At first the paleontologists thought the T-Rex was related with the Gigantisaures. But after studies and many clues being found throughout the year, the paleontologists then realized that they weren't in common. The timeline of these 2 reptiles was far far away.
A Gigantisaures is from Southern America and would probably live in the bushes or forests. Gigantisaures lived in the Cretaceous period of the Mesozioc era (around 100 million years ago).
A Gigantisaures would have eaten other slow dinosaures or carnivores and would have been a Meat-eater.
The tail would be very important part of a Gigantisaures because the techneqe for a Gigantisaures's is way to catch it's prey needs balance. A Gigantisaures 's tail is pointy and is really long.