Pawson has spent the last 60 years carefully studying and classifying thousands of echinoderms, a diverse and ancient group of marine invertebrates. Adrian James Testa, Smithsonian Institution ...

Researchers examine a 500-million-year-old fossil from Morocco and find out that echinoderms went from bilateral to pentaradial symmetry.

Learn how starfish got their shape after a complicated evolutionary process, starting with an ancestor that lived 500 million ...

Starfish are echinoderms, a form of invertebrate marine animals known for radial symmetry and having spiny skin. Researchers said most animal species have similar genetic structures, prompting ...

The heads of most animals are easily identifiable, but scientists haven’t been able to say the same for sea stars — until now.

Image: McLaughlin, Wilson, Rouse/Invertebrate Systematics. These animals are broadly related to starfish, sea cucumbers, and other echinoderms, but not too much is known about them.

Invertebrates, which constitute over 95% of all animal species, are the unheralded engine underpinning Earth’s biodiversity and ecosystem functioning. Their astonishing diversity – ranging ...