IN NATURE of December 8 there appears an article by my friend Dr. F. A. Bather entitled “Echinoderm Larvæ and their Bearing on Classification.” The article consists of a review of Dr. Mortensen's work ...

Scientists have discovered a new species that lived more than 500 million years ago -- a form of ancient echinoderm that was ancestral to modern-day groups such as sea cucumbers, sea urchins, sea ...

The end-Paleozoic witnessed the most devastating mass extinction in Earth's history so far, killing the majority of species and profoundly shaping the evolutionary history of the survivors.

Researchers in Japan have finally observed living larvae of a sea lily, a marine invertebrate with a 500-million-year fossil record. The finding supports a century-old hypothesis about how the ...

The evolution of the sea star, sea urchin, and other echinoderms’ body shape during the Cambrian and Ordovician periods was faster and more dramatic than their ecological innovation, according to a ...

Ophiothrix angulata, a widely recognized and prevalent ophiuroid species in the Western Atlantic, has long been the subject of taxonomic debate due to its remarkable morphological diversity. A new ...

Sea stars and their relatives eat, breathe and scuttle around the seafloor with tiny tube feet. Now researchers have gotten their first-ever look at similar tentacle-like structures in an extinct ...

See more of our trusted coverage when you search. Prefer Newsweek on Google to see more of our trusted coverage when you search. Sea urchins have a body that is entirely made up of "head"—with a ...

THOUGH loth to prolong this discussion, I wish, in fairness to Dr. Mortensen and myself, to say that I did not accuse Dr. Mortensen of regarding the echinoderm metamorphosis as a case of metagenesis.