Extinct

Units that are listed as extinct for a given era have zero known, extant, functioning examples operating during that time.

Stocks contained in forgotten bunkers, non-functional museum or display pieces, carcasses in scrapyards, or any other situation in which the unit is not used by an active public or private military or individual are not counted as a functioning example.

Extinct units can and are occasionally brought back in later era or eras (eg: Primitive designs during the Jihad)