[3] Only one incomplete specimen is known, and the probability of finding more is low, as the Sinsk Algal Lens has been nearly destroyed by fossil poachers.

Its body is annulated, and while the head preserves large appendages and a radial mouth further details are unclear.

Siberion has at least 12 pairs of legs which may have gill branches like other siberiids, however as mentioned previously they are incomplete.

At the posterior end there is a bulbous structure, which is likely an extension of the body due to similar muscle impressions.

The only internal structure seen is the digestive tract which resembles that of dinocaridids, however it is unclear whether gut diverticulae are present.