Ancient slowpoke

A 1-centimeter-long, 505-million-year-old fossil from British Columbia connects two lineages of marine invertebrates from the Cambrian period that scientists hadn’t previously linked.

One group, the halkieriids, protected themselves with plates and mineralized shells—”like armored slugs,” says Simon Conway Morris, a paleontologist at the University of Cambridge in England. Wiwaxiids, the other lineage, carried spiny plates.