Yicaris dianensis is a species of microscopic pancrustacean[1][2] found in the Yu’anshan Formation, Yunnan Province, China.

[4] The name Yicaris dianensis honors the ethnic minority Yi people of Yunnan Province, while Dian is an ancient kingdom of southern China.

[3] Yicaris' body consists of a cephalothorax covered by a head shield and limb-bearing segments.

[3] Out of the thirty-four specimens examined, six consecutive growth stages are known, the smallest one being 460 μm while the largest fossil, though fragmentary, reaches 1.8 mm long.

This structure is considered important due to its potential significance in the evolution of wings in insects, which evolved from within Pancrustacea.