WMG / Dog Nigga

Rex and Trish are actually the product of genetic engineering.

The explanation of how both were created seems really far fetched, even by this story's standards. In reality, Rex's Father is a geneticist who wants to create the perfect specimen. Rex and Trish are the result of him splicing human genes with canine and feline genes respectively, and the whole rape thing is a cover-up story of their true origins. Despite being quite powerful, neither of them were up to his standards, so Rex's father abandoned both and continued his research. His interest in capturing a live dinosaur is so he can create a T-Rex and human hybrid, hoping that the result will be significantly more powerful.