_Introduction._
Unlike its sister science of Invertebrate Paleontology, which has been
approached so largely from the viewpoint of stratigraphic geology, that
of the vertebrates is essentially a biologic science, having its
inception in the masterly work of Cuvier, who is also to be regarded as
the founder of comparative anatomy. For long decades, vertebrate
paleontology was simply a branch of comparative anatomy or morphology in
that it dealt almost exclusively with the form and other peculiarities
of fossil bones and teeth, often in a more or less fragmentary
condition, very little or no attention being paid to any other system of
the creature’s anatomy. Distribution both in space and in time was
recorded, but the value of vertebrates in stratigraphy was still to be
appreciated and has hardly yet come into its own. It is readily seen,
therefore, that the two departments of paleontology did not enlist the
same workers or even the same type of investigators, for while the two
sciences have much in common and should have more, the vertebratist
must, above all else, be a morphologist, with a keen appreciation of
form, and a mind capable of retaining endless structural details and of
visualizing as a whole what may be known only in part. The initial work
of the brilliant Cuvier set so high a standard of preparedness and
mental equipment that as a consequence, the number of those engaged in
vertebrate research has never been large as compared with the workers in
some other branches of science, but the results achieved by the few who
have consecrated their research to the fossil vertebrates has been in
the main of a high order.
At first, as has been emphasized, this work was largely morphological,
dealing both with the individual skeletal elements and later with the
bony framework as a whole. Then came the endeavor to clothe the bones
with sinews and with flesh—to imagine, in other words, the
life-appearance of the ages-departed form—with such of its habits as
could be deduced from structure of body, tooth, and limb. Next came the
working out of systematic series of vertebrates and their marshalling
into species, genera, and larger groups, and much time was thus spent,
especially when rapid discovery brought a continual stream of new forms
before the systematist, and hence some appreciation of the countless
hosts of bygone creatures which peopled the world in the geologic past.
This systematic work, however, was based upon the most painstaking
morphologic comparisons and so the science was still within the scope of
comparative anatomy.
In connection with taxonomic research came increasingly tangible
evidence in favor of the law of evolution; investigators turned to the
working out of phyletic series showing the actual record of the
successive evolutionary changes that the various races had undergone.
Coupled with this evolutionary evidence came an increased attention to
the sequential occurrence in successive geologic strata, and the
stratigraphic distribution of vertebrates became known with greater and
greater detail. Then followed the assemblage of faunas, which brought
the study of the fossil forms within the realm of historical geology,
rather than being the mere phylogeny of a single race, and the value of
vertebrate fossils as horizon markers became more and more appreciated
by the stratigrapher. They serve to supplement the knowledge gained from
the invertebrates, and in this connection are especially valuable in
that they often give data concerning continental formations about which
invertebrate paleontology is largely silent.
_Rise of Vertebrate Paleontology in Europe._
To those who had been nurtured in the belief in a relatively recent
creation covering in its entirety a period of but six days, and
occurring but four millenniums before the time of Christ, the appearance
of the remains of creatures in the rocks, the like of which no man ever
saw alive, must have given scope to the wildest imaginings concerning
their origin and significance; for many believed that not only had no
new forms been added to the world’s fauna since the creation, except
possibly by hybridizing, but that none had become extinct save a very
few through the agency of human interference. The supposition was,
therefore, that such creatures as were thus discovered were still extant
in some more remote fastnesses of the world. Thus, our second president,
Thomas Jefferson, who wrote one of the first papers on American fossil
vertebrates, published in 1798, discussed therein the remains of a huge
ground-sloth which has since borne the name _Megalonyx jeffersoni_.
Jefferson, however, described the great claws as pertaining to a huge
leonine animal which he firmly believed was yet living among the
mountains of Virginia.
Cuvier (1769–1832) has been spoken of as the founder of our science. His
opportunity lay in the profusion of bones buried in the gypsum deposits
of Montmartre within the environs of the city of Paris. Cuvier’s studies
of these remains, done in the light of his very broad anatomical
knowledge, enabled him to prepare the first reconstructions of fossil
vertebrates ever attempted and to bring before the eyes of his
contemporaries a world peopled with forms which were utterly extinct.
That these creatures were no longer living, none was a better judge than
Cuvier, for his prominence was such that material was sent him from all
parts of the world, to which must be added that which he saw in his
visits to the various museums of Europe. He felt it safe, therefore, to
affirm the unlikelihood of any further discovery of unknown forms among
the great mammals of the present fauna of our globe, and few indeed have
been the additions since his day. To Cuvier is due not alone the
masterly contribution to the sister sciences of comparative anatomy and
vertebrate paleontology—the Ossements Fossiles (1812)—but he also
announced the presence in continental strata of a series of faunas which
showed a gradual organic improvement from the earliest such assemblage
to the most modern, an idea of the most fundamental importance and one
with which he is rarely credited. He believed in the sudden and complete
extinction of faunas, and the facts then known were in accord with this
idea, as no common genera nor transitional forms connected the creatures
of the Paris gypsum with the mastodons, elephants, and hippopotami which
the later strata disclosed. It is not remarkable, therefore, that Cuvier
advanced his theory of catastrophism to account for these extinctions.
He should not, however, according to Depéret, be credited with the idea
of successive re-creations, such as that held by D’Orbigny and others,
but of repopulation by immigration from some area which the catastrophe,
be it flood or other destructive agency, failed to reach.
Cuvier was followed in Europe by a number of illustrious men, none of
whom, however, with the exception of Sir Richard Owen, possessed his
breadth of knowledge of comparative anatomy upon which to base their
researches among the prehistoric. The more notable of them may be
enumerated before going on to a discussion of the American contributions
to the science.
They were, first, Louis Agassiz, a pupil of Cuvier and later a resident
of America, whose researches on the fossil fishes of Europe are a
monumental work, the result of ten years of investigation in all of the
larger museums of that continent, and which appeared in 1833–43, while
he was yet a young man. The fishes were practically the only fossil
vertebrates to come within the scope of his investigations, for his
later time was consumed in the study of glaciers and of recent marine
zoology. Another student of these most primitive vertebrates who left an
enduring monument was Johannes Mϋller. Huxley, Traquair, and Jaekel also
did masterly work upon this group, while Smith Woodward of the British
Museum is considered the highest living authority upon fossil fishes.
Of the Amphibia, the most famous foreign students were Brongniart,
Jaeger, Burmeister, Von Meyer, and Owen, although Owen’s claim to
eminence lies rather in the investigations of fossil reptiles which he
began in 1839 and continued over a period of fifty years of remarkable
achievement. Not only did he describe the dinosaurs of Great Britain in
a series of splendidly illustrated monographs, but extended his
researches to the curious reptilian forms from the Karroo formation of
South Africa. It was to him, moreover, that the establishment of the
true position of the famous _Archœopteryx_ as the earliest known bird
and not a reptile is due. Von Meyer also enriched the literature of
fossil reptiles, discussing exhaustively those occurring in Germany,
while Huxley’s classic work on the crocodiles as well as on dinosaurs,
and the labors of Buckland, Fraas, Koken, Von Huene, Gaudry, Hulke,
Seeley, and Lydekker have added immensely to our knowledge of the group.
Of the birds, which at best are rare as fossils, our knowledge,
especially of the huge flightless moas, is due largely again to Owen,
and his realization of the systematic position of _Archœopteryx_ has
already been mentioned.
The mammals were, perhaps, the most prolific source of paleontological
research during the nineteenth century, for, as Zittel has said,
Cuvier’s famous investigations on the fossil bones, mentioned above, not
only contain the principles of comparative osteology, but also show in a
manner which has never been surpassed how fossil vertebrates ought to be
studied, and what are the broad inductions which may be drawn from a
series of methodical observations. Such was Cuvier’s influence that
until Darwin began to interest himself in mammalian paleontology the
study of these forms was conducted entirely along the lines indicated by
the French savant. This was seen in a large work, Osteology of Recent
and Fossil Mammalia, by De Blainville, which, although not up to the
standard set by the master, is nevertheless a notable contribution, as
was also the Osteology prepared by Pander and D’Alton. A summary of the
knowledge of the fossil Mammalia up to the year 1847 is contained in
Giebel’s Fauna der Vorwelt, and Lydekker has done for the mammals in the
British Museum what Smith Woodward did for the fishes, producing vastly
more than the mere catalogue which the title implies.
The first work wherein the fossil mammals were treated genealogically
was Gaudry’s Enchaînements du Monde Animal, written in 1878. Other work
on the fossil Mammalia was done by Kaup, who described those from the
Mainz basin and from Epplesheim near Worms whence came one of the most
famous of prehistoric horses, the _Hipparion_; this horse, together with
the remarkable proboscidean _Dinotherium_, was described by Von Meyer.
One of the most remarkable discoveries, ranking in importance, perhaps,
next to Montmartre, was that of the Pliocene fauna of Pikermi near
Athens, Greece, first made known through the publications of A. Wagner
of Munich and later, and much more extensively, through that of Gaudry
(1862–1867). H. von Meyer was Germany’s best authority on fossil
Mammalia. After his death the work was carried on by Quenstedt, Oscar
Fraas, Schlosser, Koken, and Pohlig, among others.
In France, rich deposits of fossil mammals were discovered in the
Department of Puy-de-Dôme, the Rhone basin, Sansan, Quercy, and near
Rheims. These were described by a number of writers, notably Croizet and
Jobert, Pomel, Lartet, Filhol, and Lemoine.
Rütimeyer of Bâle was one of the most famous European writers on
mammalian paleontology, and his researches were both comprehensive and
clothed in such form as to give them a high place in paleontological
literature. He studied comparatively the teeth of ungulates, discussed
the genealogy of mammals, and the relationships of those of the Old and
New Worlds. He was an exponent of the law of evolution as set forth by
Darwin, and his “genealogical trees of the Mammalia show a complete
knowledge of all the data concerning the different members in the
succession, and are amongst the finest results hitherto obtained by
means of strict scientific methods of investigation” (Zittel, History of
Geology and Palæontology, 1901). The mammals of the Swiss Eocene have
been studied in much detail by Stehlin.
For Great Britain, the most notable contributors were Buckland in his
Reliquiæ Diluvianæ; Falconer, co-author with Cautley on the Tertiary
mammals of India; Charles Murchison, who wrote on rhinoceroses and
proboscideans; and more recently Bush, Flower, Lydekker, Boyd Dawkins,
L. Adams, and C. W. Andrews. But by far the most commanding figure of
all was Sir Richard Owen, who for half a century stood without a peer as
the greatest of authorities on fossil mammals. It was the Natural
History of the British Fossil Mammals and Birds, published in 1846, that
established Sir Richard’s reputation.
Russia has produced much mammalian material, especially from the
Tertiary of Odessa and Bessarabia, and from the Quaternary of northern
Russia and Siberia. These have been described mainly by J. F. Brandt, A.
von Nordmann, but especially by Mme. M. Pavlow of Moscow.
Forsyth-Major discovered in 1887 a fauna contemporaneous with that of
Pikermi in the Island of Samos in the Mediterranean.
One of the most remarkable recent discoveries of fossil localities was
that announced in 1901 by Mr. Hugh J. L. Beadnell of the Geological
Survey of Egypt and Doctor C. W. Andrews of the British Museum of
London, of numerous land and sea mammals of Upper Eocene and Lower
Oligocene age in northern Egypt. The exposures lay about 80 miles
southwest of Cairo in the Fayûm district and are the sediments of an
ancient Tertiary lake, a relic of which, Birket-el-Qurun, yet remains.
These beds contained ancient Hyracoidea, Sirenia, and Zeuglodontia, but
above all, ancestral Proboscidea which, together with those known
elsewhere, enabled Andrews to demonstrate the origin and evolutionary
features of this most remarkable group of beasts. This discovery in the
Fayûm lends color to the belief that Africa may have been the ancestral
home of at least five of the mammalian orders, those mentioned above,
together with the Embrithopoda, a group unknown elsewhere. This theory
had been advanced independently by Tullberg, Stehlin, and Osborn, before
the discovery in Egypt.
Another European worker of pre-eminence who wrote more broadly than the
faunal studies mentioned above was W. Kowalewsky. He discussed
especially the evolutionary changes of feet and teeth in ungulates, a
line of research afterward developed in greater detail by the Americans,
Cope and Osborn.
South America has yielded series of rich faunas which have been
exploited by the great Argentinian, Florentino Ameghino, and by the
Europeans, Owen, Gervais, Huxley, Von Meyer, and more recently by
Burmeister and Lydekker. Later exploration and research by Hatcher and
Scott of North America will be discussed further on in this paper.
_Vertebrate Paleontology in America._
_Early Writers._—Having thus summarized paleontological progress in the
Old World, we can turn to a consideration of the work done in the New,
especially in the United States, because while the Old World
investigation has been invaluable, a science of vertebrate paleontology,
very complete both as to its zoological and geological scope and in the
extent and value of published results, could be built exclusively upon
the discoveries and researches made by Americans. The science of
vertebrate paleontology may be said to have had its beginnings in North
America with the activities of Thomas Jefferson, who, like Franklin,
felt so strong an interest in scientific pursuits that even the graver
duties of the highest office in the gift of the American people could
not deter him from them. When in 1797 Jefferson came to be inaugurated
as vice-president of the United States, he brought with him to
Philadelphia not only his manuscript but the actual fossil bones upon
which it was based. Again in 1801 he was greatly interested in the
Shawangunk mastodon, despite heavy cares of state, and in 1808 made part
of the executive mansion in Washington serve as a paleontological
laboratory, displaying therein for study the bones of proboscideans and
their contemporaries which the Big Bone Lick of Kentucky had produced.
Jefferson’s work would not, perhaps, have been epoch-making were it not
for its unique chronological position in the annals of the science.
Jefferson was followed by another man—this time one whose diverging
lines of interest led him not into the realm of political service, but
of art, for Rembrandt Peale possessed an enviable reputation among the
early painters of America. Peale published in 1802 an account of the
skeleton of the “mammoth,” really the mastodon, _M. americanus_,
speaking of it as a nondescript carnivorous animal of immense size found
in America. It was because of the form of the molar teeth that Peale
said of it: “If this animal was indeed carnivorous, which I believe
cannot be doubted, though we may as philosophers regret it, as men we
cannot but thank Heaven that its whole generation is probably extinct.”
With the work of these men as a beginning, it is not strange that the
more conspicuous Pleistocene fossils of the East should have attracted
the attention of many subsequent writers in the first part of the
nineteenth century, nor that the early papers to appear in the Journal
should pertain to proboscideans or to the huge edentate ground-sloths
and the aberrant zeuglodons whose bones frequently came to light.
Therefore a number of men such as Koch, both Sillimans, J. C. Warren,
and others made these forms their chief concern.
_Fossil Footprints._—Among the early writers who concerned themselves
with these greater fossils was Edward Hitchcock, sometime president of
Amherst College, and a geologist of high repute among his
contemporaries. Hitchcock is, however, better and more widely known as
the pioneer worker on a series of phenomena displayed as in no other
place in the region in which he made his home. These are fossil
footprints impressed upon the Triassic rocks of the Connecticut valley.
It was in the Journal for the year 1836 (=29=, 307–340) that Hitchcock
first called attention to the footmarks, although they had been known
and discussed popularly for a number of years previous. James Deane, of
Greenfield, was perhaps the first to appreciate the scientific interest
of these phenomena, but deeming his own qualifications insufficient
properly to describe them, he brought them to the attention of
Hitchcock, and the interest of the latter never waned until his death in
1864. Hitchcock wrote paper after paper, publishing many of them in the
Journal, again in his Final Report on the Geology of Massachusetts
(1841), and later in quarto works, one in the Memoirs of the American
Academy of Arts and Sciences and the two others under the authority of
the Commonwealth, the Ichnology in 1858, and the Supplement in 1865, the
last being a posthumous work edited by his son, Charles H. Hitchcock.
Hitchcock’s conception of the track-makers was more or less imperfect
because of the fact that for a long time but a few fragmentary osseous
remains were known, either directly or indirectly associated with the
tracks, while on the other hand the bird-like character of many of the
latter and the discovery of huge flightless birds elsewhere on the globe
suggested a very close analogy if not a direct relationship. Hence “bird
tracks” they were straightway called, a designation which it has been
difficult to remove, even though in 1843 Owen called attention to the
need of caution in assuming the existence of so highly organized birds
at so early a period, especially when large _reptiles_ were known which
might readily form very similar tracks. The footprints are now believed
to be very largely of dinosaurian origin, and dinosaurs whose feet
corresponded in every detail with the footprints have actually come to
light within the same geologic and geographic limitations. This of
course refers to the bipedal, functionally three-toed tracks. Of the
makers of certain of the obscurer of the quadrupedal trails we are as
much in the dark to-day as were the first discoverers of a century ago,
so far as demonstrable proof is concerned. We assume, however, that they
were the tracks of amphibia and reptiles, beyond which we may not go
with certainty.
Agassiz, writing in 1865 (Geological Sketches), says:
“To sum up my opinion respecting these footmarks, I believe that they
were made by animals of a prophetic type, belonging to the class of
reptiles, and exhibiting many synthetic characters. The more closely
we study past creations, the more impressive and significant do the
synthetic types, presenting features of the higher classes under the
guise of the lower ones, become. They hold the promise of the future.
As the opening overture of an opera contains all the musical elements
to be therein developed, so this living prelude of the creative work
comprises all the organic elements to be successively developed in the
course of time.”
Of those whose work was contemporaneous with that of Hitchcock, but one,
W. C. Redfield, wrote on Triassic phenomena, and he concerned himself
mainly with the fossil fishes of that time, his first paper on this
subject appearing in 1837 in the Journal (=34=, 201), and the last
twenty years later.
_Paleozoic Vertebrates._—Later the vertebrates of the Paleozoic began to
attract attention, footprints from Pennsylvania being described by Isaac
Lea, beginning in 1849, a notice of his first paper appearing in the
Journal for that year (=9=, 124). Several papers followed on the reptile
_Clepsysaurus_. Alfred King also wrote on the Carboniferous ichnites,
his work slightly antedating that of Lea, but being less authoritative.
But by far the most illuminating of the mid-century writers on Paleozoic
vertebrates was Sir William Dawson, a very large proportion of whose
numerous papers relate to the Coal Measures of Nova Scotia and their
contained plant and animal remains. In 1853 appeared Dawson’s first
announcement, written in collaboration with Sir Charles Lyell, of the
finding of the bones of vertebrates within the base of an upright fossil
tree trunk at South Joggins. These bones were identified by Owen and
Wyman as pertaining to a reptilian or amphibian to which the name
_Dendrerpeton acadianum_ was given. Following this were several papers
published in the Quarterly Journal of the Geological Society, London,
describing more vertebrates and associated terrestrial molluscs. In 1863
Dawson summarized his discoveries in the Journal (=36=, 430–432) under
the title of “Air-breathers of the Coal Period,” a paper which was
expanded and published under the same title in the Canadian Naturalist
and Geologist for the same year. Dawson also printed in the same volume
the first account of reptilian(?) footprints from the coal. Thus from
time to time there emanated from his prolific pen the account of further
discoveries, both in bones and footprints, his final synopsis of the
air-breathing animals of the Paleozoic of Canada appearing in 1895. The
only other group of vertebrates which claimed his attention were certain
whales, on which he occasionally wrote.
_Fishes._—The fossil fishes from the Devonian of Ohio found their first
exponent in J. S. Newberry, appointed chief geologist of the second
geological survey of Ohio, which was established in 1869. These fishes
from the Devonian shales belonged for the greater part to the curious
group of armored placoderms, the remains of which consist very largely
of armor plates with little or no traces of internal skeleton. There was
also found in association a shark, _Cladoselache_, of such marvelous
preservation that from some of the Newberry specimens now in the
American Museum of Natural History, New York, Bashford Dean has
demonstrated the histology of muscle and visceral organs, in addition to
the very complete skeletal remains.
Newberry’s work on these forms, begun in 1868, has been carried to
further completion by Bashford Dean and his pupil L. Hussakof, as well
as by C. R. Eastman. Newberry’s other paleontological work was with the
Carboniferous fishes of Ohio, the Carboniferous and Triassic fishes of
the region from Sante Fé to the Grand and Green rivers, Colorado, and on
the fishes and plants of the Newark system of the Connecticut valley and
New Jersey. He also discussed certain mastodon and mammoth remains, and
those of the peccary of Ohio, _Dicotyles_.
_Joseph Leidy (1823–1891)._
We now come to a consideration of the work of Joseph Leidy, one of the
three great pioneers in American vertebrate paleontology, for if we
disregard the work of Hitchcock and others on the fossil footprints, few
of the results thus far obtained were based upon the fruits of organized
research. Leidy began his publication in 1847 and continued to issue
papers and books from time to time until the year 1892, having published
no fewer than 219 paleontological titles, and 553 all told. His earlier
paleontological researches were exclusively on the Mammalia, which were
then coming in from the newly discovered fossil localities of the West.
The discovery of these forms, one of the most notable events in the
history of our science, will bear re-telling.
The first announcement was made in 1847, when Hiram A. Prout of St.
Louis published in the Journal (3, 248–250) the description of the
maxillary bone of “_Palæotherium_” (= _Titanotherium proutii_)from near
White River, Nebraska. This at once drew the attention of geologists and
paleontologists to the Bad Lands, or Mauvaises Terres, which were to
prove so highly productive of fossil forms. About the same time S. D.
Culbertson of Chambersburg, Pennsylvania, submitted to the Academy of
Natural Sciences at Philadelphia some fossils sent to him from Nebraska
by Alexander Culbertson. These were afterward described by Leidy in the
Proceedings of the Academy, together with the paleotheroid jaw, in
addition to which three other collections which had been made were also
placed at his disposal for study.
This aroused the interest of Doctor Spencer F. Baird of the Smithsonian
Institution, who sent T. A. Culbertson to the Bad Lands to make further
collections. The latter was successful in securing a valuable series of
mammalian and chelonian remains. These, together with other specimens
from the same locality, were sent to Leidy, for, as Baird remarked,
Leidy, although only thirty years of age, was the only anatomist in the
United States qualified to determine their nature. The outcome of
Leidy’s study of this material was “The Ancient Fauna of Nebraska,”
published in 1853, and constituting the most brilliant work which up to
that time American paleontology had produced. Leidy’s determinations,
which are in the main correct, are the more remarkable when it is
realized that he had little recent osteological material for comparative
study. The forms thus described by him were new to science, of a more
generalized character than those now living, and yet their distinguished
describer recognized, either at that time or a little later, their true
relationship to the modern types. The extent of Leidy’s anatomical
knowledge was almost Cuvierian, and Cuvier-like he established the fact
of the presence of the rhinoceroses, then unheard of in the American
fauna, from a few small fragments of molar teeth, an opinion shortly to
be fully sustained through the finding of complete molars and the entire
skull of the _same individual animal_.
Leidy next turned his attention to the huge edentates, which he studied
exhaustively, publishing his results in the form of a memoir in 1855,
two years after the appearance of the “Ancient Fauna.”
Extinct fishes of the Devonian of Illinois and Missouri and the Devonian
and Carboniferous of Pennsylvania were made the subjects of his next
researches, after which he described the peccaries of Ohio, and later,
in a much larger and most important work, the Cretaceous reptiles of the
United States (1865). Most of the fossils discussed in this last work
are from the New Jersey Cretaceous marls and of them the most notable
was the herbivorous dinosaur _Hadrosaurus_, the structure and habits of
which, together with its affinities with the Old World iguanodons, Leidy
described in detail. From Leidy’s descriptions and with his aid,
Waterhouse Hawkins was enabled to restore a replica of the skeleton in a
remarkably efficient way. This restoration for a long time graced the
museum of the Philadelphia Academy of Natural Sciences and there was a
plaster replica of it in the United States National Museum. These,
together with plaster replicas of _Iguanodon_ from the Royal College of
Surgeons in London, gave to Americans their first real conceptions of
members of this most remarkable group. The associated fossils from the
New Jersey marls were chiefly crocodiles and turtles.
From 1853 to 1866 F. V. Hayden was carrying on a series of most
energetic explorations in the West, especially in Nebraska and Dakota as
then delimited, returning from each trip laden with fossils which were
given to Leidy for determination. The results appeared in 1869 in
Leidy’s Extinct Mammalian Fauna of Dakota and Nebraska, published as
volume =7= of the Journal of the Philadelphia Academy. In this large
volume no fewer than seventy genera and numerous species of forms, many
of them new to science, were described, representing many of the
principal mammalian orders; horses were, however, especially
conspicuous. This last group led Leidy to the conclusion, afterward
emphasized by Huxley, that North America was the home of the horse in
geologic time, there being here a greater representation of different
species than in any recent fauna of the world. Leidy’s interest in the
horses, for the forwarding of which he made a large collection of recent
material, extended over many years, as his first paper on the subject
bears the date of 1847, the last that of 1890.
Next came the discovery of Eocene material from the vicinity of Fort
Bridger, Wyoming, geologically older than the Nebraska and Dakota
formations. This, together with specimens from the Green River and
Sweetwater River deposits of Wyoming and the John Day River (Oligocene)
of Oregon, was also referred to Leidy, and added yet more to the list of
newly discovered species with which he had already become familiar in
his earlier researches. The results of this study were published by the
Hayden Survey in 1873, under the title “Contributions to the Extinct
Vertebrate Fauna of the Western Territories.” This was the last of
Leidy’s major works, but he continued up to the time of his death to
report to the Academy concerning the various fossil forms that were
submitted to him for identification. Of such reports the most important
was one on the fossils of the phosphate beds of South Carolina,
published in the Journal of the Academy in 1887.
As a paleontologist, Leidy ranks with Cope and Marsh high among those
who enriched the American literature of the subject, but it must be
remembered that this was but a single aspect of his many-sided
scientific career, for he made many contributions of high order to
botany, zoology, and general and comparative anatomy as well, nor did
his knowledge and usefulness as an instructor of his fellow men keep
within the limitations of these subjects.
_Othniel Charles Marsh (1831–1899)._
The sixth decade of the nineteenth century saw the beginning of the
labors of several paleontologists who, like Leidy, were destined to
raise the science of fossil vertebrates in America to the level of
attainment of the Old World. They were, among others, Othniel Charles
Marsh and Edward Drinker Cope. Of these the names of Marsh and Cope are
linked together by the brilliance of their attainments, their
contemporaneity, and the rivalry which the similarity of their pursuits
unfortunately engendered. Marsh produced his first paleontological paper
in 1862 (=33=, 278), Cope in 1864, but the latter died first, so that
his life of research was shorter.
[Illustration: O. C. Marsh]
To Professor Marsh should be given credit for the first organized
expedition designed exclusively for the collection of vertebrate
remains, the results of which contain so much material that it has not
yet entirely seen the light of scientific exposition. Marsh’s first trip
to the West was in 1868, the first formal expedition being organized two
years later. These expeditions, of which there were four, were privately
financed except for the material and military escort furnished by the
United States Government, and consisted of a personnel drawn entirely
from the graduate or undergraduate body of Yale University. These
parties explored Kansas, Nebraska, Wyoming, Utah, and Oregon, and
returned laden with material from the Cretaceous and Tertiary formations
of the West. Some of this is of necessity somewhat fragmentary, but type
after type was secured which, with his exhaustive knowledge of
comparative anatomy, enabled Marsh to announce discovery after discovery
of species, genera, families, and even orders of mammals, birds, and
reptiles which were unknown to science. The year 1873 saw the last of
the student expeditions, and thereafter until the close of his life the
work of collecting was done under Marsh’s supervision, but by paid
explorers, many of whom had been his scouts and guides in the formal
expeditions or had been especially trained by him in the East. In 1882,
after fourteen years of the experience thus gained, Marsh was appointed
vertebrate paleontologist to the United States Geological Survey, which
relieved him in part of the personal expense connected with the
collecting, although up to within a short time of his death his own
fortune was very largely spent in enlarging his collections. After his
connection with the Survey was established, Marsh had two main purposes
in view in making the collections: (1) to determine the geological
horizon of each locality where a large series of vertebrate fossils was
found, and (2) to secure from these localities large collections of the
more important forms sufficiently extensive to reveal, if possible, the
life histories of each. Marsh believed that the material thus secured
would serve as key or diagnostic fossils to all horizons of our western
geology above the Paleozoic, a belief in which he was in advance of his
time, for few of his contemporaries appreciated the value of vertebrates
as horizon markers. The result of the fulfilment of his second purpose
saw the accumulation of huge collections from all horizons above the
Triassic and some Paleozoic and Triassic as well. These contained some
very remarkable series, each of which Marsh hoped to make the basis of
an elaborate monograph to be published under the auspices of the Survey.
One can visualize the scope of his ambitions by the fact that no fewer
than twenty-seven projected quarto volumes, to contain at least 850
lithographic plates, were listed by him in 1877. These covered, among
other groups, the toothed birds (Odontornithes), Dinocerata, horses,
brontotheres, pterodactyls, mosasaurs and plesiosaurs, monkeys,
carnivores, perissodactyls and artiodactyls, crocodiles, lizards,
dinosaurs, various birds, proboscideans, edentates and marsupials, brain
evolution, and the Connecticut Valley footprints. Much was done towards
the preparation of these memoirs, as evidenced by the long list of
preliminary papers, admirably illustrated by woodcuts which were to form
the text figures of the memoirs, which appeared with great regularity in
the pages of the Journal for a period of thirty years. Of the actual
memoirs, however, but two had been published at the time of Marsh’s
death in 1899—the Odontornithes in 1880 and the Dinocerata in 1884. One
must not overlook, however, the epoch-making Dinosaurs of North America,
which was published by the Survey in 1896, although it was not in the
form nor had it the scope of the proposed monographs. This was not due
to lack of application, for Professor Marsh was an indefatigable worker,
but rather to the fact that the program was of such magnitude as to
necessitate a patriarchal life span for its consummation. As it is,
Professor Marsh’s fame rests first upon his ability and intrepidity as a
collector, ready himself to brave the very certain hardships and dangers
which beset the field paleontologist in the pioneer days, and also by
his judgment and command of men to secure the very adequate services of
others and so to direct their endeavors that the results were of the
highest value. The material witness to Marsh’s skill as a collector lies
in the collections of the Peabody Museum at Yale and in the Marsh
collection at the United States National Museum, the latter secured
through the funds of the United States Geological Survey. Together they
constitute what is possibly the greatest collection of fossil
vertebrates in America, if not in the world; individually, they are
second only to that of the American Museum in New York City, the result
of the combined labors of Osborn and Cope and their very able corps of
assistants.
As a scientist Marsh possessed in large measure that wide knowledge of
comparative anatomy so necessary to the vertebrate paleontologist, and
as a consequence was not only able to recognize affinities and classify
unerringly, but also to recognize the salient diagnostic features of the
form before him and in few words so to describe them as to render the
recognition of the species by another worker relatively easy. The
publication of hundreds of these specific diagnoses in the Journal
constitutes a very large and valuable part of that periodical’s
contribution to the advancement of our science. Marsh’s method of
indicating forms by so brief a statement leaves much to be done,
however, in the way of further description of his types, which in many
instances were but partially prepared.
Yet another important service which Marsh rendered to science was the
restoration of the creatures as a whole, made with the most painstaking
care and precision through assembling the drawings of the individual
bones. These restorations have become classic, embracing as they did a
score or more of forms, of beast, bird, and reptile. They also were
published first in the Journal, although they have subsequently been
reproduced in text-books and other works the world over. Part of Marsh’s
popular reputation, at least, which was second to that of no other
American in his line, was due to his skill in attaining publicity, for
his papers, of whatever extent, were carefully and methodically sent to
correspondents in the uttermost parts of the earth, and thus the Marsh
collection has reflected the fame of its maker.
_Edward Drinker Cope (1840–1897)._
The third great name in American vertebrate paleontology, that of Edward
Drinker Cope, stands out in sharp contrast with the other two, although
in the range of his interests he was probably more nearly comparable
with Leidy than with Marsh. The beginning of Cope’s scientific labors
dates from 1859, the year made famous in the annals of science by the
appearance of Darwin’s Origin of Species. It is not surprising,
therefore, that matters evolutional should have interested him to the
very end of his career. Cope was not merely a paleontologist, but was
interested in recent forms, especially the three lower classes of
vertebrates, to such an extent that his work therewith is highly
authoritative and in some respects epoch-making. Thirty-eight years of
almost continual toil were his, and the mere mass of his literary
productions is prodigious, especially when one realizes that, unlike
those of a writer of fiction, they were based on painstaking research
and philosophical thought. The greater part of Cope’s life was spent in
or near Philadelphia except for his western explorations, and he is best
known as professor of geology and paleontology in the University of
Pennsylvania, although he served other institutions as well.
Cope’s early work was among the amphibia and reptiles, his first
paleontological paper, the description of _Amphibamus grandiceps_,
appearing in 1865. This year he also began his studies of the mammals,
especially the Cetacea, both living and extinct, from the Atlantic
seaboard. The next year saw the beginning of his work on the material
from the Cretaceous marls of New Jersey, describing therefrom one of the
first carnivorous dinosaurs, _Lælaps_, to be discovered in America. In
1868 Cope began to describe the vertebrates from the Kansas chalk and
three years later made his first exploration of these beds. This led to
his connection with the United States Geological Survey of the
Territories under Hayden, and to continued exploration of Wyoming and
Colorado in 1872 and 1873. The material thus gained, consisting of
fishes, mosasaurs, dinosaurs, and other reptiles, was described in the
Transactions of the American Philosophical Society as well as in the
Survey Bulletins. In 1875 these results were summarized in a large
quarto volume entitled “Vertebrata of the Cretaceous formations of the
West.” Subsequent summers were spent in further exploration of the
Bridger, Washakie, and Wasatch formations of Wyoming, the Puerco and
Torrejon of New Mexico, and the Judith River of Montana. The material
gathered in New Mexico proved particularly valuable, and led to the
publication in 1877 of another notable volume entitled “Report upon the
Extinct Vertebrata obtained in New Mexico by Parties of the Expedition
of 1874.”
Material was now accumulating so fast as to necessitate the
concentration of Cope’s own time on research, so that, while he
continued to make brief journeys to the West, the real work of
exploration was delegated to Charles H. Sternberg and J. L. Wortman,
both of whom became subsequently very well known, the former as a
collector whose active service has not yet ceased, the latter as an
explorer and later an investigator of extremely high promise.
As early as 1865, Cope began no fewer than five separate lines of
research which he pursued concurrently for the remainder of his career.
On the fishes, he became a high authority in the larger classification,
owing to his researches into their phylogeny, for which a knowledge of
extinct forms is imperative. On amphibia, he wrote more voluminously
than any other naturalist, discussing not only the morphology but the
paleontology and taxonomy as well. In this connection must be mentioned
not only Cope’s exploration and collections in the Permian of Ohio and
Illinois, but especially the remains from the Texas Permian, first
received in 1877, upon which some of his most brilliant results were
based; these of course included reptilian as well as amphibian material.
His third line of research, the Reptilia, is in part included in the
foregoing, but also embraced the reptiles of the Bridger and other
Tertiary deposits, those of the Kansas Cretaceous, and the Cretaceous
dinosaurs.
Up to 1868 Leidy alone was engaged in research in the West, but that
year saw the simultaneous entrance of Marsh and Cope into this new field
of research, and their exploration and descriptions of similar regions
and forms soon led to a rivalry which in turn developed into a most
unfortunate series of controversies, mainly over the subject of
priority. This resulted in a permanent rupture of friendship and the
division of American workers into two opposing camps to the detriment of
the progress of our science. This breach has now been happily healed,
and for a number of years the degree of mutual good will and aid on the
part of our workers has been of the highest sort.
The extent of the western fossil area, and particularly the explorations
of three of Cope’s aids, Wortman in the Big Horn and Wasatch basins,
Baldwin in the Puerco of New Mexico, and Cummins in the Permian of
Texas, gave him so fruitful a field of endeavor that the occasion for
jealous rivalry was largely removed. The most manifest result of Cope’s
western work was the publication in 1883 of his Vertebrata of the
Tertiary Formations of the West, which formed volume =3= of the quarto
publications of the Hayden Survey. This huge book contains more than
1000 pages and 80 plates and has been facetiously called “Cope’s Bible.”
Cope’s philosophical contributions, which covered the domains of
evolution, psychology, ethics, and metaphysics, began in 1868 with his
paper on The Origin of Genera. In evolution he was a follower of
Lamarck, and as such, with Hyatt, Ryder, and Packard, was one of the
founders of the so-called Neo-Lamarckian School in America. Cope’s
principal contribution, set forth in his Factors of Organic Evolution,
is the idea of kinetogenesis or mechanical genesis, the principle that
all structures are the direct outcome of the stresses and strains to
which the organism is subjected. Weismann’s forcible attack on the
transmission theory did not shake Cope’s faith in these doctrines, for
he claimed that the paleontological evidence for the inheritance of such
characters as are apparently the result of _individual_ modification was
too strong to be refuted. Cope was more like Lamarck than any other
naturalist in his mental make-up as well as his ideas. He was also, like
Haeckel, given to working out the phylogeny of whatever type lay before
him, and in many instances arrived marvellously near the truth as we now
see it.
Associated for a while with A. S. Packard, Cope soon became chief editor
and proprietor of the American Naturalist, which was for many years his
main means of publication and thus served our science in a way
comparable to the Journal. As Osborn says by way of summation:
“Cope is not to be thought of merely as a specialist in Paleontology.
After Huxley he was the last representative of the old broad-gauge
school of anatomists and is only to be compared with members of that
school. His life work bears marks of great genius, of solid and
accurate observation, and at times of inaccuracy due to bad logic or
haste and overpressure of work.... As a comparative anatomist he ranks
both in the range and effectiveness of his knowledge and his ideas
with Cuvier and Owen.... As a natural philosopher, while far less
logical than Huxley, he was more creative and constructive, his
metaphysics ending in theism rather than agnosticism.”
_1870–1880._
The seventh decade was productive of comparatively few great names in
the history of our science, but two, J. A. Ryder and Samuel W.
Williston, being notable contributors. The former produced but few
papers and those between 1877 and 1892, yet they were of note and such
was their influence that he is named with Hyatt, Packard, and Cope as
one of the founders of the Neo-Lamarckian School of evolutionists in
America. Ryder was a particular friend and a colleague of Cope, as they
were both concerned with the back-boned animals, while the other two
were invertebratists. Ryder wrote on mechanical genesis of tooth forms
and on scales of fishes, also on the morphology and evolution of the
tails of fishes, cetaceans, and sirenians, and of the other fins of
aquatic types. He did, on the other hand, practically no systematic or
descriptive work.
Williston, on the contrary, has had a long and varied career as an
investigator and as an educator. Trained at Yale, he prepared for
medicine, and much of his teaching has been of human anatomy, both at
Yale and at the University of Kansas where he served for a number of
years as dean of the Medical School. He is also a student of flies, and
as such not only the foremost but indeed almost the only dipterologist
in the United States. But it is with his work as a vertebrate
paleontologist that we are chiefly concerned, and here again he stands
among the foremost. His initial work and training in this department of
science were with Marsh, for whom he spent many months in field work,
collecting largely in the Niobrara Cretaceous of Kansas. He did,
however, no research while with Marsh, owing to the latter’s
disinclination to foster such work on the part of his associates.
Williston began his publications in 1878 and has continued them until
the present, working mainly with Cretaceous mosasaurs, plesiosaurs, and
pterodactyls. Of late, since his transference to the University of
Chicago, where as professor of paleontology and director of the Walker
Museum he has served since 1902, his interest has lain mainly among the
Paleozoic reptiles and amphibia. Williston’s more notable works are
American Permian Vertebrates and Water Reptiles of the Past and Present,
wherein he sets forth his views of the phylogenesis and taxonomy of the
reptilian class. He is at present at work on the evolution of the
reptiles, a volume which is eagerly awaited by his colleagues. It is in
morphology that Williston’s greatest strength lies and some of his most
effective work on the mosasaurs has appeared in the Journal.
_1880–1900._
The next decade, that of 1880–1890, saw a number of notable additions to
the workers in vertebrate paleontology: Henry F. Osborn, W. B. Scott, R.
W. Shufeldt, J. L. Wortman, George Baur, F. A. Lucas, and F. W. True.
Shufeldt is our highest authority on the osteology of birds, both recent
and extinct, having recently described all of the extinct forms
contained in the Marsh collection; True wrote of Cetacea; Lucas of
marine and Pleistocene mammals and birds, and has also written popular
books on prehistoric life. Lucas’s greatest service, however, lies in
the museums, where he has manifested a genius second to none in the
installation of mute evidences of living and past organisms. Wortman was
for a time associated with Cope, later with Osborn in the American
Museum, again at the Carnegie Museum at Pittsburgh, and finally at Yale
in research on the Bridger Eocene portion of the Marsh collection. His
work has been chiefly the perfection of field methods in vertebrate
paleontology, and as a special investigator of Tertiary Mammalia,
treating the latter largely from the morphologic and taxonomic
standpoints. Wortman’s Yale results on the carnivores and primates of
the Eocene, as yet unfinished, were published in the Journal in
1901–1904.
William B. Scott is a graduate of Princeton, and has spent thirty-four
years in her service as Blair Professor of Geology and Paleontology. His
first publication, in 1878, issued in conjunction with Osborn and Speir,
described material collected by them in the Eocene formations of the
West, and since that time Scott’s research has been entirely with the
mammals, on which he is one of our highest authorities. His most notable
works have been a History of Land Mammals of the Western Hemisphere,
1913, and the results of the Patagonian expeditions by Hatcher, which
are published in a quarto series in conjunction with W. J. Sinclair,
although they are the authors of separate volumes, Scott’s work being
mainly on the carnivores and edentates of the Santa Cruz formation. It
is as a systematist in research and as an educator that Scott has
attained his highest usefulness.
The man who, next to the three pioneers, has attained the highest
reputation in vertebrate paleontologic research, is Henry Fairfield
Osborn. Graduate of Princeton in the same class that produced Scott,
Osborn served for a time as professor of comparative anatomy in that
institution, and in 1891 was called to New York to organize the
department of zoology in Columbia University and that of vertebrate
paleontology in the American Museum of Natural History. He had, early in
his career, gone west in company with Professor Scott, and had collected
material from the Eocene formation of Wyoming, upon which they based
their first joint paper in 1878, Osborn’s first independent production,
a memoir on two genera of Dinocerata, appearing in 1881. A number of
papers followed, on the Mesozoic Mammalia, on Cope’s tritubercular
theory, and on certain apparent evidences for the transmission of
acquired characters. It was, however, with his acceptance of the New
York responsibilities, especially at the American Museum, that Osborn’s
most significant work began. Aided first by Wortman and Earle, later by
W. D. Matthew and others, he has built up the greatest and most complete
collection of fossil vertebrates extant; its value, however, was largely
enhanced through the purchase of the private collection of Professor
Cope, which of course included a large number of types. The American
Museum collection thus contains not only a vast series of representative
specimens from every class and order of vertebrates, secured by purchase
or expedition from nearly all the great localities of the world, but an
exhibition series of skulls and partial and entire skeletons and
restorations which no other institution can hope to equal. Based upon
this wonderful material is a large amount of research, filling many
volumes, published for the greater part in the bulletin and memoirs of
the Museum. This research is not only the product of the staff,
including Walter Granger, Barnum Brown, W. D. Matthew, and W. K.
Gregory, but also of a number of other American and some foreign
paleontologists as well.
Professor Osborn’s own work has been voluminous, his bibliography from
1877 to 1916 containing no fewer than 441 titles, ranging over the
fields of paleontology,—which of course includes the greater
number—geology, correlation and paleogeography, evolutionary principles
exemplified in the Mammalia, man, neurology and embryology, biographies,
and the theory of education.
In paleontology, Osborn’s researches have been largely with the Reptilia
and Mammalia, partly morphological, but also taxonomic and evolutional.
Faunistic studies have also been made of the mammals. Of his published
volumes the most important are, first, the Age of Mammals (1910), in
which he treats not of evolutionary series of phylogenies, but of faunas
and their origin, migrations, and extinctions, and of the correlation of
Old and New World Tertiary deposits and their contents. Men of the Old
Stone Age (1916) is an exhaustive treatise and is the first full and
authoritative American presentation of what has been discovered up to
the present time throughout the world in regard to human prehistory. In
his latest volume, The Origin and Evolution of Life (1917), Osborn
presents a new energy conception of evolution and heredity as against
the prevailing matter and form conceptions. In this volume there is
summed up the whole story of the origin and evolution of life on earth
up to the appearance of man. This last book is novel in its conceptions,
but it is too early as yet to judge of the acceptance of Osborn’s theses
by his fellow workers in science.
Since the death of Professor Marsh, Osborn has served as vertebrate
paleontologist to the United States Geological Survey, and has in charge
the carrying through to completion of the many monographs proposed by
his distinguished predecessor. One of these, that on the horned
dinosaurs, has been completed by Hatcher and Lull (1907), another on the
stegosaurian dinosaurs has been carried forward by C. W. Gilmore of the
United States National Museum, while under Osborn’s own hand are the
memoirs on the titanotheres (aided by W. K. Gregory), the horses, and
the sauropod dinosaurs. Of these, the first, when it shall have been
completed, promises to be the most monumental and exhaustive study of a
group of fossil organisms ever undertaken.
As a leader in science, a teacher and administrator, Professor Osborn’s
rank is high among the leading vertebratists. He is remarkably
successful in his choice of assistants and in stimulating them in their
productiveness so that their combined results form a very considerable
share of the later literature in America.
The ninth decade ushered in the work of a valuable group of students, of
whom John Bell Hatcher should be mentioned in particular, as his work is
done. Graduate of Yale in 1884, he spent a number of years assisting his
teacher, Professor Marsh, mainly in the field, collecting during that
time, either for Yale or for the United States Geological Survey, an
enormous amount of very fine material, especially from the West,
although he also collected in the older Tertiary and Potomac beds near
Washington. In the West he secured no fewer than 105 titanothere skulls,
explored the Tertiary, Judith River, and Lance formations, collected and
in fact virtually discovered the remains of the Cretaceous mammals and
of the horned dinosaurs which he was later privileged to describe. He
then (1893) went to Princeton, which he served for seven years, his
principal work being explorations in Patagonia for the E. and M. Museum,
one direct result of which was the publication of a large quarto on the
narrative of the expedition and the geography and ethnography of the
region. Going to the Carnegie Museum in Pittsburgh in 1900, Hatcher
carried forward the work of exploration and collecting begun for that
institution by Wortman, and as a partial result prepared many papers,
the principal ones being memoirs on the dinosaurs _Haplocanthosaurus_
and _Diplodocus_. In 1903, with T. W. Stanton of the United States
Geological Survey, Hatcher explored the Judith River beds and together
they settled the vexatious problem of their age, the published results
appearing in 1905, after Hatcher’s death. His last piece of research,
begun in 1902 and continued until his death in 1904, was an elaborate
monograph on the Ceratopsia, one of the many projected by Marsh. Of this
memoir Hatcher had completed some 150 printed quarto pages, giving a
rare insight into the anatomy of these strange forms. The final
chapters, however, which were based very largely upon Hatcher’s own
opinions, had to be prepared by another hand.
Despite his early death, therefore, Hatcher rendered a very signal
service to American paleontology—in exploration, stratigraphy,
morphology, and systematic revision—and his activity in planning new
fields of research, such, for instance, as the exploration of the
Antarctic continent, gave promise of further high attainment, when his
hand was arrested by death.
_Summary._
It is not surprising that American vertebrate paleontology has arisen to
so high a plane, when one considers the material at its disposal. Having
a vast and virgin field for exploration, a sufficient number of
collectors, some of whom have devoted much of their lives to the work,
and a refinement of technique that permitted the preservation of the
fragmental and ill conserved as well as the finer specimens, the results
could hardly have been otherwise. Thus it has been possible to secure
material almost unique throughout the world for extent, for
completeness, and for variety. To this must be added a certain American
daring in the matter of the restoration of missing portions, both of the
individual bones and of the skeleton as a whole, such as European
conservatism will not as a rule permit. This work has for the most part
been done after the most painstaking comparison and research and is
highly justified in the accuracy of the results, which render the fabric
of the skeleton much more intelligible, both to the scientist and to the
layman. Material once secured and prepared is then mounted, and here
again American ingenuity has accomplished some remarkable results. Some
of the specimens thus mounted are so small and delicate as to require
holding devices comparable to those for the display of jewels; yet
others—huge dinosaurs the bones of which are enormously heavy, but so
brittle that they will not bear even the weight of a process
unsupported—require a carefully designed and skilfully worked out series
of supports of steel or iron which must be perfectly secure and at the
same time as inconspicuous as possible. And of late the lifelike pose of
the individual skeleton has been augmented by the preparation of groups
of several animals which collectively exhibit sex, size, or other
individual variations and the full mechanics of the skeleton under the
varying poses assumed by the creature during life.
The work of further restoration has been rendered possible through
comparative anatomical study, enabling us to essay restorations in
entirety by means of models and drawings, clothing the bones with sinews
and with flesh and the flesh with skin and hair, if such the creature
bore; while the laws of faunal coloration have permitted the coloring of
the restoration in a way which if not the actual hue of life is a very
reasonable possibility.
Thus the American paleontologists have blazed a trail which has been
followed to good effect by certain of their Old World colleagues.
With such means and methods and such material available, it is again not
surprising that American paleontology has furnished more and more of the
evidences of evolution, and disclosed to the eyes of scientists animal
relationships which were undreamed of by the systematist whose research
dealt only with the existing. It has also explained some vexatious
problems of animal distribution and of extinction, and has connected up
cause and effect in the great evolutionary movements which are recorded.
The results of systematic research have added hosts of new genera and
species and of families, but of orders there are relatively few.
Nevertheless a number, especially among reptiles and mammals, have come
to light as the fruits of American discovery. But aside from the dry
cataloguing of such groups, the American systematists have worked out
some very remarkable phylogenies and have thus clarified our vision of
animal relationships in a way which the recent zoologist could never
have done. In this connection, the Permian vertebrates, which have been
collected and studied with amazing success, principally by Williston and
Case, should be mentioned, although the work is yet incomplete. Some of
these forms are amphibian, others reptilian, yet others of such
character as to link the two classes as transitional forms. Of the
Mesozoic reptiles, a very remarkable assemblage has come to light, in a
degree of perfection unknown elsewhere. These are dinosaurs, of which
several phyla are now known; carnivores both great and small, some of
the latter being actually toothless; Sauropoda, whose perfection and
dimensions are incomparable except for those found in East Africa; and
predentates, armored, unarmored, and horned, the last exclusively
American. The unarmored trachodonts are now known in their entirety, for
not only has our West produced articulated skeletons but mummified
carcasses whose skin and other portions of their soft anatomy are
represented, and which are thus far without a parallel elsewhere in the
world. Other reptilian groups are well known, notably the Triassic
ichthyosaurs, and the mosasaurs and plesiosaurs of the Kansas chalk. The
last formation has also produced toothed birds, _Hesperornis_ and
_Ichthyornis_, which again are absolutely unique.
But it is in the mammalian class that the phylogenies become so highly
complete and of such great importance as evolutionary evidences, for
nowhere else than in our own West have such series been found as the
Dinocerata and creodonts among archaic forms, the primitive primates
from the Eocene, the carnivores such as the dogs and cats and
mustellids, but especially the hoofed orders such as the horses. Of
these hoofed orders, the classic American series of horses is complete,
that of the camels probably no less so, while much is known of the deer
and oreodonts, the last showing several parallel phyla, and of the
proboscideans, which while having their pristine home in the Old World
nevertheless soon sought the new where their remains are found from the
Miocene until their final and apparently very recent extinction. These
creatures show increase of bulk, perfection of feet and teeth,
development of various weapons, horns and antlers, which may be studied
in their relationship with the other organs to make the evolving whole,
or their evolution may be traced as individual structures which have
their rise, culmination, and sometimes their senile atrophy in a way
comparable to that of the representatives of the order as a whole. Thus,
for example, Osborn has traced the evolution of the molar teeth, and
Cope of the feet, while Marsh has shown that brain development runs a
similar course and that its degree of perfection within a group is a
potent factor for survival.
As a student of evolution, the paleontologist sees things in a very
different light from the zoologist. The latter is concerned largely with
matters of detail—with the inheritance of color or of the minor and more
superficial characteristics of animals—and the period of observation of
such phenomena is of necessity brief because of the mortality of the
observer. Whereas the paleontologist has a perspective which the other
lacks, since for him time means little in the terms of his own life, and
he can look into the past and see the great and fundamental changes
which evolution has wrought, the rise of phyla, of classes, of orders,
and he alone can see the orderliness of the process and sense the
majesty of the laws which govern it.
_Influence of the American Journal of Science._
The influence of the American Journal of Science as a medium for the
dissemination of the results of vertebrate research has been in evidence
throughout this discussion, but it were well, perhaps, to emphasize that
service more fully. The Journal was, as we have seen, the chief outlet
for Professor Marsh’s research, for there were published in it during
his lifetime no fewer than 175 papers descriptive of the forms which he
studied, as well as a great part of the material in the published
monographs. As Marsh left very few manuscript notes, the importance of
these frequent publications in thus setting forth much that he thought
and learned concerning the material is very great indeed. The combined
titles of all other authors in the Journal in this line of research for
the century of its life fall far short of the number produced by Marsh
alone, as they include 136 all told, but the range of subjects is highly
representative of the entire field of vertebrate research. It should be
borne in mind, moreover, that Leidy, Cope, and Osborn each had another
medium of publication, which of course is true of other workers in the
great museums such as the American, National, and Carnegie, all of which
issue bulletins and quarto publications for the purpose of disseminating
the work of their staff. Many of the earlier announcements of the
discovery of vertebrate relics appeared in the Journal, as did
practically all the literature of the science of fossil footprints
(ichnology), except of course the larger quartos of Hitchcock and Deane.
Of the footprint papers by Hitchcock, Deane, and others, there were no
fewer than thirty-two, with a number of additional communications on
attendant phenomena bones and plants.
Up to 1847, except for a few foreign announcements, the Journal
published almost exclusively on eastern American paleontology, the only
exception being a notice of bones from Oregon by Perkins in 1842. In
1847 came the announcement of a western “Palæothere” by Prout, which
marked the beginning of the researches of Leidy and others in the Bad
Lands of the great Nebraska plains. The Journal thenceforth published
paper after paper on forms from all over North America, and on all
aspects of our science: discovery, systematic description, faunal
relationships, evolutionary evidences—thus showing that breadth and
catholicity which has made it so great a power in the advancement of
science.
VII
THE RISE OF PETROLOGY AS A SCIENCE