The mystery of chordate origins has endured for more than 150 years. Shortly after Darwin's On the Origin of Species, acorn worms were discovered to have chordate-like pharyngeal gill slits 1,2 and to ...

The Middle Cambrian chordate known as Pikaia gracilens was once thought to be humanity’s earliest known ancestor, and the earliest known member of the phylum Chordata. Now, a new study flips this ...

Lancelets, or amphioxus, are small worm-like marine animals that spend most of their lives buried in the sea floor, filter-feeding through jawless, ciliated mouths. The vertebrate affinities of these ...

Life began on earth more than 3.5 billion years ago, but the history of humans and other vertebrates accounts for only a fraction of this timescale. Chordates (a group that includes vertebrates) and ...