A 505-million-year-old fossil provides hard proof of what scientists had previously only suspected: Ancient arthropods shed their exoskeletons during growth, just as their modern relatives do.
Arthropods, a class of animals named after the jointed legs characteristic of its member species, includes creatures as diverse as king crabs, insects, and scorpions.
Log in
Subscribers, enter your e-mail address for full access to the Science News archives and digital editions.