Lufengosaurus

Lufengosaurus Temporal range: Early Jurassic 190 Ma PreЄ Є O S D C P T J K Pg N ↓
Mounted skeleton in bipedal pose
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Clade:	Dinosauria
Order:	Saurischia
Family:	†Massospondylidae
Genus:	†Lufengosaurus Young, 1941
Species
†L. huenei Young, 1941(type) †L. magnus Young, 1947
Synonyms
Tawasaurus Young, 1982 ?Gyposaurus Broom, 1911

Lufengosaurus (Chinese: 祿豐龍 or 禄丰龙, meaning "Lufeng Lizard") is a genus of massospondylid dinosaur which lived during the Early Jurassic period in what is now southwestern China.^[1]

Discovery and species

Lufengosaurus in a quadrupedal pose, skeleton donated to the Hong Kong Science Museum in 1998

During the late 1930s geologist Bien Meinian began to uncover fossils at Shawan near Lufeng in Yunnan province. In 1938 he was joined by paleontologist Yang Zhongjian, at the time better known as "C.C. Young" in the West. In 1941, Yang named remains of a "prosauropod" Lufengosaurus huenei. The generic name refers to Lufeng. The specific name honours Yang's old tutor, the German paleontologist Friedrich von Huene.^[2]

The holotype, IVPP V15, a partial skeleton, was found in the Lower Lufeng Formation. Originally considered Triassic, this formation is now seen as dating to the Lower Jurassic (Hettangian–Sinemurian). A second species was named by Yang in 1940/1941 and fully described in 1947:^[3] Lufengosaurus magnus was, as its specific name suggests ("the large one" in Latin), a significantly (up to a third in length) larger creature than L. huenei. However, in the West this is often considered a junior synonym of Lufengosaurus huenei, representing large individuals. About thirty major specimens have been discovered, including those of juveniles.^[4] In 1958 an exemplar of Lufengosaurus was the first complete dinosaur skeleton mounted in China; a commemorative postage stamp^[1] of 8 yuan was issued on 15 April 1958 to celebrate the event, the first time ever a dinosaur was depicted on a stamp.^[1]

In 1940 Yang named another prosauropod: Gyposaurus sinensis. In 1976 Peter Galton considered this species to be identical to Lufengosaurus. As it is found in Bajocian stage deposits of China, this would make Lufengosaurus one of the few "prosauropod" genera to survive into the Middle Jurassic. However, the identity is today generally doubted.^[5]

In 1981, Michael Cooper suggested that Lufengosaurus and Yunnanosaurus were species of the South African genus Massospondylus.^[6] However, a reanalysis in 2005 by Paul Barrett and colleagues of the skull of Lufengosaurus huenei establishes it as a distinct genus separate from either Massospondylus or Yunnanosaurus.^[7]

In 1985 Zhao Xijin in a species list named another species: Lufengosaurus changduensis, based on a specimen found in Tibet.^[8] This has remained an undescribed nomen nudum.

Description

Restoration of Lufengosaurus

Lufengosaurus is often described as a rather small early sauropodomorph, about 6 metres (20 ft) long.^[1] However, when the "L. magnus" specimens are included, its size is more considerable: Gregory S. Paul estimated a length of 9 metres (30 ft) and a weight of 1.7 metric tons (1.9 short tons) in 2010.^[9] For an early sauropodomorph, its neck is rather long and the forelimbs are relatively short. From these it was inferred that the species was bipedal, even before it became common to assume this for all basal sauropodomorphs. Yang published a full osteology of Lufengosaurus in 1941,^[10] but was severely hampered in his diagnosis by the war conditions, preventing a full access to literature and making an adequate comparison with related forms impossible. Of the skull a modern description exists. The skull of the holotype is 25 centimetres (9.8 in) long.^[11]

Skull

"Lufengosaurus magnus" skull, Beijing Museum of Natural History

Lufengosaurus snout was deep and broad, and it had distinctive bony bumps just behind its large nostrils and on its cheeks. A bony ridge on the side of its upper jaw might have helped anchor soft tissue. If so, then Lufengosaurus must have had larger cheeks than most other sauropodomorphs. Its closely spaced, serrated teeth suited a diet of leaves.^[12]

Classification

Yang assigned Lufengosaurus to the Plateosauridae and this is still a common classification in China. Some cladistic analyses have found Lufengosaurus as a member of the Massospondylidae. Lufengosaurus was often thought to be very similar to Plateosaurus from Europe. However, new work has proven that the pair are quite different, and Lufengosaurus was closer to Coloradisaurus and Massospondylus.^[12]

Palaeobiology

Lufengosaurus huenei pelvis.

Like all early sauropodomorphs, Lufengosaurus had much longer hindlimbs than forelimbs and was probably bipedal. It was herbivorous, although it had sharp claws (with an especially large thumb claw) and teeth.^[1] These features have been used to support claims, the most recent by Cooper in 1981, that Lufengosaurus may have been at least partially omnivorous,^[1] but the sharp teeth witnessed in Lufengosaurus and other early sauropodomorphs are similar to those seen in iguanaian lizards — which are herbivorous.^[13] Alternatively, the claws may have been used for defense or raking foliage from trees.^[1] Embryos of this genus also represent the earliest evidence of vertebrate soft tissue preservation.^[14]

References

Sources

• Dong Zhiming (1988). Dinosaurs from China. China Ocean Press, Beijing & British Museum (Natural History). ISBN 0-565-01073-5. 
• Dong Zhiming (1992). Dinosaurian Faunas of China. China Ocean Press, Beijing. ISBN 3-540-52084-8. 

External links

• Lufengosaurus on stamp
• Prehistoric animals