one of the largest land mammals that ever lived was the woolly mammoth. woolly mammoths were very large, elephant-like creatures covered in long, thick,warn hair. They needed their warm coats because they lived during the last ice age. They became extinct thousands of years ago. In places such as Siberia, in Russia, thousands of woolly mammoths because mummies after they died. Today, some of these frozen mummies can be found in very good condition