| Acosmia Temporal range: | |
|---|---|
 | |
| Fossil specimen | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Superphylum: | Ecdysozoa |
| Genus: | † Acosmia Chen & Zhoi 1997 |
| Species: | †A. maotiania |
| Binomial name | |
| †Acosmia maotiania Chen & Zhoi 1997 | |
Acosmia is an extinct genus of marine worm from the Cambrian aged Chengjiang biota of Yunnan, China. It is represented by a single rare species, Acosmia maotiania, that reached 45 mm in length and 9 mm in width. [1] It was likely a burrowing animal that fed by deposit feeding. [2] While originally suggested it to be a priapulid (penis worm), a 2020 study proposed to be a stem-group ecdysozoan, due to lacking the radial pharygneal armature that characterises modern ecdysozoans, including priapulids. [2] Later studies suggested that Acosmia was more likely a crown-group ecdysozoan possibly alied with nematoids. [3] [4]
