Nectocarididae is a controversial family of animals that superficially resemble squids. Represented by Nectocaris (=Vetustovermis, Petalilium?) from the Cambrian period. Some researchers claim they are cephalopods, however, this is heavily disputed and most reject this claim. A 2025 paper describing the new genus Nektognathus found paired jaw elements in both it and Nectocaris which revealed them to be related to chaetognaths (arrow worms), in particular the superficially similar Timorebestia.