Sinornithosaurus

Sine-or-nith-oh-sore-s.
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Harper Gray

Paleoartist

Harper Grey combines artistic talent with scientific precision to bring extinct creatures and environments back to life. Collaborating closely with paleontologists

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Name

Sinornithosaurus ‭(‬Chinese bird lizard‭)‬.

Phonetic

Sine-or-nith-oh-sore-s.

Named By

Xu,‭ ‬Wang‭ & ‬Wu‭ ‬-‭ ‬1999.

Classification

Chordata,‭ ‬Reptilia,‭ ‬Dinosauria,‭ ‬Saurischia,‭ ‬Theropoda,‭ ‬Dromaeosauridae,‭ ‬Microraptoria,‭ ‬Microraptorinae.

Diet

Carnivore.

Species

S.millenii‭

Size

Around 120 ‬centimetres long.

Known locations

China,‭ ‬Liaoning Province‭ ‬-‭ ‬Yixian Formation.

Time Period

Aptian of the Cretaceous.

Fossil representation

2‭ ‬specimens,‭ ‬with some other specimens possibly being examples of the genus.

In Depth

       Sinornithosaurus was especially well preserved,‭ ‬and not only were the presence of feathers clearly revealed‭; ‬they showed indications of having differing colours for different body areas.‭ ‬The feathers,‭ ‬while not exactly like those of modern birds,‭ ‬are still more advanced than in other species,‭ ‬including some of the later dromaeosaurids.‭ ‬This is significant as it helps cement the argument that birds evolved from dinosaurs,‭ ‬but not from the later and larger dromaesarids,‭ ‬which detractors to the theory say is impossible.‭ ‬Instead it proves that the transition happened earlier with smaller dinosaurs that possibly also led arboreal lifestyles.

       As a living creature,‭ ‬Sinornithosaurus probably hunted around the forest floor looking for things like small mammals.‭ ‬Very interestingly the scleral rings indicate a cathermal lifestyle,‭ ‬meaning that Sinornithosaurus would have been active for small periods throughout the day or night.‭ ‬Aside from the usual night or day scenario,‭ ‬this would be good advantage for a forest hunter as light levels would be constantly changing as it moved through varying vegetation densities in the forest.

       Sinornithosaurus once had the suggestion put forward that it had a venomous bite.‭ ‬This was based on an interpretation of the front teeth being elongated and grooved to allow poison to run through,‭ ‬with space for poison glands in the skull.‭ ‬However a subsequent study has cast significant doubts against this theory on the basis that grooved teeth are known throughout all theropods,‭ ‬and are not indicative of poison delivery.‭ ‬The study also explained the elongated teeth simply as regular sized teeth that had partially fallen out as a result of the skull being crushed during the preservation process.‭ ‬No evidence was found to support the presence of poison glands on the basis that all the internal skull areas were as expected to be,‭ ‬with no special area for glands.

Further Reading

– Cretaceous age for the feathered dinosaurs of Liaoning, China. – Nature 400:58-61 1 July 1999. – Carl C. Swisher, Yuan-qing Wang, Xiao-lin Wang, Xing Xu & Yuan Wang – 1999. – A dromaeosaurid dinosaur with a filamentous integument from the Yixian Formation of China. – Nature” 401:262-266. – Xing Xu, Xiao-Lin Wang & Xiao-chun Wu – 1999. – Branched integumental structures in Sinornithosaurus and the origin of feathers. – Nature 410 (6825): 200–204. – X. Xu, Z. Zhou & R. O. Prum – 2001. – The distribution of integumentary structures in a feathered dinosaur. – Nature 410(6832) 1084-1087. – Q. Ji, M. A. Norell, K. Q. Gao, S. -A. Ji & D. Ren – 2001. – Restudy on a small dromaeosaurid dinosaur with feathers over its entire body. – Earth Science Frontiers 9 (3): 57–63. – Q. Ji, S. -A. Ji, C. -X. Yuan, X. -X. Ji – 2002. – A new species of dromaeosaurids from the Yixian Formation of western Liaoning. – Geological Bulletin of China. 23 (8): 778–783. – J. Liu, S. Ji, F. Tang & C. Gao – 2004. – The birdlike raptor Sinornithosaurus was venomous. – Proceedings of the National Academy of Sciences. – E. Gong, L. D. Martin, D. E. Burnham & A. R. Falk – 2009. – Evidence for a venomous Sinornithosaurus. – Pal�ontologische Zeitschrift – E. Gong, L. D. Martin, D. A. Burnham, A. R. Falk – 2010. – A reassessment of the purported venom delivery system of the bird-like raptor Sinornithosaurus. – Pal�ontologische Zeitschrift – F. A. Gianechini, F. L. Agnolin & M. D. Ezcurra – 2010. – Fossilized melanosomes and the colour of Cretaceous dinosaurs and birds – Nature 463(7284), p. 1075. – Funcheng Zhang, Stuart L. Kearns, Patrick J. Orr, Michael J. Benton, Zhonge Zhou, Diane Johnson, Xing Xu & Xiaolin Wang – 2010.

SPECIES SPOTLIGHT

varanus priscus a.k.a Megalania