The Pleistocene of North America and its Vertebrated Animals from the States east of the Mississippi River and from the Canadian Provinces East of Longitude 95°
9781465642189
200 pages
Library of Alexandria
Overview
The writer has been engaged for several years on an investigation of the Pleistocene geology of North America and of the Vertebrata which have been discovered in the deposits of this epoch. It had been his expectation to publish the results of all his studies at the same date. However, on consultation with Dr. John C. Merriam, it was agreed that it would be better to publish immediately that part which pertains to the region lying east of the Mississippi River and, as to the country further north, that east of longitude 95°. At the outset the writer was convinced that, before just conclusions could be reached, it was necessary to know what fossil materials had been collected and under what geological and geographical conditions. He therefore made as thorough a search as possible of the literature for reports of discoveries of fossil vertebrates. Also, when in scientific journals or in newspapers the finding of fossils was recorded, recourse was had to correspondence, thus securing much exact information as to locality, kind of matrix, depth, and other important data. Often photographs have been obtained and even the materials themselves. The writer has also visited many museums and colleges throughout the country and examined their collections. Even in the smaller institutions, where perhaps only a few objects have been secured and preserved, some of these have furnished important information. Regret may be expressed that in the larger museums and colleges, as well as the smaller ones, too often there have been preserved only meager or no records regarding the history of what would otherwise be valuable specimens. The Pleistocene is regarded as being equivalent to what is known as the Glacial period. It began with the deployment of the ice-sheets which, proceeding from their centers of accumulation in British America, laid down in the East the Jerseyan drift and in the West the Nebraskan. The more the Glacial period is studied the more one becomes impressed with the significance of its physical effects on the northern hemisphere and with its influence on the vertebrate life. Doubtless its effects on the world in general are only beginning to be comprehended. The writer knows of no other phenomena, geological or biological, which so well characterize the Pleistocene period as do those comprehended under the term Glacial. They constitute the key to the determination of the subdivisions of the epoch and of their succession and to the history of the vertebrates which during this time occupied the continent.
