[Mesozoic]—the geologic [era] between the [Paleozoic] and [Cenozoic] Eras; the “Age of Reptiles.”
[Metamorphic rock]—[rock] formed from [igneous] or [sedimentary rocks] that have been subjected to great changes in temperature, pressure, or chemical environment.
[Metamorphism]—the process whereby [rocks] are changed physically by heat, pressure, or chemical environment into different kinds.
[Mineral]—a naturally occurring inorganic substance possessing definite chemical and physical properties.
[Nodule]—rounded lump of [rock] or [mineral].
[Outcrop]—the area where a particular [rock] [formation] comes to the surface.
[Paleontology]—the science which deals with the study of [fossils].
[Paleozoic]—that [era] of [geologic time] following the [Proterozoic] and preceding the [Mesozoic].
[Period]—a basic unit of the [geologic time scale] into which the eras are divided, such as the Pennsylvanian [Period] of the [Paleozoic] [Era].
[Permian]—the seventh and last [period] of the [Paleozoic] [Era].