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!
[Illustration: Fig. 9.--Restored skeleton of _Brontosaurus excelsus_.
(After Marsh.)]
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.)
[Illustration: Fig. 10.--Neck vertebræ of _Brontosaurus_.
1. Front view. 2. Back view.]
[Illustration: Plate IV.
A GIGANTIC DINOSAUR, BRONTOSAURUS EXCELSUS.
Length nearly 60 feet.]
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.
[Illustration: Plate V.
THIGH-BONE OF THE LARGEST OF THE DINOSAURS, ATLANTOSAURUS.
From a cast in the Natural History Museum. Length 6 feet 2 inches.]
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.
[Illustration: Fig. 11.--Head of _Diplodocus_.
1. Side view. 2. Front view.]
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.