Tharosaurus Indicus

Syllabus:GS3/ Science and Technology

News

• The Oldest fossils of a plant-eating dinosaur have been found in the Thar desert near the Jaisalmer Basin, Rajasthan by the Geological Survey of India.

Background

• The scientists discovered the remains of a Sauropod dinosaur, which is the same clade as the long-necked herbivores in Jurassic Park – these happened to be the oldest known fossils of this particular kind of sauropod.
• The fossils belong to the family Dicraeosauridae and from the superfamily Diplodocoidea.
• These are the first Dicraeosaurid sauropods to have been found in India.

Tharosaurus Indicus

• 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. 
• However, members of the Dicraeosauridae family of sauropods – to which Tharasaurus belongs – were not nearly as large. This family was unique: its members were smaller and had shorter necks and tails compared to the other long-necked sauropods.

History of Sauropods

• 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.
• However in India, sauropod fossils from the Early Jurassic and the Late Cretaceous period have been found, very few have from the Middle or Late Jurassic period, which would be about 160-180 million years ago.
• 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.
• In 2006, another middle Jurassic sauropod dinosaur fossil was found in the Kutch basin of Gujarat, named Camarasaurus supremus, which was also the oldest fossil of that group found at the time.

India: The Site of Radiation of Diplodocoid Dinosaurs 

• Some 167 million years ago when Tharosaurus lived, India was part of a group of continents in the southern hemisphere with Africa, South America, Madagascar, and Antarctica, together called Gondwanaland. 
• With the discovery of the oldest diplodocoid, it is highly likely 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.
• Another piece of evidence that supports their theory was that diplodocoid fossils in other continents like Africa, the Americas, and Asia come from a younger geological interval.
• Also Archaic sauropod fossils from during the start of the Jurassic period –like of Kotasaurus and Barapasaurus – were also found in India.
• 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.

Source: TH