DINOSAURS (_continued_).
"Everything in Nature is engaged in writing its own history:
the planet and the pebble are attended by their shadows, the
rolling rock leaves its furrows on the mountain side, the
river its channel in the soil, the animal its bones in the
stratum, the fern and the leaf inscribe their modest epitaphs
on the coal, the falling drop sculptures its story on the
sand and on the stone,--not a footstep on the snow or on the
ground, but traces in characters more or less enduring the
record of its progress."--Emerson.
In the year 1878 was announced one of the most fortunate discoveries
known in the whole history of geological science--a discovery unique
of its kind, and one which throws considerable light on the nature of
the monster first discovered by Dr. Mantell. In that year came the
good news that no less than twenty-three Iguanodons had been found in
the colliery of Bernissart, in Belgium, between Mons and Tournai, near
the French frontier. The coal-bearing rocks (coal-measures) of this
colliery, overlain by chalk and other deposits of later age, are
fissured in many places by deep valleys or chasms more than 218 yards
deep. Though now filled up, they must at one time have been open
gorges on an old land surface. Into one of these chasms were somehow
precipitated twenty-three Iguanodons, numbers of fish, a frog-like
animal, several species of turtles, crocodiles, and numerous ferns
similar to those described by Mantell from the Weald. It it not easy
to conjecture how this large and varied assemblage of animals came to
be collected together and entombed in this one place, but possibly
their carcases were swept by some flood into the chasm in which the
remains were discovered. They were buried in clay interstratified with
sand, a fact which was interpreted in accordance with the above
suggestion.
M. de Pauw, the accomplished controller of the workshops in the Royal
Museum of Natural History at Brussels, spent three whole years in
extracting this splendid series of fossils from the pit-shaft, the
bones being brought up from a depth of rather more than 350 yards. But
at the end of this time it was only the rough material that had been
got together, and every block containing bones requires a great deal
of most careful labour before the bones in it are so exposed that they
can be properly studied. Out of the twenty-three specimens, fifteen
had, in the year 1883, been chiselled out, eight remaining to be
worked at; and although five skilled workmen were then constantly at
work, progress was necessarily slow.
In 1883, that is after seven years, two huge entire skeletons had been
set up in a great glass case in the Courtyard of the Museum at
Brussels, and these exhibit with marvellous completeness the structure
of the extinct monster.[17] The work reflects the highest credit on M.
de Pauw;[18] and the director of the Bernissart Mining Company, M.
Fages, deserves the thanks of all scientific men for so liberally
aiding this important undertaking. These specimens illustrate the
conclusion, previously arrived at by Professor Huxley, that Dinosaurs,
as a group, occupy a position in the great chain of animal life
intermediate between reptiles and birds. Indeed, it is the opinion of
this great authority, and of many naturalists of the present day, that
whenever future discoveries may reveal the ancestry of birds, it will
be found that they came from Dinosaurs, or that both originated from a
common ancestor.
[17] In August, 1892, Mr. Dollo wrote, in answer to inquiries from
South Kensington, to say that five are already mounted and exhibited,
and five more are almost ready for mounting. He also stated that the
remains represent twenty-nine individuals, not twenty-three, as above.
[18] _Geological Magazine_, January, 1885.
The specimens so skilfully set up by M. de Pauw represent two
distinct species. The larger one, Iguanodon Bernissartensis, cannot be
less than fifteen feet high, and, measured from the tip of the snout
to the end of the tail, is rather over thirty feet long, covering
nearly twenty-four feet of ground in its erect position (see Fig. 21).
Iguanodon Mantelli is smaller and more slender looking, with a height
of over ten feet, and a length of about twenty feet. (See Fig. 22.)
[Illustration: Fig. 21.--Skeleton of _Iguanodon Bernissartensis_.]
[Illustration: Plate VIII.
IGUANODON MANTELLI.
Length about 20 feet.]
[Illustration: Fig. 22.--Skull and skeleton of _Iguanodon Mantelli_.
(From Bernissart.)]
The huge three-toed impressions found in Sussex prove that the
monster, although owning a body as large as that of an elephant,
habitually walked on its hind legs! Some of the thighbones found by
Dr. Mantell measured between four and five feet in length. It will be
seen that the fore limbs are small in comparison to the hind limbs. A
remarkable feature of the hand is the large pointed bone at the end of
the thumb, forming a kind of spur. The conical shape of this bone
found by Dr. Mantell, who had no clue to its place in the skeleton,
led him to suppose that it was a horn answering to that of a
rhinoceros--a conclusion which Professor Owen refused for various
reasons to accept. The latter concluded that it belonged to the hand,
and now we see that he was right. Unfortunately, certain popular works
on geology, such as _Our Earth and its Story_ (Cassell) still continue
to spread this error, by showing a (very indifferent) restoration of
the Iguanodon with the impossible horn on its nose. It has been
suggested that the spur was a weapon of offence, and that, when
attacked, an Iguanodon may have seized its aggressor in its short
arms, and made use of the spur as a dagger. But this is only
conjecture, and perhaps the spur may have been useful in seizing and
pulling down the foliage and branches of trees, or in grubbing them up
by the roots. Detached specimens of this curious bone may be seen
among the other remains of Iguanodon at South Kensington, and also
some of the gigantic tracks already alluded to. (Gallery IV. on plan,
Wall-cases 5 and 6; and Gallery XI., Wall-case 7.)
The Bernissart specimens even afford some evidence as to the nature of
the integument, or skin, and this supports the idea previously held
that the creature possessed a smooth skin, or, at least, only slightly
roughened. The muzzle was quite toothless, and perhaps may have been
sheathed in horn, like the beak of turtles--an arrangement highly
useful for biting off the leaves of trees.
[Illustration: Fig. 23.--Tracks of _Iguanodon_, much reduced. (From
Wealden strata, Sussex.)]
Probably it passed much of its time in the water, using its immense
powerful tail as an organ of propulsion. When swimming slowly it may
have used both sets of limbs, but when going fast it probably fixed
its fore limbs closely beside its body, and drove itself through the
water by means of the long hind limbs alone. Mr. Dollo, of Brussels,
is preparing a final monograph on the Bernissart Iguanodons, a work to
which palæontologists eagerly look forward. There cannot be much doubt
that these unarmoured Dinosaurs were molested and preyed upon by
their carnivorous contemporaries, such as the fierce Megalosaurus,
previously described (p. 76). And with regard to this, Mr. Dollo makes
the suggestion that, when on land, their great height and erect
posture enabled them to descry such enemies a long way off. Their
great height must also have stood them in good stead, by enabling them
easily to reach the leaves of trees, tree-ferns, cycads, and other
forms of vegetable life, which constituted their daily food. (See
restorations, Plates VII. and VIII.)
Should the reader visit the "geological island" in the grounds of the
Crystal Palace, he will see that Mr. Waterhouse Hawkins's great model
Iguanodon there set up is by no means in accordance with the
description given above; but we must remember how imperfect was the
material at his command.
Another Dinosaur, of considerable dimensions, that flourished during
the Wealden period was the Hylæosaurus, also discovered by Dr.
Mantell, and so named by him because it came from the Weald.[19] In the
summer of 1832, upon visiting a quarry in Tilgate Forest, which had
yielded many organic remains, he perceived in some fragments of a
large mass of stone which had recently been broken up and thrown in
the roadside, traces of numerous pieces of bone. With great care he
cemented together and fixed in a stout frame, all the portions of this
block that he could find, and set to work to "develop" the block with
his chisel. This work occupied many weeks, but his labour was rewarded
by the discovery of certain new and remarkable features displayed by
this monster; for it must have presented, when alive, a formidable
array of bony plates and long sharp spines, the latter of which
probably stood in bristling array along the back and tail, and other
parts of the body. (Wall-case 4.) Of the spines no less than ten were
found in this block, varying in length from five to seventeen inches,
the largest being four inches thick. It is known that many lizards,
such as Iguanas and Cycluras, have large processes with horny
coverings, forming a kind of fringe or crest along the back, and,
judging by analogy, Dr. Mantell concluded that this gigantic saurian
was similarly armed with a row of large angular spines covered by a
thick horny investment. As weapons of offence and defence, they were
no doubt highly effective, but their precise arrangement is still a
matter of speculation.
[19] From Greek--_hule_, wood, or weald; and _sauros_, lizard.
This first specimen displayed, besides the bony scutes and spines, a
portion of the backbone, eleven ribs and portions of the pectoral
arch. A second specimen was found near Bolney, in Sussex, and was
unfortunately almost wholly destroyed by the labourers; but Dr.
Mantell was able to obtain many of the bones, such as ribs and
limb-bones, and they also indicated a reptile of great size. A third
specimen was brought to light in Tilgate Forest in 1837; but,
unfortunately, this also fell into the hands of the parish labourers,
who were unacquainted with its value. Although with due care a much
larger portion of the skeleton might have been kept, yet Dr. Mantell
was able to obtain a fine series of twenty-six vertebræ belonging to
the tail, with a total length of nearly six feet: the same spines were
present here also.
No specimen of the skull of this strange monster is known, and no
teeth that can be with certainty referred to it.
Mr. Waterhouse Hawkins's model at Sydenham, near the Iguanodon, was
based on the above discoveries, which are insufficient, and is far
from the truth.
[Illustration: Plate IX.
AN ARMOURED DINOSAUR, SCELIDOSAURUS HARRISONI.
Length 12 feet or more.]
[Illustration: Fig. 24.--Restored skeleton of _Scelidosaurus
Harrisoni_ (after Woodward), greatly reduced, from the Lower Lias of
Charmouth, Dorset. The figure shows the large lateral dermal spines on
the shoulders, and the long lateral line of smaller spines, reaching
from the pectoral region to the extremity of the tail.]
* * * * *
The next monster to be described is one that has fortunately left to
posterity a much better record of itself, and probably was not very
unlike the Hylæosaurus of Mantell. This is the Scelidosaurus: so named
by Professor Owen from the indications of greater power in the hind
legs than in most saurians.[20] It is the only known example of an
almost entire skeleton of an English Dinosaur, and the history of its
discovery is rather curious. Some time previous to 1861, Mr. J.
Harrison, of Charmouth, obtained from the Lower Lias of that
neighbourhood portions of the hind limb of a Dinosaur, and, later on,
a nearly complete skull. These specimens were described by Owen, and
the genus was founded on them. Mr. Harrison, whose discovery aroused
great interest, continued to search on the same spot, and was rewarded
by finding all the rest of the skeleton, except most of the neck
vertebræ. This was extracted in several blocks, and these, after
careful "development" of the bones, were fitted together so as to
exhibit the whole skeleton. This most valuable specimen can now be
seen at South Kensington in a separate glass case, and is one of the
treasures of the unrivalled gallery of fossil reptiles. The case is
placed so that both sides of the specimen can be seen (Case Y, Gallery
IV., on plan). Its length is about twelve feet; perhaps the
individual it represents was not fully grown, but, on account of the
absence of most of the neck vertebræ, it is impossible to give the
exact length. Both hind limbs are entire and well seen, but of the
fore limbs the hands are wanting. The former were provided with four
"functional" toes--that is, toes that were used,--and one
"rudimentary" or unused one. There were two big spines, one placed on
each shoulder, and a series of long plates arranged in lines along the
back and side. Plate IX. shows an attempted restoration of this
remarkable Dinosaur based upon the skeleton just described. It seems
to have been organised for a terrestrial rather than an aquatic life,
but to have been amphibious, frequenting the margins of rivers or
lakes. Professor Owen considers that the carcase of this individual
drifted down a river emptying itself in the old Liassic Sea, on the
muddy bottom of which it would settle down when the skin had been so
far decomposed as to permit the escape of gases due to decomposition.
In that case the carcase would attract large carnivorous fishes and
reptiles, such as swarmed in this old sea, so that portions of the
skin and flesh would probably be torn away before the weight of the
bones had completely buried it in mud. In this way, perhaps, the loss
of much of the external armature and of the two fore feet may be
accounted for. The hind limbs, being stronger, were better able to
resist such attacks, and they are therefore preserved. Like many other
specimens, this fossil has, in the course of ages, been subjected to
enormous pressure from overlying strata, causing compression and
dislocation or fracture.
[20] From Greek--_scelis_, limb, and _sauros_, lizard.
But there were in existence during the long Jurassic period, other and
even stranger forms of armoured Dinosaurs. One of these, only
imperfectly known at present, was the many-spined Polacanthus.[21] This
remarkable monster had the whole region of the loins and haunches
protected by a continuous sheet of bony plate armour, rising into
knobs and spines, after the fashion of the shield or carapace of
certain extinct armadillos known as Glyptodonts (see Chapter XII.). A
specimen of such a shield is to be seen in the collection at South
Kensington (Wall-case 4). It is to be hoped that, some day, further
remains of the Polacanthus will be brought to light, so that a
restoration may become possible. Dr. Mantell had already pointed out
certain analogies between Iguanodon and the huge extinct sloths of the
South American continent, that flourished in the much more recent
Pleistocene period; and this idea is now considerably strengthened by
the later discoveries of armoured Dinosaurs. These are his words: "In
fine, we have in the Iguanodon the type of the terrestrial herbivora
which, in the remote epoch of the earth's physical history termed by
geologists _the age of Reptiles_, occupied the same relative position
in the scale of being, and fulfilled the same general purposes in the
economy of nature, as the Mastodons, Mammoths, and Mylodons (extinct
sloths) of the Tertiary period, and the existing pachyderms."
[21] From Greek--_polus_, many, and _acantha_, spine.
It is, perhaps, one of the most interesting discoveries of modern
geology, that certain races of animals now extinct have in various
ways assumed some of the characteristics presented by animals much
higher in the scale of being, that flourish in the present day. It
seems as if there had been some strange law of anticipation at work,
if we may venture so to formulate the idea. It has already been shown
how the great saurians Ichthyosaurus and Plesiosaurus presumed to put
on some of the characters of whales, and to play their _rôle_ in
nature, though they were only reptiles; how the carnivorous Dinosaurs
acquired teeth like those now possessed by lions and tigers, which
also are mammals; and now we find herbivorous Dinosaurs imitating the
Glyptodon, an armadillo that lived in South America almost down to the
human period. We shall not lose sight of this very interesting and
curious discovery, for other cases will present themselves to our view
in future chapters. The reader might ask, "If reptiles were able in
these and other ways to imitate the mammals of to-day, or of
yesterday, why should they not have been able to go a few steps
further, and actually _become_ mammals?" The Evolutionist, if
confronted with such a question, would say, that there is no evidence
of Dinosaurs turning into mammals, but that both may have branched off
at an early geological period (say the Permian) from a primitive group
of reptiles, or even of amphibians.
It must be borne in mind that, during the "age of reptiles" (Mesozoic
period), the mammalian type was but feebly represented by certain
small and humble forms, probably marsupials. As far as we know, there
were no big quadrupeds such as flourish to-day; therefore reptiles
played their part, and in so doing acquired some of their habits and
structural peculiarities. It is difficult for us, living in an age of
quadrupeds, to realise this, and to picture to ourselves reptilian
types posing as "lords of creation," or, to use a homely phrase,
"strutting in peacock's feathers."
* * * * *
Leaving now the English herbivorous Dinosaurs, we pass on to those
still more wonderful forms discovered of late years by Professor
Marsh. The former have been treated at considerable length, first
because they are English, and, as such, the history of their discovery
possesses considerable interest; secondly, because their elucidation
reflects the highest credit on our great pioneers in this fruitful
field of research, and illustrates the manner in which great
naturalists have been able to draw most important and wonderful
conclusions (afterwards verified in most cases) from material
apparently far from promising. For example, Cuvier's prophecy of the
Iguanodon from a few teeth is a striking example of the result of
reasoning from the known to the unknown, an example which seems to us
worthy to be ranked with the discovery of Neptune by Adams and
Leverrier, or, to take a more recent case, the discovery by Mendeleef
of the Periodic Law, by means of which he has foretold the discovery
of new chemical elements.
Whatever may have been the origin of the great mammalian class, the
possibility and even probability of birds and Dinosaurs being
descended from a common ancestor is a theory for which much may be
said, and it has been adopted by many leading naturalists of the
present day, who have been convinced by Professor Huxley's clear
elucidation of the nature of the pelvic region in the group of
Dinosaurs which has been above described (the Ornithopoda, or
bird-footed group). It was Professor Huxley who first propounded this
interesting speculation, basing his belief on the many bird-like
characters presented by this strange group of extinct reptiles--the
small head and fore limbs, the long and often three-toed hollow hind
limbs, the bones of the pelvis or haunch, their habit of walking in a
semi-erect position on those limbs (as proved by their tracks), and in
some of hopping, as the little Compsognathus most probably did. And,
last but not least, the strange mixture of bird-like and reptilian
characters presented by certain most anomalous birds discovered by
Professor Marsh in American Cretaceous rocks, viz. the huge
Hesperornis and the smaller Ichthyornis. Speaking on this subject some
years ago, Professor Marsh said, "It is now generally admitted by
biologists who have made a study of vertebrates, that birds have come
down to us through the Dinosaurs, and the close affinity of the latter
with recent struthious birds (ostrich, etc.), will hardly be
questioned. The case amounts almost to a demonstration, if we compare
with Dinosaurs their contemporaries, the Mesozoic birds. The classes
of birds and reptiles, as now living, are separated by a gulf so
profound that a few years since it was cited by the opponents of
Evolution as the most important break in the animal series, and one
which that doctrine could not bridge over. Since then, as Professor
Huxley has clearly shown, this gap has been virtually filled by the
discovery of bird-like reptiles and reptilian birds. Compsognathus and
Archæopteryx of the Old World, and Ichthyornis and Hesperornis of the
New, are the stepping-stones by which the Evolutionist of to-day
leads the doubting brother across the shallow remnant of the gulf,
once thought impassable."[22]
[22] _The Introduction and Succession of Vertebrate Life in America._
An address delivered before the American Association for the
Advancement of Science, at Nashville, Tenn., August, 1877. See
_Nature_, vol. xvi.
We now pass on to describe two of the strangest and most wonderful of
all the Dinosaurs, recently discovered in the far West. The first of
these is the Stegosaurus,[23] or plated lizard, not wholly unknown
before, because part of its skeleton was found some years ago in a
brickfield in the Kimmeridge Clay at Swindon. It has been proved that
some of the bones to which the name Omosaurus[24] has been applied
really belonged to the former genus.
[23] Greek--_stegos_, roof or covering; _sauros_, lizard.
[24] Greek--_omos_, humerus, and _sauros_, lizard.
With such complete specimens now known by Professor Marsh's
descriptions, it will not be necessary to mention the meagre remains
discovered in this country, or the conclusions arrived at by Owen and
Seeley, interesting as they are.
In the year 1877 Professor Marsh described, in the _American Journal
of Science_, a considerable portion of a skeleton of a Stegosaur,
remarking that this genus proved to be one of the most remarkable
animals yet discovered. It was found on the eastern flank of the Rocky
Mountains, in strata of Jurassic age; they indicated an animal about
twenty-five feet long, and for this discovery Science is indebted to
Professor A. Lakes and Engineer H. C. Beckwith of the United States
Navy, who found the remains in Colorado, near the locality of the
gigantic Atlantosaurus. The solid limb-bones seem to point to an
aquatic life, but there can be little doubt that the monster did not
pass all its time in the water. (Fig. 25 shows the skeleton.)[25]
[25] The writer is informed that this skeleton is not yet mounted in
the Yale College Museum, but that it will be before long. Our artist
has drawn it as if set up, with a man standing by for comparison.
In 1879 Professor Marsh announced the discovery of additional remains
from several localities. The most striking feature--from which the
Stegosaur takes its name--was the presence of huge bony plates
belonging to its skin, as well as large and small spines. Some of the
plates were from two to three feet in diameter, and they were of
various shapes. Of the spines, some were of great size and power, one
pair being each over two feet long! The skull was remarkably small,
and more like that of a lizard than we find in most Dinosaurs; the
jaws were short and massive. Little was known at first of the brain,
but fortunately a later discovery showed the brain-case well
preserved. Later still, more than twenty other specimens of this
Dinosaur were obtained, so that nearly every portion of the skeleton
is now known. The skulls indicate that the creature possessed large
eyes and a considerable power of smell. The jaws contain but a single
row of teeth in actual use; but as these wore out, they were replaced
by others lodged in a cavity below. Teeth, however, were not its
strong point; they indicate a diet of soft succulent vegetation. The
vertebræ have the faces of their centra more or less bi-concave. Many
curious features in the skeleton can only be explained with reference
to the heavy armour of plates and spines with which the Stegosaur was
provided. Thus the vertebræ have their "neural spines" expanded at the
summit to aid in supporting part of the armour. (See Fig. 26.) The
fore limbs were short and massive, but provided with five fingers; the
hind limbs were very much larger and more powerful. These and the
powerful tail show that the monster could support itself on them as on
a tripod, in an upright position, and this position must have been
easily assumed in consequence of the massive hind quarters. As in
Iguanodon, there were three toes to the hind feet, and these were
probably covered by strong hoofs. The fore limbs could move freely in
various directions like a human arm, and were probably used in
self-defence. (See Fig. 27.) But for this purpose the tail with its
four pairs of huge spines would be very effective, and one could
easily imagine that a single deadly blow from such a tail would be
sufficient to drive away, if not to kill, one of the carnivorous
enemies of the species. All the plates and spines were, during life,
protected by a thick horny covering, which must have increased their
size and weight. Such a covering seems to be clearly indicated by
certain grooves and impressions that mark their surfaces. (See Fig.
28.) The largest plates are unsymmetrical, and were probably arranged
along the back, as in our restoration, Plate IX. It will be noticed,
by those who are familiar with our first edition that Plate X. gives a
somewhat different representation of the Stegosaur, in which the
length of the hind limbs is more apparent, and also they are more free
from the body.
[Illustration: Fig. 25--Skeleton of _Stegosaurus ungulatus_; length
about 25 feet. (After Marsh.)]
[Illustration: Plate X.
A GIGANTIC ARMOURED DINOSAUR, STEGOSAURUS UNGULATUS.
Length about 30 feet.]
[Illustration: Fig. 26.--Tail vertebræ of _Stegosaurus_. (After
Marsh.)
1. Side view. 2. Front view.]
Finally, the Stegosaur displays a rather remarkable feature; for a
very large chamber was found in the sacrum[26] formed by an enlargement
of the spinal cord. The chamber strongly resembled the brain-case in
the skull, but was about ten times as large! So this anomalous
monster had two sets of brains, one in its skull, and the other in the
region of its haunches! and the latter, in directing the movements of
the huge hind limbs and tail, did a large share of the work. The
subject is a highly suggestive one, but at present requires further
explanation.
[26] The sacrum may be thus defined: the Vertebræ (usually fused
together) which unite with the haunch-bones (_ilia_) to form the
pelvis.
[Illustration: Fig. 27.--Limb-bones of _Stegosaurus_. (After Marsh.)
1. Fore leg. 2. Hind leg.]
On the walls of the fossil reptile gallery at South Kensington the
reader will find a large framed drawing of the skeleton of
Stegosaurus, kindly sent by Professor Marsh, whose forthcoming
monograph will be welcomed by all palæontologists.
[Illustration: Fig. 28.--1, 2. Plates of Stegosaurus. The middle
figures show their thickness. (After Marsh.)]
[Illustration: Fig. 29.-Head of _Triceratops_, seen from above. (After
Marsh.)]
The last, and in some ways the strangest of the Dinosaurs, was the
Triceratops[27] that flourished in America at the end of the long
Mesozoic era, during the Cretaceous period. The name refers to the
three horn-cores found on the skull, which probably supported true
horns like those of oxen. Whereas the Stegosaur was provided with
quite a small skull, this monster had one of huge dimensions and
remarkable shape (see Figs. 29 and 30).[28] In the younger ones it was
about six feet long, but in an old individual must have reached a
length of seven or eight feet. Such a skull is only surpassed by some
whales of the present day. Twenty different skulls of this kind have
been found, and Professor Marsh places the horned Dinosaurs in a
separate family, to which he has given the name Ceratopsidæ, or
horn-faced. Their remains come from the Laramie beds, believed to be
of Cretaceous age, but representing a remarkably mixed fauna and
flora, so that some have considered them to be Tertiary. The strata
containing these fossils are very rich in organic remains, and have
yielded not only other Dinosaurs, but Plesiosaurs, crocodiles,
turtles, many small reptiles, a few birds, fishes, and small mammals.
The Ceratops beds are of fresh-water or brackish origin, and can now
be traced for nearly eight hundred miles along the east flank of the
Rocky Mountains.
[27] Greek--_treis_, three; _ceras_, horn; _ops_, face.
[28] This skeleton has not yet been set up in the Yale College Museum,
but will be before long. Our artist has drawn it as if set up, with a
man standing by for comparison. In an article in _The Californian
Illustrated Magazine_ for April, 1892 (quoted in the _Review of
Reviews_ for May), an American writer incorrectly describes this
monster as "higher than Jumbo, and longer than two Jumbos placed in a
row." But the article is altogether untrustworthy, and the two
"restorations" are absurd.
[Illustration: Fig. 30.--Skeleton of _Triceratops prorsus_; length
about 25 feet. (After Marsh.)]
In this Dinosaur we find the fore feet larger than usual in proportion
to the hind limbs, and there can be no doubt that it walked on all
fours. Its length was about twenty-five feet. All the vertebræ and
limb-bones are solid. The brain was smaller in proportion to the skull
than in any known vertebrate.
The teeth are remarkable in having two distinct roots. The wedge-like
form of the skull is also very peculiar. The two large horns come
immediately over the eyes, and the small one above the nose; this
Dinosaur was, therefore, well provided with weapons of offence, such
as would be highly useful in driving away or wounding carnivorous
enemies. The back part of the skull rises up into a kind of huge
crest, and this during life was protected by a special fringe of bony
plates. Such an arrangement doubtless formed an effective shield to
ward off blows when one Triceratops was fighting another, as bulls or
buffaloes of the present day fight with their horns. The mouths of
these Dinosaurs formed a kind of beak, sheathed in horn.
The body as well as the skull was protected, but the nature and
position of the defensive parts in different forms cannot yet be
determined with certainty. Various spines, bones, and plates have been
found that evidently were meant for the protection of the creature's
body, and belonged to the skin. Probably some of these were placed on
the back, behind the crest of the skull; some may have defended the
throat, as in Stegosaurus. Altogether, Triceratops is very different
to any other Dinosaur. One cannot help picturing it rather as a fierce
rhinoceros-like animal. In the restoration (Plate XI., Frontispiece)
our artist has given it a thick skin, rather like that of the
rhinoceros, only indicating small bony plates, etc., here and there.
Professor Marsh thinks that as the head increased in size to bear its
armour of bony plates, the neck first, then the fore feet, and then
the whole skeleton was specially modified to support it; and he
concludes that as these changes took place in the course of the
evolution of this wonderful Dinosaur, the head at last became so large
and heavy that it must have been too much for the body to bear, and so
have led to its destruction! This conclusion, if sound, is a warning
against carrying "specialisation" too far. If we wished to write an
epitaph on the tomb of the monster, it ought (according to Professor
Marsh) to be, "I and my race died of over-specialisation."
[Illustration: Fig. 31.--Bony spines belonging to the skin of
_Triceratops_. (After Marsh.)]
After all these various efforts to improve themselves and to perfect
their organisation so as to bring it into harmony with their
surroundings, or "environment," as the biologists say, it seems rather
hard that the Dinosaurs should have been extinguished, and their place
in Nature taken by a higher type; but all things have their day, even
Dinosaurs.
With regard to the difficulties, hardships, and dangers attending the
discovery and transport of the remains, Professor Marsh's concluding
remarks may be quoted here, since they give us a glimpse into the
nature of his explorations in the far West that have now become so
famous. He says, "In conclusion, let me say a word as to how the
discoveries here recorded have been accomplished. The main credit for
the work justly belongs to my able assistant, Mr. J. B. Hatcher, who
has done so much to bring to light the ancient life of the Rocky
Mountain regions. I can only claim to have shared a few of the dangers
and hardships with him, but without his skill little would have been
accomplished. If you will bear in mind that two of the skulls weighed
nearly two tons each, when partially freed from their matrix and ready
for shipment, in a deep desert cañon, fifty miles from a railway, you
will appreciate one of the mechanical difficulties overcome. When I
add that some of the most interesting discoveries were made in the
hunting-grounds of the hostile Sioux Indians, who regard such
explorations with superstitious dread, you will understand another
phase of the problem. I might speak of even greater difficulties and
dangers, but the results attained repay all past efforts, and I hope
at no distant day to have something more of interest to lay before
you."[29]
[29] _American Journal of Science_, vol. xli. p. 176.