With all the talk of unused type combinations, I thought it might be interesting to look at some facts about unused pure-type setups. You'd think by now that each single type would have all three of the evolutionary possibilities: no evolution, one evolution, or two evolution--but this isn't the case.

Here are some facts:
>There are no one-stage pure-Ghost Pokemon.
>There are no two-stage pure-Flying, pure-Dragon, or pure-Steel Pokemon.
>There are no three-stage pure-Flying, pure-Ground, pure-Poison, pure-Bug, or pure-Dark Pokemon.
>There are no non-legendary one-stage pure-Flying (Tornadus), pure-Ground (Groudon), pure-Rock (Regirock), pure-Steel (Registeel), or pure-Fairy (Xerneas) Pokemon.
>There isn’t a one-stage Dark-type that either isn’t a legendary (Darkrai) or doesn’t have a mega evolution (Absol).
>There are no non-legendary, one-stage Psychic types that have only a single forme (Unown).
>There isn’t a one-stage Fighting type that isn’t a part of a pair (Throh and Sawk).
>There isn’t a one-stage Electric type that isn’t a Pikaclone (Pachirisu, Plusle, Minun)
>There isn’t a one-stage Bug-type that either isn’t part of a pair (Volbeat and Illumise) or doesn’t have a mega evolution (Pinsir).

Here is a list of each type with examples of evolutionary lines: http://pastebin.com/MA1bFcRR

So, do you think any of these unused pure-type setups will be in SM? Gen V brought us the first single-stage pure-Ice type (Cryogonal) as well as the first three-stage pure-Ice type (Vanillite line) and three-stage pure-Rock type (Roggenrola line). Gen VI brought us the Flabébé line--obviously. What do you think Gen VII will add?

Pic related are my ideas for pure-Bug and pure-Flying three-stage lines.