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and leg proportions that suggested it could walk on all fours. This was a big predat-
ory dinosaur but built unlike most known at that time, thus provoking a good ques-
tion: With adaptations like these, what did it eat?
Inamoredetailedstudyofthisspecimenpublishedin1997,CharigandMilner
concluded that all of these traits made
Baryonyx
well suited for grabbing, hand-
ling, chomping on, and eating fish. In other words, it acted like a grizzly bear, al-
beit a massively up-scaled one. Preposterous? Not when the same specimen also
had acid-etched fish bones and scales in the area of its former stomach. These bits
belonged to a bony fish identified as
Scheenstia
, a common fossil in Early Creta-
ceous rocks in England, France, and Germany. Consequently, Charig and Milner
speculated that
Baryonyx
was comfortable wading into and swimming in lakes and
streams to find food. So thanks to this combination of body and trace fossil evid-
ence, paleontologists began to think more often of some theropods as
piscivorous
(fish-eating), whether as a main part of their diet or whenever they felt like having
fish. (As learned previously, paleontologists were further encouraged to adopt this
formerly strange idea of fish-eating theropods when they found thousands of thero-
pod swim tracks in Early Jurassic rocks of Utah.)
This same specimen of
Baryonyx
included lots of other ichnological extras,
such as the remains of a juvenile ornithopod (identified as
Iguanodon
), gastroliths,
and its own broken bones. The
Iguanodon
remains included neck, back, and tail
vertebrae aswell asarm,leg,finger,andtoebones.Thusthe“grizzly bear” analogy
holds up well for
Baryonyx
in this respect, as these modern carnivores are not just
restricted to eating fish but also deer, elk, caribou, moose, and other animals. The
Iguanodon
bones were eroded, probably by stomach acids, just like the hadrosaur
bones in
Daspletosaurus
.
Charig and Milner also mentioned gastroliths as being present and associated
with the skeleton; sadly, they gave no other description of these trace fossils. Oddly
enough, they mention “gastroliths” in their 1986 paper, but only “an apparent gast-
rolith” in the 1997 one. Did the others get misplaced during that eleven-year gap?
