Shyness is the lack of self esteem in social circumstances, it's more than feasible to be a shy extrovert. The best explanation I've heard is that introverts spend a majority of their time in social circumstances scanning people, trying to understand how that person "works". That takes a LOT of mental energy.

That makes a lot of sense. I can see some naturally shy people filled with nervous energy from conflict shying away, and other naturally shy people feeling the nervousness and doing it anyway because it needs to be done.

Introvert shy away from things that doesn't really matter to them,but talk about something that they are interested - honestly you will find them as most aggressive people. :)