Isisaurus
- Lived
- 72 to 66 million years ago, Late Cretaceous
- Diet
- Herbivore
- Group
- Sauropods
- Found in
- India and Pakistan
- Named by
- Wilson and Upchurch 2003
Where its fossils were found
The evidence
Today
70 million years ago
Habitat
River channels, floodplains and shallow lakes covered parts of its home in India. The Lameta Formation also contains Jainosaurus, Rajasaurus and Indosaurus.
Field notes
About Isisaurus
What it was like
Isisaurus was a titanosaur, one of the long-necked, four-legged plant eaters that spread across the southern continents in the Cretaceous. Compared with many of its relatives it had fairly long front legs and a short, sturdy neck, so it may have fed from trees rather than close to the ground.
Its world
It lived about 72 to 66 million years ago, at the very end of the Late Cretaceous, in what is now India, with fossils also reported from Pakistan. Its bones come from the Lameta Formation, where it shared the land with the hunter Rajasaurus and other titanosaurs such as Jainosaurus.
How it was found
Wilson and Upchurch named Isisaurus in 2003 for bones that had earlier been placed in another genus. The name honors the institute in India whose team collected the skeleton.
Field gallery
More views of Isisaurus
Scenes reconstructed from the available fossil evidence.
1 of 3
Lived alongside
Found in the same rock formations
A rock formation can hold fossils laid down millions of years apart, so not every animal here met Isisaurus.
The evidence
The science behind Isisaurus
Which parts of the picture come from its own bones, and which come from its relatives.
From its own fossils
- An associated partial skeleton preserves much of the backbone, shoulder and hip bones, and parts of the front limbs.
- The middle neck bones are compact from front to back, with ribs attached relatively high on their sides.
Borrowed from relatives
- Tapuiasaurus provides a guide to a long, low head and the missing hind limbs.
- The reduced front toes and compact hind feet of Opisthocoelicaudia guide the restoration of its feet.
Still unknown
- Its complete neck length and usual head position.
- Its exact toe and claw arrangement.
- Its skin, color and whether it carried bony armor.
Discovery timeline
- 2003Named itWilson & Upchurch
- 2011Close relativeZaher et al.
- 2013PostureTaylor & Wedel
- 2016Close relativeGonzález Riga et al.
Key papers
The research behind what we know of Isisaurus
Named it
Recognized Isisaurus as a separate genus using distinctive features of its backbone, shoulders and hips.
A revision ofTitanosaurusLydekker (dinosauria ‐ sauropoda), the first dinosaur genus with a ‘Gondwanan’ distribution. Journal of Systematic Palaeontology 1: 125-160
Read the paper : A revision ofTitanosaurusLydekker (dinosauria ‐ sauropoda), the first dinosaur genus with a ‘Gondwanan’ distribution (opens in a new tab)Close relative
Described the skull of Tapuiasaurus, a titanosaur with a long, low snout that helps restore the missing heads of related animals.
A Complete Skull of an Early Cretaceous Sauropod and the Evolution of Advanced Titanosaurians. PLoS ONE 6: e16663
Read the paper : A Complete Skull of an Early Cretaceous Sauropod and the Evolution of Advanced Titanosaurians (opens in a new tab)Posture
Compared sauropod neck construction, including the compact middle neck bones and high rib attachments of Isisaurus.
Why sauropods had long necks; and why giraffes have short necks. PeerJ 1: e36
Read the paper : Why sauropods had long necks; and why giraffes have short necks (opens in a new tab)Close relative
Compared titanosaur feet and traced changes in their toes and claws, providing a guide to restoring missing feet.
A gigantic new dinosaur from Argentina and the evolution of the sauropod hind foot. Scientific Reports 6
Read the paper : A gigantic new dinosaur from Argentina and the evolution of the sauropod hind foot (opens in a new tab)
Close relatives
Other members of Saltasauroidea
Sources: Wikidata