"a new study suggests" != "new science"

As good as it is to have new papers on the topic, let's not fall into the pop-science trap of thinking every new research will "cure cancer", "change our entire understanding of physics" and all the other premature comments that people make.

Dinos were not on the way out. That reading comes from a misinterpretation of the fossil record and bad statistics. Some species are represented near the extinction event; some are not found except in layers some time before the event. This is in fact the expected distribution with normal sampling. Since the record is fragmentary, and some species are hard to find in any event, its normal to not find them all exactly at the boundary between pre- and post-event.

This may be an artifact of how sparse the fossil record is. If something was around for 0.5m years it's far less likely to be seen than something around for 5m years. Combined with the facts that smaller animals evolve faster, and efficient body-types are preserved. EX: Sharks.

It's called "megatsunami".