Andrew Sparkes/Alamy
What is the largest size an animal can be?
Mike Follows
Sutton Coldfield, West Midlands, UK
It is usually claimed that the blue whale is the biggest animal that has ever lived on Earth. The largest recorded mass of a blue whale is around 190 tonnes, though a bigger individual has been observed that might have tipped the scales at 250 tonnes. However, this might yet be surpassed by a marine reptile that lived at the same time as the dinosaurs, called Ichthyotitan severnensis.
The so-called square-cube law, something first observed by Galileo Galilei in 1638, sets an upper…
