Tar Command – How to Extract Multiple .tar.gz Files with a Single Call

I was wondering whether (and, of course, how) it’s possible to tell tar to extract multiple files in a single run.

I’m an experienced Unix user for several years and of course I know that you can use for or find or things like that to call tar once for each archive you want to extract, but I couldn’t come up with a working command line that caused my tar to extract two .tar.gz files at once. (And no, there’s nothing wrong with for, I’m merely asking whether it’s possible to do without.)

I’m asking this question rather out of curiosity, maybe

• there’s a strange fork of tar somewhere that supports this
• someone knows how to use the -M parameter that tar suggested to me when I tried tar -zxv -f a.tgz -f b.tgz
• we’re all blind and it’s totally easy to do — but I couldn’t find any hint in the web that didn’t utilize for or find or xargs or the like.

Please don’t reply with tar -zxvf *.tar.gz (because that does not work) and only reply with “doesn’t work” if you’re absolutely sure about it (and maybe have a good explanation why, too).

Edit: I was pointed to an answer to this question on Stack Overflow which says in great detail that it’s not possible without breaking current tar syntax, but I don’t think that’s true. Using tar -zxv -f a.tgz -f b.tgz or tar -zxv --all-args-are-archives *.tar.gz would break no existing syntax, imho.