We all know dinosaurs were (for the most part) huge. The dinosaur called Brachiosaurus was so big that even three elephants would not equal its size! How and why did dinosaurs attain their humongous size?

Scientists believe a meteorite impact at the end of the Triassic (202 million years ago) could have cleared the stage of other large reptiles, explaining why there was a rapid evolution of massive carnivores.

Another study show that carbon dioxide levels were five times today’s level, giving plant growth a gigantic boost. Seeing they didn’t need to fit into a bikini, this made for big momma herbivores.

Yet another good reason to recycle and keep those carbon levels down!

• A few other theories
• Think the Brachiosaurus was the tallest dino? Think again…
• Take a peek at the dino timeline to put millions of years in perspective
• A quick Q&A to straighten out a few dino question marks
• Ever wished you could eat faster? This dinosaur could - it vacuumed up its food!