The story of these fossils was popularized by Stephen Jay Gould's book wonderful life in 1989. So this really caught the public eye and these weird and wonderful creatures became more known to people in the public and you know the research community is still really focused on the Cambrian explosion at the moment. Fossils from the period of the cambrian explosion happened found all over the world. One of the most famous sites where they were first found is the Burgess Shale which is located in the Rocky Mountains in Canada. The fossils there are fantastic and really different from what you normally think of from a fossil normally you think of say bones or teeth really hard things. The fossils of the Burgess Shale are completely soft bodied. So you get all of these soft things preserved which you don't normally see you get skin, eyes. You can get tiny little spines, little hairs. You can even see internal structures so sometimess we get the gut with the last meal still in place in the stomach. So this is really exceptional preservation really really outstanding.