The anterior section had five equally sized pairs of appendages with two setal rows along the margins.

The posterior section was pear-shaped and had three rows of hooks surrounding the anus.

[2] The possible priapulid "Xishania" longiusula's fragmentary remains closely resembles the pear-shaped end of Facivermis, so Huang et al. assigned "X".

[5] Facivermis was previously interpreted as a predator that anchored itself into sediment with its hooked posterior end and used its anterior appendages to catch prey.

[1] However the new specimens described in 2020 suggest a suspension-feeding lifestyle similar to feather duster worms, with the posterior hooks used to anchor itself into their cylindrical tube.