Jobaria

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Jobaria
Fossil range: Early Cretaceous

Mounted cast of a Jobaria tiguidensis skeleton at the Australian Museum, Sydney.

Kingdom:	Animalia
Phylum:	Chordata
Superorder:	Dinosauria
Order:	Saurischia
Suborder:	Sauropodomorpha
Infraorder:	Sauropoda
(unranked)	Eusauropoda
Genus:	Jobaria
Species:	J. tiguidensis

Binomial name

Jobaria tiguidensis
Sereno et al., 1999

Jobaria was a sauropod dinosaur discovered in the Sahara Desert in 1997, and is one of the most completely known Cretaceous sauropods. It was named after "Jobar", a creature of local legends, and is thought to have been about 18 metres long. It lived in the Early Cretaceous (Aptian or Albian age).

Unusually for its late occurrence, Jobaria seems to be a very primitive sauropod. It has been interpreted either as a basal macronarian (Upchurch et al., 2004), or as a non-neosauropod eusauropod, basal to the neosauropod clade.

The backbone and tail of Jobaria are simple compared to the complex vertebrae and whiplast tail of the older North America sauropods Diplodocus and Apatosaurus. Unlike other Cretaceous sauropods, Jobaria had spoon-shaped teeth.

[edit] Posture

Paul Sereno concluded, after comparing the ratios of humerus and femur circumferences in Jobaria to extant elephants, that Jobaria may have been able to rear up on its hind legs^[1]. As the weight distribution of Jobaria indicates that it was supported by the rear limbs rather than the forelimbs (as in elephants), it has been speculation that as elephants can rear-up, then Jobaria would have been able to more easily.

[edit] Bibliography

Sereno, P.C., Beck, A.L., Dutheil, D.B., Larsson, H.C.E., Lyon, G.H., Moussa, B., Sadleir, R.W., Sidor, C.A., Varricchio, D.J., Wilson, G. P. & Wilson, J.A., (1999), Cretaceous Sauropods from the Sahara and the Uneven Rate of Skeletal Evolution Among Dinosaurs, Science 286(5443): 1342-1347 (Nov 12 1999)
Upchurch, P., Barrett, P.M., and Dodson, P. 2004. Sauropoda. In The Dinosauria, 2nd edition. D. Weishampel, P. Dodson, and H. Osmólska (eds.). University of California Press, Berkeley.
Fantastic Facts About Dinosaurs (ISBN 0-7525-3166-2)