It emerged that the anhanguera had an elongated limb called the pteroid.
It had previously been thought the pteroid pointed towards the shoulder
of the creature and supported a soft forewing in front of the arm. But
if that were the case, the forewing would have been too small and
ineffectual for flight. However, to the surprise of many scientists,
fossils from the Araripe basin showed the pteroid possibly faced the
opposite way, creating a much greater forewing that would have caught
the air, working in the same way as the flaps on the wings of an
aeroplane. So, with both feet on the ground, the anhanguera might have
simply faced into the wind, spread its wings and risen up into the sky.
Initial trials in wind tunnels proved the point---models of pterosaurs
with forward-facing pteroids were not only adept at gliding, but were
agile flyers in spite of their size. 'This high-lift capability would
have significantly reduced the minimum flight speed, allowing even the
largest forms to take off without difficulty,' Wilkinson says, 'It
would have enabled them to glide very slowly and may have been
instrumental in the evolution of large size by the pterosaurs.'
1. What did Professor Wilkinson discover about a bone in pterosaurs
A. It was in an unexpected position.
B. It existed only in large species of pterosaurs.
C. It allowed pterosaurs to glide rather than fly.
D. It increased the speed pterosaurs could reach in the air.