The extant telephone-pole beetle genus Micromalthus discovered in mid-Cretaceous amber from northern Myanmar (Coleoptera: Archostemata: Micromalthidae)

ABSTRACT

The telephone-pole beetle family Micromalthidae has attracted the attention of entomologists and biologists because of its enigmatic morphology, systematic position, and complex life cycle. With only a single extant and four extinct species, the micromalthid beetles are a small but important lineage within the primitive suborder Archostemata. Fossil micromathids, known mainly from different amber deposits, are not commonly found. Here, I report the first Mesozoic fossil of the sole extant micromalthid genus Micromalthus in the mid-Cretaceous Kachin amber from northern Myanmar. Due to its rather poor preservation, this provisional new species remains unnamed, tentatively identified as Micromalthus sp. The newly found specimen is about 46 Ma older than an Eocene Micromalthus fossil from the Oise amber of France. My study greatly expands our knowledge of the origin and early evolution of Micromalthus beetles.

KEYWORDS:

• Micromalthus
• Micromalthidae
• Archostemata
• Burmese amber
• Cenomanian
• fossil

Acknowledgments

The author (SY) is sincerely grateful to Julia Snyder (FMNH) for registering the specimen, and to Stephanie Ware (FMNH) for supporting the imaging. I also thank four anonymous reviewers and Gareth Dyke (Editor-in-Chief) for their suggestions, which improved the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author.

Additional information

Funding

This work was partly supported by the JSPS (Japan Society for the Promotion of Science, Tokyo, Japan) Overseas Research Fellowship [number 29-212];Japan Society for the Promotion of Science.