The fossils were unearthed in what is now central Niger by a team led by Paul Sereno of the University of Chicago. Some of them went on display at the National Geographic Society here and the researchers described their finds in the journal Science on Thursday.

Jobaria Tiguidensis would have lived about 135 million years ago in the Sahara desert, which was then a lush forest with broad rivers. At that time, the supercontinent called Pangea had just started to break up and Africa and South America were still joined.

Jobaria Tiguidensis would have roamed in thick forests and foraged along wide rivers, Sereno's team said. The scientists think the collection of fossils they found came from a family group drowned and buried in a flash flood.