"Biovular" is rare. You'll find it mostly in the research literature. People normally refer to "non-identical twins."
Identical twins rarely, if ever, refer to themselves as "uniovular."
My sister and brother are twins. Everyone uses the term 'fraternal' for them - although this has always bothered me on grounds of etymology! ;-) I'd never met biovular before I read your post.
My ex-husband had a twin sister. It was very hard to resist the urge to say "Are you KIDDING ME?" when people would ask if they were identical or fraternal.
Anyway, like the others (aside from Ray), I've never seen that other term before.
I just learned the expression "fraternal twins" from keannu and I went on to read on the internet that there is also the term "sororal twins". Is the latter equally common? Could two sisters be called "fraternal twins"?
I just learned the expression "fraternal twins" from keannu and I went on to read on the internet that there is also the term "sororal twins". Is the latter equally common? Could two sisters be called "fraternal twins"?