Another specimen of the same quadruped, the most complete and probably the largest ever found, was exhumed in 1845 in the town of Newburg, New York, the length of the skeleton being 25 feet, and its height 12 feet. The anchylosing of the last two ribs on the right side afforded Dr. John C. Warren a true gauge for the space occupied by the intervertebrate substance, so as to enable him to form a correct estimate of the entire length. The tusks when discovered were 10 feet long, but a part only could be preserved. The large proportion of animal matter in the tusk, teeth, and bones of some of these fossil mammalia is truly astonishing. It amounts in some cases, as Dr. C. T. Jackson has ascertained by analysis, to 27 per cent., so that when all the earthy ingredients are removed by acids, the form of the bone remains as perfect, and the mass of animal matter is almost as firm, as in a recent bone subjected to similar treatment.
It would be rash, however, to infer from such data that these quadrupeds were mired in _modern_ times, unless we use that term strictly in a geological sense. I have shown that there is a fluviatile deposit in the valley of the Niagara, containing shells of the genera _Melania_, _Lymnea_, _Planorbis_, _Valvata_, _Cyclas_, _Unio_, and _Helix_, &c., all of recent species, from which the bones of the great Mastodon have been taken in a very perfect state. Yet the whole excavation of the ravine, for many miles below the Falls, has been slowly effected since that fluviatile deposit was thrown down.
Whether or not, in assigning a period of more than 30,000 years for the recession of the Falls from Queenstown to their present site, I have over or under estimated the time required for that operation, no one can doubt that a vast number of centuries must have elapsed before so great a series of geographical changes were brought about as have occurred since the entombment of this elephantine quadruped. The freshwater gravel which incloses it is decidedly of much more modern origin than the drift or boulder clay of the same region.[138-A]
Other extinct animals accompany the _Mastodon giganteus_ in the post-glacial deposits of the United States, among which the _Castoroides ohioensis_, Foster and Wyman, a huge rodent allied to the beaver, and the _Capybara_ may be mentioned. But whether the "loess," and other freshwater and marine strata of the Southern States, in which skeletons of the same Mastodon are mingled with the bones of the Megatherium, Mylodon, and Megalonyx, were contemporaneous with the drift, or were of subsequent date, is a chronological question still open to discussion. It appears clear, however, from what we know of the tertiary fossils of Europe--and I believe the same will hold true in North America--that many species of testacea and some mammalia, which existed prior to the glacial epoch, survived that era. As European examples among the warm-blooded quadrupeds, the _Elephas primigenius_ and _Rhinoceros tichorinus_ may be mentioned. As to the shells, whether fresh water, terrestrial, or marine, they need not be enumerated here, as allusion will be made to them in the sequel, when the pliocene tertiary fossils of Suffolk are described. The fact is important, as refuting the hypothesis that the cold of the glacial period was so intense and universal as to annihilate all living creatures throughout the globe.