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paleoecologistKatherineWillis,whereintheyexaminedhowherbivorousdinosaurs
and fossil angiosperms overlapped in time and space during the Cretaceous, they
could not conclusively say “Dinosaurs invented flowers.” Instead, they concluded
that other animal-plant interactions—such as between insects (especially bees and
wasps), mammals, and plants—probably had a greater impact in angiosperm evol-
ution, as well as extended periods of global warming. Yet they also admitted that
dinosaurs and flowering plants likely affected each group's evolutionary histories,
even though the evidence supporting this was still fairly meager.
Similarly, another review done in 2008 by Graeme Lloyd and eight other pale-
ontologists examined how what they called the “Cretaceous Terrestrial Revolution”
implicated many groups of animals—not just dinosaurs—in the evolution of angio-
sperms. They also found that the supposed “boom” in the biodiversity of dinosaurs
toward the end of the Cretaceous was likely a consequence of paleontologists look-
ing more closely for dinosaur fossils in Late Cretaceous rocks; after all, the more
you look, the more you find. (Granted, the Late Jurassic Morrison Formation has
been studied intensively too, but its dinosaurs are still not as biodiverse as those
from the Late Cretaceous.) They also pointed out that direct evidence of dinosaurs
eatingfruitsorotherpartsoffloweringplantsisactuallyquiterare,andonlyrepres-
ented by a few trace fossils such as dental microwear in hadrosaurs, an ankylosaur
cololite, and ornithopod and sauropod coprolites.
Sowhatevidencewouldbeneededforthosewhofindthemselvesromantically
attachedtotheideathatdinosaurshadsomehowcontributedtoValentine'sDayfest-
ivities and were behind the evolution of roses, tulips, petunias, azaleas, and other
gorgeous flowers we see, smell, and appreciate today? As just mentioned, some
Cretaceous dinosaur trace fossils gave paleontologists specific examples of how
these dinosaurs interacted with plants in their ecosystems. Also, in places where
herbivorous-dinosaur tracks are common but their bones are rare or absent, these
trace fossils help paleontologists to at least say whether or not these dinosaurs were
in the same places as flowering plants, which they could have eaten. But these few
