Jobaria is a genus of sauropod dinosaur that lived in what is now Niger during the middle Jurassic Period, between 164 and 161 million years ago.

The genus is named after a local mythical giant beast, Jobar, whose bones some Tuaregs believed the fossils to be. The specific name tiguidensis comes from the cliff of Tiguidi, the site of discovery.

The sediments in which it was found were originally thought to represent the Hauterivian to Barremian stages of the early Cretaceous Period, dating Jobaria to approximately 132 million years ago.

Description

thumbnail|left|[[Life restoration]]

thumb|Size of Jobaria compared to a human

Jobaria was a primitive sauropod, about long and estimated to weigh about . In 2016 Gregory S. Paul gave a lower estimation of and . Its backbone and tail were simple compared to the complex vertebrae and whiplash tail of the later North America sauropods Diplodocus and Apatosaurus.

It may also have been able to rear up on its hind legs as Paul Sereno concluded, after comparing the ratios of humerus and femur circumferences in Jobaria to extant elephants. The weight distribution of Jobaria indicates that it was supported by the rear limbs rather than the forelimbs (as in elephants) and is speculated that as elephants can rear up, then Jobaria would have been able to more easily.

Classification

thumb|upright|Head cast, Montshire Museum of Science

The phylogenetic relationships of Jobaria are uncertain; it has been interpreted either as a basal macronarian, or as a non-neosauropod eusauropod, basal to the neosauropod clade.

The following cladogram shows the position of Jobaria within the Eusauropoda.

References

  • Jobaria in the Dino Directory