User blog comment:Lord Loss/Monster Hunter Theory... Blog/@comment-1758220-20110712233022/@comment-1758220-20110713182437

I think it would more likely be a high concentration of Carbon, rather than Oxygen, that results in large life forms. Back in the carboniferous period (Note: CARBONiferous), when there was a n abundance of carbon, insects grew to ridiculous sizes. There was a dragonfly the size of a seagull and Arthropleura, a centipede that was meters long.