A stunningly-preserved, half-billion year old fossil of a strange Cambrian creature could shift our understanding of how a sister group to vertebrates evolved, a new study suggests.
The fossil, described July 6 in the journal Nature Communications, is the oldest of its kind and belongs to an ancient species of tunicate, Megasiphon thylakos. The discovery answers a fundamental question about what the earliest tunicates looked like, filling an important gap in the animal tree of life.
