relic

relic    [Rel-ik] 

noun.   a thing of the past

"The idea of an Internet portal, like Yahoo or AOL, is a relic of a Web era 15 years ago. That model doesn’t compute in the mobile era, where apps and social networks dominate."

"A crumbling Roman wall is a relic of a once-great civilization."

"The food pyramid that we were taught  growing up is now a relic of the past. The US dumped its pyramid for the MyPlate guide in 2011."