Early Jurassic Coleopterans from the Mintaja Insect Locality, Western Australia

Abstract

Beetles (Coleoptera) are the most common insects recovered from the Lower Jurassic Mintaja insect locality of Western Australia, with over half of the fossils recorded from this site being isolated coleopteran elytra. A range of partial beetle bodies and other isolated beetle sclerites have also been recovered from the locality; much of this material is taxonomically unidentifiable due to its disarticulation and poor preservation. A number of the Mintaja coleopterans are assigned to the archostematan family Ommatidae, including Zygadenia westraliensis (Riek, 1968) comb. nov, previously placed in the morphogenus Mesothoris, and an unnamed species of Tetraphalerus. Also recorded is a new species of elaterid, Lithomerus wunda sp. nov., along with other fragments likely attributable to the same family. The remaining material is assigned into morphospecies, separated primarily on preserved body parts — specifically, there are three morphospecies based on partially articulated coleopteran bodies, two morphospecies based on isolated head capsules, three morphospecies based on isolated thoracic sclerites, three morphospecies based on isolated abdominal sclerites, and 13 morphospecies based on isolated elytra. Overall, the ecology of these fossils is difficult to interpret due to poor preservation, although some of the beetles were likely aquatic, and the Ommatidae and Elateridae were both likely xylophilous. There is a strong similarity between the Mintaja coleopterans and those from the Late Triassic Denmark Hill locality of Queensland, though many of these similarities are based on morphotaxa and may be superficial in nature. Of the species that have been assigned to named taxa, all are generally typical of the Late Mesozoic worldwide, with Zygadenia, Tetraphalerus and Lithomerus all long‐ranging, cosmopolitan genera.

Early Triassic (early Olenekian) life in the interior of East Gondwana: mixed marine–terrestrial biota from the Kockatea Shale, Western Australia

“…Of interest is the shared record of roachoid material, the earliest finds of this order in Australia (Jell, 2004). However, blattodeans are very common and diverse in both the Middle and Late Triassic insect assemblages of eastern Australia (Tillyard, 1916(Tillyard, , 1919(Tillyard, , 1936(Tillyard, , 1937Dodds, 1949;Riek, 1955Riek, , 1962Riek, , 1967, a dominance that continues into the later Mesozoic Australia-wide (Riek, 1968;Jell and Duncan, 1986;Vršanský, 2004;Martin, 2010; McLoughlin et al, in press).…”

New fossil species of ommatids (Coleoptera: Archostemata) from the Middle Mesozoic of China illuminating the phylogeny of Ommatidae

“…In contrast to the very limited range of the genera today, the recorded distribution in the Mesozoic was much broader. In addition to well preserved ommatid fossils in Mesozoic Lagerstätten of the eastern part of Russia and central Asia [3,16-18], interesting and important fossils of the group were discovered not only at fossil sites in northeastern China [19], but also at sites in Spain [20] and other localities [2,21]. Up to now, thirteen fossil genera with more than 100 species of ommatids have been described [2,3,16-26].…”

Low diversity cockroach assemblage from Chernovskie Kopi in Russia confirms wing deformities in insects at the Jurassic/Cretaceous boundary

“…The Chernovskie Kopi assemblage is generally similar to that from the Early Jurassic Mintaja locality in Western Australia (Martin 2010) because of similar composition down to genus level, as well as the character of fossil preservation (almost all are fragmentary fore wings). The same similarity is observed at the Toarcian Early Jurassic localities in Germany and England (Vršanský & Ansorge 2007), which contrasts with the composition and preservation of the richest assemblages of the Middle and Late Jurassic, which are closer in age to that from Chernovskie Kopi (Vishniakova 1968(Vishniakova , 1983Vršanský 2007Vršanský , 2008b.…”

“…indet. (Martin 2010) are fragmentary therefore complete comparison was not possible. Sizes differ as follows.…”