New mid-Cretaceous cryptic slime mold beetles and the early evolution of Sphindidae (Coleoptera: Cucujoidea)

Abstract

The cryptic slime mold beetles, Sphindidae, are a moderately diverse cucujoid beetle family, whose members are obligately tied to slime molds throughout their life. The fossil record of sphindid beetles is sparse; stem-sphindids and crown-group members of uncertain systematic placement have been reported from Cretaceous ambers. Here we review the Mesozoic fossil record of Sphindidae and report a new sphindid genus and species, Trematosphindus newtonigen. et sp. nov., from Albian/Cenomanian amber from northern Myanmar (ca. 99 Ma). Trematosphindus is set apart from all other sphindids by the presence of distinct lateral cavities on the anterior pronotal angles. Our phylogenetic analysis identifies Trematosphindus as an early-diverging genus within Sphindidae, sister to the remainder of the family except Protosphindus, or Protosphindus and Odontosphindus. The new fossils provide evidence that basal crown slime mold beetles begun to diversify by the mid-Cretaceous, providing a valuable calibration point for understanding timescale of sphindid co-evolution with slime molds.

Protoliota paleus sp. nov. (Coleoptera: Silvanidae) – new long antennae beetle in mid-Cretaceous Burmese amber

“…The family Parandrexidae Kirejtshuk, 1994 is known only from the fossil state (Soriano et al 2006). Representatives of 15 families (Table 2) have been reported from mid-Cretaceous Kachin amber (Cai & Huang 2016Cai et al 2018;Jin et al 2019;Kirejtshuk & Chetverikov 2018;Kirejtshuk et al 2019;Li et al 2021aLi et al , 2021bLi et al , 2022aLi et al , 2022bLi et al , 2022cLiu et al 2018Liu et al , 2019aLiu et al , 2019bPeris & Declòs 2015;Peris & Jelínek 2019Poinar & Brown 2018;Poinar & Kirejtshuk 2008;Tihelka et al 2020Tihelka et al , 2021aTihelka et al , 2021bTomaszewska et al 2018Tomaszewska et al , 2022Wu et al 2018;Zhao et al 2022).…”

The Earliest Corotocini (Insecta: Coleoptera: Staphylinidae) from Dominican Amber, with Remarks on Post-Imaginal Growth Influence on Termitophile Taxonomy

“…Helicon Focus v. 8.1.1 and Zerene Stacker v. 1.04 were used for image stacking. Using the same method as Li et al [ 21 ], the amber inclusion was imaged using high-resolution X-ray microtomography (micro-CT) to uncover fine morphological detail. Scans were made using a Zeiss Xradia 520 versa at the micro-CT laboratory of the Nanjing Institute of Geology and Palaeontology, CAS.…”

A new species of the genus Trematosphindus Li et Cai, 2021 (Coleoptera: Sphindidae) from Cenomanian Taimyr amber

“…The genera Burmops Kirejtshuk, 2019 and Pleuroceratos Poinar et Kirejtshuk, 2008 placed in the Protosphindinae (Kirejtshuk et al 2019) were transferred to the family Phloeostichidae (Tihelka et al 2020). The genus Trematosphindus Li et Cai, 2021 was found in mid-Cretaceous Burmese amber (Li et al 2021). Undeterminate representatives of this family were also found in late Eocene Baltic amber (Hieke & Pietrzeniuk 1984).…”