a fossil known to have lived in a particular geologic age that can be used to date the rock layer in which it is found
the remains (or an impression) of a plant or animal that existed in a past geological age and that has been excavated from the soil
someone whose style is out of fashion
a numerical scale used to compare variables with one another or with some reference number
a number or ratio (a value on a scale of measurement) derived from a series of observed facts; can reveal relative changes as a function of time
a mathematical notation indicating the number of times a quantity is multiplied by itself
an alphabetical listing of names and topics along with page numbers where they are discussed
the finger next to the thumb
