Oliver Perry Hay

“ The bone-bed lay at an elevation of only 5 or 6 feet above an ordinary stage of low water. It was composed of a ferruginous sand and contained various species of fresh-water mollusks and stems and limbs of trees. This was underlain by a bluish clay, while above it, rising 40 or 50 feet, were beds of siliceous earth and widely spread marls. Neither the geology of the place, so far as the writer knows, nor the history of the animal requires us to believe that the geological age is beyond that of the Late Wisconsin or Wisconsin. ”

“ In case the high percentage of extinct species is not recognized as being decisive, we may consider the assemblage from another point of view. Certain species of the list appear to have existed throughout the Pleistocene, at least from the time of the first interglacial stage. These are Megalonyx jeffersonii, Mammut americanum, Elephas columbi, and Castoroides ohioensis, and their presence indicates only a Pleistocene time. Others of the list are not known to have existed after the time of the last Wisconsin drift-sheet, and may be supposed to have become extinct before that time. ”

“ As no Iowan drift is known to be present in Illinois to separate the loess of the Sangamon from the Peorian, it must be difficult, often impossible in our present state of knowledge, to distinguish the one from the other. The Sangamon loess was laid down probably long after the Illinoian ice disappeared, so that there was time for the Illinoian drift to become leached and otherwise modified and for the accumulation of old soils and peat-beds. ”

“ It is almost inconceivable that the ocean could occupy the Coastal Plain from New Jersey to Mexico for thousands of years and lay down great thicknesses of clay, sand, and gravel without having left somewhere beds of molluscan shells in such situations that they would have been discovered. While these marine fossils are lacking, there are found on all these terraces from Maryland to Florida and to the Rio Grande an abundance of land vertebrates such as elephants, mastodons, horses, camels, peccaries, and many other forms. ”

“ The considerable number of extinct species, certainly 7 out of about 18, makes it probable that the fauna is not so recent as the Late Wisconsin.
It appears to be determined that the Iowan loess was formed immediately after the retirement of the Iowan ice-sheet. It might, therefore, be a question whether all of these animals might have got into those crevices in time to be covered in by the loess. On the other hand, the Illinoian drift was, for a long time, exposed to weathering and erosion before the Iowan drift and loess were laid down. ”

“ Of all the genera and species of mammals and reptiles appearing in the list, there is none that it is necessary to suppose was derived from Pliocene deposits, or even from those of a Pleistocene stage earlier than the first interglacial. The marine fishes and sharks have been derived possibly from the Arcadia marls. On the other hand, the presence of Elephas imperator, the species of Equus, Hipparion, Glyptodon, Chlamytherium, and the gigantic tortoise Testudo crassiscutata furnishes evidence that the age was about that of the Equus, or Aftonian, beds of the Great Plains. ”

“ Unfortunately, the desired indications of geological age are not always present where bones and teeth are found; or, if present, are not always observed. We must, therefore, make our assignments of fossils to one stage or the other with great circumspection or leave the decision in abeyance.
Reference has already been made to the presence of Kansan drift in western Illinois and of black soils intervening between it and the Illinoian. Such soils must be referred to the Yarmouth interglacial stage. Whether or not still older glacial or interglacial deposits occur in Illinois is problematic. ”

“ It is hardly necessary to take up one by one all the cases of vertebrates that have been met with within the area covered by Wisconsin drift. With the few exceptions noted below, their geological age is usually to be regarded as Late Wisconsin. Along the southern border of this drift, where the remains are deeply buried, it is not unlikely that they lie in a pre-Wisconsin interglacial deposit. Along Great Miami and Muskingum Rivers there is always a possibility that the fossils may occur in a terrace or in a deep valley deposit of Illinoian age. ”

“ Nearly everywhere, even on the southern coast of Long Island as outwash, it left its burden of clay, sand, gravel and boulders, usually many feet in thickness; in the mountainous regions this drift material is present, at least in the valleys. At the extreme southern edge of the glacial sheet there was laid down the terminal moraine, which, more or less distinctly determinable, has been traced from the eastern end of Long Island to the southwestern corner of Cattaraugus County, and onward into Pennsylvania. ”

“ It is probably true, however, that some of those small changes by which we distinguish one species from another have been produced. Some small but persistent differences might, for example, have arisen in the teeth or in the form of the skull of a group of muskrats which would justify us in regarding it as forming a new species. It is extremely doubtful that any new genus of vertebrates has been developed since the first interglacial stage. ”

“ On the other hand, it is also possible that all over the world climatic conditions were at intervals unfavorably affected by the development of the great glaciers and that all life was retarded in its evolution. The writer believes, therefore, that it can not be shown with certainty that new forms of living things, especially vertebrates, were developed in North America during the Pleistocene. It may be quite as difficult to prove that any genera or species of importance entered from other lands after the first invasion. ”

“ While the teeth of our cattle may have been picked up along the shores of Ashley River, it is highly probable that the great majority of similar teeth belonged to some extinct species of Bison. Probably only the discovery of horn-cores will lead to the determination of the species. Leidy probably used the name Bison latifrons in a very wide sense. In the collection at Amherst College the writer has seen an upper molar of a bison, apparently the second molar, which is 38 mm. long on the outer face. This length is too great for B. bison and the tooth probably belongs to B. latifrons. ”

“ It is evident that this elephant lived and died after the Lake Michigan ice-lobe had withdrawn from that vicinity. It may, however, not have been long after that withdrawal; for it is probable that the muddy waters from the foot of that glacial lobe furnished the blue clay which enveloped the bones. Later peat and muck and mixtures of these with clay accumulated over the blue clay. The place is within the area of what Alden has mapped as ground moraine of Lake Michigan glacier. ”

“ Why, then, in deposits overlying the Wisconsin drift have there never been found any remains of the four Port Kennedy species of Megalonyx, of Mylodon, of the two species of horses, of the tapir, of the three species of peccaries, of the deer Odocoileus lævicornis, of the five extinct species of cricetids, of Ochotona, of the extinct species of Blarina, of the great bear Arctotherium, of the six extinct species of skunks, of the extinct otter, of the extinct dog, of the extinct fox, of any species of saber-tooth tiger, or of the extinct cats Felis inexpectata and Lynx calcaratus? ”

“ Mastodon remains are not uncommon, especially in the northern half of the State. It is hardly to be supposed that these animals were more abundant there during the late Pleistocene than in many other places in the region east of the Mississippi. The conditions for their preservation were evidently more favorable there than anywhere else, unless in Orange County, New York. Burial in swamp mud kept the bones from decay; and the imperfect drainage protected them from destruction by erosion. ”

“ On the map referred to are shown the various moraines that were left by the Wisconsin ice-sheet in its retreat toward the north. Inasmuch as most of the burials were in swamps resting on the drift, the animals must have lived and died there after the ice had left that vicinity; how long after one may not be able to determine. The mastodons and elephants which have been found close to the shore of Lake Erie, especially if buried near the surface, must have lived there at or after the time when the waters had shrunken into Lake Warren. ”

“ According to Clark and Stephenson, the Pleistocene of North Carolina comprises five formations; the oldest is the Coharie, farthest removed from the coast and lying back against the so-called Lafayette, itself supposed, with some doubt, to belong to the Pliocene. Toward the coast there come in, in succession of position and time, the Sunderland, the Wicomico, the Chowan, and the Pamlico. These formations are described as forming more or less well-defined terraces having higher and higher elevations as they are followed back from the coast. The Pamlico nowhere exceeds 25 feet above sea-level. ”

“ Animal remains are not likely to be inclosed in the materials of the moraines or of the intermorainal till; but this is possible. A musk-ox or a hairy mammoth might have died not far away from the foot of a stationary or advancing glacier and its bones might have become incorporated in the moraine. Furthermore, inasmuch as any glacial stage began while the glacier was yet in the far north and ended only when it got back there, many non-glacial deposits belonging to that glacial stage were probably laid down south of it ”

“ It was natural that the advocates of this theory of the formation of these terraces during the Pleistocene should distribute them somewhat impartially over the time of this epoch, assigning the Talbot to a late interval. On page 11 the writer has called attention to the fact that in many places along the coast from southeastern Texas to New Jersey, at or near sea-level, there are beds which contain a vertebrate fauna of the Aftonian or first interglacial stage. Probably nowhere do these beds have any large amount of later materials overlying them; it is often extremely little. ”

“ We are now to study a case which furnishes us with a store of knowledge regarding the life of the Pleistocene. In 1871 there was found at Port Kennedy, Montgomery County, a cave which was worked for its fossils by Charles Wheatley and later by Dixon, Mercer, and Cope, the latter having devoted himself to the description of the vertebrates. First of all will be given a list of the species of vertebrates, mostly mammals which have been recognized in the materials found in the cave. When Cope’s names differ from those employed here they are put in parenthesis. ”

“ It is interesting to find in eastern Tennessee the remains of Elephas primigenius. The discovery of teeth of this animal at Beaufort, North Carolina, in eastern Tennessee, and especially in Texas, proves that the range of that species extended even farther south in the New World than it did in the old. It is not improbable that the animal withdrew to the south during one or more of the glacial stages. However, none of the other species found at Whitesburg suggests a cooler climate than now prevails there. ”

“ When we reflect that the greater part of the sediments which, during the Pleistocene epoch, were deposited at the mouth of Mississippi River and 387on its flood-plain from Kentucky southward, were certainly derived from the glaciated portions of its great valley, and that those regions were alternately affected by the events of five glacial and four interglacial epochs, we must conclude that corresponding deposits or phenomena of some kind exist throughout the valley. The matter is, however, so complicated that many years must elapse before a satisfactory solution will have been reached. ”

“ In our existing mammalian fauna there are recognized 111 genera; in the Pleistocene, with hardly half as many species recorded, 138 genera are counted. In order to realize more vividly the variety of Pleistocene forms, we have only to recall the animals then present, now absent, namely, the great ground-sloths, the glyptodons, the numerous species of horses, tapirs, numerous peccaries, camels, the extinct relatives of the musk-oxen, extinct bisons, elephants, mastodons of three or four genera, the giant beaver, and the saber-tooth tigers. ”

“ It has been seen that at many points along the coast there is a fossiliferous stratum varying from 2 to 8 feet. At most localities the fossils consist principally of marine animals, especially mollusks, and the deposits have evidently been laid down in salt water. Along Ashley River and at some localities in the region about Beaufort it seems evident that the surface was above, but not far above, sea-level, and that it formed a swamp on which a great variety of land animals could move about and feed. After death their bones would suffer the fate which befalls them in such cases. ”

“ Had horses lived at Fish House during the deposition of the Cape May they would (as did the mastodon, Elephas primigenius, and E. columbi) quite certainly have spread out over northern New Jersey and over the grassy plains of New York and Ohio; and their remains would somewhere have been found, as are those of the other species just mentioned, in old swamp and lake deposits overlying the Wisconsin drift; but no horse remains have ever been reported from such deposits. ”

“ The most interesting locality in Canada for the student of vertebrate palæontology is doubtless Toronto, because of the presence there of Pleistocene deposits belonging to more than one stage, and because of the discovery of several species of extinct vertebrates and of many mollusks, insects, and plants. ”

“ Underlying the loess everywhere is the Illinoian drift.
As regards the geological age of the elephant described above, it is quite certain that it lived after the Illinoian stage. It is quite probable, too, that its teeth and bones were found in the loess which overlies the Sangamon soil in some places in the quadrangle. This loess may have accumulated during the Iowan glacial stage or during the succeeding Peorian interglacial. ”