Oldest yet fossils of a plant-eating dinosaur found in Rajasthan

Subject: Geography

Section: Physical geography

Context:

Scientists from IIT Roorkee have characterized dinosaur fossils from the Middle Jurassic period, found in the Thar desert near the Jaisalmer Basin by the Geological Survey of India.

What have the scientists found?

They have uncovered remains of a sauropod dinosaur, which happened to be the oldest known fossils of this particular kind of sauropod.
The fossils were found by Triparna Ghosh, Pragya Pandey, and Krishna Kumar from the Geological Survey of India.

Sauropods- Tharosaurus indicus:

Sauropods first appeared on the earth during the Jurassic period, about 200 million years ago. They were one of the most dominant clades of dinosaurs, surviving until the late Cretaceous period 65 million years ago, when dinosaurs went extinct.
Belonging to the family Dicraeosauridae and from the superfamily Diplodocoidea, these fossils are the firstdicraeosaurid sauropods to have been found in India.
The scientists named the dinosaur Tharosaurus indicus, with Tharo deriving from the Thar desert;saurus from the Greek ‘sauros’, or lizard; and indicus from its Indian origin.
At 167 million years old, they are the oldest known diplodocoid fossils in the world.
They can grow more than a hundred feet. There are many sauropod groups that are even longer than the blue whale.
India has also been home to a few early, more primitive sauropods, like Kotasaurus and Barapasaurus. They were both discovered in the Kota Formation, a geological rock unit in Telangana, from the Early Jurassic period.

Importance of Indian landmass:

167 million years ago, India was a part of a group of continents in the southern hemisphere with Africa, South America, Madagascar, and Antarctica, together called Gondwanaland.
The scientists reasoned that these diplodocoid sauropods could have originated in India during the Middle Jurassic period and used the land connections at the time to migrate to Madagascar, Africa, and South America. After that they could have made their way to North America and the rest of the world.
The diplodocoid fossils in other continents like Africa, the Americas, and Asia come from a younger geological interval. This increases the possibility that the Indian landmass was the site for the Tharosaurus’ early radiation.
Together, the record from India suggests that the Indian landmass was one of the most important places for the early evolutionary history of sauropod dinosaurs.

Need of more fossils:

In the Middle Jurassic, when Tharosaurus lived, the continents were beginning to split apart from the supercontinent Pangea, and as these dinosaurs spread, they evolved into new forms.
More fossils of different parts of the Tharosaurus skeleton or of other related skeletons will help us better understand endemic sauropod evolution in India and global sauropod evolution and biogeography.
In 2006, an Indo-German team found another middle Jurassic sauropod dinosaur fossil in the Kutch basin of Gujarat, named Camarasaurus supremus, which was also the oldest fossil of that group found at the time. There have been subsequent finds of extremely old sauropod fossils in the region by the same team since.