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.

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.

Our vertebrate origins lie deep in the history of animal life on ... we looked at the number of changes in DNA that were found in both the vertebrates and the echinoderms but not in other animals.

Sea cucumbers might look like the lumpy cylindrical vegetable but these bizarre animals are echinoderms—an invertebrate like starfish, sea urchins, and feather stars. There are around 1,200 ...

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.

The defense mechanisms animals use to evade or fight off predators can be both bizarre and fascinating. Some use camouflage or mimicry, while others have protective armor. Sea cucumbers, however, use ...

Go back far enough in our history–maybe about 650 million years–and you come to a time when our ancestors were still invertebrates. That is, they had no skulls, teeth, or other bones. They ...