One explanation for the gigantic scale of pre-historic life

I am continually looking for additional data to add to this and my other graphs of the size reduction of life. I would be most interested in receiving information about the estimated mass of various land based large animals (these can be Dinosaurs, Supergiant mammals or Giant Mammals) and the time periods they were alive. The information I use is: Was the animal quadipedal (four footed) or bipedal (two footed)? The estimated mass of the animal (or the circumference of the humerous leg bones) The estimated age when the animal lived The reference source where the information came from

RELATED INFORMATION Graph of Dinosaurs' and other lifes' mass plotted over time Main Page