A new theory to explain how dinosaurs learned to
fly emerged in 2002. According to a US scientist, flight may have
evolved in two-legged dinosaurs which flapped their feathered
forelimbs in order to climb slopes.
They eventually developed true wings and became
flying birds, according to Kenneth Dial of the University of
Montana. The idea was based on a study of the habits of modern
flightless birds, which beat their wings to scurry up hills and
get away from predators. It turns out that the physics behind this
sort of flapping motion are different from those of aerial flight.
Professor Dial stated that this method helps to push
the birds' feet against the slope, thereby improving traction - in
the same way that spoilers work on a racing car. He came to this
conclusion by studying partridges running up hills and measuring their
Even chicks with downy fluff were better at getting
up steep slopes than those whose flight feathers had been trimmed or
removed. By modifying these wing movements, birds or their ancestors
- the dinosaurs - may have been able to launch themselves into the
Fossils show that some dinosaurs had feathered
forelimbs but were unable to fly - something that long puzzled
palaeontologists. The big dilemma had involved the need to explain
the partial wing, pointed out Professor Dial.
It turned out that the proto-wings - precursors to
the wings which modern birds have - actually acted more like a spoiler
on the back of a racing car in order to keep the animal sure-footed
even while climbing up nearly vertical surfaces.
Professor Dial believed that what he called
wing-assisted incline running was first seen in prehistoric times.
But the idea was likely to ruffle a few feathers. There was already
a good deal of heated debate amongst academics when it came to
resolving the issue of how dinosaurs had learned to fly.
One camp believed that ground-dwellers grew feathers
which helped them to run faster and eventually become airborne. A
more recent school of thought favoured the idea that flight arose
from tree habitation - as small meat-eating dinosaurs leapt from
branch to branch in the canopies.
Dr Angela Milner, a dinosaur expert at London's
Natural History Museum, pointed to the latest theory as a kind of
'third way'. According to her, this new work served to add a new
dimension to the whole debate about how flight had evolved.
She was of the opinion that a predator escape
mechanism using wing-assisted incline running fitted in with what
could be seen in the fossils.
The research was published in the journal Science.
Professor Dial's theory was featured in an exhibition called 'Dino
Birds, the feathered dinosaurs of China', at London's Natural History
Museum in 2003.