (?) of Germany,[731]the sole records of the existence of any of the highest types of animal organization throughout the vast periods of the secondary formations—are so fully treated of in theWonders of Geology, that I need not dwell upon the subject in the present volumes. Neither is it desirable to enter at large upon this department of Palæontology, for it were vain to attempt the elucidation of the anatomical characters of but one extinct species of Mammalia, without giving details of structure, that could only be successfully demonstrated in a work expressly devoted to the subject. Referring, therefore, to Cuvier’sOssemens Fossiles, and to Professor Owen’s "History of the British Fossil Mammalia," 8vo. 1846, I must limit my remarks on the Fossil Mammalia to a brief summary of modern discoveries, with suggestions for the identification and collection of some of the most interesting or prevalent remains.

[730]For a notice of the distribution of mammalian remains in the Upper Tertiaries of Europe, see Phillips’sGeology, 1853, vol. i. p. 45, &c.[731]For an account of these teeth of small insectivorous mammals from the "bone-bed" of Würtemberg, which has an analogous position at the top of the Trias with the "bone-bed" of Axmouth and Aust Cliff, seeLy.p. xiv. figs. 529-531.

[730]For a notice of the distribution of mammalian remains in the Upper Tertiaries of Europe, see Phillips’sGeology, 1853, vol. i. p. 45, &c.

[731]For an account of these teeth of small insectivorous mammals from the "bone-bed" of Würtemberg, which has an analogous position at the top of the Trias with the "bone-bed" of Axmouth and Aust Cliff, seeLy.p. xiv. figs. 529-531.

The fossil remains of Mammalia will be considered under the following heads:—

FOSSIL WHALES.

I. Fossil Cetacea.[732]—TheCetaceans, although popularly termed fishes, are as perfect air-breathing vertebrated animals, as the terrestrial mammalia, and, like them, give suck to their young. Instead of fore-feet or arms, they have a pair of fins or paddles, but are destitute of hinder extremities, the place of the latter organs being supplied by a powerful cartilaginous horizontal fin, appended to the tail. The Cetaceans, therefore, differ in this respect from the fossil marine reptiles, the Ichthyosaurus and Plesiosaurus (see p. 662), which have two pairs of paddles. This order, as is well known, comprises the most colossal forms of animal existence,—the Whales. Some are herbivorous, others carnivorous; many have powerful teeth; others are edentulous, the jaw being furnished with a series of elongate plates of the substance familiarly known by the name ofwhale-bone.

[732]Cetacea: an order of aquatic mammalia, comprising the W hales, Narwhals, Porpoises, Dolphins, and Dugongs.

The fossil remains of Cetaceans have, for the most part, been observed in alluvial silt and beds of drift, in valleys still traversed by rivers; but many examples have been discovered in elevated sea-beaches, proving that, although,geologically speaking, these beds are of modern origin, yet great changes in the relative level of the land and sea must have taken place since these remains were imbedded. Thus, on the banks of the river Forth, near Alloa, in Scotland, the skeleton of a Whale (Balænoptera), seventy-two feet long, was discovered imbedded in clay, twenty feet above the highest tide.[733]Cuvier mentions the discovery of bones of aLamantinat Angers; of a Dolphin, and Rorqual, in Lombardy; and of a Grampus, in the pliocene of the Sub-Apennines.[734]

[733]Dr. Fleming’sBritish Animals, p. 39.[734]For notices and descriptions of Cetacean remains found in England, see Owen’sBrit. Foss. Mammalia, p. 516,et seq.

[733]Dr. Fleming’sBritish Animals, p. 39.

[734]For notices and descriptions of Cetacean remains found in England, see Owen’sBrit. Foss. Mammalia, p. 516,et seq.

Otolithes of Cetaceans.—Petro-tympanic bones of several large whales have been found in great numbers in the red Crag of Felixstow; among them is one of the genus Physeter, or Sperm-Whale.[735]

[735]Proc. Geol. Soc. for 1845, p. 41; and Brit. Foss. Mam. p. 526, &c.

Brighton Fossil Whale.—An interesting discovery of the anterior half of one side of the lower jaw of a Whale, undoubtedly coeval with the extinct Mammoth (Elephas primigenius), was made in 1828 in the Cliff, east of Kemp Town, Brighton, under the following circumstances. On the face of the Cliff, in the ancient shingle which lies immediately upon the chalk and is surmounted by beds of calcareous rubble, containing bones and teeth of Elephants, to the height of one hundred and twenty feet, some fishermen had observed a huge bone, that had been laid bare by an unusually high tide and now projected two or three feet beyond the face of the Cliff. Unable to remove it, they broke off the extremity, a fragment of which was sent to me. Upon repairing to the spot a few days afterwards, I found that the fishermen had renewed their attack, and demolished a considerable portion of the bone in ineffectual attempts to dislodge it from its bed; and had desisted only from theapprehension of being buried beneath the overhanging cliff, which is composed of loosely aggregated materials. Unfortunately, the bone extended directly into the cliff, and it required several hours of labour, not unattended with danger, before an excavation was made sufficiently large to expose the entire specimen. It proved to be the anterior nine feet of the left branch of the lower jaw of a whale-bone Whale (Balæna mysticetus). It was of a light fawn colour externally, but the internal coarse osseous structure was delicately white; it was extremely brittle, and, upon attempting to move it, broke into a thousand pieces. Time would not permit of the application of a coating of plaster of Paris, for ere we had completed our task the tide was rapidly approaching, or this interesting relic might have been extracted entire. This portion of lower jaw, before it was mutilated by the fishermen, was twelve feet long, and thirty-six inches in circumference at the largest extremity. It must have belonged to a Whale from sixty to seventy feet in length.[736]

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