For the past four years, during the school year, I've worked at the Lawrence Hall of Science in Berkeley. Most of the time I've worked at the Front Desk, collecting admission and giving directions, but during the Spring of 2001, I also began doing brief talks about dinosaurs. Our exhibit at the time was on loan from the Museum of the Rockies in Montana. Their curator, Jack Horner, has a somewhat controversial theory that Tyrannosaurus Rex was actually a scavenger, not a predator.

My job was to discuss various features of the T. Rex with our school-age visitors, with the help of audience participation and some cheaply-made props. I would choose child volunteers to wear small Triceratops masks and operate cardboard jaws, to show the difficulties T. Rex may have had as a hunter. Big fun for all, except when the occasional volunteer would run amok and go after innocent audience members.

I had some issues with the mask, though. It was painted a ridiculus shade of green, and featured large cardboard teeth wrapped in masking tape. As one might imagine, this didn't make for the sturdiest arrangement. It wasn't long before the lower jaw had caved in, and half of the teeth were bent. As a result, it soon looked like an alligator, not a dinosaur. The kids pretty much bought into the T. Rex illusion, but it always bothered me. I'd ask "How fast was T. Rex?" but in the back of my mind I'd think "alligator." "Do you think that a T. Rex could swim?" (No, but an alligator could) "Where would a T. Rex live?" (Alligators probably lived in swamps.) And all the while, a child is prancing around the stage roaring, looking like an understudy from an elementary school production of Peter Pan.

The most crowd-pleasing part of the demonstration came when I discussed the T. Rex's disproportionately short arms. A child volunteer would come up, and I'd use a strip of velcro to bind their arms close to their chest. Then I'd explain that, relative to its forty-foot body, the T. Rex's three-foot arms were quite small. In fact, if T. Rex were kid-sized, his arms would be just four inches long!

Much hilarity ensued. The volunteer would invariably wave their arms ineffectually while the audience roared with laughter. Imagine having four-inch arms!, I'd nearly shout. You couldn't do anything! What a freak you would be! It was somewhat less comical the day that the audience contained a little girl whose arms really were only four inches long. Which, of course, wasn't noticed until the child volunteer had donned the velcro strap and fake claws.

So the demonstration had a slight change: "If T. Rex was your height, his arms would be only four inches long... which there is absolutely nothing wrong with. At all. He may not have been able to be a predator, but he was probably good at math, or...holding objects extremely close to his body." Luckily, there were no children with oversized, alligator-like heads in the audience, or I would have had to go work in the book store or something.