“We are now sure she was a primitive marine arthropod, but her precise evolutionary relationships remain frustratingly elusive.” Sarah Gabbott, the study’s lead author and a professor in the School of ...

Since the 1970s, populations of arthropods—a group of animals that includes exoskeleton-bearing critters such as insects, spiders, centipedes, and millipedes—in the Puerto Rican rainforest have ...