But on average, sauropods appear to have declined in body mass heading into the end of the Cretaceous.
You're probably right, but we are not talking about the average. :-)
OK, that surprises me. I would have thought the effect of those runty mid-Cretaceous psittacosaurs and "protoceratopsians", at one end, and the ginormous Maastrichtian ceratopsids (like _Torosaurus_ and _Triceratops_), at the other, would have given you a statistically significant trend.
Sure, but *Leptoceratops* is just as Maastrichtian as *Triceratops*.
Yes, I suppose the coprolites would get bigger too. But here we are really
constrained by taxon sampling.
:-D