Deuterostomes constitute a superphylum of animals, which includes myriad groups, from humans to starfish. Previously discovered deuterostome fossils date back to about 520 million years. At 540 ...

One step forward, one step back for paleobiologists. Most animals are bilaterally symmetrical. They have a left and a right side. These animals form two distinct groups, protostomes and deuterostomes.

Lynn Margulis classified the Chaetognaths, known as arrow worms, as deuterostomes. Deuterostomy is characterized by several developmental characteristics including radial, indeterminate cleavage, a ...

Our oldest known living ancestor was called a deuterostome, which gave rise to a huge swathe of life including present-day starfish and sea squirts, has been discovered fossilised in ...