Oldest Rock (about 3.8 BYA)
![Picture](/uploads/2/5/8/6/25868552/732984304.jpg)
Some of the oldest rocks are found all over the world and put into museums. In two locations scientists have found Zircon rocks, Australia and Canada. Rocks called Faux-amphibolite's have been found and may even be considered to be remnants of the Earths Crust.
Prokaryotic Cell (Simple Cell) (about 3.5 BYA)
![Picture](/uploads/2/5/8/6/25868552/3896749.jpg)
A prokaryotic cell is a one celled organism without a nucleus. These cells lack a membrane bound nucleus. They have a few internal structures that are distinguishable under a microscope. In the picture to the left of the text it shows a prokaryotic cell. It is labeled with all of the parts to a prokaryotic cell.