Crowsonium succinium Abdullah, 1964

Alekseev, Vitalii I., Kupryjanowicz, Janusz, Kairišs, Kristaps & Bukejs, Andris, 2020, The first described fossil species of Litargus Erichson (Coleoptera: Mycetophagidae) from Eocene Baltic amber examined with X-ray microtomography, and new records of Crowsonium succinium Abdullah, 1964, Zootaxa 4768 (3), pp. 405-414 : 413

Notes on Crowsonium succinium Abdullah, 1964 from Baltic amber

The study of available private and institutional collections (e.g., Alekseev (2019) and also the data provided in the present paper), shows that Crowsonium succinium is the most commonly encountered species of hairy fungus beetle in Baltic amber. The beetle that was described as a new taxon at the generic level under this name by Abdullah (1964) was based on material collected by Klebs. This material resembles the extant genus Typhaea Stephens in several morphological characters, and could even be easily misidentified as a representative of Typhaea by researchers well-versed in the study of the inclusions in amber. Perhaps it was Crowsonium that was identified by Edmund Reitter and later reported by Klebs (1910) as “ Typhaea ” (17 specimens) and “near Typhaea ” (5 specimens). However, the presence of true representatives of Typhaea Stephens, 1829 in the Eocene of Europe, and hence reports of the genus, remain obscure and should be checked. The best character for distinguishing between Typhaea and Crowsonium seems to be restricted to the loose antennal club tapering apically beyond its middle in Crowsonium ; other differential characters provided in the original description are dubious at best. Without doubt, more detailed studies of the Crowsonium succinium holotype, and a clarification of its systematic placement are needed: the type should be deposited in the Natural History Museum, London (No 18777) at present. Analogous to our conclusions, Larsson (1978) supposed that “the majority of those specimens determined by Reitter as belonging to Typhaea have belonged to Crowsonia [sic], which at that time was undescribed, but which appears to have been the dominating genus in the amber forest”. Few additional reports of other hairy fungus beetle genera (i.e., not Typhaea and not Crowsonium ) have been made from Baltic amber ( Klebs 1910), but these reports suggest that a rather diverse Mycetophagidae species assemblage existed in Eocene Baltic amber, and that it may be possible to make interesting new discoveries findings in future studies. However, our experience working with Baltic amber collections suggests that all non-illustrated reports should be taken with caution, and the taxa involved (except Crowsonium ) should be considered rare in Baltic amber until proven otherwise.