The FAUNA ISN'T SEXUALLY DIMORPHOUS? WHOEVER WROTE THIS NEEDS TO BE KIDNAPPED AND BROUGHT TO ME SO I CAN SHOW THEM PICTURES OF BUGS AND FISH AND HE CAN GUESS THEIR GENDER. Unless you know what the fuck to look for telling the sex of different animals can be really fucking hard. And that's the animals on earth. Aliens are aliens. Not only is this severely anthropomorphic idea of sexual dimorphism which is I'm gonna take a big leap here and say is almost certainly not based to this poster in any anthropology or evolutionary biology but fairly recent cultural norms they've confused for such. And then also decides it's a good idea to apply this to alien animals.