I have been tinkering around with the code in Pearson's "Generative Art" and came up with this and the image above.
The author's intention was to show how complex patterns could spontaneously emerge from the interaction of multiple components that individually exhibit simple behavior. In this case, a couple of dozen invisible disks track across the display; whenever the disks intersect they cause a circle to suddenly appear at the point of intersection. So a little like the bubble chamber that I'd used in physics lab at university. You don't observe the particle directly, you observe the evidence of its passage through a medium. (My code is here if you want to play around with it.)
Belemnites are the fossilized remains of little squid-like creatures. Most of the times you find individuals—a small one looks a little like a shark's tooth—but sometimes you find a mass of them in a single slab, a "belemnite battlefield".
How do these battlefields occur? I found a paper by Doyle and MacDonald from 1993 in which the authors identify five pathways: post-spawning mortality, catastrophic mass mortality, predation concentration, stratigraphical condensation, and resedimentation. I don't know which occurred in the slab shown above but hey, I now know more potential pathways than I did before I read that paper.
And that's why art is fun. One moment you are messing around with RGB codes to get just the right sandy color for the background of a picture, the next you are researching natural phenomena that until an hour ago you never knew even had a name.