paleozoic

As an adjective paleozoic

is (geology) of a geologic era within the phanerozoic eon that comprises the cambrian, ordovician, silurian, devonian, carboniferous and permian periods from about 542 to 250 million years ago, from the age of trilobites to that of reptiles.

As a proper noun paleozoic

is (geology) the paleozoic era.

As a noun laboratory is

a room, building or institution equipped for scientific research, experimentation or analysis.

In geology terms the difference between paleozoic and neozoic

is that paleozoic is the Paleozoic era while neozoic is more recent than the Paleozoic era, i.e. including the Mesozoic and Cenozoic.

As a proper noun Paleozoic

is the Paleozoic era.