Introduction and Succession of Vertebrate Life in America: An Address Delivered Before the American Association for the Advancement of Science, at Nashville, Tenn., Aug. 30, 1877 |
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abundant affinities American forms Amphibians anatomist ancient animals appearance Artiodactyles became extinct belong Birds brain Carnivores Cetacea characters close continent Coryphodon Cretaceous Cretaceous sea Crocodilia deposits Devonian Diceratherium Dinosaurs Diplacodon discovered distinct doubt doubtless early Tertiary Edentates Eocene Eohippus essentially Europe evidence existing genera fact fauna feet foot-prints forty-four teeth fossil fresh-water Ganoids genealogy genus Helohyus higher horizon Horse Hyrachyus important incisors indicate Insectivores Jurassic lake-basins latter Lemurs living lower Eocene lower Pliocene Machairodus mammalian mammals Marsupials Mesozoic middle Eocene migration Miocene modern types molars Mosasaurus nearly allied form North numerous Old World oldest known Oreodon Peccary peculiar Perissodactyle Placoderms Pliocene Post-Pliocene Post-Tertiary premolars present Primates probably Proboscideans recently region remains of fishes represented Reptiles resemblance Rhinoceros rocks Rocky Mountains Rodents Selenodont skeleton skull South America species specimens strata Suillines Tapir three toes to-day Trias Triassic true reptiles Ungulates upper Eocene vertebrate West
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Page 11 - Serpents" abounded ; and many were entombed in its muddy bottom. On one occasion, as I rode through a valley washed out of this old ocean bed, I saw no less than seven different skeletons of these monsters in sight at once.
Page 20 - ... animal life, are of value in this respect, mainly according to the perfection of their organization, or zoological rank. Fishes, for example, are but slightly affected by changes that would destroy Reptiles or Birds, and the higher Mammals succumb under influences that the lower forms pass through in safety. The more special applications of this general law, and its value in geology, will readily suggest themselves.
Page 20 - Palaeontology, one to which my attention was drawn several years since, namely : the comparative value of different groups of fossils in marking geological time. In examining the subject with some care, I found that, for this purpose, plants, as their nature indicates, are most unsatisfactory witnesses; that invertebrate animals are much better ; and that vertebrates afford the most reliable evidence of climatic and other geological changes. The subdivisions of the latter group, moreover, and in...
Page 48 - In these relations alone, it is my purpose here to treat him. The evidence, as it stands to-day, although not conclusive, seems to place the first appearance of Man in this country in the Pliocene, and the best proof of this has been found on the Pacific coast. During several visits to that region, many facts were brought to my knowledge which render this more than probable. Man at this time was a savage, and was doubtless forced by the great volcanic outbreaks to continue his migration. This was...
Page 18 - It is now generally admitted by biologists who have made a study of the vertebrates, that Birds have come down to us through the Dinosaurs, and the close affinity of the latter with recent Struthious Birds will hardly be questioned.
Page 20 - The Tertiary of Western America comprises the most extensive series of deposits of this age known to geologists, and important breaks in both the rocks and the fossils separate it into three wellmarked divisions. These natural divisions are not the exact equivalents of the Eocene, Miocene, and Pliocene of Europe, although usually so considered, and known by the same names ; but, in general, the fauna of each appears to be older than that of its corresponding representative in the other hemisphere...
Page 27 - I can offer you no better illustration than this of the advance vertebrate palaeontology has made during the last decade, or of the important contributions to this progress which our Rocky Mountain region has supplied. The oldest representative of the horse, at present known, is the diminutive Eohippus from the lower Eocene. Several species have been found, all about the size of a fox. Like most of the early mammals, these Ungulates had forty-four teeth, the molars with short crowns, and quite distinct...
Page 17 - Wealden have just furnished us with a genuine "missing link," a saurian (Diplosaurus) with essentially the skull and teeth of a modern Crocodile, and the vertebrae of its predecessor from the Trias. This peculiar reptile clearly represents an important stage in the progressive series, and evidently one soon after the separation of the Crocodile branch from the main stem. The modern Gavial type appears to have been developed about the same time, as the form was well established in the Upper Cretaceous...
Page 20 - Mountains has been much in dispute during the last few years, mainly in consequence of the uncertain geological bearings of the fossil plants found near this horizon. The accompanying invertebrate fossils have thrown little light on the question, which is essentially whether the great Lignite series of the West is uppermost Cretaceous or lowest Eocene. The evidence of the numerous vertebrate remains is, in my judgment, decisive, and in favor of the former view.
Page 21 - The lowest of these, resting uncouformably on the Cretaceous, has been termed the Vermilion Creek, or Wahsatch, Group. It contains a well-marked mammalian fauna, the largest and most characteristic genus of which is the ungulate Coryphodon, and hence I have called these deposits the Coryphodon Beds. The middle Eocene strata, which have been termed the Green River and Bridger Series, may be designated as the Dinoceras Beds, as the gigantic animals of this order are only found here. The uppermost Eocene,...