The fossil beetle discovered in the 16-23 million years old sediments of the Irtysh River in southern Siberia belongs to the modern species Helophorus sibiricus, a member of the water scavenger beetles (Hydrophiloidea), which is at present widely distributed in Eurasia and reaches even North America. The species was originally described in 1860 by the Russian entomologist Victor Motschulsky based on specimens collected at Lake Baikal. It is aquatic and inhabits various kinds of standing waters, predominantly the grassy temporary pools. Larvae are unknown so far, but are supposed to be terrestrial and predaceous, preying on various invertebrates, as in most other species of the genus.
The Siberian fossil provides new data for the long-lasting debate among scientists about the average duration of an insect species. It was originally estimated to be ca. 2-3 million years based on the available fossil record, but slowly accumulating data begin to show that such an estimate is an oversimplification of the problem. Recently, evolutionary trees dated using molecular clocks suggested that some insect species are rather young, originating during the Ice Ages, but others may have been able to survive the last 10-20 million years until today. The long-living species had to survive the massive changes of the Earth's climate during the last millions of years - how they managed to do so is another question for scientists to address.
A large missing piece for the acceptance of long-living insects as a general phenomenon and for understanding the reasons for survival of the particular species is the scarcity of the fossils of such species. The reasons seem to be rather straightforward the majority of the fossils bear too few details to allow a detailed comparison with living species, whose taxonomy is often based on
|Contact: Martin Fikacek|