More proof you have absolutely no idea of that which you speak. More than 75 percent of all extant species (not just the dinosaurs) became extinct at the K-T boundary.
So how many species were there before the K-T boundary? How many after? To the nearest hundred will be sufficient. Who counted them?
Your statement is just part of the evo garbage dished out constantly without any evidence. The fact is that of the major classifications of living animals, the only one that became extinct at the 65 million year or so point, is dinosaurs. Reptiles, amniotes, fish, mammals, birds, etc. all survived just fine into our time.