Cambrian Rock

I found out that the rock I took back from the campsight is from the time that little things living in oceans moved from being little sticks of cells hovered together to little swimmy things with shells and claws. There was more oxygen in the water at the time and so animal's bodies could have a bigger surface area without having to gasp for the oxygen they needed. Thank you to the New York Natural History museum. I remember sitting in a room, overhead hearing the sound of lapping water, being surrounded by paintings of tiny creatures and watching an animation of Cambrian creatures. It was that that gentle introduction that first got me interested in the life stages of the Earth. Now I have a real rock from that time. Incredible!!