Wrong for So Long

I discovered yesterday that I have been spelling a word wrong my entire life. It's a word that I haven't used with great frequency, but still, I am chagrined. Here's the word.

Spatial.

I must admit, I have always thought it was spelled "spacial."

Now tell me, why is there a "t" in that word? It is a form of the word space, right? Kind of like "race" becomes "racial" and "face" becomes "facial"... you get an idea of where I got that letter c from, right?

A quick dictionary check, however, reveals that "space" comes from the Latin spatium, so I can see where this is going. Face, on the other hand, comes from facia, and race comes from old Italian razza, so there's no vestigial "t" in their etymological heritage.

In my own defense, I should note that "spacial" is included in the dictionary as a variant spelling, but it's pretty clear that it is not the preferred one. As the Church Lady would say, Now isn't that spatial.