Earliest siphuncle-bearing cephalopod from the early Cambrian

Nature, Published online: 29 July 2026; doi:10.1038/s41586-026-10868-yEarly Cambrian Eoceras shaanxiense gen. et sp. nov. preserves septa and a segmented tube resembling a primordial siphuncle, extending cephalopod origins and revealing early assembly of chambered shells used for buoyancy regulation.