Geoscience Reference
In-Depth Information
A couple of Early Cretaceous theropods from China,
Sinosauropteryx
and
Sinocalliopteryx
, also have intriguing enterolites.
Sinosauropteryx
, a fuzzy thero-
pod covered by a thin coat of down, is famous as the first of many feathered thero-
pods discovered in China starting in the 1990s. As a special bonus, the first spe-
cimen also had a lizard in its gut, but farther down—closer to its hips—were two
eggs. Did this dinosaur die after attempting to reenact a scene from the movie
Cool
Hand Luke
(1967)? No, as any swallowed eggs would have never made it intact
to the intestines. That meant this
Sinosauropteryx
was female, pregnant, probably
haddualoviducts(remember
Troodon
andthepairedeggsinitsnest?),andhadjust
gained some needed sustenance before giving birth, but instead died and became
part of the fossil record; its loss, our gain.
Another
Sinosauropteryx
contained jaws from three different small mammals.
These remains demonstrated how this dinosaur terrorized mammals more than a
hundredmillionyearsbeforedinosaur-worshippinghumansmademoviesdepicting
similar scenarios, perhaps reflecting an ancestral memory. Fortunately for Mesozo-
ic mammals, at least one struck a blow against its dinosaurian oppressors: stomach
contents of the Early Cretaceous
Repenomamus
, a badger-sized mammal that also
livedinChina,includedthebonesofababy
Psittacosaurus
,andthusstartedalong-
time tradition of mammals eating dinosaurs.
Based on other stomach contents, another feathered theropod, the Early Creta-
ceous
Sinocalliopteryx
ofChina,alsoatebirdsandnon-aviandinosaurs.Oneskelet-
on had two specimens of the bird
Confuciusornis
in its body cavity, as well as acid-
etchedbonesofanunidentified ornithischian dinosaur.Inthisinstance, twobirdsin
the gut was worth one neat hypothesis, as the birds were nearly complete and in the
same digested state, meaning they were likely caught and gulped quickly, one after
the other. Yet
Sinocalliopteryx
had no apparent adaptations for climbing trees, and
at more than 2 m (6.6 ft) long, it was likely too big to scale a tree trunk anyway.
A different specimen of the same species also contained a “drumstick” (leg) of an-
other theropod—probably
Sinornithosaurus
—an example of theropod-on-theropod
