Sicarius and Homalonycus are two spider genera that shared a common ancestor over two hundred million years ago, but their natural history is astonishingly similar: They are both ground-dwelling and occupy the sandy substrate of deserts and dry forests and they both cover their bodies in dirt or sand particles, which transforms their coloration to match the color of the ground where they live. We suspect that this might function as camouflage. Rebecca Duncan, '06 conducted her senior thesis research on the comparative functional morphology of these spiders' tiny hairs, or setae, and discovered that both Sicarius and Homalonychus evolved an identical setal structure which aids in trapping sand particles to the spiders' bodies. Explore the world of microscopic spider hairs with these images!
