Welcome to MinDat -- hope you can find some useful background and information here.

In this photo I really just see what looks like a chert or (given your hardness results) maybe a fine-grained limestone.  No fossil or skull to me.  What I'd suggest is that you're experiencing "pareidolia", basically the tendency for the human brain to want to find images or interpretations of things it sees to impose something familiar on it.  Very common with rocks and minerals, as sometimes they can actually represent fossils.

For some light-hearted discussions, see this thread https://www.mindat.org/mesg-567249.html where members shared some of their favorite examples of seeing things in their rocks, as well as rocks with faces in https://www.mindat.org/mesg-509094.html .

For a poorer example, see https://www.mindat.org/mesg-579511.html where an individual refused to listen to the suggestions the multiple experts on the site made regarding his finds -- I'm not sure whether they really believed it and were desperate for validation or were just trolling the site, but the thread was ultimately closed as no longer going anywhere useful.

Personally I love specimens with obvious pareidolia -- they make for fun conversation starters with visitors.

Cheers,

D.