The Cambrian is rightly famous for being the period when animal life first exploded into a dizzying diversity of forms, including some body plans that remain with us today. But the first animals in ...

Segmentation, the replication of anatomical structures throughout the body, is found in many animal species. It’s also a huge reason why all those species succeeded, and it comes from a single common ...

Recent molecular phylogenetic analysis has shown that the marine animals known as peanut worms are not a separate phylum, but are definitely part of the family of annelids, also known as segmented ...

A team of biologists report in this week's Nature the genome sequences of three organisms that represent more than one-quarter of marine species, including clams, octopuses and the segmented worms, ...