Complex sentence: It was about 10-11 feet long and had a very stocky torso, while on its hind legs, it could have touched an object nineteen feet off the ground with its front claws.
Split into simpler sentences: It was about 10-11 feet long and had a very stocky torso. While on its hind legs, it could have touched an object 19 feet off the ground with its front claws.