Produced by Chris Curnow, Matthew Wheaton and the Online Distributed Proofreading Team at http://www.pgdp.net (This file was produced from images generously made available by The Internet Archive) ANIMALS OF THE PAST [Illustration: Phororhacos, a Patagonian Giant of the Miocene. _From a drawing by Charles R. Knight._] _Science for Everybody_ ANIMALS OF THE PAST BY FREDERIC A. LUCAS _Curator of the Division of Comparative Anatomy, United States National Museum_ FULLY ILLUSTRATED NEW YORK McCLURE, PHILLIPS & CO. 1901 COPYRIGHT, 1900, BY S. S. MCCLURE CO. 1901, BY MCCLURE, PHILLIPS & CO. PUBLISHED NOVEMBER, 1901. TABLE OF CONTENTS INTRODUCTORY AND EXPLANATORY Use of scientific names, xvi; estimates of age of earth, xvii; restorations by Mr. Knight, xviii; Works of Reference, xix. I. FOSSILS, AND HOW THEY ARE FORMED Definition of fossils, 1; fossils may be indications of animals or plants, 2; casts and impressions, 3; why fossils are not more abundant, 4; conditions under which fossils are formed, 5; enemies of bones, 6; Dinosaurs engulfed in quicksand, 8; formation of fossils, 9; petrified bodies frauds, 10; natural casts, 10; leaves, 13; incrustations, 14; destruction of fossils, 15; references, 17. II. THE EARLIEST KNOWN VERTEBRATES Methods of interrogating Nature, 18; thickness of sedimentary rocks, 20; earliest traces of life, 21; early vertebrates difficult of preservation, 22; armored fishes, 23; abundance of early fishes, 25; destruction of fish, 26; carboniferous sharks, 29; known mostly from teeth and spines, 30; references, 32. III. IMPRESSIONS OF THE PAST Records of extinct animals, 33; earliest traces of animal life, 34; formation of tracks, 35; tracks in all strata, 36; discovery of tracks, 37; tracks of Dinosaurs, 39; species named from tracks, 41; footprints aid in determining attitude of animals, 43; tracks at Carson City, 45; references, 47. IV. RULERS OF THE ANCIENT SEAS The Mosasaurs, 49; history of the first known Mosasaur, 50; jaws of reptiles, 53; extinction of Mosasaurs, 55; the sea-serpent, 56; Zeuglodon, 58; its habits, 59; Koch's Hydrarchus, 61; bones collected by Mr. Schuchert, 63; abundance of sharks, 64; the great Carcharodon, 65; arrangement of sharks' teeth, 67; references, 68. V. BIRDS OF OLD Earliest birds, 70; wings, 71; study of young animals, 73; the curious Hoactzin, 74; first intimation of birds, 76; Archaeopteryx, 77; birds with teeth, 78; cretaceous birds, 79; Hesperornis, 80; loss of power of flight, 81; covering of Hesperornis, 82; attitude of Hesperornis, 83; curious position of legs, 84; toothed birds disappointing, 85; early development of birds, 86; eggs of early birds, 87; references, 88. VI. THE DINOSAURS