Revisiting the morphology of the Cretaceous ommatid beetle Clessidromma palmeri (Coleoptera: Archostemata: Ommatidae)

Abstract

The morphology of Clessidromma palmeri Jarzembowski et al. from mid-Cretaceous Burmese amber is revised based on a reexamination of the type specimen. Contrary to previous studies, our observation confirms that Clessidromma has open procoxal cavities. The characters such as platform on the ventral side of head, modified metacoxae, and ridges on head and pronotum are suggested to be diagnostic characters for Clessidromma. Clessidromma zengi Kirejtshuk from the same deposit is transferred into a new genus, as Kirejtomma zengi comb. nov.

Cretaceous beetles of the Jinju Formation (Coleoptera): Archostemata

“…Extensive studies have been conducted on the Mesozoic archostematan fossils from Asia in the past decades, especially on those from Central Asia (Ponomarenko, 1964(Ponomarenko, , 1966(Ponomarenko, , 1969, Mongolia (Ponomarenko, 1994(Ponomarenko, , 1997, Northeast China (e.g., Tan & Ren, 2009;Jarzembowski et al, 2013aJarzembowski et al, , b, 2015Yan et al, 2014;Cai & Huang, 2017), and Burmese (Myanmar) amber (e.g., Yamamoto, 2017Yamamoto, , 2021Li et al, 2019Li et al, , 2020bLi et al, , 2021cLi et al, , 2021dTihelka et al, 2020b;Li & Cai, 2021;Song et al, 2022). Most archostematan fossils discovered from the Cretaceous Jinju Formation in Korea belong to the common and widespread genera (Brochocoleus, Omma, and Notocupes/Zygadenia).…”