Ptinid beetles from the Cretaceous gymnosperm-dominated forests

Abstract

The diversity of ptinid beetles (Coleoptera: Ptinidae) is described from Cretaceous amber that originated from the North Atlantic and Western Tethian resiniferous forests. All studied specimens belong to the subfamily Anobiinae. Stegobium raritanensis sp. nov. is described from Raritan amber (Turonian in age) of Sayreville (New Jersey, USA), whereas Actenobius magneoculus sp. nov. is described from San Just amber (early Albian in age) of Utrillas (Teruel Province, Spain). Both species have been examined using propagation phase-contrast X-ray synchrotron microtomography. An additional specimen from Peñacerrada I amber (Moraza, Burgos Province, Spain) is described without further taxonomic placement due to poor preservation. The Spanish specimens represent the most ancient adult record of the family Ptinidae to date. Mesernobius anawrahtai from Burmese amber (late Albian–early Cenomanian in age), the only previously described Cretaceous ptinid species, is transferred to Scirtidae based on a re-examination of the holotype. Hypotheses about ecological habits of fossil ptinids are also provided.