Other similar remains possibly referrable to the genus are known from the Emu Bay Shale of Australia and Chengjiang Biota of China.

[6] The small head had two stalked eyes, a single pair of tentacles, and a flexible funnel-shaped structure opening out to the underside of the body.

[1] Although Nectocaris is known from Canada, China and Australia, in rocks spanning some 20 million years, there does not seem to be much diversity; size excepted, all specimens are anatomically very similar.

Historically, three genera have been erected for nectocaridid taxa from different localities, but these 'species' – Petalilium latus and Vetustovermis planus – likely belong to the same genus or even the same species as N. pteryx.

[1] They are thought to have been freely-swimming nektonic organisms,[3] that were either scavengers or predators on soft-bodied animals, using their tentacles to manipulate food items.

[1] However, other authors contend that the morphology of nectocaridids is contrary to what is known about cephalopod and mollusc evolution, and they cannot be accommodated within these groups,[2][3][7] and can only be confidently placed as members of Bilateria.

The structure previous researchers had identified as an oval carapace or shield behind the eyes[12] was suggested to be a soft funnel, similar to the ones used for propulsion by modern cephalopods.

[13][7][3][2] Vetustovermis (from Latin: "very old worm")[14] is a soft-bodied middle Cambrian animal, known from a single reported fossil specimen from the South Australian Emu Bay shale.

Petalilium (sometimes misspelled Petalium)[17] is an enigmatic genus of Cambrian organism known from the Haikou area,[18] from the Maotianshan mudstone member of the Chengjiang biota.

It has an ovate trunk region and a large muscular foot, and a head with stalked eyes and a pair of long tentacles.

The trunk region possesses about 50 soft, flexible, transverse bars, lateral serialised structures of unknown function.

The upper part of the body, interpreted as a mantle, is covered with a random array of spines on the back, while gills project underneath.