Tuanshanzia is a genus of Proterozoic eukaryote, known from several locations across China and India, including the Gaoyuzhuang and Chuanlinggou formations, the eponymous Tuanshanzi Formation, [1] as well as the Vindhya Basin.

Tuanshanzia seems to be part of a wider group of elongate Proterozoic algae, alongside Changchengia and Eopalmaria.

[3] Tuanshanzia specimens range from 4 to 30 cm (1.6 to 11.8 in) long, and are often preserved as carbonaceous films with a wide range of shapes, varying by species.

As a form taxon, Tuanshanzia is likely paraphyletic, although as no practical alternative exists it remains a valid genus.

[1][3][2] Many of the specimens from the Tuanshanzi Formation are likely microbial mat fragments due to their rough edges and irregularity, however some are likely actual algae due to smooth and regular margins, alongside carbon isotope analysis showing similarities to eukaryotes.