"Mythical" Dragon Fossil Found
Chive Mynde
Fossil boosts trees-down start for flight
Four-winged dinosaur fuels debate over evolution of air-borne birds.
23 January 2003
HENRY GEE
The discovery in China of a remarkable dinosaur with birdlike feathers
on its hindlimbs and tail as well as its forelimbs will re-ignite
debate about the origins of birds, feathers and flight.
Xing Xu from the Institute of Vertebrate Palaeontology and
Palaeoanthropology in Beijing and his colleagues found six specimens
of the new, 77-cm-long dinosaur in the fossil beds of Liaoning
Province, in the north-east of China1. They are believed to belong to
a new species - Microraptor gui - of the previously known genus
Microraptor.
The researchers think that the animals lived between 124 and 145
million years ago in trees and used their two pairs of wings, limbs
outstretched, to glide between branches - much as flying squirrels,
though entirely unrelated, use inter-limb skin flaps to leap from
branch to branch.
The new specimens will certainly fuel the long-running argument about
precisely which group of extinct reptiles are birds' closest cousins.
Flight club
Thanks largely to a series of remarkable discoveries, mainly in the
Liaoning fossil beds of China2, most palaeontologists now agree that
birds share a common ancestry with dinosaurs, in particular with small
carnivores called dromaeosaurs.
The large group that includes dromaeosaurs, as well as Tyrannosaurus
and many others, is called the theropods. Many theropods sported
feathers similar to birds', or had feather-like quills like those of
flightless birds such as the kiwi.
Theropods were bipeds, with long back legs adapted for running, and
front legs suited to other tasks such as manipulation - or indeed
flight.
So some argue that birds evolved from fast, two-legged runners, given
that wings can contribute to the thrust necessary for take-off from
the ground. Only last week Kenneth P. Dial of the University of
Montana reported that chicks can escape threats even before they learn
to fly, by running straight up trees aided by lift from flapping their
stubby wings3.
Opponents of this ground-up idea point out that it is much easier to
generate lift by climbing a tree and falling out of it, letting
gravity take the strain. Many tree-dwellers, including frogs,
squirrels, lizards and snakes, have become expert parachutists and
even gliders. The ease with which such habits have evolved, and in so
many different animal groups, suggests to many researchers that birds
could have evolved the same way, developing passive gliding into
powered flight.
To solve the impasse, one would need to find a feathered dromaeosaur
adapted to life in the trees rather than on the ground. That's exactly
what Microraptor gui seems to be.
Four wings good...
At first sight, Microraptor gui looks just like the hypothetical
'tetrapteryx' mooted in 1915 as a precursor to birds4. In other words,
it supports a trees-down, rather than a ground-up, evolution of
flight.
Four wings is a perfect recipe for gliding, but not for powered,
flapping flight. When flight evolved in later dromaeosaurs and birds,
the hindwing might have been lost and the hindlimbs reverted to
walking and perching.
Researchers will be keen to study the hip and shoulder joints of
Microraptor gui to judge precisely how far its limbs could have
splayed out to adopt the gliding posture. This is particularly
important as regards the hindlimbs. In dinosaurs these are usually
tucked in underneath the body, rather than articulating at the sides
as they do in reptiles.
References
1.Xu, X. et al. Four-winged dinosaurs from China. Nature, 421, 335 -
340, (2003).
2.Gee, H. (ed.) Rise of the Dragon: Readings from Nature on the
Chinese Fossil Record. (Chicago and London; Chicago University Press,
2001)(2002).
3.Dial, K.P.Wing-assisted incline running and the evolution of flight.
Science, 299, 402 - 404, (2003).
4.Beebe, W. H.. Zoologica, 2, 39 - 52, (1915).
© Nature News Service / Macmillan Magazines Ltd 2003
QuickDraw
> Four-winged dinosaur fuels debate over evolution of air-borne birds.
>
Wasn't this one the clever fake I saw a documentary on a few months back?
WB-LM
"QuickDraw" wrote
> > Fossil boosts trees-down start for flight
> > Four-winged dinosaur fuels debate over evolution of air-borne birds.
> >
>
> Wasn't this one the clever fake I saw a documentary on a few months back?
Nah...
...that docu was the one that sucked in the national geographic about the
'missing link' dino....essentially a bird with teeth
Rev. Figley E. Whipsnade
news:b0p6ml$53i$1...@athena.ukc.ac.uk...
> > Fossil boosts trees-down start for flight
> > Four-winged dinosaur fuels debate over evolution of air-borne birds.
> >
>
> Wasn't this one the clever fake I saw a documentary on a few months back?
>
--
Regards,
Rev. Figley E. Whipsnade, ULC
Lord Drakumo Songblade
<quickdra...@yahoo.co.uk> inflicted the following upon an
unsuspecting badger:
>> Fossil boosts trees-down start for flight
>> Four-winged dinosaur fuels debate over evolution of air-borne birds.
>>
>
>Wasn't this one the clever fake I saw a documentary on a few months back?
No, this is a new fake done by the Chinese. Gaah... I hate China.
--
Lord Drakumo Songblade
DC2.Dw Gm L W T Phlwf Sks Cbk@re-lum Bfl A+++ Fr- Nj M+1 O
H+++! $ F+++c R++ Ac+++ J++ S? U+++! I# V+++! Q+++! Tc~ E+
Dr. Twisted
"Chive Mynde" <chive...@texas.usa.com> wrote in message
news:bbc27b18.03012...@posting.google.com...
Wow...that's pretty cool.
Wyrm
"Lord Drakumo Songblade" <j...@fullcircuit.com> wrote in message
news:qar13v83bs2cim5me...@4ax.com...
> In alt.fan.dragons, on Thu, 23 Jan 2003 16:53:40 -0000, "QuickDraw"
> <quickdra...@yahoo.co.uk> inflicted the following upon an
> unsuspecting badger:
> >> Fossil boosts trees-down start for flight
> >> Four-winged dinosaur fuels debate over evolution of air-borne birds.
> >Wasn't this one the clever fake I saw a documentary on a few months back?
> No, this is a new fake done by the Chinese. Gaah... I hate China.
I don't believe that it has been shown to be a fake, but then I don't
believe it has been independently verified either yet.
--
Wyrm: http://www.wyrm.org.uk/
DC2.DGmA+++!L700fW--T-PhlltCre'SksBflF~+++!R+++!Ac++NfS
J+++Fr+++!U+++!I++H++$M+"Arabella"O/V+++!Q---Tc++E
Dragon's, coming, out of the sea.
Shimmering silver head of wisdom looking at me.
Peter Gabriel - Genesis