Found some sandstone boulders that had a lot of very old clams and snails fossils in them and decided to see how many I could dig out.. One of the stones was littered with microscopic specimen, there were hundreds of them. I'm told that the clams and snails in these boulders are between 2.5 - 55 million year old so these micro fossil are too. Some of the micro fossil have been identified as foraminifera but most can not be identified. I'm still trying to find a scientist that can ID the unknowns. They range is size from about 3mm to less than 0.50mm.