How this finding situates trilobites “more securely in between older arthropods … and crustaceans” is unclear. Apparently, crustaceans don’t breathe through their legs. Did the older arthropods breathe through THEIR legs? In any event, this find implies that the crustaceans underwent a dramatic switch in breathing mechanics, of which we apparently don’t have an account. How could we? We only found out about what the trilobites do very recently.