Name:
Microraptor
(Small thief).
Phonetic: My-crow-rap-tor.
Named By: Xu Xing et al - 2000.
Synonyms: Archaeoraptor,
Cryptovolans.
Classification: Chordata, Reptilia, Dinosauria,
Saurischia, Theropoda, Dromaeosauridae, Microraptoria,
Microraptorinae.
Species: M. zhaoianus (type),
M. gui, M. hanqingi.
Type: Carnivore.
Size: Roughly about 1 meter long.
Known locations: China, Liaoning Province.
Time period: Aptian of the Cretaceous.
Fossil representation: Approximately 300 remains
of individuals.
Microraptor
was first presented to the world as part of the composite fossil called
Archaeoraptor,
where the tail of a Microraptor
was added to the upper
body of a Yanornis.
Archaeoraptor
was a scandalous fake that made
headlines around the world, but in the aftermath of this,
Microraptor would become known to science.
Because
Arcaheoraptor was found to be a fake before it was
ever officially
named it was never an officially recognised genus. In fact its full
name, Archaeoraptor liaoningensis, was printed
before it was
officially granted as a recognised specimen. In the wake of the
discovery of Archaeoraptor being a fake, the
avian paleontologists
Storrs L. Olson tried to get the name Archaeoraptor
assigned to the
part that was from Microraptor to remove the
Archaeoraptor
taint from
the palaeornithological record.
However
Xu Xing, one of the palaeontologists who was part of the
Arhcaeoraptor study team, had already found the
counter slab and
further remains, naming them Microraptor zhaoianus.
Although Olson
was first, he named the Microraptor part as a
lectotype, a name
that is taken from a group of specimens of the same name. But
remember, the name Archaeoraptor was never
officially recognised,
and the specimen was only named as such in the media which does not
count. As such no part of Archaeoraptor could be
assigned the name as
a lectotype, and it is for this reason Xu's name and description has
gained wider acceptance and is now used the world over.
Microraptor
is very special and is often called a 'four-winged' dromaeosaur.
This is because not only did Microraptor have
extensive feather
coverage over its arms, it also has a similar extent of feather
growth on its legs too. Although not a flyer like a true bird would
be, Microraptor may have been able to use these
feathered areas along
with its small size and light build to glide across the tree canopies
of the forests of Cretaceous China. As an arboreal dinosaur,
Microraptor may well have lived like a bird. As
a living animal, Microraptor is thought to have
been most active at
night as evidenced by the scleral rings. Stomach contents have also
been preserved, revealing that smaller mammals formed at least a part
of Microraptor's diet.
How
Microraptor moved through the air is quite
interesting. Initially it
was thought that the arms and legs would have been held at the same
level, and perhaps overlaid one another. However in 2005 the
palaeontologist Sankar Chattrerjee said that an overlaid posture was
not anatomically possible and instead proposed what has been termed
the 'biplane method'. The biplane method is where the hind legs
are held at a different height to the arms so that when viewed from the
front, Microraptor would look like it had two
pairs of
wings. Chatterjee
also constructed computer model that demonstrated Microraptor
actually
being capable of powered level flight, and if the living creature did
indeed do this, Microraptor would have had quite
a considerable range
when airborne.
Other
researchers have done their own studies on the flight ability of
Microraptor, and while some of these recognise
the 'biplane'
method as possible, some consider it to have been inefficient and
suggested that Microraptor had a different
orientation when flying.
What can also be considered is that Microraptor
may not have had just
one method of gliding and may have adapted different configurations
to changing needs.
Further reading
- The smallest known non-avian theropod dinosaur. Nature 408:705-708. -
X. Xu, Z. Zhou, & X. Wang - 1999.
- New Specimens of Microraptor zhaoianus
(Theropoda: Dromaeosauridae)
from Northeastern China. - American Museum Novitates, 3381: 44pp. - S.
H. Hwang, M. A. Norell, Q. Ji & K. Gao - 2002.
- Four-winged dinosaurs from China. - Nature, 421(6921): 335-340. - X.
Xu, Z. Zhou, X. Wang, X. Kuang, F. Zhang & X. Du - 2003.
- Biplane wing planform and flight performance of the feathered
dinosaur Microraptor gui. - Proceedings of the
National Academy of
Sciences, 104(5): 1576-1580. - S. Chatterjee & R. J. Templin -
2007.
- The winged non-avian dinosaur Microraptor fed on
mammals:
implications for the Jehol biota ecosystem. - Program and Abstracts.
70th Anniversary Meeting Society of Vertebrate Paleontology. - Hans
Larsson, David Hone, Alexander T. Dececchi, Corwin Sullivan &
Xu Xing - 2010.
- Distorted Microraptor specimen is not ideal for
understanding the
origin of avian flight. - Proceedings of the National Academy of
Science, USA. - Stephen L. Brusatte & Jason Brougham - 2010.
- The extent of the preserved feathers on the four-winged dinosaur
Microraptor gui under ultraviolet light. - PLoS ONE,
5(2): e9223. - D.
W. E. Hone, H. Tischlinger, X. Xu & Z. Zhang - 2010.
- Model tests of gliding with different hindwing configurations in the
four-winged dromaeosaurid Microraptor gui. -
Proceedings of the
National Academy of Science, USA, 107: 2972–2976. - D. E. Alexander, E.
Gong, L. D. Martin, D. A. Burnham & A. R. Falk - 2010.
- Additional specimen of Microraptor provides
unique evidence of
dinosaurs preying on birds. - Proceedings of the National Academy of
Sciences of the United States of America 108 (49): 19662–19665. -
Jingmai O'Connor, Zhonghe Zhou, & Xing Xu - 2011.
- Reconstruction of Microraptor and the Evolution
of Iridescent
Plumage. - Science 335: 1215–1219. - Quanguo Li - 2012
- Piscivory in the feathered dinosaur Microraptor.
- Evolution vol67. -
Lida Xing, W. Scott Persons, Phil R. Bell, Xing Xu, Jianping Zhang,
Tetsuto Miyashita, Fengping Wang & Philip J. Currie - 2013.