(1915) dinosaurs with special reference to the american museum

8/14/2019 (1915) Dinosaurs With Special Reference to the American Museum

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THE LIBRARYOFTHE UNIVERSITYOF CALIFORNIALOS ANGELES


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DINOSAURSW. D. MATTHEW

NEW YORKAMERICAN MUSEUM OF NATURAL HISTORY

1915

HANDBOOK SERIES No. 5.


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oCX


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DINOSAURSWITH SPECIAL REFERENCE TO

THE AMERICAN MUSEUM COLLECTIONSBY

W. D. MATTHEWCURATOR OF VERTEBRATE PALEONTOLOGY

. . . 'Dragons of the primeThat tare each other in their slime'

NEW YORKAMERICAN MUSEUM OF NATURAL HISTORY

1915


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GeologyLibra*

DINOSAURS.TABLE OF CONTENTS. D5M4

CHAPTER I. The Ago of Reptiles. Its Antiquity, Durationand Significance in Geological History 9CHAPTER II. North America in the Age of Reptiles.

Its Geographic and Climatic Changes 16CHAPTER III. Kinds of Dinosaurs. Common Characters and

Differences between the various Groups.Classification 25

CHAPTER IV. The Carnivorous Dinosaurs Allosaurus, Tyran-nosaurus, Ornitholestes, etc 33

CHAPTER V. The Amphibious Dinosaurs Brontosaurus,Diplodocus, etc 60

CHAPTER VI. The Beaked Dinosaurs.The Iguanodonts Iguanodon,Camptosaurus. . 75

CHAPTER VII. The Beaked Dinosaurs (continued).The Duckbilled Dinosaurs Trachodon, Sauro-lophus 82

CHAPTER VIII. The Beaked Dinosaurs (continued).The Armored Dinosaurs Stegosaurus, Ankylo-saurus 101

CHAPTER IX. The Beaked Dinosaurs (concluded).The Horned Dinosaurs Triceratops, etc 107CHAPTER X. Geographical Distribution of Dinosaurs 114CHAPTER XI. Collecting Dinosaurs. How and Where they

are Found. The First Discovery of Dinosaursin the West. The Bone-Cabin Quarry. FossilHunting by Boat in Canada 116


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PREFACE.This volume is in large part a reprint of various

popular descriptions and notices in the AmericanMuseum Journal and elsewhere by Professor HenryFairfield Osborn, Mr. Barnum Brown, and the writer.There has been a considerable demand for these articleswhich are now mostly out of print. In reprinting itseemed best to combine and supplement them so as tomake a consecutive and intelligible account of theDinosaur collections in the Museum. The originalnotices are quoted verbatim; for the remainder of thetext the present writer is responsible. Professor S. W.Williston of Chicago University has kindly contributeda chapter all too brief describing the first discoveriesof dinosaurs in the Western formations that have sinceyielded so large a harvest.The photographs of American Museum specimens areby Mr. A. E. Anderson; the field photographs by variousMuseum expeditions; the restorations by Mr. CharlesR. Knight. Most of these illustrations have beenpublished elsewhere by Professor Osborn, Mr. Brownand others. The diagrams, figs. 1-9, 24, 25, 37 and 40,are mv own. W. D. M.


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CHAPTER I.THE AGE OF REPTILES.

ITS ANTIQUITY, DURATION AND SIGNIFICANCE INGEOLOGIC HISTORY.

Palaeontology deals with the History of Life. Itstime is measured in geologic epochs and periods, inmillions of years instead of centuries. Man, by thismeasure, is but a creature of yesterday his "fortycenturies of civilization"* but a passing episode. It isby no means easy for us to adjust our perspective tothe immensely long spaces of time involved in geolog-ical evolution. We are apt to think of all these extinctanimals merely as prehistoric to imagine them allliving at the same time and contending with our cave-dwelling ancestors for the mastery of the earth.In order to understand the place of the Dinosaurs in

world-history, we must first get some idea of the lengthof geologic periods and the immense space of timeseparating one extinct fauna from another.

The Age of Man. Prehistoric time, as it is commonlyunderstood, is the time when barbaric and savage tribesof men inhabited the world but before civilizationbegan, and earlier than the written records on whichhistory is based. This corresponds roughly to the*Thc records of Egypt and Chaldaea extend back at least sixtycenturies.


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10 DINOSAURSPleistocene epoch of geology; it is included along withthe much shorter time during which civilization hasexisted, in the latest and shortest of the geologicalperiods, the Quaternary. It was the age of the mam-moth and the mastodon, the megatherium and Irishdeer and of other quadrupeds large and small whichare now extinct; but most of its animals were the samespecies as now exist. It was marked by the greatepisode of the Ice Age, when considerable parts of theearth's surface were buried under immense accumula-tions of ice, remnants of which are still with us in theicy covering of Greenland and Antarctica.

The Age of Mammals. Before this period was a verymuch longer one at least thirty times as long duringwhich modern quadrupeds were slowly evolving fromsmall and primitive ancestors into their present varietyof form and size. This is the Tertiary Period or Ageof Mammals. Through this long period we can tracestep by step the successive stages through which theancestors of horses, camels, elephants, rhinoceroses,etc., were gradually converted into their present formin adaptation to their various habits and environment.And with them were slowly evolved various kinds ofquadrupeds whose descendants do not now exist, theTitanotheres, Elotheres, Oreodonts, etc., extinct raceswhich have not survived to our time. Man, as such,had not yet come into existence, nor are we able totrace any direct and complete line of ancestry amongthe fossil species known to us; but his collateral an-


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THE AGE OF REPTILES 11cestors were represented by the fossil species of monkeysand lemurs of the Tertiary period.

The Age of Reptiles. Preceding the Age of Mammalslies a long vista of geologic periods of which the laterTHE LATER AGES OF GEOLOGIC TIME

Fig. 1. The Later Ages of Geologic Time.


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12 DINOSAURSones are marked by the dominance of Reptiles, and aregrouped together as the Age of Reptiles or MesozoicEra. This was the reign of the Dinosaurs, and in itwe are introduced to a world of life so different from thatof today that we might well imagine ourselves uponanother planet.None of the ordinary quadrupeds with which we are

familiar then existed, nor any related to nor resemblingt hem. But in their place were reptiles large and small,carnivorous and herbivorous, walking, swimming andeven flying.

Crocodiles, Turtles and 8ea Reptiles. The Crocodilesand Turtles of the swamps were not so very differentfrom their modern descendants; there were also sea-crocodiles, sea-turtles, huge marine lizards (Mosasaurs)\\ it h flippers instead of feet; and another group of greatmarine reptiles (Plesiosaurs) somewhat like sea-turtlesbut with long neck and toothed jaws and without anycarapace. These various kinds of sea-reptiles took theplace of the great sea mammals of modern times (whichwere evolved during the Age of Mammals); of whalesand dolphins, seals and walruses, and manatees.

Pterodactyls. The flying Reptiles or Pterosaurians,partly took the place of birds, and most of them were ofsmall size. Strange bat-winged creatures, the wingmembrane stretched on the enormously elongatedfourth finger, they are of all extinct reptiles the leastunderstood, the most difficult to reconstruct andvisualize as they were in life.


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THE AGE OF REPTILES li*Dinosaurs. The land reptiles were chiefly Dinosaurs,

a group which flourished throughout the Age of Reptilesand became extinct at its close. "Dinosaur" is ageneral term which covers as wide a variety in size andappearance as "Quadruped" among modern animals.And the Dinosaurs in the Age of Reptiles occupiedabout the same place in nature as the larger quadrupedsdo today. They have been called the Giant Reptiles,for those we know most about were gigantic in size, butthere were also numerous smaller kinds, the smallest nolarger than a cat. All of them had short, compactbodies, long tails, and long legs for a reptile, and insteadof crawling, they walked or ran, sometimes upon altfours, more generally upon the hind limbs, like ostriches,the long tail balancing the weight of the body. Somemodern lizards run this way on occasion, especiallyif they are in a hurry. But the bodies of lizards are toolong and their limbs too small and slender for this to bethe usual mode of progress, as it seems to have beenamong the Dinosaurs.ANIMALS OF THE AGE OF REPTILES.LAND REPTILES.DINOSAURS corresponding to the larger quadrupeds or landmammals of today.CROCODILES, LIZARDS AND TURTLES still surviving.SEA REPTILES.PLESIOSAURS 1 corresponding to whales, dolphins, seals, etc.,ICHTHYOSAURS \ or sea-mammals of today.MOSASAURSFLYING REPTILES OR PTEROSAURS.BIRDS WITH TEETH (scarce and little known).PRIMITIVE MAMMALS of minute size (scarce and little known).FISHES and INVERTEBRATES many of them of extinct races, allmore or less different from modern kinds.


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1 4 DINOSAURSFishes, large and small, were common in the seas and

rivers of the Age of Reptiles but all of them were moreor less different from modern kinds, and many belongedto ancient races now rare or extinct.The lower animals or Invertebrates were also different

from those of today, although some would not be verynoticeably so at first glance. Among molluscs, theAmmonites, related to the modern Pearly Nautilus, arean example of a race very numerous and varied duringall the periods of the Reptilian Era, but disappearingat its close, leaving only a few collateral descendants inthe squids, cuttlefish and nautili of the modern seas.The Brachiopods were another group of molluscs, orrather molluscoids for they were not true molluscs, lessabundant even then than in previous ages and now sur-viving only in a few rare and little known types such asthe lamp-shell ( Terebratulina) .

Insects. The Insect life of the earlier part of the Ageof Reptiles was notable for the absence of all the highergroups and orders, especially those adapted to feed onflowers. There were no butterflies or moths, no beesor wasps or ants although there were plenty of dragon-flies, cockroaches, bugs and beetles. But in the latterpart of this era, all these higher orders appeared alongwith the flowering plants and trees.

Plants. The vegetation in the early part of the erawas very different both from the gloomy forests of themore ancient Coal Era and from that which prevailstoday. Cycads, ferns and fern-like plants, coniferous


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THE AGE OF REPTILES 15trees, especially related to the modern Araucaria orNorfolk Island Pine, Ginkgos still surviving in China,and huge equisetae or horsetail rushes, still surviving inSouth American swamps and with dwarfed relativesthroughout the world, were the dominant plant typesof that era. The flowering plants and deciduous treeshad not appeared. But in the latter half of the erathese appeared in ever increasing multitudes, displacingthe lower types and relegating them to a subordinateposition. Unlike the more rapidly changing higheranimals these ancient Mesozoic groups of plants havenot wholly disappeared, but still survive, mostly intropical and southern regions or as a scanty remnant incontrast with their once varied and dominant role.There is every reason to believe that upon the appear-

ance of these higher plants whose flower and fruitafforded a more concentrated and nourishing food,depended largely the evolution of the higher animallife both vertebrate and insect, of the Cenozoic ormodern era.


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CHAPTER II.NORTH AMERICA IN THE AGE OF REPTILES.

ITS GEOGRAPHIC AND CLIMATIC CHANGES.North America in the Age of Reptiles would have

seemed almost as strange to our eyes in its geography asin its animals and plants. The present outlines of itscoast, its mountains and valleys, its rivers and lakes,have mostly arisen since that time. Even the moreancient parts of the continent have been profoundlymodified through the incessant work of rain and riversand of the waves, tending to wear down the land sur-faces, of volcanic outbursts building them up, and ofI IK- more mysterious agencies which raise or depressvast stretches of mountain chains or even the wholearea of a continent, and which tend on the whole so faras we can see, to restore or increase the relief of thecontinents, as the action of the surface waters tends tobring them down to or beneath the sea level.

Alternate Overflow and Emergence of Continents. Ina broad way these agencies of elevation and of erosionhave caused in their age-long struggle an alternation ofperiods of overflow and periods of continental emergenceduring geologic time. During the periods of overflow,great portions of the low-lying parts of the continentswere submerged, and formed extensive but compara-tively shallow seas. The mountains through long


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GEOGRAPHIC AND CLIMATIC CHANGES 1?

Fig. 2. North America in the Later Cretacic Period. Map outlines afterSchuchert.continued erosion were reduced to gentle and uniformslopes of comparatively slight elevation. Their ma-terials were brought down by rivers to the sea-coast,and distributed as sedimentary formations over the


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18 DINOSAURSshallow interior seas or along the margins of the conti-nents. But this load of sediments, transferred fromthe dry land to the ocean margins and shallow seas,disturbed the balance of weight (isostasy) whichnormally keeps the continental platforms above thelevel of the ocean basins (which as shown by gravitymeasurement are underlain by materials of higherspecific gravity than the continents). In due course oftime, when the strain became sufficient, it was read-justed by earth movements of a slowness proportionedto their vastness. These movements while tendingupon the whole to raise the continents to or sometimesbeyond their former relief, did not reverse the action oferosion agencies in detail, but often produced new linesor areas of high elevation.

Geologic Periods. A geologic period is the record ofone of these immense and long continued movements ofalternate submergence and elevation of the continents.It begins, therefore, and ends with a time of emergence,and includes a long era of submergence.

These epochs of elevation are accompanied by thedevelopment of cold climates at the poles, and else-where of arid conditions in the interior of the conti-nents. The epochs of submergence are accompaniedby a warm, humid climate, more or less uniform fromthe equator to the poles.The earth has very recently, in a geologic sense,passed through an epoch of extreme continental eleva-tion the maximum of which was marked by the "Ice


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GEOGRAPHIC AND CLIMATIC CHANGES 19Age." The continents are still emerged for the mostpart almost to the borders of the "continental shelf"which forms their maximum limit. And in the icycovering of Greenland and Antarctica a considerableportion still remains of the great ice-sheets which attheir maximum covered large parts of North Americaand Europe. We are now at the beginning of a longperiod of slow erosion and subsidence which, if thisinterpretation of the geologic record be correct, will inthe course of time reduce the mountains to plains andsubmerge great parts of the lowlands beneath the

. . = 1 million years AGE OFThe duration of uvijizafion, upon fKi's scale, would, be represented

by a lm< JZOQ l'Tlc '1 thick > quit* I'livis/fc/e. to the eye .Fig. 3. Relative Length of Ages of Reptiles, Mammals and Man.

ocean. As compensation for the lesser extent of dryland we may look forward to a more genial and favor-able climate in the reduced areas that remain abovewater.

Length of Geologic Cycles. But these vast cycles ofgeographic and climatic change will take millions ofyears to accomplish their course. The brief span ofhuman life, or even the few centuries of recorded civil-ization are far too short to show any perceptible changein climate due to this cause. The utmost stretch of a


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20 DINOSAURSman's life will cover perhaps one-two hundred thou-sandth part of a geologic period. The time elapsedsince the dawn of civilization is less than a three-thou-sandth part. Of the days and hours of this geologicyear, our historic records cover but two or three minutes,our individual lives but a fraction of a second. We mustnot expect to find records of its changing seasons inhuman history, still less to observe them personally.

There are indeed minor cycles of climate within thisgreat cycle. The great Ice Age through which theearth has so recently passed was marked by alternations

AGE OFP R E H I S-T R 1 C

u - 1 thousand years The Sixfy Cenfar res of Cw/i'zafioUpon tins scale- tJ keqiWng of tht A


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GEOGRAPHIC AND CLIMATIC CHANGES 21rivalled that of the Glacial Epoch and was similarlyaccompanied by extensive glaciation of which sometraces are preserved to our day in characteristic glacialboulders, ice scratches, and till, imbedded or inter-stratified in the strata of the Permian age. Betweenthese two extremes of continental emergence, thePermian and the Pleistocene, we can trace six cycles ofalternate submergence and elevation, as shown in thediagram (Fig. 5), representing the proportion ofNorth America which is known to have been abovewater during the six geologic periods that intervene.From this diagram it will appear that the six cyclesor periods were by no means equal in the amount ofoverflow or complete recovery of the drowned lands.The Cretacic period was marked by a much moreextensive and long continued flooding; the great plainswest of the Mississippi were mostly under water fromthe Gulf of Mexico to the Arctic Ocean. The earlieroverflows were neither so extensive nor so long con-tinued. The great uplift of the close of the Cretacicregained permanently the great central region andunited East and West, and the overflows of the Age ofMammals were mostly limited to the South Atlanticand Gulf coasts.

Sedimentary Formations. During the epochs ofgreatest overflow great marine formations were depos-ited over large areas of what is now dry land. Thesewere followed as the land rose to sea level by extensivemarsh and delta formations, and these in turn by


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DINOSAURSscattered and fragmentary dry land deposits spread byrivers over their flood plains. In the marine formationsare found the fossil remains of the sea-animals of theperiod; in the coast and delta formations are the

-Geologic Cycles andstch1fuLand )Area of North America (after

remains of those which inhabited the marshes andrests of the coast regions; while the animals of thedryland, of plains and upland, left their remains in theriver-plain formations.


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GEOGRAPHIC AND CLIMATIC CHANGES 23These last, however, fragmentary and loose and over-

lying the rest, were the first to be swept away by erosionduring the periods of elevation; and of such formationsin the Age of Reptiles very little, if anything, seems tohave been preserved to our day. Consequently weknow very little about the upland animals of thosetimes, if as seems very probable, they were more orless different from the animals of the coast-forests andswamps. The river-plain deposits of the Age ofMammals on the other hand, are still quite extensive,especially those of its later epochs, and afford a fairlycomplete record in some parts of the continent of theupland fauna of those regions.

Occurrence of Dinosaur Bones. Dinosaur bones arefound mostly in the great delta formations, and sincethose were accumulated chiefly in the early stages ofgreat continental elevations, it follows that ouracquaintance with Dinosaurs is mostly limited to thoseliving at certain epochs during the Age of Reptiles. Inpoint of fact so far as explorations have yet gone in thiscountry, the Dinosaur fauna of the close of the Jurassicand beginning of the Comanchic and that of thelater Cretacic are the only ones we know much about.The immense interval of time that preceded, and theno less vast stretch of time that separated them, isrepresented in the record of Dinosaur history by amultitude of tracks and a few imperfect skeletonsassigned to the close of the Triassic period, and by afew fragments from formations which may be inter-


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24 DINOSAURSmediate in age between the Jurassic-Comanchic andthe late Cretacic. Consequently we cannot expect totrace among the Dinosaurs, the gradual evolution ofdifferent races, as we can do among the quadrupeds ofthe Age of Mammals.

Imperfection of the Geologic Record. The Age ofMammals in North America presents a moving pictureof the successive stages in the evolution of modernquadrupeds; the Age of Reptiles shows (broadly con-sidered) two photographs representing the land verte-brates of two long distant periods, as remote in timefrom each otlier as the later one is remote from thepresent day. Of the earlier stages in the evolution ofthe Dinosaurs there are but a few imperfect sketches inthis country; in Europe the picture is more complete.In the course of time, as exploration progresses, we shallno doubt recover more complete records. But probablywe shall never have so complete a history of the ter-restrial life of the Age of Reptiles as we have of the Ageof Mammals. The records are defective, a large partof them destroyed or forever inaccessible.


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CHAPTER III.KINDS OF DINOSAURS.

COMMON CHARACTERS AND DIFFERENCES BETWEENTHE VARIOUS GROUPS.

In the preceding chapter we have attempted to pointout the place in nature that the Dinosaurs occupied andthe conditions under which they lived. They were thedominant land animals of their time, just as the quadru-peds were during the Age of Mammals. Their swayendured for a long era, estimated at nine millions ofyears, and about three times as long as the period whichhas elapsed since their disappearance. They survivedvast changes in geography and climate, and becameextinct through a combination of causes not fullyunderstood as yet; probably the great changes inphysical conditions at the end of the Cretacic period,and the development of mammals and birds, moreintelligent, more active, and better adapted to the newconditions of life, were the most important factors intheir extinction.The Dinosaurs originated, so far as we can judge, as

lizard-like reptiles with comparatively long limbs, longtails, five toes on each foot, tipped with sharp claws,and with a complete series of sharp pointed teeth. Itwould seem probable that these ancestors were more


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DINOSAURSor less bipedal, and adapted to live on dry land. Theywere probably much like the modern lizards in size,appearance and habitat:*From this ancestral type the Dinosaurs evolved intoa great variety of different kinds, many of them ofgigantic size, some herbivorous, some carnivorous; somebipedal, others quadrupedal; many of them protectedby various kinds of bony armor-plates, or providedwith horns or spines; some with sharp claws, otherswith blunted claws or hoofs.These various kinds of Dinosaurs are customarily

grouped as follows:

Duck- billed Dinosa. of Dino.urs. Scale about nineteen

*If some vast catastrophe should today blot nut all traces including man, and the birds, but leave thVlIr


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KINDS OF DINOSAURSI. Carnivorous Dinosaurs or Theropoda. With sharp

pointed teeth, sharp claws; bipedal, with bird-like hindfeet, generally three-toed;* the fore-limbs adapted forgrasping or tearing, but not for support of the body.

Horned DinTRIC ERATO P S ared DinosaurANK YLOSAURU SFig. 7. Skulls of Dinosaurs, illustrating the principal types AnchisaurusafteriMarsh, the others from American Museum specimens.The head is large, neck of moderate length, body un-armored. The principal Dinosaurs of this group inAmerica are

Allosaurus, Ornitholestes Upper Jurassic period."The ancestral types have four complete toes, but in the true Thero-poda the inner digit is reduced to a small incomplete remnant, its clawreversed and projecting at the back of the foot, as in birds.


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28 DINOSAURS

Tyrannosaurus, Deinodon, Albertosaurus, Ornith-omimus Upper Cretacic period.

II. Amphibious Dinosaurs or Sauropoda. Withblunt-pointed teeth and blunt claws, quadrupedal, withelephant-like limbs and feet, long neck and small head.Unarmored. Principal dinosaurs of this group inAmerica are Brontosaurus, Diplodocus, Camarasaurust.Moroxaunis) and Brachiosaurus, all of the UpperJurassic and Comanchic periods.III. Beaked Dinosaurs or Predentates. With ahorny beak on the front of the jaw, cutting or grindingteeth behind it. All herbivorous, with pelvis of peculiartype, with hoofs instead of claws, and many generaheavily armored. Mostly three short toes on the hindfoot, four or five on the fore foot. This group com-prises animals of very different proportions as follows:

1. Iguanodonts. Bipedal, unarmored, with a singlerow of serrated cutting teeth, three-toed hind feet.Upper Jurassic, Comanchic and Cretacic. Camp-tosaurus is the best known American genus.

2. Trachodonts or Duck-billed Dinosaurs. Like theIguanodonts but with numerous rows of small teeth setclose together to form a grinding surface. Cretacicperiod. Trachodon, Hadrosaurus, Claosaurus, Saurolo-phus, Corythosaurus, etc.

3. Stegosaurs or Armored Dinosaurs. Quadrupedaldinosaurs with elephantine feet, short neck, small head,body and tail armored with massive bony plates andoften with large bony spines. Teeth in a single row,


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KINDS OF DINOSAURS

BEAKED D/NOSAURS(TRACHODON)

AMPHIB/OUS( BRONTOSAURUS)

Fig. 8. Hind Feet of Dinosaurs, to show the three chief types (Theropoda,Orthopoda, Sauropoda).


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30 DINOSAURSlike those of Iguanodonts. Stegosaurus of the UpperJurassic, Ankylosaurus of the Upper Cretacic.

4. Ceratopsian or Horned Dinosaurs. Quadrupedalwith elephantine feet, short neck, very large head en-larged by an enormous bony frill covering the neck,with a pair of horns over the eyes and a single horn infront. Teeth in a single row, but broadened out andadapted for grinding the food. No body armor.Triceratops is the best known type. Monoclonius,Ceratops, Torosaurus and Anchiceratops are also of thisgroup. All from the Cretacic period.

Classification of Dinosaurs. It is probable that theDinosaurs are not really a natural group or order ofreptiles, although they have been generally so con-sidered. The Carnivorous and Amphibious Dinosaursin spite of their diverse appearance and habits, arerather nearly related, while the Beaked Dinosaurs forma group apart, and may be descendants of a differentgroup of primitive reptiles. These relations are mostclearly seen in the construction of the pelvis (see fig. 9).In the first two groups the pubis projects downward andforward as it does in the majority of reptiles, and theilium is a high rounded plate; while in the others thepelvis is of a wholly different type, strongly suggestingthe pelvis of birds.Recent researches upon Triassic dinosaurs, especially

by the distinguished German savants, Friedrich vonHuene, Otto Jaekel and the late Eberhard Fraas, andthe discovery of more complete specimens of these


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KINDS OF DINOSAURS 31CARNIVOROUS DINOSAURS AMPHIBIOUS DINOSAURS

( TH E ROPODA) (SAU ROPO OA )

B E A K E D D/NOSAUKS ( P ft DE N TA TA )Fig. 9. Pelves^of Dinosaurs illustrating the two chief types (Saurischia,Ornithischia) and their variations.


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32 DINOSAURSanimals, also clear up the true relationships of theseprimitive dinosaurs which have mostly been referredhitherto to the Theropoda or Megalosaurians. Thefollowing classification is somewhat more conservativethan the arrangement recently proposed by von Huene.ORDER SAURISCHIA Seeley.Suborder Coelurosa uria von Huene (=Compsognatha Huxley, Sym-phypoda Cope.)Fam. Podokesauridae Triassic, Connecticut." Hallopodidse Jurassic, Colorado.

Coeluridae Jurassic and Comanchic, North America." Compsognathidae Jurassic, Europe.Suborder Pachypodosauria von Huene.Fam. Anchisauridae Triassic, North America and Europe.

*. Europe.-Suborder Theropoda Marsh (=Goniopoda Cope)

Fara. Megalosauridae Jurassic and Comanchic.Deinodontidae Cretacic.Ornithomimidae Cretacic, North America.Suborder Sauropoda Marsh (=Opisthocoelia Owen, CetiosauriaSeeley.)Fam. Cetiosaurida;

]Morosauridae [Jurassic and Comanchic.Diplodocidae jOrder ORNITHISCHIA Seeley (=Orthopoda Cope, Predentata Marsh.)Suborder OrnUhopoda Marsh (Iguanodontia Dollo)Fam. Nanosauridae Jurassic. Colorado."Camptosauridae 1 TIguanodontida; )Jurasslc and Comanchic." Trachodontidae (=Hadrosaurid{e), Cretacic.Suborder Stegosaurm Marsh.Fam. Scelidosauridse \ TStegosauridaB JJurassic and Comanchic." Ankylosauridae (=Nodosaurida?), CretacicSuborder Ceratopsin Marsh.Fam. Ceratopsidae Cretacic.

to the Thero-


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CHAPTER IV.THE CARNIVOROUS DINOSAURS, ALLOSAU-RUS, TYRANNOSAURUS, ORNITHOLESTES,

ETC.SUB-ORDER THEROPODA.The sharp teeth, compressed and serrated like a

palaeolithic spear point, and the powerful sharp-pointedcurved claws on the feet, prove the carnivorous habitsof these dinosaurs. The well-finished joints, densetexture of the hollow bones and strongly marked muscle-scars indicate that they were active and powerful beastsof prey. They range from small slender animals up tothe gigantic Tyrannosaurus equalling the modernelephant in bulk. They were half lizard, half bird inproportions, combining the head, the short neck andsmall fore limbs and long snaky tail of the lizard withthe short, compact body, long powerful hind limbs andthree-toed feet of the bird. The skin was probablyeither naked or covered with horny scales as in lizardsand snakes; at all events it was not armor-plated as inthe crocodile.* They walked or ran upon the hindlegs; in many of them the fore limbs are quite unfittedThis is still doubtful in Tyrannosaurus. A number of very curious

plates were found with one specimen in a quarry. B. Brown, 1913.


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DINOSAURSfor support of the body and must have been used solelyin fighting or tearing their prey.The huge size of some of these Mesozoic beasts of

prey finds no parallelamong their modernanalogues. It isonly among marineanimals that we findpredaceous types ofsuch gigantic size.But among the car-nivorous dinosaurswe fail to find anyindications of aqua-tic or even amphibi-ous habits. Theymight indeed wadein the water, butthey could hardlybe at home in it, forthey were clearlynot good swimmers.We must supposethat they were dryland animals or atFig 1a Hind Limb of Allosaurus, Dr JL. Wortman standing to one side. Dr'Wortman is one of the most notable andsuccessful collectors of fossil vertebratesand was in charge of the Museum's fieldwork in this department from 1891-1898. most swamp dwell-ers.

Dinosaur Footprints. The ancestors of the Thero-poda appear first in the Triassic period, already of large


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THE CARNIVOROUS DINOSAURS 35size, but less completely bipedal than their successors.Incomplete skeletons have been found in the Triassicformations of Germany* but in this country they arechiefly known from the famous fossil footprints (or"bird-tracks" as they were at first thought to be),found in the flagstone quarries at Turner's Falls on theConnecticut River, in the vicinity of Boonton, NewJersey, and elsewhere. These tracks are the footprintsof numerous kinds of dinosaurs, large and small, mostlyof the carnivorous group, which lived in that region inthe earlier part of the Age of Reptiles, and much hasbeen learned from them as to the habits of the animalsthat made them. The tracks ascribed to carnivorousdinosaurs run in series with narrow tread, short or longsteps, here and there a light impression of tail or fore-foot and occasionally the mark of the shank and pelviswhen the animal settled back and squatted down to resta moment. The modern crocodiles when they lift thebody off the ground, waddle forward with the shortlimbs wide apart, and even the lizards which run on theirhind legs have a rather wide tread. But these dino-saurs ran like birds, setting one foot nearly in front ofthe other, so that the prints of right and left feet arenearly in a straight line. This was on account of theirgreater length of limb, which made it easy for them to

*Quite recently a series of more or less complete skeletons have beensecured from the upper Triassic (Keuper) near Halberstadt in Germany.They are not true Megalosaurians, but primitive types (Pachypodosau-ria) ancestral to both these and the Sauropoda. Probably many of theConnecticut footprints were mad'e by animals of this primitive group.Anchisaurus certainly belongs to it.


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36 DINOSAURS

swing the foot directly underneath the body at eachstep like mammals and birds, and thus maintain an evenbalance, instead of wabbling from side to side as shortlegged animals are compelled to do.Of the animals that made these innumerable tracks

the actual remains found thus far in this country areexceedingly scanty. Two or three incomplete skeletonsof small kinds are in the Yale Museum, of whichAnchisqurus is the best known.Megahsaurus. Fragmentary remains of this huge

carnivorous dinosaur were found in England nearly acentury ago, and the descriptions by Dean Bucklandand Sir Richard Owen and the restorations due to theimaginative chisel of Waterhouse Hawkins, have madeit familar to most English readers. Unfortunately itwas, and still remains, very imperfectly known. It wasvery closely related to the American Allosaurus andunquestionably similar in appearance and habits.*

The following extract is from theALLOSAURUS. American Museum Journal forJanuary 1908.**

"Although smaller than its huge contemporaryBrontosaurus, this animal is of gigantic proportionsbeing 34 feet 2 inches in length, and 8 feet 3 inches high.

*It is evidently "the dinosaur" of Sir Conan Doyle's "Lost World"but the vivid description which the great English novelist gives of itsappearance and habits, based probably upon the Hawkins restoration,is not at all in accord with inferences from what is now known of theseanimals. See p. 44.**Allosaurus, a carnivorous Dinosaur, and its Prey. By W. D.Matthew. Am. Mus. Nat. Hist. Jour. Vol. viii, pp. 3-5, pi. 1.


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THE CARNIVOROUS DINOSAURS 37


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History of the Allosaurus Skeleton. "This rare andfinely preserved skeleton was collected by Mr. F. F.Hubbell in October 1879, in the Como Bluffs nearMedicine Bow, Wyoming, the richest locality inAmerica for dinosaur skeletons, and is a part of thegreat collection of fossil reptiles, amphibians and fishesgathered together by the late Professor E. D. Cope,and presented to the American Museum in 1899 byPresident Jesup."Shortly after the Centennial Exposition (1876) ithad been planned that Professor Cope's collection offossils should form part of a great public museum inFail-mount Park, Philadelphia, the city undertaking thecost of preparing and exhibiting the specimens, anarrangement similar to that existing between the Ameri-can Museum and the City of New York.*"The plan, however, fell through, and the greater part

of this magnificent collection remained in storage in thebasement of Memorial Hall in Fairmount Park, for thenext twenty years. From time to time Professor Coperemoved parts of the collection to his private museumin Pine Street, for purposes of study and scientificdescription. He seems, however, to have had no ideaof the perfection and value of this specimen. In 1899when the collection was purchased from his executorsby Mr. Jesup, the writer went to Philadelphia under theinstructions of Professor Osborn, Curator of FossilVertebrates, to superintend the packing and removal to*The cost of preparation is now defrayed by the Museum.


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THE CARNIVOROUS DINOSAURS 39the American Museum. At that time the collectionmade by Hubbell was still in Memorial Hall, and theboxes were piled up just as they came in from the West,never having been unpacked. Professor Cope's assist-ant, Mr. Geismar, informed the writer that Hubbell'scollection was mostly fragmentary and not of any greatvalue. Mr. Hubbell's letters from the field unfortu-nately were not preserved, but it is likely that they didnot make clear what a splendid find he had made, andas some of his earlier collections had been fragmentaryand of no great interest, the rest were supposed to be ofthe same kind."When the Cope Collection was unpacked at the

American Museum, this lot of boxes, not thought likelyto be of much interest, was left until the last, and nottaken in hand until 1902 or 1903. But when this speci-men was laid out, it appeared that a treasure had cometo light. Although collected by the crude methods ofearly days, it consisted of the greater part of the skele-ton of a single individual, with the bones in wonder-fully fine preservation, considering that they had beenburied for say eight million years. They were denseblack, hard and uncrushed, even better preserved andsomewhat more complete than the two fine skeletonsof Allosaurus from Bone-Cabin Quarry, the greatesttreasures that this famous quarry had supplied. Thegreat carnivorous dinosaurs are much rarer than theherbivorous kinds, and these three skeletons are themost complete that have ever been found. In all the


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40 DINOSAURS

years of energetic exploration that the late ProfessorMarsh devoted to searching for dinosaurs in the Jurassicand Cretaceous formations of the West, he did not ob-tain any skeletons of carnivorous kinds anywhere nearas complete as these, and their anatomy was in manyrespects unknown or conjectural. By comparison ofthe three Allosaurus skeletons with one another andwith other specimens of carnivorous dinosaurs ofsmaller size in this and other museums, particularly inthe National Museum and the Kansas UniversityMuseum, we have been able to reconstruct the missingparts of the Cope specimen with very little possibilityof serious error.

Evidence for Combining and Posing this Mount. "Anincomplete specimen of Brontosaurus, found by DoctorWortman and Professor W. C. Knight of the AmericanMuseum Expedition of 1897, had furnished interestingdata as to the food and habits of Allosaurus, which wereconfirmed by several other fragmentary specimensobtained later in the Bone-Cabin Quarry. In thisBrontosaurus skeleton several of the bones, especiallythe spines of the tail vertebrae, when found in the rock,looked as if they had been scored and bitten off, asthough by some carnivorous animal which had eitherattacked the Brontosaurus when alive, or had feastedupon the carcass. When the Allosaurus jaw was com-pared with these score marks, it was found to fit themexactly, the spacing of the scratches being the same asthe spacing of the teeth. Moreover, on taking out the


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THE CARNIVOROUS DINOSAURS 41Brontosaurus vertebrae from the quarry, a number ofbroken off teeth of Allosaurus were found lying besidethem. As no other remains of Allosaurus or any otheranimal were intermingled with the Brontosaurus skele-ton, the most obvious explanation was that these teethwere broken off by an Allosaurus while devouring theBrontosaurus carcass. Many of the bones of otherherbivorous dinosaurs found in the Bone-Cabin Quarrywere similarly scored and bitten off, and the teeth ofAllosaurus were also found close to them."With these data at hand the original idea was con-

ceived of combining these two skeletons, both from thesame formation and found within a few miles of eachother, to represent what must actually have happenedto them in the remote Jurassic period, and mount theAllosaurus skeleton standing over the remains of aBrontosaurus in the attitude of feeding upon its carcass.Some modifications were made in the position to suitthe exigencies of an open mount, and to accommodatethe pose to the particular action ; the head of the animalwas lifted a little, one hind foot planted upon the car-cass, while the other, resting upon the ground bearsmost of the weight. The fore feet, used in theseanimals only for fighting or for tearing their prey, notfor support, are given characteristic attitudes, and thewhole pose represents the Allosaurus devouring thecarcass and raising head and fore foot in a threateningmanner as though to drive away intruders. Thebalance of the various parts was carefully studied and


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42 DINOSAURSadjusted under direction of the curator. The prepara-tion and mounting of the specimen were done by Mr.Adam Hermann, head preparator, and his assistants,especially Messrs. Falkenbach and Lang."As now exhibited in the Dinosaur Hall, this group

gives to the imaginative observer a most vivid pictureof a characteristic scene in that bygone age, millions ofyears ago, when reptiles were the lords of creation, and

Fig. 12. Restoration of Allosaurus by C. R. Kni'Nature, red in tooth and claw' had lost none of herprimitive savagery, and the era of brute force andferocity showed little sign of the gradual ameliorationwhich was to come to pass in future ages through thepredominance of superior intelligence."Appearance and Habits of Allosaurus. A study of

the mechanism of the Allosaurus skeleton shows us inthe first place that the animal is balanced on the hind


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THE CARNIVOROUS DINOSAURS 43limbs, the long heavy tail making an adequate counter-poise for the short compact body and head. The hindlimbs are nine feet in length when extended, about equalto the length of the body and neck, and the bones aremassively proportioned. When the thigh bone is setin its normal position, as indicated by the position ofthe scars and processes for attachment of the principalmuscles (see under Brontosaurus for the method usedto determine this), the knee bends forward as in mam-mals and birds, not outward as in most modern reptiles.The articulations of the foot bones show that the animalrested upon the ends of the metapodials, as birds andmany mammals do, not upon the sole of the foot likecrocodiles or lizards. The flat vertebral joints showthat the short compact body was not as flexible as thelonger body of crocodiles or lizards, in which the artic-ulations are of the ball and socket type showing thatin them this region was very flexible. The tail alsoshows a limited flexibility. It could not be curled orthrown over the back, but projected out behind theanimal, swinging from side to side or up and down asmuch as was needed for balance. The curvature of theribs shows that the body was narrow and deep, unlikethe broad flattened body of the crocodile or the lessflattened but still broad body of the lizard. The loosehung jaw, articulated far back, shows by the set of itsmuscles that it was capable of an enormous gape;while in the skull there is evidence of a limited move-ment of the upper jaw on the cranial portion, intended


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44 DINOSAURSprobably to assist in the swallowing of large objects,like the double jointed jaw of a snake.As to the nature of the skin we have no exact knowl-edge. We may be sure that it had no bony armor like

the crocodile, for remains of any such armor could notfail to be preserved with the skeletons, as it always is infossil crocodiles or turtles. Perhaps it was scaly likethe skin of lizards and snakes, for the horny scales ofthe body are not preserved in fossil skeletons of thesereptiles. But if so we might expect from the analogyof the lizard that the scales of the head would be ossifiedand preserved in the fossil; and there is nothing of thiskind in the Carnivorous Dinosaurs. We can excludefeathers from consideration, for these dinosaurs haveno affinities to birds, and there is no evidence forfeathers in any dinosaur. Probably the best evidenceis that of the Trachodon or duck-billed dinosaur al-though this animal was but distantly related to theAllosaurus. In Trachodon (see p. 94), we know thatthe skin bore neither feathers nor overlapping scalesbut had a curiously patterned mosaic of tiny polygonalplates and was thin and quite flexible. Some suchtype of skin as this, in default of better evidence, wemay ascribe to the Allosaurus.As to its probable habits, it is safe to infer (see p. 33),that it was predaceous, active and powerful, and

adapted to terrestrial life. Its methods of attack andcombat must have been more like those of modernreptiles than the more intelligent methods of the


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THE CARNIVOROUS DINOSAURS 45mammalian carnivore. The brain cast of Allosaurusindicates a brain of similar type and somewhat inferiorgrade to that of the modern crocodile or lizard, and farbelow the bird or mammal in intelligence. The keensense of smell of the mammal, the keen vision of thebird, the highly developed reasoning power of both,were absent in the dinosaur as in the lizard or crocodile.

Fig. 13. View in the Hell Creek badlands in central Montana, where theTyrannosaurus skeleton was found.

We may imagine the Allosaurus lying in wait, watchinghis prey until its near approach stimulates him into asemi-instinctive activity; then a sudden swift rush, afierce snap of the huge jaws and a savage attack withteeth and claws until the victim is torn in pieces orswallowed whole. But the stealthy, persistent trackingof the cat or weasel tribe, the intelligent generalship of


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46 DINOSAURSthe wolf pack, the well planned attack at the most vulner-able point in the prey, characteristic of all the preda-ceous mammals, would be quite impossible to the dino-saur. By watching the habits of modern reptiles wemay gain a much better idea of his capacities andlimitations than if we judge only from the efficiency ofhis teeth and claws, and forget the inferior intelligencethat animated these terrible weapons.

The "Tyrant Saurian" asTYRANNOSAURUS. Professor Osborn has namedhim, was the climax of evolu-

tion of the giant flesh-eating dinosaurs. It reached alength of forty-seven feet, and in bulk must haveequalled the mammoth or the mastodon or the largestliving elephants. The massive hind limbs, supportingt IK- whole weight of the body, exceeded the limbs of thegreat proboscideans in bulk, and in a standing positionthe animal was eighteen to twenty feet high, as againsttwelve for the largest African elephants or the southernmammoth. The head (see frontispiece) is 4 feet 3inches long, 3 ft. 4 inches deep, and 2 ft. 9 incheswide; the long deep powerful jaws set with teeth from3 to 6 inches long and an inch wide. To this powerfularmament was added the great sharp claws of the hindfeet, and probably the fore feet, curved like those ofeagles, but six or eight inches in length.During ten years explorations in the Western Cretace-

ous formations, Mr. Brown has secured for the Museumthree skeletons of this magnificent dinosaur, incom-


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THE CARNIVOROUS DINOSAURS 47plete, but finely preserved. The first, found in 1900,included the jaws, a large part of backbone and ribs,and some limb bones. The second included most ofskull and jaws, backbone, ribs and pelvis and the hindlimbs and feet, but not tail. The third consisted of aperfect skull and jaws, the backbone, ribs, pelvis andnearly all of the tail, but no limbs. From these three

Fig. 14. Quarry from which the Tyrannosaurus skeleton was taken.American Museum camp in foreground.specimens it has been possible to reconstruct the entireskeleton. The exact construction of the fore feet isthe only doubtful part. The fore-limb is very smallrelatively to the huge size of the animal, but probablywas constructed much as in the Allosaurus with two orthree large curved claws, the inner claw opposing theothers.


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48 DINOSAURSThe missing parts of the two best skeletons have been

restored, and with the help of two small models of theskeleton, a group has been made ready for mounting asthe central piece of the proposed Cretaceous DinosaurHall. One of the skeletons is temporarily placed in thecentre of the Quaternary Hall, space for it in the presentDinosaur Hall being lacking. Following is ProfessorOsborn's description of the preparation of this group:*"The mounting of these two skeletons presents

mechanical problems of very great difficulty. The sizeand weight of the various parts are enormous. Theheight of the head in the standing position reaches from18 to 20 feet above the ground; the knee joint alonereaches 6 feet above the ground. All the bones aremassive; the pelvis, femur and skull are extremelyheavy. Experience with Brontosaurus and with otherlarge dinosaurs proves that it is impossible to design ametallic frame in the right pose in advance of assemblingthe parts. Even a scale restoration model of the animalas a whole does not obviate the difficulty.

"Accordingly in preparing to mount Tyrannosaurusfor exhibition a new method has been adopted, namely,to prepare a scale model of every bone in the skeleton andmount this small skeleton with flexible joints and partsso that all studies and experiments as to pose can bemade with the models.

*Tyrannosaurus, Restoration and Model of the Skeleton. ByHenry Fairfield Osborn. Bull. Amer. Mus. Nat. Hist., 1913, vol.xxxn, art. iv, pp. 91-92.


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THE CARNIVOROUS DINOSAURS 49"This difficult and delicate undertaking was entrusted

to Mr. Erwin Christman of the artistic staff of theDepartment of Vertebrate Palaeontology of the Mu-seum, who has prepared two very exact models to aone-sixth scale, representing our two skeletons ofTyrannosaurus rex, which fortunately are of exactlythe same size. A series of three experiments by Mr.Christman on the pose of Tyrannosaurus, under the

Fig. 15. Model of Tyrannosaurus group for the Cretaceous Dinosaur Hall.

direction of the author and Curator Matthew, were notsatisfactory. The advice of Mr. Raymond L. Ditmars,Curator of Reptiles in the New York Zoological Park,was sought and we thus obtained the fourth pose, whichis shown in the photographs published herewith."The fourth pose or study, for the proposed full sized

mount, is that of two reptiles of the same size attractedto the same prey. One reptile is crouching over itsprey (which is represented by a portion of a skeleton).


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50 DINOSAURSThe object of this depressed pose is to bring the per-fectly preserved skull and pelvis very near the groundwithin easy reach of the visiting observer. Thesecond reptile is advancing, and attains very nearlythe full height of the animal. The general effect of thisgroup is the best that can be had and is very realistic,particularly the crouching figure. A fifth study willembody some further changes. The upright figure isnot well balanced and will be more effective with thefeet closer together, the legs straighter and the bodymore erect. These reptiles have a series of strongabdominal ribs not shown in the models. The fourthposition places the pelvis in an almost impossibleposition as will be noted from the ischium and pubis."The lateral view of this fourth pose represents theanimals just prior to the convulsive single spring andtooth grip which distinguishes the combat of reptilesfrom that of all mammals, according to Mr. Ditmars."The rear view of the standing skeleton displays thepeculiarly avian structure of the iliac junction with thesacral plate, characteristic of these very highly special-ized dinosaurs, also the marked reduction of the upperend of the median metatarsal bone, which formerlywas believed to be peculiar to Ornithomimus."

This model of the group is on exhibition with themounted skeleton.As compared with its predecessor Allosaurus, the

Tyrannosaurus is much more massively proportionedthroughout. The skull is more solid, the jaws much


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52 DINOSAURS

deeper and more powerful, the fore limb much smaller,the tail shorter, the hind limb straighter and the footbones more compacted so that the animal was morestrictly "digitigrade," approaching the ostriches moreclosely in this particular.

This animal probably reached the maximum of sizeand of development of teeth and claws of which itstype of animal mechanism was capable. Its bulkprecluded quickness and agility. It must have beendesigned to attack and prey upon the ponderous andslow moving Horned and Armored Dinosaurs withwhich its remains are found, and whose massive cuirassand weapons of defense are well matched with its teethand claws. The momentum of its huge body involveda seemingly slow and lumbering action, an inertia ofits movements, difficult to start and difficult to shiftor to stop. Such movements are widely different fromthe agile swiftness which we naturally associate with abeast of prey. But an animal which exceeds anaverage elephant in bulk, no matter what its habits,is compelled by the laws of mechanics to the ponderousmovements appropriate to its gigantic size. Thesemovements, directed and controlled by a reptilianbrain, must needs be largely automatic and instinctive.We cannot doubt indeed that the Carnivorous Din-osaurs developed, along with their elaborately perfectedmechanism for attack, an equally elaborate series ofinstincts guiding their action to effective purpose; anda complex series of automatic responses to the stimulus


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THE CARNIVOROUS DINOSAURS 53afforded by the sight and action of their prey mightvery well mimic intelligent pursuit and attack, alwayswith certain limits set by the inflexible character of suchautomatic adjustments. But no animal as large asTyrannosaurus could leap or spring upon another, andits slow stride quickening into a swift resistless rush,might well end in unavoidable impalement upon thegreat horns of Triceratops, futile weapons against asmall and active enemy, but designed no doubt tomeet just such attacks as these. A true picture ofthese combats of titans of the ancient world we cannotdraw; perhaps we will never be able to reconstruct it.But the above considerations may serve to show howwidely it would differ from the pictures based uponany modern analogies.One may well inquire why it is that no such giganticcarnivora have evolved among the mammalian landanimals. The largest predaceous quadrupeds livingtoday are the lion and tiger. The bears although someof them are much larger, are not generally carnivorous,except for the polar bear, which is partly aquatic, prey-ing chiefly upon seals and fish. There are indeedcarnivorous whales of gigantic size, but no very largeland carnivore. There were, it is true, during theTertiary and Pleistocene, lions and other carnivoresconsiderably larger than the living species. But noneof them attained the size of their largest herbivorouscontemporaries, or even approached it. Among thedinosaurs on the other hand we find that setting


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54 DINOSAURSaside Brontosaurus and its allies as aquatic thepredaceous kinds equalled or exceeded the largest ofthe herbivorous sorts. The difference is striking, andit does not seem likely that it is merely accidental.The explanation lies probably in the fact that the

large herbivorous mammals are much more intelligentand active, and would be able to use their weapons ofdefense so as to defy the attacks of relatively slowmoving giant beasts of prey, as they do also the moreactive but less powerful assaults of smaller ones. Theelephant or the rhinoceros is in fact practically immunefrom the attacks of carnivora, and would still be sowere the carnivora to increase in size. The largemodern carnivora prey upon herbivores of medium orsmaller size, which they are active enough to surpriseor run down. Carnivora of much larger size would betoo slow and heavy in movements to catch small prey,while the larger herbivores by intelligent use of theirdefensive weapons could still fend them off successfully.In consequence giant carnivores would find no field foraction in the Cenozoic world, and hence they have notbeen evolved.But the giant herbivorous dinosaurs, well armed or

well defended though they were, had not the intelligenceto use those weapons effectively under all circum-stances. Thus they might be successfully attacked,at least sometimes, by the powerful although slow mov-ing Megalosaurians.The suggestion has also been made that these giant


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THE CARNIVOROUS DINOSAURS 55carnivores were carrion-eaters rather than truly pre-daceous. The hypothesis can hardly be effectivelysupported nor attacked. It is presented as a possiblealternate.

Albertosaurus. Closely allied to the Tyrannosaurusbut smaller, about equal in size to Allosaurus, was theAlbertosaurus of the Edmonton formation in Canada.It is somewhat older than the Tyrannosaur althoughstill of the late Cretacic period, and may have beenancestral to it. A fine series of limbs and feet as alsoskull, tail, etc., are in the Museum's collections. At orabout this time carnivorous dinosaurs of slightlysmaller size are known to have inhabited New Jersey;a fragmentary skeleton of one secured by ProfessorCope in 1869 was described as Laelaps (=Dryptosau-rus)*

Orniiholestes. In contrast with the Allosaurus andTyrannosaurus this skeleton represents the smaller andmore agile carnivorous dinosaurs which preyed uponthe lesser herbivorous reptiles of the period. Theselittle dinosaurs were probably common during all theAge of Reptiles, much as the smaller quadrupeds aretoday, but skulls or skeletons are rarely found in theformations known to us. The Anchisaurus, Podokesau-rus and other genera of the Triassic Period have leftinnumerable tracks upon the sandy shales of theNewark formation, but only two or three skeletons are

*Since these lines were written the Museum has secured finely pre-served skeletons of two or more kinds of Carnivorous Dinosaurs fromthe Belly River formation in Canada.


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56 DINOSAURSknown. A cast of one of them is exhibited here. Theoriginal is preserved in the Yale Museum. In thesucceeding Jurassic Period we have the Compsognathus,smallest of known dinosaurs, and this Ornitholestessome six feet long. A cast of the Compsognathus skele-ton is shown, the original found in the lithographic lime-stone of Solenhofen is preserved in the Munich Mu-seum. The Ornitholestes is from the Bone-Cabin

Fig. 17. Skeleton of Ornitholestes a small carnivorous dinosaur of theJurassic period. American Museum No. 619.Quarry in Wyoming. The forefoot with its longslender digits is supposed to have been adapted forgrasping an active and elusive prey, and the name(Ornitho-lestes=b{rd-robber) indicates that that preymay sometimes have been the primitive birds whichwere its contemporaries. In the Cretacic Period,there were also small and medium sized carnivorousdinosaurs, contemporary with the gigantic kinds; acomplete skeleton of Ornithomimus at the entrance


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THE CARNIVOROUS DINOSAURS 57to the Dinosaur Hall finely illustrates this group. Inappearance most of these small dinosaurs must havesuggested long-legged bipedal lizards, running andwalking on their hind limbs, with the long tail stretchedout behind to balance the body. From what we knowof their tracks it seems that they walked or ran with

Fig. 18. Restoration of Ornithokstes, by C. R. Knight under directionof Professor Osborn.

a narrow treadway, the footsteps almost in the middleline of progress. They did not hop like perching birds,nor did they waddle like most living reptiles. Occasion-ally the tail or fore feet touched the ground as theywalked; and when they sat down, they rested on the


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58 DINOSAURSend of the pubic bones and on the tail. So much wecan infer from the footprint impressions. The generalappearance is shown in the restorations of Ornitholestes,Compsognathus and Anchisaurus by Charles Knight.

Ornithomimus. The skeleton of this animal from theCretacic of Alberta was found by the Museumexpedition of 1914. It is exceptionally complete, andhas been mounted as a panel, in position as it lay in therock, and with considerable parts of the original sand-stone matrix still adherent. The long slender limbs,long neck, small head and toothless jaws are all sin-gularly bird-like, and afford a striking contrast to theTyrannosaurus. At the time of writing, its adapta-tion and relationships have not yet been thoroughlyinvestigated.


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CHAPTER V.THE AMPHIBIOUS DINOSAURS, BRONTO-

SAURUS, DIPLODOCUS, ETC.SUB-ORDER OPISTHOCCELIA (CETIOSAURIA

OR SAUROPODA).These were the Giant Reptiles par-excellence, for all

of them were of enormous size, and some were by farthe largest of all four-footed animals, exceeded in bulkonly by the modern whales. In contrast to the car-nivorous dinosaurs these are quadrupedal, with verysmall head, blunt teeth, long giraffe-like neck, elephant-ine body and limbs, long massive tail prolonged at thetip into a whip-lash as in the lizards. Like the ele-phant they have five short toes on each foot, probablyburied in life in a large soft pad, but the inner digitsbear large claws, blunt like those of turtles, one in thefore foot, three in the hind foot.To this group belong the Brontosaurus and Diplo-

docus, the Camarasaurus, Morosaurus and other lessknown kinds. All of them lived during the lateJurassic and Comanchic ("Lower Cretaceous") andbelong to the older of the two principal Dinosaurfaunas. They were contemporaries of the Allosaurusand Megalosaurus, the Stegosaurus arid Iguanodon,


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THE AMPHIBIOUS DINOSAURS

i

Ii

liQ S11


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62 DINOSAURSbut unlike the Carnivorous and Beaked Dinosaurs theybecame wholly extinct before the Upper or true Cre-tacic, and left no relatives to take part in the finalepoch of expansion and prosperity of the dinosaurianrace at the close of the Reptilian era.

The following description ofBRONTOSAURUS. the Brontosaurus skeleton in theAmerican Museum was first pub-

lished in the American Museum Journal of April, 1905 :*"The Brontosaurus skeleton, the principal feature ofthe hall, is sixty-six feet eight inches long. (The weightof the animal when alive is estimated by W. K. Gregoryat 38 tons). About one-third of the skeleton includingthe skull is restored in plaster modelled or cast fromother incomplete skeletons. The remaining two-thirdsbelong to one individual, except for a part of the tail,one shoulder-blade and one hind limb, supplied fromanother skeleton of the same species."The skeleton was discovered by Mr. Walter Grangerof the Museum expedition of 1898, about nine milesnorth of Medicine Bow, Wyoming. It took the wholeof the succeeding summer to extract it from the rock,pack it, and ship it to the Museum. Nearly two yearswere consumed in removing the matrix, piecing to-gether and cementing the brittle and shattered petrifiedbone, strengthening it so that it would bear handling,and restoring the missing parts of the bones in tinted*The mounted Skeleton of Brontosaurus, bv W. D. Matthew, Amer.Mus. Jour. Vol. v, pp. 63-70, figs. 1-5.


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THE AMPHIBIOUS DINOSAURS 63

Fig. 21.-Excavating the Brontosaurus skeleton. The upper photographshows the anterior ribs of one side still lying in position. Thebackbone is being prepared for removal, the sections each containing three vertebrae, partly cased in plaster and burlap (see chapterXI. The lower photograph shows a later stage of progress, theblocks being undercut and nearly ready to turn over and incasethe under side. Strips of wood have been pasted into each sectionto strengthen it.


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plaster. The articulation and mounting of the skeletonand modelling of the missing bones took an even longertime, so that it was not until February, 1905, that theBrontosaurus was at last ready for exhibition.

" It will appear, therefore, that the collection, prepar-ation and mounting of this gigantic fossil has been atask of extraordinary difficulty. No museum has everbefore attempted to mount so large a fossil skeleton,and the great weight and fragile character of the bonesmade it necessary to devise especial methods to giveeach bone a rigid and complete support as otherwise itwould soon break in pieces from its own weight. Theproper articulating of the bones and posing of the limbswere equally difficult problems, for the AmphibiousDinosaurs, to which this animal belongs, disappearedfrom the earth long before the dawn of the Age ofMammals, and their nearest relatives, the livinglizards, crocodiles, etc., are so remote from them ineither proportions or habits that they are unsatisfactoryguides in determining how the bones were articulatedand are of but little use in posing the limbs and otherparts of the body in positions that they must havetaken during life. Nor among the higher animals ofmodern times is there one which has any analogy inappearance or habits of life to those which we havebeen obliged by the study of the skeleton to ascribe tothe Brontosaurus."As far as the backbone and ribs were concerned, thearticulating surfaces of the bones were a sufficient


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THE AMPHIBIOUS DINOSAURS 65guide to enable us to pose this part of the skeletonproperly. The limb joints, however, are so imperfectthat we could not in this way make sure of having thebones in a correct position. The following method,therefore, was adopted."A dissection and thorough study was made by thewriter, with the assistance of Mr. Granger, of thelimbs of alligators and other reptiles, and the position,size and action of the principal muscles were carefullyworked out. Then the corresponding bones of theBrontosaurus were studied, and the position and sizeof the corresponding muscles were worked out, so faras they could be recognized from the scars and processespreserved on the bone. The Brontosaurus limbs werethen provisionally articulated and posed, and theposition and size of each muscle were represented by abroad strip of paper extending from its origin to itsinsertion. The action and play of the muscles on thelimb of the Brontosaurus could then be studied, andthe bones adjusted until a proper and mechanicallycorrect pose was reached. The limbs were then per-manently mounted in these poses, and the skeletonas it stands is believed to represent, as nearly as studyof the fossil enables us to know, a characteristic posi-tion that the animal actually assumed during life."In proportions and appearance the Brontosaurus

was quite unlike any living animal. It had a long thicktail like the lizards and crocodiles, a long, flexible necklike an ostrich, a thick short, slab-sided body and


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66 DINOSAURSstraight, massive, post-like limbs suggesting the ele-phant, and a remarkably small head for the size of thebeast. The ribs, limb-bones and tail-bones are excep-tionally solid and heavy; the vertebrae of the back andneck, and the skull, on the contrary are constructed soas to combine the minimum of weight with the largesurface necessary for the attachment of the hugemuscles, the largest possible articulating surfaces, andthe necessary strength at all points of strain. For thispurpose they are constructed with an elaborate systemof braces and buttresses of thin bony plates connectingthe broad articulating surfaces and muscular attach-ments, all the bone between these thin plates beinghollowed into a complicated system of air-cavities.

. This remarkable structure can be best seen in the un-mounted skeleton of Camarasaurus, another Amphi-bious Dinosaur." (The scientific name Camarasaurus=chambered lizard, has reference to this pecularityof construction.)"The teeth of the Brontosaurus indicate that it was

an herbivorous animal, feeding on soft vegetable food.Three opinions as to the habitat of Amphibious Din-osaurs have been held by scientific authorities. Thefirst, advocated by Professor Owen, who described thefirst specimens found sixty years ago (1841-60) and sup-ported especially by Professor Cope, has been mostgenerally adopted. This regards the animals asspending their lives entirely in shallow water, partlyimmersed, wading about on the bottom, or perhaps


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THE AMPHIBIOUS DINOSAURS 67


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68 DINOSAURSoccasionally swimming, but unable to emerge entirelyupon dry land.* More recently, Professor Osborn hasadvocated the view that they resorted occasionally tothe land for egg laying or other purposes, and still morerecently the view has been taken by Mr. Riggs and thelate Professor Hatcher that they were chiefly ter-restrial animals. The writer inclines to the view ofOwen and Cope, whose unequalled knowledge of com-parative anatomy renders their opinion on this doubt-ful question especially authoritative."The contrast between the massive structure of thelimb-bones, ribs and tail, and the light construction ofthe backbone, neck and skull, suggests that the animalwas amphibious, living chiefly in shallow water, whereit could wade about on the bottom, feeding upon theabundant vegetation of the coastal swamps andmarshes, and pretty much out of reach of the powerfuland active Carnivorous Dinosaurs which were itsprincipal enemies. The water would buoy up themassive body and prevent its weight from pressing tooheavily on the imperfect joints of the limb and footbones, which were covered during life with thick carti-lage, like the joints of whales, sea-lizards and other aquatic-animals. If the full weight of the animal came on theseimperfect joints the cartilage would yield and the ends

Professor Williston makes the following criticism of this theory:"I cannot agree with this view the animals must have laidtheir eggs upon land for the reason that reptile eggs cannothatch in water. S. W. W."But with deference to Williston's high authority I may note that thereis no evidence that the Sauropoda were egg-laying reptiles. They,or some of them, may have been viviparous like the Ichthyosaurus.


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THE AMPHIBIOUS DINOSAURS 69of the bones would grind against each other, thus pre-venting the limb from moving without tearing the jointto pieces. The massive, solid limb and foot bonesweighted the limbs while immersed in water, and servedthe same purpose as the lead in a diver's shoes, enablingthe Brontosaurus to walk about firmly and securelyunder water. On the other hand, the joints of theneck and back are exceptionally broad, well fitting andcovered with a much thinner surface of cartilage. Thepressure was thus much better distributed over thejoint, and the full weight of the part of the animal abovewater (reduced as it was by the cellular construction ofthe bones) might be borne on these joints without thecartilage giving way."Looking at the mounted skeleton we may see that if

a line be drawn from the hip joint to the shoulder-blade,all the bones below this are massive, all above (includ-ing neck and head) are lightly constructed. This linemay be taken to indicate the average water-line, so tospeak, of this Leviathan of the Shallows. The longneck would enable the animal, however, to wade to aconsiderable depth, and it might forage for food eitherin the branches or the tops of trees, or more probably,among the soft succulent water-plants of the bottom.The row of short spoon-shaped stubby teeth aroundthe front of the mouth would serve to bite or pull offsoft leaves and water-plants, but the animal evidentlycould not masticate its food, and must have swallowedit without chewing as do modern reptiles and birds.


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70 DINOSAURS"The brain-case occupies only a small part of the

back of the skull, so that the brain nust have beensmall even for a reptile, and its organization (as inferredfrom the form of the brain-case) indicates a very lowgrade of intelligence. Much larger than the brainproper was the spinal cord, especially in the region ofthe sacrum, controlling most of the reflex and involun-tary actions of the huge organism. Hence we canbest regard the Brontosaurus as a great, slow-movinganimal automaton, a vast storehouse of organizedmatter directed chiefly or solely by instinct, and to avery limited degree, if at all, by conscious intelligence.Its huge size and its imperfect organization, comparedwith the great quadrupeds of today, rendered its move-ments slow and clumsy; its small and low brain showsthat it must have been automatic, instinctive and un-intelligent.

Composition of the Brontosaurus Skeleton. "The prin-cipal specimen, No. 460, is from the Nine Mile Crossingof the Little Medicine Bow River, Wyoming.It consists of the 5th, 6th, and 8th to 13th cervicalvertebrae, 1st to 9th dorsal and 3rd to 19th caudalvertebrae, all the ribs, both coracoids, parts ofsacrum and ilia, both ischia and pubes, left femur andastragalus, and part of left fibula. The backbone andmost of the neck of this specimen were found articu-lated together in the quarry, the ribs of one side inposition, the remainder of the bones scattered around


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THE AMPHIBIOUS DINOSAURS 71them, and some of the tail bones weathered out on thesurface."From No. 222, found at Como Bluffs, Wyo., were

supplied the right scapula, 10th dorsal vertebra, andright femur and tibia."No. 339, from Bone-Cabin Quarry, Wyoming, sup-

plied the 20th to 40th caudal vertebrae, No. 592, from

Fig. 23. Skull of Diplodocus from Bone-Cabin Quarry, north of MedicineBow, Wyoming.the same locality the metatarsals of the right hind foot;and a few toe bones are supplied from other specimens."The remainder of the skeleton is modelled in plaster,the scapula, humerus, radius and ulna from the skele-ton in the Yale Museum, the rest principally from speci-mens in our own collections. The modelling of theskull is based partly upon specimens in the YaleMuseum, but principally upon the complete skull ofMorosaurus shown in another case."Mounted by A. Hermann, completed Feb. 10, 1905."


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72 DINOSAURS

Diplodocus. The Diplodocusnearly equalled theBron-tosaurus in bulk and exceeded it in length. A skeleton inthe Carnegie Museum at Pittsburgh measures 87 feet intotal length; although the mount is composed fromseveral individuals these proportions are probably notfar from correct. The skull is smaller and differentlyshaped and the teeth are of quite different type. Inthe American Museum of Natural History, a partialskeleton is exhibited in the wall case to the left of theentrance of the Dinosaur Hall, and in an A-case near byare skulls of Diplodocus and Morosaurus and a model ofthe skull of Brontosaurus. The Diplodocus skull iswidely different from the other two in size and propor-tions and in the characters of teeth.When the first remains of these amphibious Dinosaurs

were found in the Oxford Clays of England, they wereconsidered by Richard Owen to be related to the Croco-diles, and named Opisthocoelia. Subsequently the find-ing of complete skeletons in this country led Cope andMarsh to place them with the true Dinosaurs and thelatter named them Sauropoda.* Remains of theseanimals have also been found in India, in German EastAfrica, in Madagascar, and in South America, so thatthey were evidently widely distributed. In the North-ern world they survived until the Comanchic or Lower

'European palaeontologists, especially Huxley and Seeley in England,had also recognized their truerelationships, and Seeley's term Cetio-sauna has precedence over Sauropoda, although the latter is in common


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THE AMPHIBIOUS DINOSAURS 73Cretaceous Period, but in the southern continents theymay have lived on into the Upper Cretaceous or trueCretacic. Some of the remains recently found in Ger-man East Africa indicate an animal exceeding eitherBrontosaurus or Diplodocus in bulk.At the date of writing this handbook only preliminary

accounts have been given of the marvellous finds made

Fig. 24. The Largest Known Dinosaur. Sketch reconstruction of Brachio-saurus, from specimens in the Field Museum in Chicago, and theNatural History Museum in Berlin.near Tendaguru by the expedition from Berlin. Fromthese it appears that in length of neck and fore limbthis East African Dinosaur greatly exceeded eitherBrontosaurus or Diplodocus. The hinder parts of theskeleton however, were relatively small. The propor-tions and measurements given tally closely with the


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74 DINOSAURSAmerican Brachiosaurus, a gigantic sauropod whoseincomplete remains are preserved in the Field Museumin Chicago and to this genus the Berlin authorities nowrefer their largest and finest skeleton. If the Berlinspecimens are correctly referred to Brachiosaurus theyindicate an animal somewhat exceeding Diplodocus orBrontosaurus in total bulk but distinguished by muchlonger fore limbs and an immensely long neck agiraffe-like wader adapted to take refuge in deeperwaters, more out of reach of the fierce carnivores of theland.*

*It is of interest to observe that in this group of Sauropoda, theBrachiosauridse, the neural spines of the vertebrae are much simplerand narrower than in the Brontosaurus and Diplodocus. The attach-ments were thus less extensive for the muscles of the back, indicatingthat these muscles were less powerful: This difference is correlated byProfessor Williston with the longer fore limbs of the Brachiosaurus, assignifying that the animal was less able, as indeed he had less need, torise up upon the hind limbs, in comparison with Diplodocus or Bronto-saurus in which the fore limbs were relatively short.


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CHAPTER VI.THE BEAKED DINOSAURS.

ORDER ORTHOPODA (ORNITHISCHIA OR PREDENTATA.)The peculiar feature of this group of Dinosaurs is the

horny beak or bill. The bony core sutured to the frontof the upper and lower jaws was covered in life by ahorny sheath, as in birds or turtles. But this is not theonly feature in which they came nearer to birds than dothe other Dinosaurs. The pelvic or hip bones are muchmore bird-like in many respects, especially the back-ward direction of the pubic bone, the presence of aprepubis, in the number of vertebrae coossified into asolid sacrum, in the proportions of the ilium and so on.Various features in the anatomy of the head, shoulder-blades and hind limbs are equally suggestive of birds,and it seems probable that the earliest ancestors of thebirds were very closely related to the ancestors of thisgroup of Dinosaurs. But the ancestral birds becameadapted to flying, the ancestral Predentates to ter-restrial life, and in their later development became aswidely diversified in form and habits as the warm-blooded quadrupeds which succeeded them in theAge of Mammals.These Beaked Dinosaurs were, so far as we can tell,all vegetarians. Unlike the birds, they retained their


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76 DINOSAURSteeth and in some cases converted them into a grindingapparatus which served the same purpose as the grindersof herbivorous quadrupeds. It is interesting to observethe different way in which this result is attained. In

Corythos


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THE BEAKED DINOSAURS 77the mammals, the teeth, originally more complex inconstruction and fewer in number, are converted intoefficient grinders by infolding and elongation of thecrown of each tooth so as to produce on the wearingsurface a complex pattern of enamel ridges with softerdentine or cement intervening, making a series of crestsand hollows continually renewed during the wear of thetooth. In the reptile the teeth, originally simple inconstruction but more numerous and continuallyrenewed as they wear down and fall out, * are banked upin several close packed rows, the enamel borders andsofter dentine giving a wearing surface of alternatingcrests and hollows continually renewed, and rein-forced from time to time, by the addition of new rowsof teeth to one side, as the first formed rows wear downto the roots. This is the best illustrated in the Tracho-don (see fig. 27) ; the other groups have not so perfect amechanism.

A. THE IGUANODONTS: IGUANODON,CAMPTOSAURUS.

Sub-Order Ornithopoda or Iguanodontia.In the early days of geology, about the middle of the

nineteenth century, bones and footprints of huge extinctreptiles were found in the rocks of the Weald in south-eastern England. They were described by Mantell andTrachodont teeth never drop out, they are completely consumed.Only in the Iguanodonts and Ceratopsia are they shed. B. Brown.


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78 DINOSAURS


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THE BEAKED DINOSAURS 79Owen and shown to pertain to an extinct group of rep-tiles which Owen called the Dinosauria. So differentwere these bones from those of any modern reptilesthat even the anatomical learning of the great Englishpalaeontologist did not enable him to place them allcorrectly or reconstruct the true proportions of theanimal to which they belonged. With them werefound associated the bones of the great carnivorousdinosaur Megalosaurus; and the weird reconstructionsof these animals, based by Waterhouse Hawkins uponthe imperfect knowledge and erroneous ideas thenprevailing, must be familiar to many of the olderreaders of this handbook. Life size restorations ofthese and other extinct animals were erected in thegrounds of the Crystal Palace at Sydenham, London,and in Central Park, New York. Those in Londonstill exist, so far as the writer is aware, but the sternmandate of a former mayor of New York ordered thedestruction of the Central Park models, not indeed asincorrect scientifically, but as inconsistent with thedoctrines of revealed religion, and they were accordinglybroken up and thrown into the waters of the Park lake.Small replicas of these early attempts at restoringdinosaurs may still be seen in some of the older museumsin this country and abroad.The real construction of the Iguanodon was gradu-

ally built up by later discoveries, and in 1877 an extra-ordinary find in a coal mine at Bernissart in Belgiumbrought to light no less than seventeen skeletons more

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(1915) dinosaurs with special reference to the american museum

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