Ercaicunia is genus of bivalved Cambrian arthropod from the Chengjiang biota of Yunnan, China.

It contains a single species, E. multinodosa that was described by Luo et al. in 1999.

The bivalved carapace covered about a third of the total body-length, and has up to six serrations on its forward edge.

Specimens were CT scanned in 2019, which suggested it to be a stem-group crustacean.

[2] Other subsequent studies have recovered it as a member of Hymenocarina, which contains other bivalved Cambrian arthropods.