With a 13-foot wingspan, a flying dinosaur soars above a
lake, scanning for dinner as its shadow glides across
the water's surface below. Spotting a fish, the
reptile, called a pterosaur, dives through the air until,
with a splash, the fish is in the pterosaur's beak.
While such a scene hasn't occurred in more than 100
million years, a study funded by NSF's Biological Sciences
Directorate gives a clearer picture of what went on inside
the pterosaur's head while it was fishing. When scientists
using fossil skulls examined the neuroanatomy responsible
for flight control and prey spotting, they found structures
that were specialized and enlarged, a discovery that could
revise views of how vision, flight and the brain itself evolved.
This research, led by Lawrence Witmer of Ohio University,
took a high-tech look through two skulls of separate species
of pterosaurs. Using computerized images derived from x-rays,
they peered into the vestibular apparatus, the passageways
and chambers responsible for maintaining equilibrium. They
also went "virtually" into the brain cavity to
analyze the regions responsible for coordinating wing movements,
for scanning the environment and for stabilizing vision,
a necessity for airborne predators of the past--and of today.
To examine the skulls' chambers, which were encased
in mineralized fossils, the scientists used non-invasive,
computerized axial tomography, more commonly known as CAT,
or CT, scans.
The researchers found a greatly enlarged neurological structure
critical to flight. Called the flocculus, this lobe of the
cerebellum has important connections with the vestibular
apparatus, the eye muscles and neck muscles, which all work
together to stabilize and sharpen an image of a prey animal
upon a predator’s retina.
The discovery has led to a better understanding of how birds
and other animals, including humans, perceive the world around
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