Ovipositor and mouthparts in a fossil insect support a novel ecological role for early orthopterans in 300 million years old forests

A high portion of the earliest known insect fauna is composed of the so-called ‘lobeattid insects’, whose systematic affinities and role as foliage feeders remain debated. We investigated hundreds of samples of a new lobeattid species from the Xiaheyan locality using a combination of photographic techniques, including reflectance transforming imaging, geometric morphometrics, and biomechanics to document its morphology, and infer its phylogenetic position and ecological role. Ctenoptilus frequens sp. nov. possessed a sword-shaped ovipositor with valves interlocked by two ball-and-socket mechanisms, lacked jumping hind-legs, and certain wing venation features. This combination of characters unambiguously supports lobeattids as stem relatives of all living Orthoptera (crickets, grasshoppers, katydids). Given the herein presented and other remains, it follows that this group experienced an early diversification and, additionally, occurred in high individual numbers. The ovipositor shape indicates that ground was the preferred substrate for eggs. Visible mouthparts made it possible to assess the efficiency of the mandibular food uptake system in comparison to a wide array of extant species. The new species was likely omnivorous which explains the paucity of external damage on contemporaneous plant foliage.

Grylloblattidan insects from Sperbersbach and Cabarz (Germany), two new early Permian and insect-rich localities

New fossil insect specimens from two new localities in Germany, namely Sperbersbach and Cabarz (Goldlauter Formation; early Permian), belonging to the Grylloblattida, are described. Abundant material is assigned to Pictoborella clara n. gen. n. sp., regarded as closely related to Pictoborella germanica (Prokop et al., 2012) n. comb., from the Saar-Nahe Basin (Germany; early Permian). Liomopterum fuscatum n. sp., represented by fewer specimens, is delimited based on previously published and new data on various Liomopterum spp. Two other Liomopteridae, Uralioma thuringiensis n. sp. and Liomopterites sperbersbachensis n. sp., each known from a single forewing, are also described. Finally, Cabarzopterum magnificus n. gen. n. sp., with unclear familial affinities, is described based on three forewings. The assemblages of grylloblattidan insects at Sperbersbach and Cabarz are generally similar, with differences probably related to different depositional environments and local paleoclimatic conditions. UUID: http://zoobank.org/25ae125c-6a17-415f-8cf0-4c0507e4f89d

PALEOENVIRONMENTAL IMPLICATIONS OF INVERTEBRATE FECAL PELLETS (EDAPHICHNIUM ISP.) AT AN ICHNOFOSSIL-RICH DINOSAUR NESTING LOCALITY, UPPER CRETACEOUS TWO MEDICINE FORMATION, MONTANA, USA

ABSTRACT The terrestrial feeding trace Edaphichnium lumbricatum is known from the Triassic to the Pleistocene and is characterized by tubular burrows with ellipsoidal fecal pellets, indicating substrate feeding by earthworms or other invertebrates. We describe 11 specimens attributable to Edaphichnium isp. from Egg Mountain, a terrestrial locality with a diverse fossil assemblage from the Upper Cretaceous Two Medicine Formation in Montana, USA, and assess their paleoenvironmental and paleoecological implications. These ichnofossils were recovered from a 1.5 meter stratigraphic succession comprised of calcareous siltstones and limestones with abundant fossil insect pupal cases, representing well-drained paleosols. Although burrows are not always present, three recurring arrangements of Edaphichnium isp. fecal pellets are identified: linearly arranged pellets, horizon-confined pellets, and pellets in clusters dispersed vertically and horizontally throughout the matrix. Two color patterns (light and dark pellets) are also distinguished. Pellets are fine-grained and have a consistently ellipsoidal shape (length:diameter of 1.57), with maximum lengths ranging from 1.9–6.7 mm (mean 4.1 mm) and maximum diameters ranging from 1.0–4.1 mm (mean 2.6 mm). Geochemical analyses indicate pellets are comprised of varying proportions of calcite, plagioclase, and quartz, and are enriched in phosphorus relative to the sedimentary host matrix. Possible trace makers include chafer or other coleopteran larvae, millipedes, and earthworms, suggesting a range of capable trace makers of Edaphichnium-like fecal pellets. Edaphichnium isp. at specific stratigraphic horizons suggests increased organic content in the subsurface, potentially connected to depositional hiatuses. Edaphichnium isp. adds a secondary component to the Celliforma ichnofacies known from Egg Mountain and surrounding strata, and to the array of nesting, feeding, and dwelling traces of wasps, beetles, other invertebrates, mammals, and dinosaurs from the locality.

Ovipositor and mouthparts in a fossil insect support a novel ecological role for early orthopterans in Pennsylvanian forests

Lobeattid insects represented a high portion of the earliest known, Pennsylvanian insect faunas. However, their systematic affinities and their role as foliage feeders which severely influenced their ecosystems remain debated. We investigated hundreds of samples of a new lobeattid species from the Xiaheyan locality using Reflectance Transforming Imaging combined with geometric morphometrics in order to assess its morphology, infer its ecological role, and phylogenetic position. Ctenoptilus frequens sp. nov. possessed a sword-shaped ovipositor whose valves interlocked by two ball-and-socket mechanisms. This unambiguously supports lobeattids as stem-relatives of all Orthoptera (crickets, grasshoppers, katydids). Given the herein presented and other remains, it follows that this group experienced an early diversification coupled with high levels of abundance. The ovipositor shape additionally indicates that ground was the preferred substrate for eggs. Visible mouthparts made it possible to assess the efficiency of the mandibular food uptake system in comparison to a wide array of recent species. The new species was omnivorous which explains the paucity of external damage on contemporaneous plant foliage.

All genera of the world: Order †Lophioneurida—fossil out-groups of Thripida (Animalia: Arthropoda: Insecta)

The present paper presents a compilation of the generic names available in the fossil insect order Lophioneurida (Insecta: Thripida). It comprises 18 accepted genera, 4 synonyms and one invalid homonym.

TAPHONOMIC ANALYSIS OF THE PALEOENTOMOFAUNA ASSEMBLAGE FROM THE CENOZOIC OF THE FONSECA BASIN, SOUTHEASTERN BRAZIL

ABSTRACT The Fonseca Formation (Eocene–Oligocene boundary, Minas Gerais, Brazil) is well known for its paleoflora, especially of flowering plants. The richness of this insect-bearing fossil locality is significantly less well understood, but we can shed light on the insect paleocommunity. One hundred and eight fossil insect specimens were examined and separated into four grades based on their preservational quality. We conducted analyses of taphonomic features, including body orientation, size, articulation, and chemical composition. Our results reveal differences in the body articulation of the insects. The fully articulated specimens apparently did not experience extensive flotation time at the water-air interface, whereas for partially articulated and disarticulated specimens the opposite is true. These taphonomic features would be acquired during the biostratinomy stage, and not early diagenesis. We also employed high resolution techniques (SEM-EDS and Raman spectroscopy) to understand their fossilization potential. Our chemical data suggest that the Fonseca insects are preserved as organic remains in carbonaceous compressions. Thus, chitin biomolecules most likely were transformed into more resistant biopolymers during diagenesis. This interpretation may also imply that the carbonaceous material originated from the insect itself. In this study, we document new discoveries and also provide future prospects for study of the Fonseca Formation.

Behavioural impacts on the taphonomy of dragonflies and damselflies (Odonata) from the Lower Cretaceous Crato Formation, Brazil

The relative completeness of Odonata (dragonflies and damselflies) fossils from the Crato Formation is investigated and compared to other fossil insect groups from the same formation. Tagma completeness is measured as present, partial, or absent, with some additional subdivision of body components (head, thorax, limbs, individual wings, anterior and posterior abdomen). These data are statistically explored for trends using principal coordinate analysis. While no definitive clustering is identified, most Crato Formation Odonata fossils plot positively on coordinate two, whereas the majority of non-odonatan insect fossils plot negatively on this coordinate. This shows that the Crato Formation odonates are less complete compared to other insect groups from the same beds. Specimens preserved as isolated wings and those preserved with damaged or lost abdomens are identified as contributing to this difference. The causes of these differences are discussed, highlighting collection bias, predation, carcass scavenging, physical conditions of the palaeoenvironment, as well as the autecology of odonates.

Supplemental Material: Climate of the Last Glacial Maximum on the western Olympic Peninsula based on insect paleoecology

Age-depth model data, images of fossil insect and plant macroscopic remains, lists of skeletal elements for fossil insects, and locality and derived climate data for Olophrum boreale and Olophrum consimile<br>