also dinosaurs/reptiles generally dont use the XY system like mammals do. they have a ZW system to determine sex, and for some its temperature based. ZZ for male birds, and ZW for female birds(ZW means 2 different chromosones, and ZZ is too similar ones). birds, reptile, seems more complicated than the mammal system. the closest in between would be monotreme xy , they behave more like ZW eventhough they have 10sex chromosomes.