Ok so
In Jurassic Park (the first one) it is explained that since only part of a dinosaur's DNA could be retrieved, they patched the rest together with a type of frog (or maybe it was a lizard) DNA
every dino was made to be female so they could not reproduce
But
The type of frog they used had a characteristic
If there were too little of one gender, some would switch gender
So not only are there trans frogs
But also TRANS DINOSAURS