Is there an in-universe, canon reason, why Nidoran has 2 separate entries in the Pokedex for it's male/female forms, while no other Pokemon do, even when they have even clearer gender differences than Nidoran ever had?
I understand Nidoran's evolution tree changes depending on Gender, but that still doesn't explain why they should have separate Pokedex entries. It seems like if Nidoran was added today, it would be 1 Pokedex entry, and players would just have to know about how it evolves differently depending on gender. But I'm trying to wrap my head around it. Is there a single explanation given to this? Or is it just kind of shrugged off?