Dinosaurs Evolve—and Fly 275popular movie Crouching Tiger, Hidden Dragon, which was partially filmed near the local-
ity where the fossil was found. Yinlong consists of a beautifully preserved skeleton of a
bipedal dinosaur not too different in proportions from Psittacosaurus. It has the rostral
bone unique to ceratopsians on the tip of its upper beak. However, its skull roof has a
unique configuration of bones found in the “bone-headed” dinosaurs, the pachycepha-
losaurs, which are famous for having a thick dome of bone in their skulls protecting
their tiny brains. Paleontologists have long argued that ceratopsians and pachycephalo-
saurs are closest relatives, based on the fact that they both have a frill of bone around the
back margin of the skull (hence their name, “Marginocephala,” or “margin heads”). But
with Yinlong, we have a beautiful transitional fossil that shows features of both ceratop-
sians and pachycephalosaurs before their lineage split into the two families that every
kid recognizes.
As usual, Gish hadn’t done his homework or bothered to read more recent sources.
The fact that he cited an out-of-context quotation from Weishampel et al. (1990) shows that
he could apparently read a more authoritative source, but either he could not read well
enough to also discover that the other transitional forms like Psittacosaurus are mentioned
in the same chapter or his biases were so strong that he can only find short snippets that
fit his prejudices. Either way, he completely missed the forest for the trees. And he defi-
nitely hasn’t looked at the fossils himself or acquired the training necessary to understand
what he was looking at. During our debate, I nailed him on this point. After he blathered
on and on about no transitional ceratopsians, I showed him not only the examples just
discussed but gave my personal testimony. When I was a graduate student, most of the
good specimens of Psittacosaurus and Protoceratops had been cluttering up my office in
the American Museum of Natural History for months because my officemate, Dan Chure
(recently retired after almost 40 years as the paleontologist at Dinosaur National Monu-
ment), had been studying the specimens for his thesis. Not only did I know more about
these transitional fossils than Gish, but I have actually studied them as well.
We could go on and on debunking creationist falsehoods about dinosaurs. Anyone
with a moderate interest in the subject can peruse the chapters in some of the books listed
at the end of this chapter (such as Norman 1985; Weishampel et al. 2004; Fastovsky and
Weishampel 2005) and see the beautiful intermediate fossils for nearly every group that
Gish denies have transitional forms. There are excellent specimens of primitive relatives
of duckbill dinosaurs (they are called ornithopods), of primitive armored ankylosaurs
known as nodosaurs (with very limited armor and very primitive delicate skeletons com-
pared to the huge Ankylosaurus), and of primitive stegosaurs, such as Scelidosaurus, which
has limited armor, smaller size, delicate limbs, and a very primitive skeleton compared
with Stegosaurus. We can trace all of these ornithischian dinosaurs (plus the ceratopsians)
back to the most primitive forms, such as Heterodontosaurus (fig. 12.6) and Fabrosaurus
from the Triassic. These creatures, in turn, looked very similar in their external features to
Eoraptor and Herrarasaurus, the earliest dinosaurs, except for a few subtle differences, such
as the presence of a predentary bone at the tip of the lower jaw and a primitive ornith-
ischian hip structure. If one reads the literature carefully and with an open mind, these
transitions are obvious. If you read with the denial filter of Gish, who only found quotes
out of context that seem to support his view, you will get the distorted, misleading version
that he presents.