Rock Layers: Timeline of Life on EarthEvolution is a complicated subject. While everybody understands that black bears are related to grizzly bears and we can even figure they are related to extinct bears, lots of people wonder how scientists can be so su
Fossil Walrus Skull BC - 8000 BC) Odobenus rosmarus rosmarusThis impressive fossilized walrus skull retains its original lower jaw and tusks and is excellently preserved. It came from the perma frost layer in Alaska. Origin: Alaska - B.