GEOLOGICAL TIME

A SKETCH OF THE ORIGIN AND SUCCESSION OF
ANIMALS AND PLANTS

BY

SIR J. WILLIAM DAWSON

C.M.G., LL.D., F.R.S., F.G.S., Etc.

AUTHOR OF
“ACADIAN GEOLOGY,” “THE STORY OF THE EARTH,” “EGYPT AND SYRIA; THEIR
PHYSICAL FEATURES IN RELATION TO BIBLE HISTORY,” ETC.

THIRD AND REVISED EDITION

WITH NUMEROUS ILLUSTRATIONS

THE RELIGIOUS TRACT SOCIETY,

56 Paternoster Row; 65 St. Paul’s Churchyard;
and 164 Piccadilly

1888

Richard Clay and Sons.
LONDON AND BUNGAY.

PREFACE.

Questions as to the origin and history of life are not at the present time answered by mere philosophical speculation and poetical imagining. Such solutions of these questions as science can profess to have obtained are based on vast accumulations of facts respecting the remains of animals and plants preserved in the rocky beds of the earth’s crust, which have been successively accumulated in the course of its long geological history. These facts undoubtedly afford the means of attaining to very certain conclusions on many points relating to the history of life on the earth. But, on the other hand, they have furnished the material for hypotheses which, though confidently affirmed to be indisputable, have no real foundation in nature, and are indirectly subversive of some of the most sacred beliefs of mankind.

In these circumstances it is most desirable that those who are not specialists in such matters should be in a position to judge for themselves; and it does not appear impossible in the actual state of knowledge, to present, in terms intelligible to the general reader, such a view of the ascertained sequence of the forms of life as may serve at once to give exalted and elevating views of the great plan of creation, and to prevent the deceptions of pseudo-scientists from doing their evil work. Difficulties, no doubt, attend the attempt. They arise from the number and variety of the facts, from the uncertainties attending many important points, from the new views constantly opening up in the progress of discovery, and from the difficulty of presenting in an intelligible form the preliminary data in biology and geology necessary for the understanding of the questions in hand. In order, as far as possible, to obviate these difficulties, the plan adopted in this work has been to note the first known appearance of each leading type of life, and to follow its progress down to the present time or until it became extinct. This method is at least natural and historical, and has commended itself to the writer as giving a very clear comprehension of the actual state of our knowledge, and as presenting some aspects of the subject which may be novel and suggestive even to those who have studied it most deeply.

In selecting examples and illustrations, the writer has endeavoured to avoid, as far as possible, those already familiar to the general reader. He has carefully sought for the latest facts, while rejecting as unproved many things that are confidently asserted; and has endeavoured to avoid all that is irrelevant to the subject in hand, and to abstain from all technical terms not absolutely essential. In a work at once so wide in its scope, so popular in its character, and so limited in its dimensions, a certain amount of hostile criticism on the part of specialists is to be expected, some portion of it perhaps just, other portions arising from narrow prejudices due to limited lines of study. The writer is willing to receive such comments with attention and gratitude, but he would deprecate the misuse of them in the interest of those coteries which are at present engaged in the effort to torture nature into a confession of belief in the doctrines of a materialistic or agnostic philosophy.

The title of the work was suggested by that of Gaudry’s recent attractive book, Les Enchaînements du Monde animal. It seemed well fitted to express the connection and succession of forms of life, without implying their derivation from one another, while it reminds us that nature is not a fortuitously tangled skein, and that the links which connect man himself with the lowest and oldest creatures bind him also to the throne of the Eternal.

In the few years that have elapsed since the publication of the first edition of this work, great additions have been made to our knowledge of fossil animals and plants. Many new species have been described, and many new facts have been discovered, respecting species previously known. This rapid progress of discovery has, however, invalidated few of the statements made in the first edition, and has certainly established nothing against the general laws of the succession of life as stated in this work.

Perhaps the most interesting phase of recent discovery is the tracing back of certain forms of life to earlier periods of the earth’s geological history. Some of the most recent facts of this kind are the finding, by M. Charles Brongniart, of a fossil insect, allied to the Blattae or cockroaches, in the Silurian of Spain, that of true Scorpions in the Upper Silurian of Sweden by Lindström, and in the Upper Silurian of Scotland by Peach, who has also described fossil Millipedes from the Lower Devonian. The tendency of such discoveries is to carry farther back the origin of highly specialised forms of life, and thus to render less probable their origin by any process of gradual derivation.

Other discoveries serve to fill up blanks in our knowledge, and thus to render the geological record less imperfect. Of this kind is the close approximation now worked out in Western America between the end of the reign of the great Mesozoïc reptiles and the beginning of that of the mammals of the Tertiary—a great and abrupt revolution, effected apparently by a coup de main. I have myself had opportunity to show that a similarly sharp line separates that quaint old Mesozoïc flora of pines, cycads and ferns, which extends upward into the Lower Cretaceous, from the rich and luxuriant assemblage of broad-leaved trees of modern aspect, which takes its place in the middle part of the same formation.

It is not too much to say that these and similar discoveries, while they serve to bridge over gaps in the succession of organic beings, do not favour the theory of slow modification of types. They rather point to a law of rapid development of new forms under special conditions as yet unknown to science, and this accompanied with the extinction of older species. Recent discoveries also present many remarkable instances of the early introduction of highly specialised types, of higher forms preceding those that are lower in the same class, and of the persistence of certain types throughout geological time without any important change.

J. W. D.

McGill College.

CONTENTS.

CHAP.		PAGE
I.	Preliminary Considerations as to the Extent and Sources of our Knowledge	[1]
II.	The Beginning of Life on the Earth	[21]
III.	The Age of Invertebrates of the Sea	[45]
IV.	The Origin of Plant Life on the Land	[89]
V.	The Appearance of Vertebrate Animals	[117]
VI.	The First Air-breathers	[137]
VII.	The Empire of the Great Reptiles	[165]
VIII.	The First Forests of Modern Type	[185]
IX.	The Reign of Mammals	[207]
X.	The Advent of Man	[233]
XI.	Review of the History of Life	[253]

LIST OF ILLUSTRATIONS.


Frontispiece.—Life in the Silurian Age		To face Title.
fig		page
1.	Bank of stream or coast, showing stratification	[4]
2.	Section of Niagara Falls	[4]
3.	Section obtained by boring, near Goderich, Ontario	[5]
4.	Inclined beds, holding fossil plants	[6]
5.	Ideal section of the Apalachian Mountains	[7]
6.	Generalised section across England from Menai Straits to the Valley of the Thames	[9]
7.	Generalised section from the Laurentian of Canada to the coal-field of Michigan	[9]
8.	Unconformable superposition of Devonian Conglomerate on Silurian slates, at St. Abb’s Head, Berwickshire	[10]
9.	Section of Trenton limestone, Montreal	[14]
10.	Diagram showing different state of fossilisation of a cell of a Tabulate Coral	[15]
11.	Cast of erect tree (Sigillaria) in Sandstone	[16]
12.	Protichnites septem-notatus	[17]
12a.	Footprints of modern Limulus, or king-crab	[18]
13.	Current markings on shale, resembling a fossil plant	[18]
	Frontispiece. Magnified and restored section of a portion of Eozoon canadense	[20]
14.	Ideal section, showing the relations of the Laurentian and Huronian	[24]
15.	Small weathered specimen of Eozoon	[28]
16.	Nature-printed specimen of Eozoon slightly etched with acid	[29]
17.	Magnified group of canals in supplemental skeleton of Eozoon	[31]
18.	Portion of Eozoon magnified 100 diameters	[31]
19.	Magnified portion of shell of Calcarina	[32]
20.	Amœba, a fresh-water naked Rhizopod; and Actinophrys, a fresh-water Protozoon	[34]
21.	Nonionina, a modern marine Foraminifer	[34]
22.	Stromatopora concentrica	[35]
23.	Caunopora planulata	[36]
24.	Archæocyathus minganensis. A Primordial Protozoon	[37]
25.	Receptaculites. Restored	[38]
26.	Section of Loftusia Persica. An Eocene Foraminifer	[39]
27.	Foraminiferal Rock Builders, in the Cretaceous and Eocene	[41]
	Frontispiece. Paradoxides Regina (Matthew)	[44]
28.	Group of Cambrian Animals	[46]
29.	Portion of skeleton of Hexactinellid Sponge (Cœloptychium)	[49]
30.	Protospongia fenestrata (Salter)	[50]
31.	Astylospongia præmorsa (Roemer)	[51]
32.	Spicules of Lithistid Sponge (Trichospongia, Billings)	[51]
33.	Oldhamia antiqua (Forbes)	[52]
34.	Dictyonema sociale. Enlarged	[52]
35.	Dictyonema Websteri (Dn.)	[53]
36.	Group of modern Hydroids allied to Graptolites	[54]
37.	Silurian Graptolitidæ	[55]
38.	Central portion of Graptolite, with membrane, or float (Dichograpsus octobrachiatus, Hall)	[55]
39.	Ptilodictya acuta (Hall). Bryozoan	[55]
39a.	Fenestella Lyelli (Dn.). A Carboniferous Bryozoan	[56]
40.	Chaetetes fibrosa. A Tabulate Coral with microscopic cells	[56]
41.	a, Stenopora exilis (Dn.). b, Chaetetes tumidus (Edwards and Haine)	[57]
42.	Living Anthozoan Coral (Astræa)	[58]
43.	Tabulate Corals (Halisites and Favosites)	[59]
44.	Rugose Coral (Heliophyllum Halli)	[59]
44a.	Zaphrentis prolifica (Billings)	[60]
45.	Rugose Corals (Zaphrentis Minas, Dn., and Cyathophyllum Billingsi, Dn.)	[60]
46.	Modern Crinoid (Rhizocrinus Lofotensis)	[61]
47.	Palæaster Niagarensis (Hall)	[62]
48.	Palæchinus ellipticus (McCoy)	[62]
49.	Pleurocystites squamosus	[63]
50.	Heterocrinus simplex (Meek)	[63]
51.	Body of Glyptocrinus	[63]
52.	Extracrinus Briareus	[64]
53.	Pentacrinus caput-medusæ	[64]
54.	Lingula anatina	[65]
55.	Cambrian and Silurian Lingulæ	[65]
56.	Terebratula sacculus (Martin)	[66]
57.	Brachiopods; genus Orthis	[66]
58.	Rhynchonella increbrescens (Hall)	[66]
59.	Spirifer mucronatus (Conrad)	[67]
59a.	Athyris subtilita (Hall)	[67]
60.	Productus cora (D’Orbigny)	[68]
61.	Group of Older Palæozoic Lamellibranchs	[69]
62.	Conularia planicostata (Dn.). A Carboniferous Pteropod	[70]
63.	Silurian Sea-snails	[70]
64.	Squid (Loligo)	[72]
65.	Pearly Nautilus (Nautilus pompilius)	[72]
66.	Orthoceras	[73]
67.	Gomphoceras	[73]
68.	Lituites	[73]
69.	Nautilus Avonensis (Dn.)	[74]
70.	Goniatites crenistria (Philips)	[74]
71.	Ceratites nodosus (Schloth)	[75]
72.	Ammonites Jason (Reinecke)	[76]
72a.	Suture of Ammonites componens (Meek)	[76]
73.	Cretaceous Ammonitidæ	[77]
74.	Belemnite	[78]
74a.	Belemnoteuthis antiquus	[78]
75.	Cambrian Trilobites	[79]
76.	Transverse section of Calymene. A Silurian Trilobite	[80]
76a.	Burrows of Trilobite and of modern King-crab	[81]
77.	Silurian Trilobites	[82]
78.	Devonian and Carboniferous Trilobites	[83]
79.	Palæozoic Ostracod Crustaceans	[83]
80.	Pterygotus anglicus	[84]
81.	Amphipeltis paradoxus (Salter)	[85]
82.	Anthropalæmon Hilliana (Dn.)	[85]
	Frontispiece. Cordaites, of the group of Dory-Cordaites	[88]
83.	Protannularia Harknessii (Nicholson)	[91]
84.	American Lower Silurian Plants	[92]
86.	Fragment of outer surface of Glyptodendron of Claypole	[93]
87.	Psilophyton princeps (Dn.)	[95]
88.	Trunk of a Devonian Tree-fern (Caulopteris Lockwoodi, Dn.)	[97]
89.	Frond of Archæopteris Jacksoni (Dn.)	[98]
90.	Portion of a branch of Leptophleum rhombicum (Dn.)	[98]
91.	Calamites radiatus (Brongniart)	[99]
92.	A Devonian Taxine Conifer (Dadoxylon ouangondianum, Dn.)	[100]
93.	Group of Devonian fruits, &c.	[101]
94.	Structures of the oldest-known Angiospermous Exogen (Syringoxylon mirabile, Dn.)	[102]
95.	Asterophyllites parvula (Dn.) and Sphenophyllum antiquum (Dn.)	[103]
96.	Calamites	[104]
97.	Carboniferous Ferns	[105]
98.	Carboniferous Tree-ferns	[107]
99.	Lepidodendron corrugatum (Dn.)	[108]
100.	Sigillariæ of the Carboniferous	[109]
101.	Trigonocarpum Hookeri (Dn.)	[111]
	Frontispiece. Pteraspis. Restored	[116]
102.	Siluro-Cambrian Conodonts	[118]
103.	Lower Carboniferous Conodont	[119]
104.	a, Head-shield of an Upper Silurian Fish (Cyathaspis); b, Spine of a Silurian Shark (Onchus tenui-striatus, Agass.); c, d, Scales of Thecodus	[121]
105.	Cephalaspis Dawsoni (Lankester)	[122]
106.	Devonian Placoganoid Fishes (Pterichthys cornutus, Cephalaspis Lyelli)	[123]
107.	Devonian Lepidoganoid Fishes (Diplacanthus and Osteolepis)	[124]
108.	Modern Dipnoi (Ceratodus Fosteri and Lepidosiren annectus)	[124]
109.	Anterior part of the palate of Dipterus	[125]
110.	Dental plate of Conchodus plicatus (Dn.)	[126]
111.	Dental plate of Ceratodus Barrandii	[126]
112.	Dental plate of Ceratodus serratus	[127]
113.	Jaws of Dinichthys Hertzeri (Newberry)	[127]
114.	Lower Jaw of Dinichthys Hertzeri	[128]
115.	Jaws of Lepidosiren	[128]
116.	A small Carboniferous Ganoid (Palæoniscus (Rhadinichthys) Modulus, Dn.)	[129]
117.	Teeth and Spines of Carboniferous Sharks	[130]
118.	Teeth of Cretaceous Sharks (Otodus and Ptychodus)	[131]
119.	Tooth of a Tertiary Shark (Carcharodon)	[132]
120.	A Liassic Ganoid (Dapedius)	[132]
121.	Cretaceous Fishes of the modern or Teleostian type (Beryx Lewesiensis and Portheus molossus, Cope)	[133]
122.	Modern Ganoids (Polypterus and Lepidosteus)	[134]
	Frontispiece. A Microsaurian of the Carboniferous Period (Hylonomus Lyelli)	[136]
123.	Wings of Devonian Insects	[140]
124.	Land-snail (Pupa vetusta, Dn.)	[143]
125.	Land-snail (Zonites (Conulus) priscus, Carpenter)	[143]
126.	Millipedes (Xylobius sigillariæ, Dn.; Archiulus Xylobioides, Scudder; X. farctus, Scudder)	[145]
127.	Wings of Cockroaches	[146]
128.	Wing of May-fly (Haplophlebium Barnesii, Scudder)	[147]
129.	A Jurassic Sphinx-moth (Sphinx Snelleri, Weyenburgh)	[148]
130.	An Eocene Butterfly (Prodryas persephone, Scudder)	[149]
131.	Abdominal part of a Carboniferous Scorpion	[150]
132.	Carboniferous Scorpion (Eoscorpius carbonarius, Meek and Worthen)	[151]
133.	Footprints of one of the oldest known Batrachians, probably a species of Dendrerpeton	[152]
134.	Archegosaurus Decheni	[154]
135.	Ptyonius	[154]
136.	A large Carboniferous Labyrinthodont (Baphetes planiceps, Owen)	[155]
137.	Baphetes planiceps (Owen)	[156]
138.	A lizard-like Amphibian (Hylonomus aciedentatus)	[157]
139.	Stelliosaurus longicostatus (Fritsch)	[158]
140.	Section showing the position of an erect Sigillaria, containing remains of land animals	[160]
140a.	Section of base of erect Sigillaria, containing remains of land animals	[161]
	Frontispiece. Inhabitants of the English Seas in the Age of Reptiles	[164]
141.	Arm of Proterosaurus Speneri	[166]
142.	Skeleton of Ichthyosaurus	[167]
142a.	Head of Pliosaurus	[168]
142b.	Paddle of Plesiosaurus Oxoniensis	[168]
143.	Skeleton of Clidastes	[170]
144.	An Anomodont Reptile of the Trias (Dicynodon lacerticeps, Owen)	[170]
145.	A Theriodont Reptile of the Trias (Lycosaurus)	[170]
146.	Skeleton of Pterodochylus crassirostris	[170]
147.	Restoration of Rhamphorhyncus Bucklandi	[171]
148.	A Jurassic bird (Archæopteryx macroura)	[172]
149.	Jaw of a Cretaceous Toothed Bird (Ichthyornis dispar)	[173]
150.	Jaw of Bathygnathus borealis (Leidy)	[174]
151.	Hadrosaurus Foulkii (Cope)	[175]
152.	Jaws of Megalosaurus	[176]
153.	Tooth of Megalosaurus	[177]
154.	Compsognathus	[179]
	Frontispiece. Lower Cretaceous Leaves	[184]
155.	Sassafras cretaceum (Newberry)	[190]
156.	Liriodendron primævum (Newberry)	[191]
157.	Onoclea sensibilis	[191]
158.	Davallia tenuifolia	[192]
159.	Eocene Leaves	[194]
160.	An Ancient Clover (Trifolium palæogæum, Saporta)	[195]
161.	An Eocene Maple (Acer sextianus, Saporta)	[195]
162.	A European Magnolia of the Eocene (M. dianæ, Saporta)	[195]
163.	Flower and Leaf of Bombax sepultiflorum	[196]
164.	Branch and Fruit of Sequoia Couttsiæ (Heer)	[197]
165.	Cinnamomum Scheuchzeri (Heer)	[198]
	Frontispiece. Sivatherium giganteum	[206]
166.	Jaw of Dromatherium sylvestre (Emmons)	[209]
167.	Myrmecobius fasciatus	[209]
168.	Jaw and Molar of Phascolotherium Bucklandi	[210]
169.	Jaw and Pre-molar of Plagiaulax Becklesii	[210]
170.	Restoration of Palæotherium magnum	[211]
171.	Skull of a Lower Eocene Perissodactyl (Coryphodon Hamatus)	[214]
172.	Fore-foot of Coryphodon	[215]
173.	Skull of Upper Eocene Perissodactyl (Dinoceras mirabilis)	[216]
174.	Fore-foot of Dinoceras	[217]
175.	Skull of Miocene Perissodactyl (Brontotherium ingens, Marsh)	[217]
176.	Series of Equine feet	[218]
177.	Skull of generalised Miocene Ruminant (Oreodon major)	[221]
178.	Lower Jaw of Megatherium	[222]
179.	Ungual Phalanx and Claw-core of Megatherium	[222]
180.	Tooth of Eocene Whale (Zeuglodon cetioides)	[223]
181.	Mastodon ohioticus	[225]
182.	Head of Dinotherium giganteum	[226]
183.	Wing of Eocene Bat (Vespertilio aquensis)	[226]
184.	Skull of a Cymetar-toothed Tiger (Machairodus cultridens)	[228]
185.	Lower Jaw of Dryopithecus Fontani	[229]
	Frontispiece. Contemporaries of Post-Glacial Man	[232]
186.	Elephas primigenius	[241]
187.	Tooth of Elasmotherium	[242]
188.	Engis Skull	[243]
189.	Outlines of Three Prehistoric European Skulls compared with an American Skull	[244]
190.	Flint Implement found in Kent’s Cavern, Torquay	[245]
191.	Bone Harpoon (Palæocosmic)	[246]
192.	Sketch of a Mammoth carved on a portion of a Tusk of the same Animal	[249]

Tabular View of Geological Periods and of Life-Epochs.

Geological Periods.			Animal Life.	Vegetable Life.
Cainozoic or Neozoic	Post-Tertiary or Tertiary	┌Modern └Post-Glacial	Age of Man and modern Mammals.	Age of Angiosperms and Palms.
Cainozoic or Neozoic	Tertiary	┌Pleistocene or │Glacial. │Pliocene. │Miocene. └Eocene.	Age of Extinct Mammals. (Earliest Placental Mammals.)	Age of Angiosperms and Palms.
Mesozoic	Cretaceous	┌Upper, │Lower, or └Neocomian	Age of Reptiles and Birds	(Earliest Modern Trees) Age of Cycads and Pines.
	Jurassic	┌Oolite └Lias	Age of Reptiles and Birds
	Triassic	┌Upper, │Middle or │Muschelkalk. └Lower.	Age of Reptiles and Birds (Earliest Marsupial Mammals.)
PalÆozoic.	Permian	┌Upper, │Upper, │Middle, or │Magnesian Limestone, └Lower.	(Earliest true Reptiles)	Age of Acrogens and Gymnodperms. (Earliest Land Plants.) Age of Algæ.
	Carboniferous	┌Upper Coal-Formation. │Coal-Formation. │Carboniferous Limestome. └Lower Coal-Formation.	(Earliest true Reptiles)
	Devonian	┌Upper. │Middle. └Lower.	Age of Amphibians and fishes.
	Silurian	┌Upper. └Lower.	Age of Mollusks Corals and Crusyaceans.
	Siluro Cambrian or Ordovician.	┌Upper. └Lower.
	Cambrian.	┌Upper. │Middle. └Lower.
Eozoic.	Huronian	┌Upper, │Upper, └Lower.	Age of Protozoa. (First animal remains)	Indications of Plants not determinable
Eozoic.	aurentian.	┌Upper. │Middle, │Lower. or └Bojian.	Age of Protozoa. (First animal remains)	Indications of Plants not determinable