Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada

Genus Palaeoxenus

Dohrn's Elegant Eucnemid Beetle - Palaeoxenus dohrnii Palaeoxenus dorhnii - Palaeoxenus dohrnii Palaeoxenus dorhnii - Palaeoxenus dohrnii click beetle? - Palaeoxenus dohrnii
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Coleoptera (Beetles)
Suborder Polyphaga (Water, Rove, Scarab, Long-horned, Leaf and Snout Beetles)
No Taxon (Series Elateriformia)
Superfamily Elateroidea (Click, Firefly and Soldier Beetles)
Family Eucnemidae (False Click Beetles)
Genus Palaeoxenus
Other Common Names
Dohrn's Elegant Eucnemid Beetle
One extant species N. of Mexico
13-19 mm long
Blood red and black colorations is the best diagnostic feature.
S. California
Largely found in a mixed coniferous forest system in the mountains.
late May through June.
Larvae have been taken in incense cedar. Adults were found beneath the bark of sugar pines and incense cedar.
Life Cycle
The highly unusual larvae were found boring in the bark near the base of the stump, close to the soil.
A very interesting paper was published in the April edition of Cladistics. Jyrki Muona and a team of Chinese Paleontologists described a first compression fossil for a eucnemid larva. This larva is none other than Palaeoxenus sinensis, exposing the extant Dohrn's elegant eucnemid beetle (Palaeoxenus dohrnii) to be the family's only living fossil. The existence of the group dates back to the Cretaceous period, roughly 123 million years ago. The article is open access through the journal's website: (Cladistics).
Print References
Boving, A.G. & Graighead, F.C. 1930. An illustrated Synopsis of the Principle Larval Forms of Coleoptera. Entomological Americana (new series) 11: 1-351. --(ventral aspect of larva illustrated, no formal description made)
Chang Huali, Jyrki Muona, et al. 2016. Chinese Cretaceous larva exposes a southern Californian living fossil (Insecta, Coleoptera, Eucnemidae). Cladistics 32: 211-214. -- (Chinese larval description)
Fenyes, A. 1903. Paleoxenus (Cryptosoma) dohrnii Horn. Entomological News 11: 220. -- (biological observations)
Horn, G.H. 1878. Contribution to the Coleopterology of the United States II. Transactions to the American Entomological Society 7: 51-60. -- (species description)
Horn, G.H. 1882. Notes on some little known genera and species of Coleoptera. Transactions of the American Entomological Society 10(1): 113- . -- (illustration of adult)
Horn, G.H. 1891. New Species and Miscellaneus Notes. Transactions of the American Entomological Society 18: 32-48. -- (description of Palaeoxenus)
Muona, J. 2000. A revision of the Nearctic Eucnemidae. Acta Zoologica Fennica 212: 1-106.