Inside the icebergs, the mammoth and other huge tropical animals, believed to be of prehistoric origin because never seen on the Earth's surface, have been found in a perfect state of preservation.Some of them have been found to have green vegetation in their mouths and stomachs at the time they were suddenly frozen. The usual explanation is that these are prehistoric animals which lived in the Arctic region at the time when it had a tropical climate, and that the coming of the Ice Age, suddenly converted the Arctic from a tropical to a frigid zone and froze them before they had time to flee southward. The great ivory deposits from elephants, found in Siberia and islands of the north, are also explained in this way. Gardner, however, holds to an entirely different theory, which was supported by the observations of Admiral Byrd of a huge mammoth-like creature in the "land beyond the Pole," which he discovered. Gardner claims that mammoths are really animals now inhabiting the interior of the Earth, which have been carried to the surface by rivers and frozen inside of the ice that formed when the rivers reached the surface, forming glaciers and icebergs.

In Siberia, along the Lena River, there lie exposed on the soil and buried within it, the bones and tusks of millions of mammoths and mastodons. The consensus of scientific opinion is that they are prehistoric remains, and that the mammoth existed some 20,000 years ago, but as wiped out in the unknown catastrophe we now call the last Ice Age.

It was Schumachoff, a fisherman living in Tongoose, Siberia, who, in 1799, first discovered a complete mammoth frozen in a clear block of ice. Hacking it free, he removed its huge tusks and left the carcass of fresh meat to be devoured by wolves. Later an expedition was sent to examine it, and today its skeleton may be seen in the Museum of Natural History in Leningrad. Source:http://www.holloworbs.com/Icebergs.htm