Which dinosaur was the heaviest

reece1 asked this weighty question recently, thanks to rekstout�for this answer.

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A.� Unfortunately the answer isn't as easy as 'what was the tallest dinosaur' or 'what was the longest dinosaur'. Calculating the weight of an extinct animal is problematic and even then the best that scientists can come up with is an estimate.

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Q.� Why is calculating weight so much harder than calculating height

A.� For the simple reason that for something like height or length the skeleton of an extinct animal gives an accurate representation of what the animal measured when it was alive.

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But weight, is made up of an animals entire body, not just the skeleton. However�these tell tale clues, from the soft parts, don't fossilise, so it's impossible to get a complete picture.

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Q.� So what do scientists estimate was the heaviest dinosaur

A.� Probably Argentinosaurus, which was an apatosaurus.

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Q.� How quickly did it gain weight

A.� It would have gained more than 100 pounds a day during its most rapid period of growth.

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Q.� So they grew quickly

A.� Yes, which contradicts the long held view of them as slow growing animals like reptiles. This finding also adds credence to the theory that dinosaurs, or at least some of them were warm blooded. Warm-blooded creatures grow much faster than cold blooded ones.

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Q.� What did Argentinosaurus eat

A.� It was a herbivore, so it got all it's pounds from sticking to a meat free diet.

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Q.� Why did dinosaurs grow so huge

A.� Not surprisingly it was probably to bag the best food on offer. Most trees were tall evergreens, so the herbivores like Argentinosaurus evolved to be taller so they could reach them: Argentinosaurus was the height of a five-storey building.

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Being large is also a good way to defend yourself against predators. An animal like Argentinosaurus would be virtually immune from attack. However, the predators soon wised up to this and soon evolved to be huge themselves, like Allosaurus and Tyrannosaurus.

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Q.� When was Argentinosaurus around

A.� 100 million years ago and, as its name suggests, so far fossils of this species have been found in Argentina.

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Do you have a question about the dinosaurs Click here to ask.

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by Lisa Cardy