I read your short story, and it's very good! However, I noticed a slight error in the history: You call the beast "Teerex" having supposedly derived from "T-rex", but that isn't hsitorically possible if the people of the story world had come from the 1700s or earlier because dragon fossils weren't classified as dinosaurs or even names like tyrannosaurus untill 1841. Before that, they were simply known by names such as "dragon" and (in the case of the tyrannosaurus) "Grendel." This being said, I think it would fit the story a lot better if the people called the T-rex a Grendel instead, since that is the only name that could have been passed down in their legends at that point in time.