The team's research shows that hadrosaurs and ceratopsids, two groups of large-bodied, bulk-feeding herbivores, animals that did not feed selectively, may have experienced a decline in biodiversity in the 12 million years before the dinosaurs ultimately went extinct. In contrast, small herbivores, carnivorous dinosaurs, and the enormous sauropods remained relatively stable or even slightly increased in biodiversity.As Brian Switek recently wrote at Dinosaur Tracking, this is a very complicated matter, and the oversimplification that casts a shadow over much popular thinking needs to be jettisoned. The dinosaurs were not marching in lockstep towards oblivion, and local trends can serve to distort what was happening globally because of selection bias. It should be a fun chat, and a great chance to get young minds to think more critically about nature (hint hint, teachers).
The AMNH also produced a summary video of the research, embedded below.
Questions can be submitted by email or via the Twitter hashtag #AMNHlive, and the chat will be hosted on the museum's site. Visit the AMNH website for more information.