Gigadino
MemberCompsognathusNovember 15, 2014 
Today, I'll show you what I think about T.rex and Giganotosaurus. I've seen some people claiming that the Carcharodontosaurid is the largest, while some people claimed that T.rex is the largest. Who is right? None fo them, at least according to my opinion. Now I'll explain you my points...
#1. Giganotosaurus' remains are much more uncommon than T.rex's. We've only got 2 specimens (and some teeth, found even before than Giganotosaurus' type specimen). The first one is the type specimen, and it's similar in lenght with "Sue" (12.4 and 12.3 m for Giganotosaurus and Tyrannosaurus respectively; that's a pretty negligible difference). Unlike the common belief, it isn't shorter than "Sue" (heightwise), because "Sue" has only got proportionally longer legs, but both of those animals are equal in height as well, both around to 3.5 meters tall. The second specimen is only a piece of jawbone, and it's estimated to belong to a specimen 6.5 % larger than the type, wich would result in a 13.2 m animal. But we don't really know how much bigger this specimen was. The proportions are always changing. Taking in accounts all tail's lenght variations, individual variability etc the best range for the two Giganotosaurus specimens is 12-13 meters. Longer than "Sue", then, but only slighty. And longer =/= heavier.
#2. The Tyrannosaurus specimen called "Sue" isn't as long as Giganotosaurus' specimens, but it's definitely more cumbersome. Its massive built allow this guy to be very heavy. Most of the modern estimates put the largest specimen at over 8 t, making it heavier than both Giganotosaurus specimens (wich are 6-8 t). So, is T.rex bigger, as bigger = heavier? Not really. "Sue" is the largest specimen, but most of the specimens are equal in size with Giganotosaurus specimens, and someone are even outweighted by Giganotosaurus. By a comparison, if someone ask you "what's the height of a man?" you would likely say 180 cm or so. But...let's meet Robert Wadlow (1918-1940), the tallest man ever:
When he died (he was only 22), he was 272 cm tall. That's pretty impressive. But I'm pretty sure you wouldn't say that a man is 272 cm tall only because Robert Wadlow was 272 cm tall. Bear in mind that Robert Wadlow was ill, so it keept growing in adult-hood because it had a high level of human growth hormone. By a comparison, in the same photo, you can see Robert's father, Harold Franklyn Wadlow. Harold Franklyn Wadlow wasn't short, as he was 1.82 m tall. But he's dwarfed by his son, who is instead an abnormal individual. Giganotosaurus' individuals and T.rex's individuals are pretty similar in size. The fact that a T.rex specimen reigns over Giganotosaurus, won't change the fact that most of the T.rex' specimens are just as big or even smaller.
In conclusion, I would say that both were about the same size, with T.rex with the largest confirmed size. But, if someone ask me "Wich is bigger, T.rex or Giganotosaurus?" I would say "They're around the same size".
