CHAPTER V.

THE DRAGONS OF OLD TIME--DINOSAURS.

"What we know is but little; what we do not know is immense."--La Place.

Was there ever an age of dragons? Tradition says there was; but there is every reason to believe that the fierce and blood-thirsty creatures, of which such a variety present themselves, are but creations of the imagination,--useful in their way, no doubt, as pointing a moral or adorning a tale, but, nevertheless, wholly without foundation in fact. The dragon figures in the earliest traditions of the human race, and crops up again in full force in European mediæval or even late romance.

In ancient Egyptian mythology, Horus, the son of Isis, slays the evil dragon. In Greece, the infant Hercules, while yet in his cradle, strangles deadly snakes; and Perseus, after engaging in fierce struggle with the sea-monster, slays it, and rescues Andromeda from a cruel death. In England, we have the heroic legend of St. George and the Dragon depicted on our sovereigns. But it is easy to see a common purpose running through these legends. They are considered by many to be solar myths, and have a moral purpose. The dragons or snakes are emblems of darkness and evil; the heroes emblems of light, and so of good. The triumph of good over evil is the theme they were intended to illustrate. The dragons, then, are clearly products of the imagination, based, no doubt, on the huge and uncouth reptiles of the present human era, such as crocodiles, pythons, and such creatures.

Amidst much diversity there is yet a strange similarity in the dragons that figure in the folk-lore of Eastern and Western peoples. Probably our European traditions were brought by the tribes which, wave after wave, poured in from Central Asia.

They are, for the most part, unnatural beasts, breathing out fire, and often endowed with wings, while at the same time possessing limbs ending in cruel claws, fitted for clutching their unfortunate victims. The wings seem, to say the least, very much in the way. Poisonous fangs, claws, scaly armour, and a long pointed tail were all very well,--but wings are hardly wanted, unless to add one more element of mystery or terror. Some, however, are devoid of wings: the Imperial Japanese dragons showing no sign of such appendages. The Temple Bar griffin is a grim example of a winged monster. Nevertheless, in spite of all the manifest absurdities of the dragons of various nations and times, geology reveals to us that there once lived upon this earth reptiles so great and uncouth that we can think of no other but the time-honoured word "dragon" to convey briefly the slightest idea of their monstrous forms and characters.

So there is some truth in dragons, after all. But then we must make this important reservation--viz. that the days of these dragons were long before the human period; they flourished in one of those dim geological ages of which the rocks around us bear ample records.

It is a strange fact that human fancy should have, in some cases at least, created monsters not very unlike some of those antediluvian animals that have, during the present century, been discovered in various parts of Europe and America. Some unreasonable persons will have it that certain monstrous reptiles of the Mesozoic era, about to be described, must have somehow managed to survive into the human period, and so have suggested to early races of men the dragons to which we have alluded. But there is no need for this untenable supposition. By a free blending together of ideas culled from living types of animals it would be very easy to construct no small variety of dragons; and so we may believe this is what the ancients did.

Having said so much of dragons in general, let us proceed to consider those both possible and real monsters revealed of late years by the researches of geologists. For this purpose we shall devote the present and two following chapters to the consideration of a great and wonderful group of fossil reptiles known as Dinosaurs. The strange fish-lizards and sea-lizards previously described were the geological contemporaries of a host of reptiles, now mostly extinct, which inhabited both the lands and waters of those periods known as the Triassic, Jurassic, and Cretaceous, which taken together represent the great Mesozoic, formerly called the Secondary, era.

The announcement by Baron Cuvier--the illustrious founder of Palæontology--that there was a period when our planet was inhabited by reptiles of appalling magnitude, with many of the features of modern quadrupeds, was of so novel and startling a character as to require the prestige of even his name to obtain for it any degree of credence. But subsequent discoveries have fully confirmed the truth of his belief, and the "age of reptiles" is no longer considered fabulous. This expression was first used by Dr. Mantell as the title of a paper published in the _Edinburgh Philosophical Journal_ in 1831, and serves to remind us that reptilian forms of life were once the ruling class among animals.

The Dinosaurs are an extinct order comprising the largest terrestrial and semi-aquatic reptiles that ever lived; and while some of them in a general way resembled crocodiles, others show in the bony structures they have left behind a very remarkable and interesting resemblance to birds of the ostrich tribe. This resemblance shows itself in the pelvis, or bony arch with which the hind limbs are connected in vertebrate or backboned animals, and in the limbs themselves. This curious fact, first brought into notice by Professor Huxley, has been variously interpreted by anatomists; some concluding, with Professor Huxley, that birds are descended from Dinosaurs; while others, with Professor Owen, consider the resemblance accidental, and in no way implying relationship. Huxley has proposed the name Ornithoscelida, or bird-legged, for these remarkable reptiles.

Dinosaurs must have formerly inhabited a large part of the primæval world; for their remains are found, not only in Europe, but in Africa, India, America, and even in Australia; and the geologist finds that they reigned supreme on the earth throughout the whole of the great Mesozoic era.

Their bodies were, in some cases, defended by a formidable coat of armour, consisting of bony plates and spines, as illustrated by the case of Scelidosaurus (p. 105), thus giving them a decidedly dragon-like appearance. The vertebræ, or bony segments of the backbone, generally have their centra hollow on both sides, as in the Ichthyosaurus; but in the neck and tail they are not unfrequently hollow on one side and convex on the other. In some of the largest forms the vertebræ are excavated into hollow chambers. This is apparently for the sake of lightness; for a very large animal with heavy solid bones would find it difficult to move freely. In this way strength was combined with lightness.

All the Dinosaurs had four limbs, and in many cases the hind pair were very large compared to the fore limbs. They varied enormously in size, as well as in appearance. Thus certain of the smaller families were only two feet long and lightly built; while others were truly colossal in size, far out-rivalling our modern rhinoceroses and elephants.

The limbs of Cetiosaurus, for example, or of Stegosaurus, remind us strikingly of those of elephants. The celebrated Von Meyer was so struck with this likeness that he proposed the name Pachypoda for them, which means thick-footed. Professor Owen opposed this name; for it was misleading, and only applied to a few of them. He therefore proposed the name we have already been using, viz. Dinosauria,[10] and this name has been generally retained. We are thus led to connect them with lizards and crocodiles, rather than with birds or quadrupeds. The strange and curiously mixed characters of the old-fashioned reptiles is forcibly illustrated by these differences of opinion among leading naturalists. Professor Seeley, another living authority, refuses to consider them as reptiles, at least in the ordinary sense of the word.

[10] Greek--_deinos_, terrible; _sauros_, lizard.

Extinct forms of life are often so very different to the creatures inhabiting the world of to-day, that naturalists find it a hard task to assign them their places in the animal kingdom. The classes, orders, and families under which living forms are grouped are often found inadequate for the purpose, so much so that new orders and new families require to be made for them; and then it is often quite impossible to determine the relations of these new groups to the old ones we are accustomed to. Dinosaurs offer a good example of this difficulty. Were they related to ancient crocodiles? No one can say for certain; but it is quite possible, and even probable. Again, did certain long-legged Dinosaurs eventually give rise by evolution to the running birds, ostriches, emeus, etc.? This, although supported by weighty authority, is a matter of speculation: we ought to be very careful in accepting such conclusions. It may perhaps be safer to look upon the ancestry of birds as one of those problems on which the oracle of science cannot at present declare itself.

Various attempts have been made to classify Dinosaurs, and arrange them in family groups; but, considering our imperfect knowledge, it will be wise to regard all such attempts as purely temporary and provisional, although in some ways convenient. Professor Marsh, of Yale College, U.S., whose wonderful discoveries in the far West have attracted universal attention, has grouped the Dinosaurs into five sub-orders. It will, however, be sufficient for our purpose if we follow certain English authorities who divide them into three groups--taking the names given by Professor Marsh, only running together some which he would separate.

We shall first consider the very interesting and huge forms included in his sub-order the Sauropoda, or lizard-footed Dinosaurs. Various parts of the skeletons, such as vertebræ, leg-bones, etc., of these cumbrous beasts have long been known in this country; but Professor Marsh was the first person to discover a complete skeleton.

We shall, therefore, now turn our attention to the bony framework of the huge Brontosaurus (Fig. 9), a vegetable-feeding lizard. But it will be necessary to completely lay aside all our previous notions taken from lizards of the present day, with their short legs and snake-like scaly bodies, before we can come to any fair conclusion with regard to this monstrous beast.

It was nearly sixty feet long, and probably when alive weighed more than twenty tons! that it was a stupid, slow-moving reptile, may be inferred from its very small brain and slender spinal cord. By taking casts of the brain-cavities in the skulls of extinct animals, anatomists can obtain a very good idea of the nature and capacity of their brains; and in this way important evidence is obtained, and such as helps to throw light upon their habits and general intelligence. No bony plates or spines have been discovered with the remains of this monster; so that we are driven to conclude that it was wholly without armour: and, moreover, there seem to be no signs of offensive weapons of any kind.

Professor Marsh concludes that it was more or less amphibious in its habits, and that it fed upon aquatic plants and other succulent vegetation. Its remains, he says, are generally found in localities where the animal had evidently become mired, just as cattle at the present day sometimes become hopelessly fixed in a swampy place on the margin of a lake or river (see p. 19). Each track made by the creature in walking occupied one square yard in extent!

The remarkably small head is one of the most striking features of this Dinosaur, and presents a curious contrast to the large and formidable skulls possessed by some other forms to be described further on. But it is clear that no animal with such a long neck as this creature had could have borne the weight of a heavy skull. Short thick necks and heavy skulls always go together. Indeed, the weight of the long neck itself would have been serious had it not been for the fact that the vertebræ in this part of the skeleton, and as far as the region of the tail, have large cavities in the sides of the centra. This cavernous structure of the vertebræ gradually decreases towards the tail. The cavities communicated with a series of internal cavities which give a kind of honeycombed structure to the whole vertebra. This arrangement affords a combination of strength and lightness in the massive supports required for the huge ribs, limbs, and muscles, such as could not have been provided by any other plan. (See Fig. 10.)

The body of the Brontosaur was comparatively short, with a fairly large paunch (see restoration, Plate IV.). The legs and feet were strong and massive, and the limb-bones solid. As if partly in order to balance the neck, we find a long and powerful tail, in which the vertebræ are nearly all solid. In most Dinosaurs the fore limbs are small compared to the hind limbs--_e.g._ Megalosaurus, Iguanodon, and Scelidosaurus,--but here we find them unusually large. In this case, then, it is hardly possible that the creature walked upon its hind legs, as many of the Dinosaurs did. But, at the same time, we may believe that occasionally it assumed a more erect position; and may not the light hollowed structure of the vertebræ in the fore part of the body, already alluded to, have imparted such lightness as made it possible for the creature to assume such attitudes? There can be little doubt but that many other fierce and formidable Dinosaurs were living at the same time and in the same region with Brontosaurus, whose remains are found in the Jurassic rocks of Colorado (Atlantosaurus beds).

How this apparently helpless and awkward animal escaped in the struggle for existence it is not easy to conjecture; but since there is reason to believe it was more or less at home in the water, and could use its powerful tail in swimming, we may perhaps find a way out of the difficulty by supposing that, when alarmed by dangerous flesh-eating foes, it took to the water, and found discretion to be the better part of valour. Although apparently stupid, the Brontosaur probably possessed a good deal of cunning, and we can fancy it stretching its long neck above reeds, ferns, and cycads to get a view of the approaching enemy.

The Sauropoda, or lizard-footed Dinosaurs, show in many ways a decided approach to a simple or generalised crocodile; so much so, that Professor Cope is inclined to include crocodiles and sauropodous Dinosaurs in the same order. Still, there are important differences in other members of this sub-order. Unfortunately, our knowledge is at present rather limited, owing to the want of complete skeletons. Vertebræ, limb-bones, skulls, and teeth have all been discovered through the zeal and energy of Professor Marsh and his comrades, in the far west of America, as well as by the researches of English geologists, assisted by the labours of many ardent collectors of fossils, in this country. Some of these may now be briefly considered.

In Plate V. we have endeavoured to give some idea of a huge thigh-bone (femur) belonging to the truly gigantic Dinosaur called Atlantosaurus. It is six feet two inches long, and a cast of it may be seen in the fossil reptile gallery of the British Museum of Natural History (Wall-case No. 3). It should be mentioned, however, that the original specimen is partly restored, so that its exact length to an inch or so is not quite certain. In our illustration it is shown to be a little taller, when placed upright, than a full-grown man. Professor Marsh, the fortunate discoverer of this wonderful bone, calculates that the Atlantosaurus must have attained a length of over eighty feet! and, assuming that it walked upon its hind feet, a height of thirty feet!

It doubtless fed upon the luxuriant foliage of the sub-tropical forests, portions of which are preserved with its remains. Besides this thigh-bone, Professor Marsh has procured specimens of vertebræ from the different parts of the vertebral column; but no skull or teeth. The vertebræ are hollowed out much in the same way as those of Brontosaurus. The fore limbs were large, as in the latter animal; and the extremities of the limbs were provided with claws. Taking all present evidence, it appears that the Atlantosaurus bore a general resemblance to its smaller contemporary. We can therefore form a fairly good idea of its aspect and proportions.

The same Jurassic strata from the Rocky Mountains have yielded remains of another big Dinosaur, belonging to the same family. This genus, which has been named the Apatosaurus, is represented by a nearly complete skeleton, in the Yale College Museum; and is fortunately in an excellent state of preservation. Another species, of smaller size, though not so complete, adorns the same collection. This was about thirty feet long, and is known as Apatosaurus grandis.

Morosaurus, another important genus, is known from a large number of individuals discovered in the now famous Atlantosaurus beds of Colorado, including one nearly complete skeleton. The head of this creature was small; the neck elongated; and the vertebræ of the neck are lightened by deep cavities in their centra, similar to those in birds of flight. The tail, also, was long. When alive, this Dinosaur was about forty feet in length. It probably walked on all fours; and in many other respects was very unlike a typical Dinosaur. The brain was small, and it must have been sluggish in all its movements. The nearly complete remains of Morosaurus grandis were found together in a very good state of preservation in Wyoming, and many of the bones lay just in their natural positions.

Diplodocus, of which several incomplete specimens have been discovered, was intermediate in size between Atlantosaurus and Morosaurus, and may have reached when living, a length of forty or fifty feet. Its skull was of moderate size, with slender jaws. The teeth were weaker than those of any other known Dinosaur, and entirely confined to the front of the jaws. Professor Marsh concludes from the teeth that Diplodocus was herbivorous, feeding on succulent vegetation, and that it probably led an aquatic life. Fig. 11 shows its skull.

The remains of this interesting Dinosaur (Brontosaurus), which in several ways differs from other members of the "lizard-footed" group, were found in Upper Jurassic beds, near Cañon City, Colorado. A second smaller species was also discovered near Morrison, Colorado. All the remains lay in the Atlantosaurus beds. These strata--the tomb in which Nature has buried up so many of her dragons of old time--can be traced for several hundred miles on the flanks of the Rocky Mountains, and are always to be known by the bones they contain. They lie above the Triassic strata and just below the Sandstone of the Dakota group. Some have regarded them as of Cretaceous age; but, judging from their fossils, there can be but little doubt that they were deposited during the Jurassic period--probably in an old estuary. They consist of shale and sandstone.

Besides the numerous Dinosaurs, Professor Marsh's colleagues have found abundant remains of crocodiles, tortoises, and fishes, with one Pterodactyl, a flying reptile (see chap. viii.), and several small marsupials. The wonderful collection of American Jurassic Dinosaurs in the Museum of Yale College includes the remains of several hundred individuals, many of them in excellent preservation, and has afforded to Professor Marsh the material for his classification already alluded to.

English Dinosaurs of the Lizard-footed Group.

Unfortunately, there are at present no complete skeletons known of English Dinosaurs related to the American forms above described. But, since the English fossils were first in evidence by many years, and Marsh's discoveries have confirmed in a remarkable way conclusions drawn by Owen, Huxley, Hulke, and Seeley, and others from materials that were rather fragmentary, it may be worth while to give some account of these remains and the interpretations they have received.

Dr. Buckland, in his _Bridgewater Treatise_, 1836, referred to a limb-bone in the Oxford Museum, from the great Oolite formation near Woodstock, which was examined by Cuvier, and pronounced to have once belonged to a whale; also a very large rib, which seemed whale-like. In 1838 Professor Owen, when collecting materials for his famous _Report on the Fossil Reptiles of Great Britain_, inspected this remarkable limb-bone, and could not match it with any bones known among the whale tribe; and yet its structure, where exposed, was like that of the long bone (humerus) of the paddle of a whale. Later on, he abandoned the idea that it once belonged to a whale, and it was thought that the extinct animal in question might have been a reptile of the crocodilean order. In time, a fine series of limb-bones and vertebræ was added to the Oxford Museum by Professor Phillips (Dr. Buckland's successor at Oxford), who pronounced them to be Dinosaurian. The name "Cetiosaurus"[11] (or Whale-lizard), originally given by Owen, was unfortunate, because there is really nothing whale-like about it, except a certain coarse texture of some of the bones.

[11] Greek--_ketion_, whale; _sauros_, lizard.

In 1848 Dr. Buckland announced the discovery of another limb-bone (a femur), which Owen referred to Cetiosaurus; it was four feet three inches in length. Between 1868 and 1870, however, a considerable portion of a skeleton was discovered in the same formation at Kirtlington Station, near Oxford. These remains were the subject of careful examination by Professors Owen and Phillips. The femur this time was five feet four inches long. Their studies threw much light on the nature and habits of Cetiosaurus.

Although showing in many ways an approach to the crocodile type of reptile, yet it was perceived from the nature of the limbs that they were better fitted for walking on land than are those of a crocodile, with its sprawling limbs. Still, Professor Owen was careful to point out that the vertebræ of its long tail indicate suitability as a powerful swimming organ, and concluded that the creature was more aquatic than terrestrial in its habits. Plaster casts of the limb-bones may be seen at the British Museum of Natural History, side by side with the huge Atlantosaurus cast sent by Professor Marsh.

The Kimmeridge clay of Weymouth has yielded a huge arm-bone (or humerus), nearly five feet long; and from Wealden strata of Sussex and the Isle of Wight vertebræ have been collected. Altogether we have remains of Cetiosaurus from at least half a dozen counties. Unfortunately, no specimen of a skull has yet been found, and only two or three small and incomplete teeth, which may possibly have belonged to some other animal. Professor Owen estimated the length of the trunk and tail of the creature to have been thirty-five or thirty-six feet; but in the absence of further evidence it was not possible to form any conclusion as to its total length. It is evident that Cetiosaurus was closely allied to the American Brontosaurus (p. 69); and so these earlier English discoveries have gained much in interest from the light thrown upon them by Professor Marsh's huge Saurian.

Another English Saurian of this group was the Ornithopsis, from Wealden strata in the Isle of Wight, which has been the subject of careful study by Mr. Hulke and Professor Seeley. Their conclusions, based on the examination of separate portions of the skeleton (such as vertebræ), have been singularly confirmed by the discovery of Brontosaurus.

In Ornithopsis the vertebræ of the neck and back, though of great size, were remarkably light, and yet of great strength. One of the vertebræ of the back had a body, or centrum, ten inches long. Hoplosaurus and Pelosaurus were evidently reptiles closely allied to the above types; but at present are so imperfectly known that we need not consider them here.