New species of Omma Newman from mid-Cretaceous Burmese amber (Coleoptera, Archostemata, Ommatidae)

Abstract

A new fossil species of the extant archostematan genus Omma Newman, O. fortesp. nov., is reported from mid-Cretaceous amber from northern Myanmar. The extinct ommatid genus, Cionocups Kirejtshuk from the same deposit, is considered as a junior synonym of Omma, and C. manukyani is transferred to Omma, as O. manukyanicomb. nov. A key to species of Omma from Burmese amber is also provided.

The evolutionary history of Coleoptera (Insecta) in the late Palaeozoic and the Mesozoic

“…Cai (e.g., Li, Tihelka et al, 2020) and by Clarke et al (2018) in their comprehensive study on Cretaceous weevils. A breakthrough was the use of μ‐CT for examining amber inclusions, using either synchrotron microtomography (e.g., Boudinot et al 2024; Jałoszyński et al, 2020) or μ‐CT desktop scanners (e.g., Li, Huang, & Cai, 2021b). Not only the quality of the μ‐CT data is important, with presently a minimum resolution of less than 1 μm, but also the reconstruction technique.…”

“…Very detailed μ-CT-based 3D reconstructions of a stem group ant (Hymenoptera, Formicidae) were presented by Richter et al (2022) and Boudinot et al (2022), with well-preserved internal organs including an almost complete cephalic muscle set. In contrast, to date, only a few beetle fossils with poorly preserved internal soft parts are known (Li, Huang, & Cai, 2021b).…”

“…Archostemata are well‐represented in the Cretaceous, documented, for instance, by species of Cupedidae (Jarzembowski et al, 2017; Li et al, 2019), Ommatidae (Figure 4; e.g., Li, Chang, Muona, et al, 2021; Li, Huang, & Cai, 2021b; Li, Yamamoto, et al, 2020) and Micromalthidae (Tihelka et al, 2020a; Yamamoto, 2021). A remarkable find is a miniaturised species of Ommatidae (Li, Yamamoto, et al, 2020), much smaller (less than 2 mm) than the extant species of this family (Escalona et al, 2020).…”

“…The evolutionary history of Coleoptera has been the topic of several well‐known scientific studies, such as those of Crowson (1975), Ponomarenko (1983a, 1986, 1995, 2003), Hunt et al (2007), McKenna (2011), and Smith & Marcot (2015). Since that time, the phylogeny of extant Coleoptera (Figure 1) has largely stabilized (e.g., Che et al, 2017; McKenna et al, 2019; McKenna, Wild, et al, 2015; Toussaint et al, 2017; Zhang et al, 2018), and numerous extinct beetle species have been discovered and described, including adpressions in the Permian and Mesozoic (e.g., Kirejtshuk et al, 2010, 2014; Ponomarenko, 2018, 2021; Ponomarenko & Prokin, 2015; Yan, Beutel, & Ponomarenko, 2017a; Yan, Beutel, & Ponomarenko, 2017b; Yan, Lawrence, et al, 2017; Yan et al, 2018, 2020) and extremely numerous inclusions in mid‐Cretaceous Burmese amber (=burmite) (e.g., Beutel et al, 2016; Clarke et al, 2018; Jałoszyński et al, 2020; Li et al, 2020a–b, 2021a–g; Yamamoto, 2021; see also Ross, 2019, 2020, 2021, 2022, 2023). The methods of examination have been distinctly improved for both categories of fossils, including μ‐computed tomography (μ‐CT) (e.g., Jałoszyński et al, 2020; Qvarnström et al, 2021; Richter et al, 2022) and reflectance transformation imaging (RTI) (Schädel et al, 2022; see also Beutel & Yavorskaya, 2024).…”

Rhomeocalpsua torosa gen. et sp. nov., a unique lineage of Endomychidae from mid‑Cretaceous Burmese amber (Coleoptera: Coccinelloidea)

“…The mid-Cretaceous Burmese amber has offered invaluable well-preserved fossils for our understanding of character evolution, phylogeny, biogeography, and palaeoecology of beetles (e.g., Cai et al, 2017aCai et al, , b, 2018Cai et al, , 2019aGimmel et al, 2019;Tihelka et al, 2021a). Burmese amber fossils also provide critical evidence of palaeodiversity of beetle families that are either currently extinct (e.g., Li et al, 2021a, b), relictual (e.g., Li et al, 2019Li et al, , 2021cTihelka et al, 2019Tihelka et al, , 2021b, or confined to the Southern Hemisphere (e.g., Li et al, 2020Li et al, , 2021d. Tomaszewska et al (2018) reported the oldest definitive fossil members of the Endomychidae entombed in the Burmese amber.…”