stupid newbie question

I have a bunch of zipped files all in one directory that I'd like to extract at once. I keep trying "tar zvxf *.tar.gz", but I keep getting just the list of .tar.gzs in that directory with the error message "not found in archive".

I just don't want to extract/unzip them all individually, because there's a lot of them. Any way to do them all at once?

Edit:

Mischief managed! :)