I can't think of any dinosaurs that first came into existence 3 years ago in 2011 and were the most recent dinosaur of its particular kind available until September 2012, 20 months ago. It seems like a terrible metaphor to say everything more than 20 months old is a "dinosaur". It's such a bad metaphor in fact that I wonder for the sanity, competence and/or neutrality of anyone seriously advocating it. I doubt anyone genuinely and sincerely believes that things more than 20 months old are all dinosaurs, even tech things. On the other hand, I would not be surprised at all if such terms were used as part of a propaganda or agenda driven attempt to mislead people. That sort of thing happens a lot.