How did dinosaurs grow so big? A new study reveals that the answer is not so much in the bones themselves, instead it is the squishy joints they lay between.

The scientists leading the new study published in PLOS ONE measured the ends of bones in both mammals and dinosaurs as well as their descendants to see how joint and bone shape changes as size increases.

As we grow, our bones become progressively rounder at the end to support the increase in weight while minimizing pressure as much as possible. Reptiles and birds however have bones that grow wider and flatter as more weight is added to the frame.

The wider, flatter bones of reptiles, solve the problem by packing as many layers of the stuff as they can—which as it turns out, is a much more efficient method. Here's what Matthew Bonnan from the Richard Stockton College found out from the study:
Which explains why they were so GD huge. [Live Science]