Nectocaris

Nectocaris pteryx is a species of possible cephalopod[2] known from the "early Cambrian" (Series 2) Emu Bay Shale and Chengjiang biota, the "middle Cambrian" (Mioalingian, Wuliuan) Burgess Shale.

Nectocaris was a free-swimming, predatory or scavenging organism. This lifestyle is reflected in its binomial name: Nectocaris means "swimming shrimp" (from the Ancient Greek νηκτόν, 'nekton', meaning "swimmer" and καρίς, 'karis', "shrimp"; πτέρυξ, 'pteryx', means "wing"). Two morphs are known: a small morph, about an inch long, and a large morph, anatomically identical but around four times longer.[3]

The closely related Ordovician taxon Nectocotis is a second genus, closely resembling Nectocaris, but possessing an internal skeletal element.[4]