I want to know the answer to the following question:
When did non-avian dinosaurs become extinct?
All the background I'm provided with is that "The line following the stem group Sphenacodontia split-off several diverse groups of non-mammalian synapsids—sometimes referred to as mammal-like reptiles—before giving rise to the proto-mammals (Therapsida) in the early Mesozoic era.". Is that enough to answer the question?