Scientist’s current theory on when animal life began on earth has been shifted. In Australia, scientist found evidence of animal life that proceeds the first animal life found by nearly 70 million years. The animals found are primitive sponge-like creatures that lived in the ocean coral reefs. The oldest known sponges to date lived 520 million years ago in the Cambrian period. Scientist found these fossils under a 635 million year old glacial deposit which was studying the severe ice age marking the end of the Cryogenian period 635 million years ago. What is fascinating about this find is that it was thought that no species survived during what scientists call the “snow ball” earth.
What is truly amazing is how the scientists examined the fossil. The composition of the fossil as well the surrounding area did not allow scientist to extract the fossil. Also since the organism was made of calcite instead of bone the scientist could not use x-rays, so other techniques were employed. In order to make a 3D model, scientists shaved off 50 microns of the sample at a time. A micron is about the size of half of the width of a human hair. They did this over 500 times, each time taking a photograph of the sample. By stacking all the photos together, they were able to create a the three-dimensional model. In the future they hope to automate the process which will have a profound impact in the science of paleontology.
Every time one of these new discoveries occurs we have to completely rethink our current way of thinking. Not only are we finding animal creatures that are surpassing our oldest records by millions of years but it has been happening with humans as well. I know that in recent years we keep finding either humans or creatures closely related to humans that keep predating each other. It really makes me wonder how close we are to knowing these facts. We learned in geology that materials recycle themselves over and over again over the geologic time scale. If you picked up a rock it could have been recycled over four times in the geologic record and you would have no idea. If this is the case, how are we supposed to know for certain what is the oldest animal when the fossils may have already been recycled? I believe we have a long way to go in finding out all these mysteries and we certainly do not have the technological capabilities at the moment to do it. I suppose we will just have to wait a bit longer.