these smaller parts of the skeleton having been washed away before the
ponderous frame was buried in the sand, and the best that can be done is
to follow the law of probabilities and put three toes on the hind foot
and five on the fore, two of these last without claws. The single blunt
round claw among our bones shows, as do the teeth, that Triceratops was
herbivorous; it also pointed a little downward, and this tells that in
the living animal the sole of the foot was a thick, soft pad, somewhat
as it is in the elephant and rhinoceros, and that the toes were not
entirely free from one another. There are less than a dozen vertebrae and
still fewer ribs, besides half a barrelful of pieces, from which to
reconstruct a backbone twenty feet long. That the ribs are part from one
side and part from another matters no more than it did in the case of
the leg-bones; but the backbone presents a more difficult problem,
since the pieces are not like so many checkers--all made after one
pattern--but each has an individuality of its own. The total number of
vertebrae must be guessed at (perhaps it would sound better to say
estimated, but it really means the same), and knowing that some sections
are from the front part of the vertebral column and some from the back,
we must fill in the gaps as best we may. The ribs offer a little aid in
this task, giving certain details of the vertebrae, while those in turn
tell something about the adjoining parts of the ribs. We finish our
Triceratops with a tail of moderate length, as indicated by the rapid
taper of the few vertebrae available, and from these we gather, too, that
in life the tail was round, and not flattened, and that it neither
served for swimming nor for a balancing pole. And so, little by little,
have been pieced together the fragments from which we have derived our
knowledge of the past, and thus has the palaeontologist read the riddles
of the rocks.
[Illustration: Fig. 26.--Triceratops, He of the Three-horned Face. _From
a statuette by Charles R. Knight._]
To make these dry bones live again, to clothe them with flesh and
reconstruct the creature as he was or may have been in life, is, to
be honest, very largely guesswork, though to make a guess that shall
come anywhere near the mark not only demands a thorough knowledge of
anatomy--for the basis of all restoration must be the skeleton--but
calls for more than a passing acquaintance with the external appearance
of living animals. And while there is nothing in the bones to tell how
an animal is, or was, clad, they will at least show to what group the
creature belonged, and, that known, there are certain probabilities in
the case. A bird, for example, would certainly be clad in feathers.
Going a little farther, we might be pretty sure that the feathers of a
water-fowl would be thick and close; those of strictly terrestrial
birds, such as the ostrich and other flightless forms, lax and long.
These as general propositions; of course, in special cases, one might
easily come to grief, as in dealing with birds like penguins, which are
particularly adapted for an aquatic life, and have the feathers highly
modified. These birds depend upon their fat, and not on their feathers,
for warmth, and so their feathers have become a sort of cross between
scales and hairs. Hair and fur belong to mammals only, although these
creatures show much variety in their outer covering. The thoroughly
marine whales have discarded furs and adopted a smooth and slippery
skin,[9] well adapted to movement through the water, relying for warmth
on a thick undershirt of blubber. The earless seals that pass much of
their time on the ice have just enough hair to keep them from absolute
contact with it, warmth again being provided for by blubber. The fur
seals, which for several months in the year dwell largely on land, have
a coat of fur and hair, although warmth is mostly furnished, or rather
kept in, by fat.
[9] _The reader is warned that this is a mere figure of speech, for, of
course, the process of adaptation to surroundings is passive, not
active, although there is a most unfortunate tendency among writers on
evolution, and particularly on mimicry, to speak of it as active. The
writer believes that no animal in the first stages of mimicry,
consciously mimics or endeavors to resemble another animal or any part
of its surroundings, but a habit at first accidental may in time become
more or less conscious._
No reptile, therefore, would be covered with feathers, neither, judging
from those we know to-day, would they be clad in fur or hair; but, such
coverings being barred out, there remain a great variety of plates and
scales to choose from. Folds and frills, crests and dewlaps, like
beauty, are but skin deep, and, being thus superficial, ordinarily leave
no trace of their former presence, and in respect to them the
reconstructor must trust to his imagination, with the law of
probabilities as a check rein to his fancy. This law would tell us that
such ornaments must not be so placed as to be in the way, and that while
there would be a possibility--one might even say probability--of the
great, short-headed, iguana-like Dinosaurs having dewlaps, that there
would be no great likelihood of their possessing ruffs such as that of
the Australian Chlamydosaurus (mantled lizard) to flap about their ears.
Even Stegosaurus, with his bizarre array of great plates and spines,
kept them on his back, out of the way. Such festal ornamentation would,
however, more likely be found in small, active creatures, the larger
beasts contenting themselves with plates and folds.
Spines and plates usually leave some trace of their existence, for they
consist of a super-structure of skin or horn, built on a foundation of
bone; and while even horn decomposes too quickly to "petrify," the bone
will become fossilized and changed into enduring stone. But while this
affords a pretty sure guide to the general shape of the investing horn,
it does not give all the details, and there may have been ridges and
furrows and sculpturing that we know not of.
Knowing, then, what the probabilities are, we have some guide to the
character of the covering that should be placed on an animal, and if we
may not be sure as to what should be done, we may be pretty certain what
should not.
For example, to depict a Dinosaur with smooth, rubbery hide walking
about on dry land would be to violate the probabilities, for only such
exclusively aquatic creatures as the whales among mammals, and the
salamanders among batrachians, are clothed in smooth, shiny skin. There
might, however, be reason to suspect that a creature largely aquatic in
its habits did occasionally venture on land, as, for instance, when
vertebrae that seem illy adapted for carrying the weight of a land animal
are found in company with huge limb-bones and massive feet we may feel
reasonably certain that their owner passed at least a portion of his
time on _terra firma_.
So much for the probabilities as to the covering of animals known to us
only by their fossil remains; but it is often possible to go beyond
this, and to state certainly how they were clad. For while the chances
are small that any trace of the covering of an extinct animal, other
than bony plates, will be preserved, Nature does now and then seem to
have relented, and occasionally some animal settled to rest where it was
so quickly and quietly covered with fine mud that the impression of
small scales, feathers, or even smooth skin, was preserved; curiously
enough, there seems to be scarcely any record of the imprint of hair.
Then, too, it is to be remembered that while the chances were very much
against such preservation, in the thousands or millions of times
creatures died the millionth chance might come uppermost.
Silhouettes of those marine reptiles, the Ichthyosaurs, have been found,
probably made by the slow carbonization of animal matter, showing not
only the form of the body and tail, but revealing the existence of an
unsuspected back fin. And yet these animals were apparently clad in a
skin as thin and smooth as that of a whale. Impressions of feathers were
known long before the discovery of Archaeopteryx; a few have been found
in the Green River and Florissant shales of Wyoming, and a Hesperornis
in the collection of the State University of Kansas shows traces of the
existence of long, soft feathers on the legs and very clear imprints of
the scales and reticulated skin that covered the tarsus. From the Chalk
of Kansas, too, came the example of Tylosaur, showing that the back of
this animal was decorated with the crest shown in Mr. Knight's
restoration, one not unlike that of the modern iguana. From the Laramie
sandstone of Montana Mr. Hatcher and Mr. Butler have obtained the
impressions of portions of the skin of the great Dinosaur, Thespesius,
which show that the covering of this animal consisted largely, if not
entirely, of small, irregularly hexagonal horny scutes, slightly
thickened in the centre. The quarries of lithographic stone at
Solenhofen have yielded a few specimens of flying reptiles,
pterodactyls, which not only verify the correctness of the inference
that these creatures possessed membranous wings, like the bats, but show
the exact shape, and it was sometimes very curious, of this membrane.
And each and all of these wonderfully preserved specimens serve both to
check and guide the restorer in his task of clothing the animal as it
was in life.
And all this help is needed, for it is an easy matter to make a
wide-sweeping deduction, apparently resting on a good basis of fact, and
yet erroneous. Remains of the Mammoth and Woolly Rhinoceros, found in
Siberia and Northern Europe, were thought to indicate that at the period
when these animals lived the climate was mild, a very natural inference,
since the elephants and rhinoceroses we now know are all inhabitants of
tropical climes. But the discovery of more or less complete specimens
makes it evident that the climate was not particularly mild; the
animals were simply adapted to it; instead of being naked like their
modern relatives, they were dressed for the climate in a woolly
covering. We think of the tiger as prowling through the jungles of
India, but he ranges so far north that in some localities this beast
preys upon reindeer, which are among the most northern of large mammals,
and there the tiger is clad in fairly thick fur.
When we come to coloring a reconstructed animal we have absolutely no
guide, unless we assume that the larger a creature the more soberly will
it be colored. The great land animals of to-day, the elephant and
rhinoceros, to say nothing of the aquatic hippopotamus, are very dully
colored, and while this sombre coloration is to-day a protection,
rendering these animals less easily seen by man than they otherwise
would be, yet at the time this color was developing man was not nor were
there enemies sufficiently formidable to menace the race of elephantine
creatures.
For where mere size furnishes sufficient protection one would hardly
expect to find protective coloration as well, unless indeed a creature
preyed upon others, when it might be advantageous to enable a predatory
animal to steal upon its prey.
Color often exists (or is supposed to) as a sexual characteristic, to
render the male of a species attractive to, or readily recognizable by,
the female, but in the case of large animals mere size is quite enough
to render them conspicuous, and possibly this may be one of the factors
in the dull coloration of large animals.
So while a green and yellow Triceratops would undoubtedly have been a
conspicuous feature in the Cretaceous landscape, from what we know of
existing animals it seems best to curb our fancy and, so far as large
Dinosaurs are concerned, employ the colors of a Rembrandt rather than
those of a sign painter.
Aids, or at least hints, to the coloration of extinct animals are to be
found in the coloration of the young of various living species, for as
the changes undergone by the embryo are in a measure an epitome of the
changes undergone by a species during its evolution, so the brief color
phases or markings of the young are considered to represent the
ordinary coloring of distant ancestors. Young thrushes are spotted,
young ostriches and grebes are irregularly striped, young lions are
spotted, and in restoring the early horse, or Hyracothere, Professor
Osborn had the animal represented as faintly striped, for the reason
that zebras, the wild horses of to-day, are striped, and because the
ass, which is a primitive type of horse, is striped over the shoulders,
these being hints that the earlier horse-like forms were also striped.
Thus just as the skeleton of a Dinosaur may be a composite structure,
made up of the bones of a dozen individuals, and these in turn mosaics
of many fragments, so may the semblance of the living animal be based on
a fact, pieced out with a probability and completed by a bit of theory.
_REFERENCES_
_There is a large series of restorations of extinct animals, prepared by
Mr. Charles R. Knight, under the direction of Professor Osborn, in the
Hall of Palaeontology of the American Museum of Natural History, and
these are later to be reproduced and issued in portfolio form._
_Should the reader visit Princeton, he may see in the museum there a
number of B. Waterhouse Hawkins's creations--creations is the proper
word--which are of interest as examples of the early work in this line._
_The "Report of the Smithsonian Institution for 1900" contains an
article on "The Restoration of Extinct Animals," pages 479-492, which
includes a number of plates showing the progress that has been made in
this direction._
[Illustration: Fig. 27.--A Hint of Buried Treasures.]
VIII
FEATHERED GIANTS
_"There were giants in the earth in those days."_
Nearly every group of animals has its giants, its species which tower
above their fellows as Goliath of Gath stood head and shoulders above
the Philistine hosts; and while some of these are giants only in
comparison with their fellows, belonging to families whose members are
short of stature, others are sufficiently great to be called giants
under any circumstances. Some of these giants live to-day, some have but
recently passed away, and some ceased to be long ages before man trod
this earth. The most gigantic of mammals--the whales--still survive, and
the elephant of to-day suffers but little in comparison with the
mammoth of yesterday; the monstrous Dinosaurs, greatest of all
reptiles--greatest, in fact, of all animals that have walked the
earth--flourished thousands upon thousands of years ago. As for birds,
some of the giants among them are still living, some existed long
geologic periods ago, and a few have so recently vanished from the scene
that their memory still lingers amid the haze of tradition. The best
known among these, as well as the most recent in point of time, are the
Moas of New Zealand, first brought to notice by the Rev. W. Colenso,
later on Bishop of New Zealand, one of the many missionaries to whom
Science is under obligations. Early in 1838, Bishop Colenso, while on a
missionary visit to the East Cape region, heard from the natives of
Waiapu tales of a monstrous bird, called Moa, having the head of a man,
that inhabited the mountain-side some eighty miles away. This mighty
bird, the last of his race, was said to be attended by two equally huge
lizards that kept guard while he slept, and on the approach of man
wakened the Moa, who immediately rushed upon the intruders and trampled
them to death. None of the Maoris had seen this bird, but they had seen
and somewhat irreverently used for making parts of their fishing
tackle, bones of its extinct relatives, and these bones they declared to
be as large as those of an ox.
About the same time another missionary, the Rev. Richard Taylor, found a
bone ascribed to the Moa, and met with a very similar tradition among
the natives of a near-by district, only, as the foot of the rainbow
moves away as we move toward it, in his case the bird was said to dwell
in quite a different locality from that given by the natives of East
Cape. While, however, the Maoris were certain that the Moa still lived,
and to doubt its existence was little short of a crime, no one had
actually seen it, and as time went on and the bird still remained unseen
by any explorer, hope became doubt and doubt certainty, until it even
became a mooted question whether such a bird had existed within the past
ten centuries, to say nothing of having lived within the memory of man.
But if we do not know the living birds, their remains are scattered
broadcast over hillside and plain, concealed in caves, buried in the mud
of swamps, and from these we gain a good idea of their size and
structure, while chance has even made it possible to know something of
their color and general appearance. This chance was the discovery of a
few specimens, preserved in exceptionally dry caves on the South Island,
which not only had some of the bones still united by ligaments, but
patches of skin clinging to the bones, and bearing numerous feathers of
a chestnut color tipped with white. These small, straggling, rusty
feathers are not much to look at, but when we reflect that they have
been preserved for centuries without any care whatever, while the
buffalo bugs have devoured our best Smyrna rugs in spite of all possible
precautions, our respect for them increases.
[Illustration: Fig. 28.--Relics of the Moa.]
From the bones we learn that there were a great many kinds of Moas,
twenty at least, ranging in size from those little larger than a turkey
to that giant among giants, _Dinornis maximus_, which stood at least ten
feet high,[10] or two feet higher than the largest ostrich, and may
well claim the distinction of being the tallest of all known birds. We
also learn from the bones that not only were the Moas flightless, but
that many of them were absolutely wingless, being devoid even of such
vestiges of wings as we find in the Cassowary or Apteryx. But if Nature
deprived these birds of wings, she made ample amends in the matter of
legs, those of some species, the Elephant-footed Moa, _Pachyornis
elephantopus_, for example, being so massively built as to cause one to
wonder what the owner used them for, although the generally accepted
theory is that they were used for scratching up the roots of ferns on
which the Moas are believed to have fed. And if a blow from an irate
ostrich is sufficient to fell a man, what must have been the kicking
power of an able-bodied Moa? Beside this bird the ostrich would appear
as slim and graceful as a gazelle beside a prize ox.
[10] _The height of the Moas, and even of some species of AEpyornis, is
often stated to be twelve or fourteen feet, but such a height can only
be obtained by placing the skeleton in a wholly unnatural attitude._
The Moas were confined to New Zealand, some species inhabiting the North
Island, some the South, very few being common to both, and from these
peculiarities of distribution geologists deduce that at some early
period in the history of the earth the two islands formed one, that
later on the land subsided, leaving the islands separated by a strait,
and that since this subsidence there has been sufficient time for the
development of the species peculiar to each island. Although Moas were
still numerous when man made his appearance in this part of the world,
the large deposits of their bones indicate that they were on the wane,
and that natural causes had already reduced the feathered population of
these islands. A glacial period is believed to have wrought their
destruction, and in one great morass, abounding in springs, their bones
occur in such enormous numbers, layer upon layer, that it is thought the
birds sought the place where the flowing springs might afford their feet
at least some respite from the biting cold, and there perished miserably
by thousands.
What Nature spared man finished, and legends of Moa hunts and Moa feasts
still lingered among the Maoris when the white man came and began in
turn the extermination of the Maori. The theory has been advanced, with
much to support it, that the big birds were eaten off the face of the
earth by an earlier race than the Maoris, and that after the extirpation
of the Moas the craving for flesh naturally led to cannibalism. But by
whomsoever the destruction was wrought, the result was the same, the
habitat of these feathered giants knew them no longer, while multitudes
of charred bones, interspersed with fragments of egg-shells, bear
testimony to former barbaric feasts.
It is a far cry from New Zealand to Madagascar, but thither must we go,
for that island was, pity we cannot say is, inhabited by a race of giant
birds from whose eggs it has been thought may have been hatched the Roc
of Sindbad. Arabian tales, as we all know, locate the Roc either in
Madagascar or in some adjacent island to the north and east, and it is
far from unlikely that legends of the AEpyornis, backed by the
substantial proof of its enormous eggs, may have been the slight
foundation of fact whereon the story-teller erected his structure of
fiction. True, the Roc of fable was a gigantic bird of prey capable of
bearing away an elephant in its talons, while the AEpyornis has shed its
wings and shrunk to dimensions little larger than an ostrich, but this
is the inevitable result of closer acquaintance and the application of a
two-foot rule.
Like the Moa the AEpyornis seems to have lived in tradition long after it
became extinct, for a French history of Madagascar, published as early
as 1658 makes mention of a large bird, or kind of ostrich, said to
inhabit the southern end of the island. Still, in spite of bones having
been found that bear evident traces of the handiwork of man, it is
possible that this and other reports were due to the obvious necessity
of having some bird to account for the presence of the eggs.
The actual introduction of the AEpyornis to science took place in 1834,
when a French traveller sent Jules Verreaux, the ornithologist, a sketch
of a huge egg, saying that he had seen two of that size, one sawed in
twain to make bowls, the other, traversed by a stick, serving in the
preparation of rice uses somewhat in contrast with the proverbial
fragility of egg-shells. A little later another traveller procured some
fragments of egg-shells, but it was not until 1851 that any entire eggs
were obtained, when two were secured, and with a few bones sent to
France, where Geoffroy St. Hilaire bestowed upon them the name of
_AEpyornis maximus_ (the greatest lofty bird). Maximus the eggs remain,
for they still hold the record for size; but so far as the bird that is
supposed to have laid them is concerned, the name was a little
premature, for other and larger species subsequently came to hand.
Between the AEpyornithes and the Moas Science has had a hard time, for
the supply of big words was not large enough to go around, and some had
to do duty twice. In the way of generic names we have Dinornis, terrible
bird; AEpyornis, high bird; Pachyornis, stout bird; and Brontornis,
thunder bird, while for specific names there are robustus, maximus,
titan; gravis, heavy; immanis, enormous; crassus, stout; ingens, great;
and elephantopus, elephant-footed--truly a goodly array of
large-sounding words. But to return to the big eggs! Usually we look
upon those of the ostrich as pretty large, but an ostrich egg measures
4-1/2 by 6 inches, while that of the AEpyornis is 9 by 13 inches; or, to
put it another way, it would hold the contents of six ostrichs' eggs, or
one hundred and forty-eight hens' eggs, or thirty thousand humming
birds' eggs; and while this is very much smaller than a waterbutt, it is
still as large as a bucket, and one or two such eggs might suffice to
make an omelet for Gargantua himself.