David Zwirner Gallery’s normally pristine white walls look as though they’ve been damaged by scraping; a closer look reveals that black markings are text fragments, printed onto posters that cover the walls of Michael Riedel’s latest solo show. Known for recycling text and image from his previous shows, Riedel takes the metaphor a step further by picturing animated dinosaur skeletons, creatures whose lives have been extended, in a sense, by being exhumed and put into the public realm again. (In Chelsea through March 25th).