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invertebrate palaeontology. In the latter branch the author
is wholly indebted to Professor Amadeus W. Grabau of Columbia
University. The subject will be treated in its biological aspects,
because the relations of palaeontology to historical and strati-
graphic geology are more appropriately considered under the
article Geology. See also, for botany, the article Palaeo-
BOTANY. We may first trace in outline the history of the birth
of palaeontological ideas, from the time of their first adum-
bration. But for full details reference must be made to the
treatises on the history of the science cited in the bibliography
at the end of the article.

I. — First Historic Period 1

The scientific recognition of fossils as connected with the past
history of the earth, from Aristotle (384-322 B.C.) to the beginning
of the igth century, in connexion with the rise of comparative
anatomy and geology. — The dawn of the science covers the first
observation of facts and the rudiments of true interpretation.
Among the Greeks, Aristotle (384-322 B.C.) Xenophon (430~3S7
B.C.) and Strabo (63 b.c.-a.d. 24) knew of the existence of fossils
and surmised in a crude way their relation to earth history.
Similar prophetic views are found among certain Roman



PALAEONTOLOGY



Plate I.




Fig. I. — An ichthyosaur (/. quadriscissus) containing in the body cavity thu partially preserved skeletons of seven young, proving that
the young of the animal developed within the maternal body and were brought forth alive; i.e. that the ichthyosaur was a
viviparous animal. (Specimen presented to the American Museum of Natural Ilistory liy the Royal Museum of Stuttgart through
Kherhnrd Fran.s.\



Professor Eberhard Fraas.)



Fig. 2. — A hypothetical pictorial
restoration of the mother
ichthyosaur accompanied by
five of its newly born young,
from the information furnished
by actual fossils.

(From a drawing by Charles R.
Knight made under the direction of
Professor Osborn.)





Fig. 3. — One of the most pertect of the many specimens discovered and prepared by Herr Bernard Hauff, and showing the extra-
ordinary preservation of the epidermis of the ichthyosaur, which gives the complete contour of the body in silhouette, the out-
lines of the paddles, of the remarkably fish-like tail, into the lower lobe of which the vertebral column extends, and the great
integumentary dorsal fin.

Materials for the Restoration of Ichthyosaurs. — This plate illustrates the exceptional opportunity afforded the palaeontologist through
the remarkably preserved remains of Ichthyosaurs in the quarries of Holzmaden near Stuttgart, Wurttemberg, excavated for many years
by Herr Bernard Haufif. (Illustrations reproduced by permission from specimens in the American Museum of Natural History, New York.)
XX. 580.



Plate II.



PALAEONTOLOGY




Fig. 4.-SKEL1:T0N OF ALLOSAURUS.




"^^^^.m^a^










s**,- . ,*>»'



Fig. 5. -restoration OF ALLOSAURUS.

Materials for the Restoration of Dinosaurs. — Carnivorous dinosaur (Allosaurus) of the Upper Jurassic period of North .-Xmerica, an ani-
mal closely related to the Mcnalosaunis type of England. The skeleton (fig. 4) was found nearly complete in the beds of the Morrison
formation, Upper Jurassic of central Wyoming. U.S..\. Near it was discovered the posterior portion of the skeleton of a giant herbivorous
dinosaur (Brontosaurus Marsh). It was observed that ten of the caudal vertebrae of the latter skeleton bore tooth marks and grooves
corresponding exactly with the sharp pointed teeth in the jaw of the carnivorous dinosaur. This proved that the great herbivorous
dinosaur had been preyed upon by its smaller carnivorous contemporary. Teeth of the carnivorous dinosaur scattered among the bones
of the herbivorous dinosaur completed the line of circumstantial evidence. Upon this testimony the restoration (fig. 5) of the Megalosaur
has been drawn by Charles R. Knight under the direction of Professor Osborn.

{Originals reproduced by permission of the American Museum of Natural History.)



PALAEONTOLOGY



581



writers. The pioneers of the science in the i6lh and 17th cen-
turies put forth anticipations of some of the well-known modern
principles, often followed by recantations, through deference
to prevailing religious or traditional beliefs. There were the
retarding influences of the Mosaic account of sudden creation,
and the belief that fossils represented relics of a universal deluge.
There were crude medieval notions that fossils were " freaks "
or " sports " of nature (lusus nalurac), or that they represented
failures of a creative force within the earth (a notion of Greek
and Arabic origin), or that larger and smaller fossils represented
the remains of races of giants or of pygmies (the mythical
idea).

As early as the middle of the 15th century Leonardo da Vinci
(1452-1519) recognized in seashells as well as in the teeth of
marine fishes proofs of ancient sea-levels on what are now the
summits of the Apennines. Successive observers in Italy,
notably Fracastoro (1483-1553), Fabio Colonna (1567-1640 or
1650) and Nicolaus Steno (1638-c. 1687), a Danish anatomist,
professor in Padua, advanced the still embryonic science and
set forth the principle of comparison of fossil with living forms.
Near the end of the 17th century Martin Lister (1638-1712),
examining the Mesozoic shell types of England, recognized the
great similarity as well as the differences between these and
modern species, and insisted on the need of close comparison
of fossil and living shells, yet he clung to the old view that
fossils were sports of nature. In Italy, where shells of the sub-
Apennine formations were discovered in the extensive quarrying
for the fortifications of cities, the close similarity between these
Tertiary and the modern species soon led to the established
recognition of their organic origin. In England Robert Hooke
(1635-1703) held to the theory of extinction of fossil forms, and
advanced the two most fertile ideas of deriving from fossils a
chronology, or series of time intervals in the earth's history, and
of primary changes of climate, to account for the former existence
of tropical species in England.

The i8th century witnessed the development of these sugges-
tions and the birth of many additional theories. Sir A. Geikie
assigns high rank to Jean Etienne Guettard (171 5-1786) for
his treatises on fossils, although admitting that he had no clear
idea of the sequence of formations. The theory of successive
formations was .soundly developing in the treatises of John
Woodward (1665-1728) in England, of Antonio Vallisnieri
(1661-1730) in Italy, and of Johann Gottlob Lehmann (d. 1767)
in Germany, who distinguished between the primary, or unfos-
siliferous, and secondary or fossiliferous, formations. The begin-
nings of palaeogeography followed those of palaeometeorology.
The Italian geologist Soldani distinguished (1758) between the
fossil fauna of the deep sea and of the shore-lines. In the same
year Johann Gesner (170Q-17Q0) set forth the theory of a great
period of time, which he estimated at 80,000 years, for the eleva-
tion of the shell-bearing levels of the Apennines to their present
height above the sea. The brilliant French naturalist Georges
Louis Leclerc, comte de Buffon (i 707-1 788), in Lcs Epoqurs de
la nature, included in his vast speculations the theory of alternate
submergence and emergence of the continents. Abraham
Gottlob Werner (i 750-181 7), the famous exponent of the aqueous
theory of earth formation, observed in successive geological
formations the gradual approach to the forms of existing species.

II. — Second Historic Period
Invertebrate palaeontology founded by Lamarck, vertebrate
palaeontology by Cuvier. Palaeontology connected with compara-
tive anatomy by Cuvier. Invertebrate fossils employed for the
definite division of all the great periods of time. — Although pre-
evolutionary, this was the heroic period of the science, extending
from the close of the i8th century to the publication of Darwin's
Origin of Species in 1859. Among the pioneers of this period
were the vertebrate zoologists and comparative anatomists
Peter Simon Pallas, Pieter Camper and Johann Friedrich
Blumenbach. Pallas (1741-1811) in his great journey (i 768-1 774)
through Siberia discovered the vast deposits of extinct mammoths
and rhinoceroses. Camper (1722-1789) contrasted (1777) the



Pleistocene and recent species of elephants and Blumenbach
(1752-1840) separated (1780) the mammoth from the exisUng
species as Elephas primigenitis. In 1793 Thomas Pennant
(1726-1798) distinguished the American mastodon as Elephas
americanus.

Political troubles and the dominating influence of Werner's
speculations checked palaeontology in Germany, while under the
leadership of Lamarck and Cuvier France came to the fore.
J. B. Lamarck (1744-1829) was the founder of invertebrate
palaeontology. The treatise which laid the foundation for all
subsequent invertebrate palaeontology was his memoir, Sur
lcs fossiles des environs de Paris . . . (1802-1806). Beginning
in 1793 he boldly advocated evolution, and further elaborated
five great principles — namely, the method of comparison of
extinct and existing forms, the broad sequence of formations
and succession of epochs, the correlation of geological horizons
by means of fossils, the climatic or environmental changes as
influencing the development of species, the inheritance of the
bodily modifications caused by change of habit and habitat.
As a natural philosopher he radically opposed Cuvier and was
distinctly a precursor of uniformitarianism, advocating the
hypothesis of slow changes and variations, both in living forms
and in their environment. His speculations on phylogeny,
or the descent of invertebrates and vertebrates, were, however,
most fantastic and bore no relation to palaeontological evidence.

It is most interesting to note that William Smith (i 769-1 839),
now known as the " father of historical geology," was born in
the same year as Cuvier. Observing for himself (1794-1800)
the stratigraphic value of fossils, he began to distinguish the
great Mesozoic formations of England (1801). Cuvier (1769-
1832) is famous as the founder of vertebrate palaeontology,
and with Alexandre Brongniart (1770-1847) as the author of the
first exact contribution to stratigraphic geology. Early trained
as a comparative anatomist, the discovery of Upper Eocene
mammals in the gypsum quarries of Montniartre found him
fully prepared (1798), and in 1812 appeared his Recherchcs sur
lcs ossemeus fossiles, brilliantly written and constituting the
foundation of the modern study of the extinct vertebrates.
Invulnerable in exact anatomical description and comparison,
he failed in all his philosophical generalizations, even in those
strictly within the domain of anatomy. His famous " law of
correlation," which by its apparent brilliancy added enormously
to his prestige, is not supported by modern philosophical ana-
tomy, and his services to stratigraphy were diminished by his
generalizations as to a succession of sudden extinctions and
renovations of life. His joint memoirs with Brongniart, Essai
snr la geographic mineralogiqiie des environs de Paris avec une carte
g^ognostique et des coupes de terrain (1808) and Description g^o-
logique des environs de Paris (1835) were based on the wonderful
succession of Tertiary faunas in the rocks of the Paris basin.
In Cuvier's defence Charles Deperet maintains that the extreme
theory of successive extinctions followed by a succession of
creations is attributable to Cuvier's followers rather than to the
master himself. Deperet points also that we owe to Cuvier the
first clear expression of the idea of the increasing organic per-
fection of all forms of life from the lower to the higher horizons,
and that, while he believed that extinctions were due to sudden
revolutions on the surface of the earth, he also set forth the
pregnant ideas that the renewals of animal life were by migration
from other regions unknown, and that these migrations were
favoured by alternate elevations and depressions which formed
various land routes between great continents and islands.
Thus Cuvier, following Buffon, clearly anticipated the modern
doctrine of faunal migrations. His reactionary and retarding
ideas as a special creationist and his advocacy of the cataclysmic
theory of change exerted a baneful influence until overthrown by
the uniformitarianism of James Hutton (1726-1797) and Charles
Lyell (1797-1875) and the evolutionism of Darwin.

The chief contributions of Cuvier's great philosophical
opponent, Etienne Geoffroy St Hilaire (1772-1844), are to be
found in his maintenance with Lamarck of the doctrine of the
mutability of species. In this connexion he developed his



582



PALAEONTOLOGY



special theory of saltations, or of sudden modifications of
structure through changes of environment, especially through the
direct influences of temperature and atmosphere. He clearly set
forth also the phenomena of analogous or parallel adaptation.

It was Alcide Dessalines d'Orbigny (1802-1857) who pushed
to an extreme Cuvier's ideas of the fixity of species and of
successive extinctions, and finally developed the wild hypothesis
of twenty-seven distinct creations. WhUe these views were
current in France, exaggerating and surpassing the thought of
Cuvier, they were strongly opposed in Germany by such authors
as Ernst Friedrich von Schlotheim (i 764-1832) and Heinrich
Georg Bronn (1800-1862); and the latter demonstrated that
certain species actually pass from one formation to another.

In the meantime the foundations of palaeobotany were being
laid (1804) by Ernst Friedrich von Schlotheim (1764-1832),
(1811) by Kaspar Maria Sternberg (1761-1838) and (1838) by
Theophile Brongniart (1801-1876).

Following Cuvier's Recherclies stir les ossemens fossiles, the
rich succession of Tertiary mammalian life was gradually
revealed to France through the explorations and descriptions
of such authors as Croizet, Jobert, de Christol, Eymar, Pomel
and Lartet, during a period of rather dry, systematic work,
which included, however, the broader generalizations of Henri
Marie Ducrotay de Blainville (177S-1850), and culminated in
the comprehensive treatises on Tertiary palaeontology of Paul
Gervais (1816-1879). Extending the knowledge of the extinct
mammals of Germany, the principal contributors were Georg
August Goldfuss (1782-1848), Georg Friedrich von Jaegar
(1785-1866), Felix F. Plieninger (1807-1873) and Johann Jacob
Kaup (1S03-1S73). As Cuvier founded the palaeontology of
mammals and reptiles, so Louis Agassiz's epoch-making works
Rcclierches sur les poissons fossiles (1833-1845) laid the secure
foundations of palaeichthyology, and were followed by Christian
Heinrich Pander's (1794-1865) classic memoirs on the fossil
fishes of Russia. In philosophy Agassiz was distinctly a disciple
of Cuvier and supporter of the doctrine of special creation, and
to a more limited extent of cataclysmic extinctions. Animals
of the next higher order, the amphibians of the coal measures
and the Permian, were first comprehensively treated in the
masterly memoirs of Christian Erich Hermann von Meyer
(1801-1869) beginning in 1829, especially in his Beitrdge ziir
Pclrefactcnkimde (1829-1830) and his Ziir Fauna der Vorwelt
(4 vols., 1845-1860). Successive discoveries gradually revealed
the world of extinct Reptilia;in 182 1 Charles Konig (i 784-1851),
the first keeper of the mineralogical collection in the British
Museum, described Ichthyosaurus from the Jurassic; in the
same year William Daniel Conybeare (1787-1857) described
Plesiosaurus; and a year later (1822) Mosasaurus; in 1824
William Buckland described the great carnivorous dinosaur
Megalosanrus; while Gideon Algernon Mantell (1790-1852) in
1848 announced the discovery of Iguanodon. Some of the fossil
Reptilia of P'rance were made known through St Hilaire's
researches on the Crocodilia (1831), and those of J. A. Deslong-
champs (1794-1867) and his son on the teleosaurs, or long-
snouted crocodiles. Materials accumulated far more rapidly,
however, than the power of generalization and classification.
Able as von Meyer was, his classification of the Reptilia failed
because based upon the single adaptive characters of foot
structure. The reptiles awaited a great classifier, and such a
one appeared in England in the person of Sir Richard Owen
(1804-1892), the direct successor of Cuvier and a comparative
anatomist of the first rank. Non-committal as regards evolu-
tion, he vastly broadened the field of vertebrate palaeontology
by his descriptions of the extinct fauna of England, of South
America (including especially the great edentates revealed by
the voyage of the " Beagle "), of Australia (the ancient and
modern marsupials) and of New Zealand (the great struthious
birds). His contributions on the Mesozoic reptiles of Great
Britain culminated in his complete rearrangement and classifi-
cation of this group, one of his greatest services to palaeontology.
Meanwhile the researches of Hugh Falconer (1808-1865) and of
Proby Thomas Cautley (1802-1871) in the sub-Himalayas



brought to light the marvellous fauna of the Siwalik hills of
India, published in Fauna antiqua Sivalensis (London, 1845)
and in the volumes of Falconer's individual researches. The
ancient life of the Atlantic border of North America was also
becoming known through the work of the pioneer vertebrate
palaeontologists Thomas Jefferson (1743-1826), Richard Harlan
(1796-1843), Jeffries Wyman (1814-1874) and Joseph Leidy
(1823-1891). This was followed by the revelation of the vast
ancient life of the western half of the American continent, which
was destined to revolutionize the science. The master works
of Joseph Leidy began with the first-fruits of western exploration
in 1847 and extended through a series of grand memoirs, culmina-
ting in 1874. Leidy adhered strictly to Cuvier's exact descriptive
methods, and while an evolutionist and recognizing clearly the
genetic relationships of the horses and other groups, he never
indulged in speculation.

The history of invertebrate palaeontology during the second
period is more closely connected with the rise of historic geology
and stratigraphy, especially with the settlement of the great
and minor time divisions of the earth's history. The path-
breaking works of Lamarck were soon followed by the monu-
mental treatise of Gerard Paul Deshayes (1795-1875) entitled
Descriptions des coquilles fossiles dcs environs de Paris (1824-
1837), the first of a series of great contributions by this and other
authors. These and other early monographs on the Tertiary
shells of the Paris basin, of the environs of Bordeaux, and of the
sub-Apennine formations of Italy, brought out the striking
distinctness of these faunas from each other and from other
molluscan faunas. Recognition of this threefo'd character
led Deshayes to establish a threefold division of the Tertiary
based on the percentage of molluscs belonging to types now
living found in each. To these divisions LyeU gave in 1833 the
names Eocene, Miocene and Pliocene.

James Hutton (1726-1797) had set forth (1788) the principle
that during all geological time there has been no essential
change in the character of events, and that uniformity of law is
perfectly consistent with mutability in the results. Lyell
marshalled all the observations he could collect in support of
this principle, teaching that the present is the key to the past,
and arraying all obtainable evidence against the cataclysmic
theories of Cuvier. He thus exerted a potent influence on
palaeontology through his persistent advocacy of uniformi-
tarianism, a doctrine with which Lamarck should also be credited.
As among the vertebrates, materials were accumulating rapidly
for the great generalizations which were to follow in the third
period. De Blainville added to the knowledge of the shells
of the Paris basin; Giovanni Battista Brocchi (1772-1826) in
1814, and Luigi Bellardi (1818-1889) and Giovanni Michelotti
(born 1812) in 1840, described the Pliocene molluscs of the sub-
Apennine formation of Italy; from Germany and Austria
appeared the epoch-making works of Heinrich Ernst Beyrich
(1815-1896) and of Moritz Hoernes (1815-1868).

We shall pass over here the labours of Adam Sedgwick
(1785-1873) and Sir Roderick !Murchison (1792-1871) in the
Palaeozoic of England, which because of their close relation to
stratigraphy more properly concern geology; but must mention
the grand contributions of Joachim Barrande (1799-1883),
published in his Systcme silurien du centre de la Boheme, the first
volume of which appeared in 1852. While establishing the
historic divisions of the Silurian in Bohemia, Barrande also
propounded his famous theory of " colonies," by which he
attempted to explain the aberrant occurrence of strata con-
taining animals of a more advanced stage among strata
containing earlier and more primitive faunas; his assumption
was that the second fauna had migrated from an unknown
neighbouring region. It is proved that the specific instances
on which Barrande's generalizations were founded were due to
his misinterpretation of the overturned and faulted strata, but
his conception of the simultaneous existence of two faunas, one
of more ancient and one of more modern type, and of their
alternation in a given area, was based on sound philosophical
principles and has been confirmed by more recent work.



PALAEONTOLOGY



583



The greatest generalization of this second period, however,
was that partly prepared for by d'Orbigny, as will be more fully
explained later in this article, and clearly expressed by Agassiz
— namely, the law of repetition of ancestral stages of life in the
course of the successive stages of individual development. This
law of recapitulation, subsequently termed the " biogenetic
law " by Ernest Haeckel, was the greatest philosophic contri-
bution of this period, and proved to be not only one of the
bulwarks of the evolution theory but one of the most
important principles in the method of palaeontology.

On the whole, as in the case of vertebrate palaeontology,
the pre-Darwinian period of invertebrate palaeontology was one
of rather dry systematic description, in which, however, the
applications of the science gradually extended to many regions
of the world and to all divisions of the kingdom of invertebrates.

III. — Third Historic Period

Beginning with the publication of Darwin's great works,
" Narrative of the Surveying Voyages of H. M.S. 'Adventure' and
' Beagle ' " (1839), and " On the Origin of Species by Means of
Natural Selection " (1859). — A review of the two first classic
works of Charles Robert Darwin (1809-1882) and of their
influence proves that he was the founder of modern palaeon-
tology. Principles of descent and other applications of uniformi-
tarianism which had been struggling for expression in the
writings of Lamarck, St Hilaire and de Blainville here found
their true interpretation, because the geological succession, the
rise, the migrations, the extinctions, were all connected with
the grand central idea of evolution from primordial forms.

A close study of the exact modes of evolution and of the
philosoph)' of evolution is the distinguishing feature of this
period. It appears from comparison of the work in the two
great divisions of vertebrate and invertebrate palaeontology
made for the first time in this article that in accuracy of observa-
tion and in close philosophical analysis of facts the students of
invertebrate palaeontology led the way. This was due to the
much greater completeness and abundance of material afforded
among invertebrate fossils, and it was manifested in the demon-
st' .on of two great principles or laws: first, the law of recapitu-
lation, which is found in its most ideal expression in the shells
of invertebrates; second, in the law of direct genetic succession
through very gradual modification. It is singular that the second
law is still ignored by many zoologists. Both laws were of
paramount importance, as direct evidence of Darwin's theory
of descent, which, it will be remembered, was at the time
regarded merely as an hypothesis. Nevertheless, the tracing
of phylogeny, or direct lines of descent, suddenly began to
attract far more interest than the naming and description of
species.

Tlie Law of Recapitulation. Acceleration. Retardation. — This
law, that in the stages of growth of individual development



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