Overview

• The July 2025 Science Advances paper presents analysis of 25 exceptionally preserved nectocaridid specimens from the Sirius Passet Lagerstätte in North Greenland.
• Researchers identified a ventral ganglion structure unique to chaetognaths, overturning the 15-year-old hypothesis that nectocaridids were early cephalopods.
• Discovery of complex camera-type eyes in these fossils indicates they were sophisticated predators occupying high trophic levels during the Cambrian Explosion.
• Presence of Isoxys arthropod carapaces in the digestive tracts of several specimens confirms a carnivorous diet among these ancient arrow worm relatives.
• The new species, Nektognathus evasmithae, honors Professor Eva Smith and sets the stage for further studies on chaetognath evolution and Cambrian food webs.