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Dragons of the Air: An Account of Extinct Flying Reptiles

Chapter 4: WITH EIGHTY ILLUSTRATIONS
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A systematic account of extinct flying reptiles examines fossil evidence, skeletal structure, and inferences about soft tissues to reconstruct anatomy and probable behavior. It outlines methods for recognizing reptiles from bones and compares limb, lung, and skull structures with those of birds, bats, and other vertebrates. Detailed chapters analyze the vertebral column, hip and shoulder girdles, limb bones, and wing membranes, supported by restorations and illustrations. The work surveys major fossil groups across geological horizons, proposes classifications and family relationships, and discusses ecological roles, modes of flight and locomotion, and hypotheses for their origin and disappearance, while showing how fragmentary remains are interpreted by paleontologists.

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Title: Dragons of the Air: An Account of Extinct Flying Reptiles

Author: H. G. Seeley

Release date: February 18, 2011 [eBook #35316]

Language: English

Credits: Produced by Chris Curnow and the Online Distributed
Proofreading Team at http://www.pgdp.net (This file was
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*** START OF THE PROJECT GUTENBERG EBOOK DRAGONS OF THE AIR: AN ACCOUNT OF EXTINCT FLYING REPTILES ***

 

DRAGONS OF THE AIR

 

 



DRAGONS OF THE AIR

AN ACCOUNT OF
EXTINCT FLYING REPTILES

BY

H. G. SEELEY, F.R.S.

PROFESSOR OF GEOLOGY IN KING'S COLLEGE, LONDON; LECTURER ON GEOLOGY
AND MINERALOGY IN THE ROYAL INDIAN ENGINEERING COLLEGE

WITH EIGHTY ILLUSTRATIONS

"I AM A BROTHER OF DRAGONS"
Job xxx. 29

NEW YORK: D. APPLETON & CO.
LONDON: METHUEN & CO.
1901


PREFACE

I was a student of law at a time when Sir Richard Owen was lecturing on Extinct Fossil Reptiles. The skill of the great master, who built bones together as a child builds with a box of bricks, taught me that the laws which determine the forms of animals were less understood at that time than the laws which govern the relations of men in their country. The laws of Nature promised a better return of new knowledge for reasonable study. A lecture on Flying Reptiles determined me to attempt to fathom the mysteries which gave new types of life to the Earth and afterwards took them away.

Thus I became the very humble servant of the Dragons of the Air. Knowing but little about them I went to Cambridge, and for ten years worked with the Professor of Geology, the late Rev. Adam Sedgwick, LL.D., F.R.S., in gathering their bones from the so-called Cambridge Coprolite bed, the Cambridge Greensand. The bones came in thousands, battered and broken, but instructive as better materials might not have been. My rooms became filled with remains of existing birds, lizards, and mammals, which threw light on the astonishing collection of old bones which I assisted in bringing together for the University.

In time I had something to say about Flying Animals which was new. The story was told in the theatre of the Royal Institution, in a series of lectures. Some of them were repeated in several English towns. There was still much to learn of foreign forms of flying animals; but at last, with the aid of the Government grant administered by the Royal Society, and the chiefs of the great Continental museums, I saw all the specimens in Europe.

So I have again written out my lectures, with the aid of the latest discoveries, and the story of animal structure has lost nothing in interest as a twice-told tale. It still presents in epitome the story of life on the Earth. He who understands whence the Flying Reptiles came, how they endured, and disappeared from the Earth, has solved some of the greatest mysteries of life. I have only contributed something towards solving the problems.

In telling my story, chiefly of facts in Nature, an attempt is made to show how a naturalist does his work, in the hope that perhaps a few readers will find happiness in following the workings of the laws of life. Such an illumination has proved to many worth seeking, a solid return for labour, which is not to be marketed on the Exchange, but may be taken freely without exhausting the treasury of Nature's truths. Such outlines of knowledge as here are offered to a larger public, may also, I believe, be acceptable to students of science and scientific men.

The drawings given in illustration of the text have been made for me by Miss E. B. Seeley.

H. G. S.

Kensington, May, 1901


CONTENTS

PAGE
CHAPTER I.
FLYING REPTILES1
CHAPTER II.
HOW A REPTILE IS KNOWN4
CHAPTER III.
A REPTILE IS KNOWN BY ITS BONES11
CHAPTER IV.
ANIMALS WHICH FLY15
CHAPTER V.
DISCOVERY OF THE PTERODACTYLE27
CHAPTER VI.
HOW ANIMALS ARE INTERPRETED BY THEIR BONES37
CHAPTER VII.
INTERPRETATION OF PTERODACTYLES BY THEIR SOFT PARTS45
CHAPTER VIII.
THE PLAN OF THE SKELETON58
CHAPTER IX.
THE BACKBONE, OR VERTEBRAL COLUMN78
CHAPTER X.
THE HIP-GIRDLE AND HIND LIMB93
CHAPTER XI.
SHOULDER-GIRDLE AND FORE LIMB107
CHAPTER XII.
EVIDENCES OF THE ANIMAL'S HABITS FROM ITS REMAINS134
CHAPTER XIII.
ANCIENT ORNITHOSAURS FROM THE LIAS143
CHAPTER XIV.
ORNITHOSAURS FROM THE MIDDLE SECONDARY ROCKS153
CHAPTER XV.
ORNITHOSAURS FROM THE UPPER SECONDARY ROCKS172
CHAPTER XVI.
CLASSIFICATION OF THE ORNITHOSAURIA187
CHAPTER XVII.
FAMILY RELATIONS OF PTERODACTYLES TO ANIMALS WHICH LIVED WITH THEM196
CHAPTER XVIII.
HOW PTERODACTYLES MAY HAVE ORIGINATED213
 
APPENDIX231
 
INDEX233

LIST OF ILLUSTRATIONS

FIG.PAGE
47.Wings of RhamphorhynchusFrontispiece
1.Lung of the lung-fish Ceratodus5
2.Attachment of the lower jaw in a Mammal and in a Pterodactyle12
3.Chaldæan Dragon15
4.Winged human figure from the Temple of Ephesus16
5.Flying fish Exocœtus18
6.Flying Frog19
7.Flying Lizard (Draco)20
8.Birds in flight22
9.Flying Squirrel (Pteromys)24
10.Bats, flying and walking25
11.Skeleton of Pterodactylus longirostris28
12.The skeleton restored29
13.The animal form restored30
14.Fore limbs in four types of mammals38
15.Pneumatic foramen in Pterodactyle bone46
16.Lungs of the bird Apteryx48
17.Air cells in the body of an Ostrich49
18.Lung of a Chameleon51
19.Brain in Pterodactyle, Mammal, Bird, and Reptiles53
20.Skull of Kingfisher and Rhamphorhynchus63
21.Skull of Heron and Rhamphorhynchus65
22.Palate of Macrocercus and ? Campylognathus71
23.Lower jaw of Echidna and Ornithostoma76
24.First two neck vertebræ of Ornithocheirus81
25.Middle neck vertebræ of Ornithocheirus83
26.Back vertebra of Ornithocheirus and Crocodile86
27.Sacrum, with hip bones, of Rhamphorhynchus88
28.Extremity of tail of Rhamphorhynchus phyllurus91
29.Hip-girdle bones in Apteryx and Rhamphorhynchus95
30.Pelvis with prepubic bone in Pterodactylus96
31.Pelvis with prepubic bones in Rhamphorhynchus97
32.Pelvis of an Alligator seen from below98
33.Femora: Echidna, Ornithocheirus, Ursus100
34.Tibia and fibula: Dimorphodon and Vulture102
35.Metatarsus and digits in three Pterodactyles104
36.Sternum in Cormorant and Rhamphorhynchus108
37.Sternum in Ornithocheirus109
38.Shoulder-girdle bones in a bird and three Pterodactyles113
39.The Notarium from the back of Ornithocheirus115
40.The shoulder-girdle of Ornithocheirus115
41.Humerus of Pigeon and Ornithocheirus119
42.Fore-arm of Golden Eagle and Dimorphodon120
43.Wrist bones of Ornithocheirus124
44.Clawed digits of the hand in two Pterodactyles125
45.Claw from the hand of Ornithocheirus129
46.The hand in Archæopteryx and the Ostrich130
48.Slab of Lias with bones of DimorphodonTo face page 143
49.Dimorphodon (restored form) at rest144
50.Dimorphodon (restored form of the animal)To face page 145
51.Dimorphodon skeleton, walking as a quadrupedTo face page 146
52.Dimorphodon skeleton as a bipedTo face page 147
53.Lower jaw of Dorygnathus149
54.Dimorphodon (wing membranes spread for flight)To face page 150
55.Pelvis of Dimorphodon151
56.Rhamphorhynchus skeleton (restored)161
57.Scaphognathus (restoration of 1875)163
58.Six restorations of Ornithosaurs164
59.Ptenodracon skeleton (restored)167
60.Cycnorhamphus suevicus slab with bonesTo face page 168
61.Cycnorhamphus suevicus (form of the animal)To face page 169
62.Cycnorhamphus suevicus skeleton (restored)170
63.Cycnorhamphus Fraasi (restored skeleton form of the animal)To face page 170
64.Cycnorhamphus Fraasi (restoration of the form of the body)To face page 171
65.Neck vertebra of Doratorhynchus from the Purbeck173
66.Neck bone of Ornithodesmus from the Wealden173
67.Sternum of Ornithodesmus, seen from the front175
68.Sternum of Ornithodesmus, side view, showing the keel175
69.Diagram of known parts of skull of Ornithocheirus177
70.Neck bone of Ornithocheirus179
71.Jaws of Ornithocheirus from the Chalk180
72.Palate of the English Toothless Pterodactyle181
73.Two views of the skull of Ornithostoma (Pteranodon)182
74.Skeleton of Ornithostoma183
75.Comparison of six skulls of Ornithosaurs192
76.Pelvis of Ornithostoma195
77.Skull of Anchisaurus and Dimorphodon199
78.Skull of Ornithosuchus and Dimorphodon201
79.The pelvis in Ornithosaur and Dinosaur204
80.The prepubic bones in Dimorphodon and Iguanodon206

These figures are greatly reduced in size, and when two or more bones are shown in the same figure all are brought to the same size to facilitate the comparison.


DRAGONS OF THE AIR


CHAPTER I

FLYING REPTILES

The history of life on the earth during the epochs of geological time unfolds no more wonderful discovery among types of animals which have become extinct than the family of fossils known as flying reptiles. Its coming into existence, its structure, and passing away from the living world are among the great mysteries of Nature.

The animals are astonishing in their plan of construction. In aspect they are unlike birds and beasts which, in this age, hover over land and sea. They gather into themselves in the body of a single individual, structures which, at the present day, are among the most distinctive characters of certain mammals, birds, and reptiles.

The name "flying reptile" expresses this anomaly. Its invention is due to the genius of the great French naturalist Cuvier, who was the first to realise that this extinct animal, entombed in slabs of stone, is one of the wonders of the world.

The word "reptile" has impressed the imagination with unpleasant sound, even when the habits of the animals it indicates are unknown. It is familiarly associated with life which is reputed venomous, and is creeping and cold. Its common type, the serpent, in many parts of the world takes a yearly toll of victims from man and beast, and has become the representative of silent, active strength, dreaded craft, and danger.

Science uses the word "reptile" in a more exact way, to define the assemblage of cold-blooded animals which in familiar description are separately named serpents, lizards, turtles, hatteria, and crocodiles.

Turtles and the rest of them survive from great geological antiquity. They present from age to age diversity of aspect and habit, and in unexpected differences of outward proportion of the body show how the laws of life have preserved each animal type. For the vital organs which constitute each animal a reptile, and the distinctive bony structures with which they are associated, remain unaffected, or but little modified, by the animal's external change in appearance.

The creeping reptile is commonly imagined as the antithesis of the bird. For the bird overcomes the forces that hold even man to the earth, and enjoys exalted aerial conditions of life. Therefore the marvel is shared equally by learned and unlearned, that the power of flight should have been an endowment of animals sprung from the breed of serpents, or crocodiles, enabling them to move through the air as though they too were of a heaven-born race. The wonder would not be lessened if the animal were a degraded representative of a nobler type, or if it should be demonstrated that even beasts have advanced in the battle of life. The winged reptile, when compared with a bird, is not less astounding than the poetic conceptions in Milton's Paradise Lost of degradation which overtakes life that once was amongst the highest. And on the other hand, from the point of view of the teaching of Darwin in the theories of modern science, we are led to ask whether a flying reptile may not be evidence of the physical exaltation which raises animals in the scale of organisation. The dominance upon the earth of flying reptiles during the great middle period of geological history will long engage the interest of those who can realise the complexity of its structure, or care to unravel the meaning of the procession of animal forms in successive geological ages which preceded the coming of man.

The outer vesture of an animal counts for little in estimating the value of ties which bind orders of animals together, which are included in the larger classes of life. The kindred relationship which makes the snake of the same class as the tortoise is determined by the soft vital organs—brain, heart, lungs—which are the essentials of an animal's existence and control its way of life. The wonder which science weaves into the meaning of the word "reptile," "bird," or "mammal," is partly in exhibiting minor changes of character in those organs and other soft parts, but far more in showing that while they endure unchanged, the hard parts of the skeleton are modified in many ways. For the bones of the reptile orders stretch their affinities in one direction towards the skeletons of salamanders and fishes; and extend them also at the same time in other directions, towards birds and mammals. This mystery we may hope to partly unravel.


CHAPTER II

HOW A REPTILE IS KNOWN

DEFINITION OF REPTILES BY THEIR VITAL ORGANS

The relations of reptiles to other animals may be stated so as to make evident the characters and affinities which bind them together. Early in the nineteenth century naturalists included with the Reptilia the tribe of salamanders and frogs which are named Amphibia. The two groups have been separated from each other because the young of Amphibia pass through a tadpole stage of development. They then breathe by gills, like fishes, taking oxygen from the air which is suspended in water, before lungs are acquired which afterwards enable the animals to take oxygen directly from the air. The amphibian sometimes sheds the gills, and leaves the water to live on land. Sometimes gills and lungs are retained through life in the same individual. This amphibian condition of lung and gill being present at the same time is paralleled by a few fishes which still exist, like the Australian Ceratodus, the lung-fish, an ancient type of fish which belongs to early days in geological time.

This metamorphosis has been held to separate the amphibian type from the reptile because no existing reptile develops gills or undergoes a metamorphosis. Yet the character may not be more important as a ground for classification than the community of gills and lungs in the fish and amphibian is ground for putting them together in one natural group. For although no gills are found in reptiles, birds, or mammals, the embryo of each in an early stage of development appears to possess gill-arches, and gill-clefts between them, through which gills might have been developed, even in the higher vertebrates, if the conditions of life had been favourable to such modification of structure. In their bones Reptiles and Amphibia have much in common. Nearly all true reptiles lay eggs, which are defined like those of birds by comparatively large size, and are contained in shells. This condition is not usual in amphibians or fishes. When hatched the young reptile is completely formed, the image of its parent, and has no need to grow a covering to its skin like some birds, or shed its tail like some tadpoles. The reptile is like the bird in freedom from important changes of form after the egg is hatched; and the only structure shed by both is the little horn upon the nose, with which the embryo breaks the shell and emerges a reptile or a bird, growing to maturity with small subsequent variations in the proportions of the body.