This is not the ideal forum to advance a paleontological thesis, but my theory is that T-rex retained their seemingly useless forearms to groom their mouths. Lizards and turtles do it all the time, and birds often use their feet for the same purpose. Keeping those teeth in good shape was a definite survival need.
This is not the ideal forum to advance a paleontological thesis, but my theory is that T-rex retained their seemingly useless forearms to groom their mouths. Lizards and turtles do it all the time, and birds often use their feet for the same purpose. Keeping those teeth in good shape was a definite survival need.