Originally Posted by
NewbieNick
Also, in looking at it, I found that several of the teeth were worn down so it wouldn't be a bad idea to replace both the chain and the crank. It's a nice light mountain bike frame. Thanks for your replies.
It's almost certainly a square taper. However, the "worn teeth" you are seeing may be intentional. Modern cranks have several specifically shaped teeth to assist shifting. Badly worn chainrings have the teeth worn to sharp points and look like a saw blade. They don't wear them down or flat.
Unless you have a LOT of miles on the bike and under harsh conditions, it is unlikely the chainrings are worn to the point of needing replacement.