Dinosaur Disparity Trends (IMAGE) American Museum of Natural History Caption This graphic shows disparity trends in four dinosaur groups during the final 12 million years of the Cretaceous (North American species only). Time (from 77-65 million years ago) is shown on the x axis. The y axis shows the disparity metric: Sum of variances derived from anatomical character databases. The error bars indicate whether comparisons between time intervals are significant or not (overlap of error bars means non-significance, no overlap means significance). Overall, the large-bodied bulk-feeding ceratopsids and hadrosauroids underwent a marked long-term decline, but the carnivorous coelurosaurs and small herbivorous pachycephalosaurs were stable. Credit AMNH/S. Brusatte Usage Restrictions Can be used as long as proper credit is given. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.