Chinese researchers have discovered exceptionally well-preserved bryozoan fossils in Hanzhong City, in northwest China's Shaanxi Province, providing definitive fossil evidence that the group originated in the Early Cambrian period (541 to 513 million years ago). The findings, published in Nature on June 3, show both mineralized skeletal structures and soft tissues, pushing the fossil record of mineralized bryozoans back by at least 50 million years. Bryozoans are colonial aquatic invertebrates t