Single Nerve Cord Reveals Ancestry of Ecdysozoan Nervous Systems
Summary: New analysis of exceptionally preserved Cambrian fossils indicates that the ancestral ecdysozoan most likely had a single ventral nerve cord. Fossil impressions from early scalidophoran species match the single midline nerve cord seen in modern priapulids, supporting the view that paired nerve cords in some groups evolved later and independently. The study suggests that … Read more