Ah, the Simpsons retcon. This has always been a show that played fast and loose with the facts and this episode is no exception OH WHO AM I KIDDING I BLUBBERED LIKE A BABY.
"Here, have a bracelet made of a '70s educational film strip."
Fred Armisen and Carrie Brownstein play an ultra-cool pair of hip parents with two sons, the elder of which (Bart's age) is named Tyrannosaur, and voiced by Patton Oswalt. Now I grant you, hipster bashing is not exactly a cutting-edge trend.