Oh my, I almost forgot to mention, everyone in this would has a large dick. Thats right in this world, like yours, there are two genders, however both male and futa have rather large dicks. The smallest they get is maybe eight inches. And all animals, have the same proportions.
While were at it, might as well mention the other differences. Firstly, humans go through two puberties, the first is simply the dropping of the balls, and awakening to lust, this occurs any time between the ages of four and eight, and marks when they can start having sex. The second is the normal puberty you go through, when futa gain their large breasts, and larger bubble butts, and men gain even larger dicks, and bubble butts.
And their are a plethora of other differences, but Let us experience them, rather then talk about them.