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
Amargasaurus, a Sauropod dinosaur from the early Cretaceous Period (around 130 million years ago). Amargasaurus was small for a Sauropod and featured two rows of spines down its neck and back. Photo taken in Victoria Museum, Melbourne, Australia.