# Synopsis of Ant Genus Proceratium Roger, 1863 from China (Hymenoptera, Formicidae), with Description of Seven New Species

## TL;DR

This study identifies and describes seven new ant species in China's Proceratium genus, expanding our understanding of their diversity.

## Contribution

The paper introduces seven new species and provides an updated identification key for Chinese Proceratium ants.

## Key findings

- Seven new Proceratium species were described from China.
- P. longigaster was removed from China's ant fauna.
- An illustrated identification key was provided for Chinese Proceratium species.

## Abstract

This study presents a taxonomic synopsis of the ant genus Proceratium Roger, 1863 in China, reviewing seven known species (P. bruelheidei Staab, Xu & Hita Garcia, 2018; P. itoi Eguchi, Yoshimura & Yamane, 2006; P. japonicum Santschi, 1937; P. kepingmai Staab, Xu & Hita Garcia, 2018; P. longmenense Xu, 2006; P. shohei Staab, Xu & Hita Garcia, 2018; and P. zhaoi Xu, 2000) while removing P. longigaster Karavaiev, 1935 from the Chinese fauna. Furthermore, we describe seven new species (P. crassopetiolum sp. nov., P. digitospinum sp. nov., P. planodorsum sp. nov., P. quandratinodum sp. nov., P. rugiceps sp. nov., P. shanyii sp. nov., and P. soinosubum sp. nov.) and provide an illustrated identification key to Chinese Proceratium species. These findings significantly expand our understanding of Proceratium diversity in China, resolve taxonomic uncertainties, and establish a foundation for future research on this cryptobiotic genus.

The genus Proceratium comprises rare but ecologically significant cryptobiotic predators of temperate and tropical forest litter. The group is known for its abdomen which can curl dorsally >90° relative to the body axis. Proceratium includes 130 described species worldwide. In China, seven species have been recorded, yet recent surveys repeatedly reveal morphologically distinctive undescribed taxa, indicating a still-underestimated diversity of Proceratium. In this study, seven known Chinese species of the ant genus Proceratium Roger, 1863 are reviewed: P. bruelheidei, P. itoi, P. japonicum, P. kepingmai, P. longmenense, P. shohei and P. zhaoi. The species P. longigaster is removed from the ant fauna of China. Additionally, seven new species are described: P. crassopetiolum sp. nov., P. digitospinum sp. nov., P. planodorsum sp. nov., P. quandratinodum sp. nov., P. rugiceps sp. nov., P. shanyii sp. nov., and P. spinosubum sp. nov. An illustrated key to Chinese species based on workers is also provided.