Fossil Record 24(2): 223-231, doi: 10.5194/fr-24-223-2021
The first extinct species of Acritus LeConte, 1853 (Histeridae: Abraeinae) from Eocene Baltic amber: a microscopic beetle inclusion studied with X-ray micro-computed tomography
expand article infoVitalii I. Alekseev, Andris Bukejs§
‡ Institute of Life Sciences, Immanuel Kant Baltic Federal University, Nevskogo street 14, Kaliningrad 236016, Russia§ Daugavpils University, Daugavpils, Latvia
Open Access

Acritus sutirca sp. nov. is described and illustrated from Eocene Baltic amber onthe basis of one adult male specimen. As the first extinct member of thesubfamily Abraeinae (Histeridae) and the smallest known fossil histeridspecimen, this material was examined using a combination of light microscopyand X-ray micro-computed tomography (µCT). Internal features of theabdomen are well preserved, allowing us to study sclerotized parts of theaedeagus and illustrate these structures in detail. The current findingexpands the range of known Histeridae diversity from the Eocene (48–34 Ma)“amber forests” of Europe. The absolute size limits and the probableaverage size for Baltic amber coleopteran inclusions are also brieflydiscussed (