Tujia dog is a small hairless beast that only lives in the southern United States. Before humans settled in the southern United States, Tujia's natural enemies were not strong, so Tujia thrived in the southern United States. When humans began to hunt them, Tujia dog became extinct. 
While humans settled in the southern United States, they also brought new species that may be natural enemies of Tujia dogs
 it must be people's minefields that led to its extinction.