Exceptionally preserved beetles in a Triassic coprolite of putative dinosauriform origin

Abstract

Exceptionally preserved beetles in a Triassic coprolite of putative dinosauriform origin Highlights d The beetle Triamyxa coprolithica is described from a Triassic coprolite d It represents the only member of the extinct myxophagan family Triamyxidae d The coprolite was likely produced by the dinosauriform Silesaurus opolensis d The beetle fossils parallel younger amber inclusions in preservation quality

Phylogeny and systematics of Sphaeriusidae (Coleoptera: Myxophaga): minute living fossils with underestimated past and present‐day diversity

“…Burmese amber Lepiceridae also include morphologically derived crown group taxa, some of which are congeneric with modern species and others representing extinct branches (Jałoszyński et al, 2017, 2020). These findings are consistent with the hypothesis that the diversification of the modern lineages (families and genera) of Myxophaga took place in the Triassic, as evidenced both by molecular time trees (Misof et al, 2014; Zhang et al, 2018) and the fossil record (Fikáček et al, 2020a; Qvarnström et al, 2021). It is evident that the specialized lifestyle in moist substrate at river edges (two of three extant Lepiceridae species and most known Sphaeriusidae) or hygropetric (Hydroscaphidae and Torridincolidae) evolved as early as the Triassic, along with a preference for algae as food, the small body size and association with hygropetric habitats.…”

“…Myxophaga is a small beetle suborder containing almost exclusively aquatic or semiaquatic species of small or very small body size (Beutel & Arce‐Pérez, 2016; Fikáček et al, 2020a; Navarrete‐Heredia et al, 2005; Vanin et al, 2016). Coleoptera time trees based on molecular data indicate the lineage likely originated during the Late Permian or Early Triassic (McKenna et al, 2019; Zhang et al, 2018) and its fossil record dates back to the Late Triassic (Fikáček et al, 2020a; Qvarnström et al, 2021). The size reduction apparently occurred early in the lineage history, as both Triassic species were already small (1.4–1.7 mm in Triamyxa Qvarnström et al and 2‐3 mm in Leehermania Chatzimanolis et al), and all species of the four modern myxophagan families have small‐sized or even minute bodies.…”

New Representative of the Family Hydroscaphidae from Tunguska Basin, the Boundary of the Permian and Triassic (Coleoptera, Myxophaga) with Review on Myxophagan Fossil Records

“…Recently one hydroscaphid specimen was found in materials in sediments from Tunguska Basin, Krasnoyarsky Kray (tentatively dated around the boundary between the Permian and Triassic). The suborder Myxophaga sensu stricto has only a few fossil records [3,4,8,9,12,13,15,16,18,19,26,34], which need to be reviewed and discussed to clarify the composition of this group in the past. The paper is aimed to describe the oldest fossil myxophagan representative (Paleoscapha tunguskaensis gen. et sp.…”

“…nov. (type genus Leehermania Chatzimanolis, Grimaldi, Engel et Fraser, 2012) [3], and a subfamily state for Triamyxidae Qvarnström, Fikáček, Wernström, Huld, Beutel, Arriaganov.) [26].…”

Integrated Micro-CT and DNA-based study reveals Cenozoic origin of mayfly genus Calliarcys and its systematic position within Leptophlebiinae (Insecta: Ephemeroptera)

“…Its description is also the rst establishment of a may y species by by Micro-CT investigation. This method has by now frequently proven its potential to address the problems linked to taxonomy and systematics of fossils embedded in Mesozoic and Cenozoic resins (see, e.g., [12][13][14][15][16][17][18]). Its application in may y systematics however has been limited so far, with the visualisation of genitalia in the redescription of two extant may y species Sartori et al [19] and the report of a potential case of phoresis in a fossil may y [20].…”