Guanlong

Guanlong Temporal range: Late Jurassic, 160Ma PreЄ Є O S D C P T J K Pg N ↓
One of the two known specimens
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Clade:	Theropoda
Superfamily:	†Tyrannosauroidea
Family:	†Proceratosauridae
Genus:	†Guanlong Xu et al., 2006
Species:	† G. wucaii
Binomial name
Guanlong wucaii Xu et al., 2006

Guanlong (Simplified Chinese: 冠龙; Hanyu Pinyin: guānlóng; means "crown dragon") was a genus of proceratosaurid tyrannosauroid dinosaur, one of the earliest known examples of the lineage.

Description and discovery

The size of Guanlong compared to a human.

About 3.0 metres (9.8 ft) long,^[1] its fossils were found in the Shishugou Formation dating to about 160 million years ago, in the Oxfordian stage of the Late Jurassic period, 92 million years before its well-known relative Tyrannosaurus. This bipedal saurischian theropod shared many traits with its descendants, and also had some unusual ones, like a large crest on its head. Unlike later tyrannosaurs, Guanlong had three long fingers on its hands. Aside from its distinctive crest, it would have resembled its close relative Dilong, and like Dilong may have had a coat of primitive feathers.

Guanlong was discovered in the Dzungaria area of China by scientists from George Washington University, and named by Xu Xing in 2006. Guanlong comes from the Chinese words for "crown" and "dragon", referring to the crest. The specific epithet (五彩冠龙), wucaii (Hanyu Pinyin: wŭcái), means "five colours" and refers to the colours of rock of the Wucaiwan, the multi-hued badlands where the creature was found.

Specimens

Fossil specimen

At present, Guanlong is known from two specimens. The holotype (IVPP V14531) is a reasonably complete, partially articulated adult skeleton. Another, immature specimen is known from fully articulated and nearly complete remains. The crest on the skull of the immature specimen is notably smaller and restricted to the forward portion of the snout, while the adult has a larger and more extensive crest. The crests of both specimens are thin, delicate structures that likely served as display organs.

Classification

In a recent study, Guanlong was found to be in a clade with both Proceratosaurus and Kileskus. Together they formed the family Proceratosauridae with a clade containing Sinotyrannus, Juratyrant and Stokesosaurus.^[2]

Below is a cladogram of Tyrannosauroidea published by Loewen et al. in 2013.^[2]

Restoration

In popular culture

A number of Guanlong were featured in the 2009 film Ice Age: Dawn of the Dinosaurs. Character designer Peter de Sève stated in a 2009 interview that the dinosaur was chosen as "a twist on a Velociraptor", which is often featured in dinosaur films.^[3]

Guanlong was featured in the National Geographic documentary Dino Death Trap, where the holotype was discussed, as well as its role in the ecosystem and its status as a tyrannosauroid.

Guanlong was also featured in the 2011 Discovery channel documentary Dinosaur Revolution, where a pair (named "Fatty" and "Skinny") chase a Castorocauda, but fail, and also chase a Volaticotherium, but fail and get surrounded by crocodiles on a tiny island.

References

• Xu X., Clark, J.M., Forster, C. A., Norell, M.A., Erickson, G.M., Eberth, D.A., Jia, C., and Zhao, Q. (2006). "A basal tyrannosauroid dinosaur from the Late Jurassic of China". Nature 439 (7077): 715–718. doi:10.1038/nature04511. PMID 16467836. 

External links

• Pictures of newly discovered tyrannosaur
• (BBC News), "Oldest T. rex relative unveiled" 8 February 2006
• (National Geographic), "Tyrannosaur Trap" July 2008 Accessed 17 June 2008