Ancient Rove Beetle in the Omaliini Tribe Discovered in Amber

A team of international scientists discovered a rove beetle - oldest definitive member of the tribe Omaliini that has ever been found in amber.

Scientists from Spain, France and the U.S. discovered and described a novel species of rove beetle that is oldest member of tribe Omaliini, which belongs to the subfamily Omaliinae of the family Staphylinidae. Staphylinidae are the largest of all beetle families that consists of more than 60,000 described species.

The team used propagation phase-contrast X ray synchrotron imaging technique to describe the finding. The technique permitted the detailed study of invisible specimen trapped in the opaque amber.

The two specimens of the novel species, dubbed Duocalcar geminum, were discovered in a single piece of opaque amber.  The specimen was found along with other arthropods that were present in the same amber.

The genus name Duocalcar indicates two spurs (in Latin) that refers to the two distinctive projections present in the hind leg i.e. near the trochanteral apex and near the tibial apex. The particular epithet, geminum is the Latin adjective which means twin born, indicating to the finding of the two specimens in the same piece of amber.

"D. geminum is the first Omaliinae described from any amber, increasing the minimum age of Omaliini to ≈100 million years, from Eocene to latest Albian," the authors wrote.

The article 'Oldest Omaliini' was discovered in the Opaque Cretaceous Amber of Charentes.

Rove beetles are the largest family of beetles in North America and include 2,900 species. They are found on agricultural lands or backyards. They feed on insects like maggots. They do not bite or sting and do not cause any real harm. Their presence indicates presence of some compost or dead animal nearby. When threatened, they raise their tails.

The finding was documented in the Annals of Entomological Society of America.