Dianmeisaurus

Dianmeisaurus is an extinct genus of pachypleurosaur from the Middle Triassic Guanling Formation in China. The type species is D. gracilis. An additional species, D. mutaensis, was named in 2024 based on a small skeleton likely belonging to an immature individual.

Classification
In their 2024 description of Dianmeisaurus mutaensis, Hu, Li & Liu recovered the two species of Dianmeisaurus as the sister taxon to Panzhousaurus in a clade of basally-branching pachypleurosaurs. In their analyses, they recovered the Pachypleurosauria as the sister taxon to the Nothosauroidea. The results of their phylogenetic analyses are shown in the cladogram below: