A new fossil species of the rove beetle subfamily Protopselaphinae (Coleoptera: Staphylinidae) from mid-Cretaceous Burmese amber

ABSTRACT

Protopselaphinae is a monogeneric subfamily of Staphylinidae comprising eight extant and one extinct species of minute rove beetles. We describe a tenth species of this enigmatic subfamily, Protopselaphus newtoni sp. nov., from mid-Cretaceous Burmese amber (~99 Ma). Protopselaphus newtoni sp. nov. differs from its congeners in its smaller body size and antennal structure. Uniquely, the apical maxillary palpomere of the new species is longer than maxillary palpomere 3. A key to the extant and fossil members of the genus Protopselaphus is provided. Extinct species of the subfamily Protopselaphinae are smaller than extant species, a trend also apparent in some other beetle lineages present in Burmese amber, opening new questions about the evolution of insect body size in the Mesozoic.

KEYWORDS:

• Protopselaphinae
• Cretaceous
• Burmese amber
• Myanmar
• key to species
• body size

Acknowledgments

We thank Shûhei Yamamoto and Alexey Solodovnikov for their valuable comments. This work was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB26000000 and XDB18000000); the National Natural Science Foundation of China (41688103 and 41672011); and the Second Tibetan Plateau Scientific Expedition and Research (2019QZKK0706).

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences [XDB26000000 and XDB18000000]; National Natural Science Foundation of China [41688103 and 41672011]; Second Tibetan Plateau Scientific Expedition and Research [2019QZKK0706].