Will (11) from Lowestoft has a question about dinosaurs.....
was there ever such a creature as "giganotosaurus" (not sure about spelling?)and if so was it bigger than a T-Rex?
And my dad wants to know if Dino's were around for so long why didn't they evolve to be a bit more intelligent? Its always puzzled him.
Well Will, there certainly was such a thing as Giganotosaurs (yes, your spelling is right!) and it was indeed 'bigger' than Tyrannosaurs. Several fossils of Giganotosaurs have been found from the rocks of Late Cretaceous in Argentina, and it is one of the biggest known carnivorous dinosaurs. It was relative of Allosaurs (although it lived much later) and may have reached more than 15 meters in length! This is quite a bit more than T.rex, although T.rex was much bulkier and as a result was probably a heavier animal. Above is a reconstruction of the skull of Giganotosaurswith that of a human!
Giganotosaurs lived at the same time and place as the largest known dinosaur, the enormous Argentinosaurs that may have been up to 50 metres long, and weighted 100 tons!!! As a result, it has been suggested that Giganotosaurs was actually a pack hunter and took on these huge dinosaurs in groups. Here is a picture of a reconstruction of the two dinosaurs.
As for dinosaur intelligence it is a difficualt question to answer. Certainly some dinosaurs would have been quite smart compared to living animals. We can get an idea oof both an dinosaurs brain size, and how it was made up by the bones that surround it. From this we can see how big the brain was and what parts were devoted to eyesight, smell etc. There is also a general correlation of intelligence with the size of the brain and the size of the animal. Large animals need large brains, so a small animal with a large brain was probably quite smart. Certainly some dinosaurs (notably the advanced predators like Troodon and Deinonychus were about as smart as some modern birds like ostriches. Our own Darren Naish discussed some of these issues recently, look here for more.
As for why more dinosaurs didn't get more intelligent sooner, well thats impossible to say. Probably they had no need to, they only had to outsmart each other, so if everyone was at the same level there would be no big evolutionary pressure to get smarter. Darren's post looks at some of the consequences of super-smart dinosaurs and how they might have evolved.