Giganotosaurus: a giant hunter from ancient Argentina
Giganotosaurus was a huge meat-eating dinosaur from Argentina. It lived during the Cretaceous Period. Its name means giant southern lizard. A long skull held sharp teeth for cutting flesh. It walked on two strong hind legs. The skull and tail extended in opposite directions from the main body. A total length includes both of them. It does not mean that every part was equally heavy or equally wide. [1] [Further source]
A different place and time
This predator lived millions of years before Tyrannosaurus rex. The two did not meet in the same ancient landscape. They also came from different branches of the dinosaur family tree. Large size evolved in more than one group. Giganotosaurus belonged to the group that also includes Carcharodontosaurus. Being large did not make Giganotosaurus an early version of Tyrannosaurus. The two inherited different features from their ancestors. Comparing the skull and hands helps show those separate histories. [1] [Further source]
A body built around a huge skull
A long tail balanced the heavy front of its body. Its arms were much shorter than its legs. Museum estimates put its total length at around 13 metres. That figure is an estimate from fossil bones. It is not a measurement of a complete living animal. Some missing pieces have to be filled in using comparisons. Even a museum mount can include reconstructed parts. Labels and research descriptions help distinguish original bones from those additions. [1] [Further source]
Why size rankings change
Length alone does not tell us which predator was heaviest. Two animals can have similar lengths and different body shapes. Missing bones add another problem to the comparison. New finds can change the size scientists calculate. Giganotosaurus remains a remarkable giant without needing a fixed place on a record table. Weight is especially sensitive to the width and depth of the trunk. A long, slender body can weigh less than a shorter, broader one. A useful comparison therefore needs to say whether it concerns length or mass. [1] [Further source]