I have decided to add a geologic time scale, which can be useful when someone mentions a fossil from a certain age, or a time in Earth's history before man. The folowing time scale is largely adapted from International Commission on Stratigraphy (ICS). There may be some different names associated with each time division, and all of the dates are somewhat tentative, depending on the method used to derive the dates. The ages given on the right hand side are very generalized. An example of how the reader might interpret them could be as follows:

When looking at the Gelasian stage, the time is from about 2.58 million years ago, to about 1.81 million years ago, give or take about 100,000 years. Other ages might have more of a variance, especially the farther back in time one goes.