Discovery of Ancient Cephalopod Fossil Sheds Light on Early Evolution
Researchers have identified the earliest known cephalopod fossil, Eoceras shaanxiense, which provides new insights into the evolution of buoyancy control in these marine animals. The fossils, found in 520-million-year-old rocks in South China, are tiny, with shells measuring just 1 millimeter long. They contain a slender tube, identified as the oldest siphuncle on record, which cephalopods use to control buoyancy. This discovery pushes back the origin of cephalopods by approximately 30 million years, aligning with genetic estimates that place their origin in the early Cambrian period. The study, published in the journal Nature, highlights the significance of early Cambrian biodiversity and the evolutionary advancements that allowed cephalopods to leave the seafloor and become active hunters.