Thinopinus pictus are beach specialists that inhabit the pacific coast of North America. They are conspicuous and attractive beetles that have attracted biologists and a fairly rich literature exists on their natural history. I particularly like the dilated stubby legs that are likely adaptive for life on sand.
The species is known to sport two pigment forms, a light tan and a melanic form. The melanic forms are less common and both types live in matching substrates. I bet given the poor dispersal abilities of these beetles (they can’t fly) that the melanic forms have arisen multiple times. We have some idea of melanic pathways in insects, it would be interesting to see if there is not only phenotypic, but also genomic convergence between geographically disperate melanic populations. Either outcome, either the melanic forms are monophyletic and not independent acquisitions, or convergent both phenotypically and genomically, or convergent phenotypcially but divergent genomically, would be an interesting find. People have started testing these sorts of questions in birds, but the beetles have not received as much attention yet.