Werebat question

[the David]

I was wondering in which kind of bat a werebat can transform into. According to the bestiary:

"Size and Type: The creature (referred to hereafter as the base creature) gains the shapechanger subtype. The lycanthrope takes on the characteristics of some type of animal (referred to hereafter as the base animal) within one size category of the base creature's size. A lycanthrope's hybrid form is the same size as the base animal or the base creature, whichever is larger."

A Dire Bat is large, while a Bat is diminutive. The hybrid form of a werebat is medium... So unless there is another kind of bat, Bestiary 4 is wrong?

[William Werminster]

Werebat from pfsrd20

Bestiary isn't wrong, just... very confusing. In this particular case they use the dire version of the animal because the normal is too weak. I think wereboars do the same.

[the David]

If it's the dire bat, shouldn't its hybrid form be large? It does say bat under shape change, while the wererat says dire rat...