As usual, I'm late to the fold, but I wanted to wish PZ a Happy Birthday! I suggest, however, that in responding late I am simply following a time-honored tradition in the O'Brien household to celebrate birthdays for an extended period of time and not just on the anniversary date (the kids and I all have birthdays in March, so this month has simply become a "birthday" month in which we celebrate on those days not already absorbed by teaching, class, out of town meetings, vollyball practice or something else that always seems to prevent celebration on the actual day!).
I was also somewhat at a loss as to what kind of cephalopod-related picture I could post in honor of PZ's 50th (not a lot of squid in northeastern California!). However, tucked away in my shed, I remembered I had these. These are fossil belemnoids, Oxyteuthis tehamaensis, from the Lower Cretaceous Paskenta Formation in the northern Sacramento Valley. For those of you who don't already know, belemnoids are...fossil squid! What you see preserved here is (if I recall correctly, it's been a while) the rostrum or "rear end" of the squid; the middle one with the groove is actually the ventral surface of the animal.
I collected these in high school with my biology teacher, Mr. Critchfield (PZ and Critchfield would have gotten along famously - when a local creationist told Mr. C he wanted equal time to talk about creationism in biology class, he is reported to have responded: "I'll let you into my class to teach creationism when I can go into your church and teach evolution". I was fortunate to have had an unapologetic biologist teaching high school biology. My advanced biology class didn't just have a section on evolution - we started with evolution and maintained discussions of biological topics within the context of evolution (which is as biology classes should be taught!).
Happy Birthday PZ!