Triassic Insect Research Articles

First Upper Triassic Diptera (Insecta) from Germany.

First Upper Triassic dipterans (Nematocera) are described based on isolated wings from Fuchsberg near Seinstedt (Sevatian, uppermost Norian of Lower Saxony, Germany): Crivoptychoptera nebrias gen. et sp. nov. (Psychodomorpha, Ptychopteridae), Ptychopteridae incertae sedis, Dohloboyia triassica gen. et sp. nov. (Bibionomorpha, Boholdoyidae) and Chironomidae incertae sedis (Culicomorpha). All taxa under discussion present the oldest occurrences of their families. Geological background and composition of the Upper Triassic insect fauna of Seinstedt are briefly discussed.

Fossil insects of the Middle Triassic Gayndah Formation of south-eastern Queensland

The Middle Triassic (Anisian) Gayndah Formation is the northernmost unit of the Early–Middle Triassic Esk Basin of south-eastern Queensland. Fossil insects were discovered in the formation in 1962 and 90 specimens have been collected since then. Of those, the 80 specimens identifiable to Order level are mainly Hemiptera (39%) and Coleoptera (36%), with much fewer Odonata s.l., Plecoptera, Neuroptera, Mecoptera and Trichoptera, and single specimens of Blattodea, Reculida, Titanoptera and ? Orthoptera. The dominance of Hemiptera and Coleoptera is likely due to the durability of their tegmina and elytra during sedimentary transport and deposition, rather than an indication of faunal composition. Faunal elements identified to family or lower level are: Reculida: Shurabia australis Rasnitsyn, 1982 (Geinitziidae); Plecoptera: ? Gondwanoperlidium spp. (Euxenoperlidae); Hemiptera: Tennentsia evansi Lambkin, 2015, Dysmorphoptiloides ellisi Lambkin, 2015, Mesonirvana dougsmithi sp. nov. (Dysmorphoptilidae), Mesoscytina woodsi Lambkin, 2016 (Scytinopteridae), Hylicellidae; Neuroptera: Riekchotes reticulatus gen. et sp. nov. (Ithonidae), Lithosmylidia baronne Lambkin, 1988, Lithosmylidia sp. (Archeosmylidae), Gayndahpsychops carsburgi Lambkin, 2014 (Osmylopsychopidae); Mecoptera: Mesoses gayndah Lambkin, 2014 (Mesopsychidae), Mesochorista sp. (Permochoristidae); Trichoptera: Prorhyacophila colliveri Riek, 1955 (Prorhyacophilidae). The fauna is a typical Triassic transitional one that has commonalities with the more extensively sampled and species-rich faunas of the Queensland Late Triassic insect localities at Denmark Hill, Dinmore and Mount Crosby. Exceptions are a hindwing base ascribed to the Titanoptera, an order known in Australia only from the Middle Triassic Hawkesbury Sandstone of New South Wales, and the forewing of Riekchotes reticulatus, the earliest and only Triassic record of the neuropteran family Ithonidae.

A new fossil insect locality from the Upper Triassic of Jiyuan, Henan Province, Central China

The Triassic insects are relatively abundant from the Anisian to Rhaetian stages. Several well-known Triassic insect localities are distributed worldwide. Examples include the Anisian Grès à Voltzia in France, the Ladinian–Carnian Madygen Formation in Kyrgyzstan, Uzbekistan, and Tajikistan, the Cow Branch Formation of the latest Triassic in the USA, and the Carnian Molteno Formation in South Africa (Grimaldi & Engel, 2005).

Evolution: Unveiling a hidden tripartite relationship

Endophytic oviposition is one of the most intricate insect reproductive behaviors. A new study characterizes Triassic insect eggs within ginkgophyte leaves, revealing the earliest known tritrophic association of a host plant, ovipositing insect, and egg-predating insect.

A review of Triassic insects in China

Abstract Studies of Triassic insects in China began in 1956, and, so far, a total of 89 genera and 109 species have been found from the Triassic of China. The fossil records from 17 provinces (or regions) in China are assigned to 11 orders, except for two genera and species considered incertae sedis in Insecta. These Chinese Triassic insects, including one Early Triassic, 53 Middle Triassic and 55 Late Triassic species, are briefly reviewed in taxonomy and distribution, and listed here with detailed taxonomic and stratigraphic information. The Middle Triassic Tongchuan and Late Triassic Toksun entomofaunas are introduced in detail from the perspectives of composition and taxonomy. Existing data indicate that the Chinese Triassic entomofauna is dominated by Hemiptera, Mecoptera and Coleoptera; the Chinese Early Triassic insects are only known from Fuyuan in Yunnan Province, Middle Triassic insects are mainly known from northern China and sporadically from Guizhou Province, southern China, and Late Triassic insects are seen widely in both northern and southern China. The Middle and Late Triassic entomofaunas have a similar abundance but show a pattern of being more common in northern China than in southern China.

The Triassic insects of Denmark Hill, Ipswich, Southeast Queensland: the creation, use and dispersal of a collection

Type and additional fossil insects from the Late Triassic Denmark Hill locality in Southeast Queensland, Australia, are held in the collections of the Queensland Museum (Brisbane), the Australian Museum (Sydney) and the Natural History Museum of the United Kingdom (London). The history of these collections shows that they were the product of a concerted effort in the first two decades of the twentieth century to extract the fossils by Benjamin Dunstan, Queensland’s Chief Government Geologist, and to describe the fossils by Dunstan and Robin Tillyard, the foremost Australian entomologist of the time. They collaborated closely to document the late Triassic insects of Australia, at the same time as Dunstan carefully curated and organised both the official government collection of these insects for the Geological Survey of Queensland, and his own private collection. The death of the two men in the 1930s led to the sale by his widow of Dunstan’s private fossil collection (including type and type counterpart specimens) to the British Museum, and the donation of Tillyard’s by his widow to the same institution, in addition to some material that went to the Australian Museum. This paper documents the locations of all of the published specimens. The history of the Denmark Hill fossils (a site no longer accessible for collection) highlights the problems for researchers of the dispersal of holdings such as these, and in particular the separation of the part and counterpart of the same insect fossils. It also raises ethical questions arising from the ownership and disposal of private holdings of important fossil material collected in an official capacity.

<p><strong>Late Triassic fossil insects from the Laohugou Formation of northern China (Qinhuangdao, Hebei Province)</strong></p>

Triassic insect fossils from China are very limited. Here we report on numerous insect fossils discovered in the Upper Triassic Laohugou Formation at Heishanyao, Qinhuangdao, Hebei Province. These fossils are represented mainly by forewings of cockroaches and coleopteran elytra. The insect assemblage is most similar to that from the Upper Triassic Momonoki Formation of Japan. Fossils of the Laohugou Formation have been poorly known, so our discovery of new fossil insects bear significance for understanding the biota and sedimentary environment of this formation. The Mesozoic stratigraphic division in the Liujiang Basin has been controversial, and the usage of stratigraphic units has been inconsistent. Here we refine the stratigraphic sequence, from the bottom to the top, of the Upper Triassic Laohugou Formation, the Lower-Middle Jurassic Yaopo Formation, the Upper-Middle Jurassic Longmen Formation, the Upper Jurassic Tiaojishan Formation, and the Lower Cretaceous Zhangjiakou Formation. The Laohugou Formation is scattered in various basins in western Liaoning and northern Hebei, with the lower part mostly characterized by thick layers of complex conglomerates, suggesting a regional tectonic uplift. There is a sedimentary discontinuity between the Laohugou Formation and the Yaopo/Beipiao Formation, reflecting the uplifting activities during the late Late Triassic-early Early Jurassic in eastern China. The Laohugou Formation is overlaying on various ancient strata, representing the first regional unconformity of the northeastern margin of the North China Craton.

Middle-Late Triassic insect radiation revealed by diverse fossils and isotopic ages from China.

The Triassic represented an important period that witnessed the diversification of marine and terrestrial ecosystems. The radiations of terrestrial plants and vertebrates during this period have been widely investigated; however, the Triassic history of insects, the most diverse group of organisms on Earth, remains enigmatic because of the rarity of Early-Middle Triassic fossils. We report new insect fossils from a Ladinian deposit (Tongchuan entomofauna) dated to approximately 238 to 237 million years ago and a Carnian deposit (Karamay entomofauna) in northwestern China, including the earliest definite caddisfly cases (Trichoptera), water boatmen (Hemiptera), diverse polyphagan beetles (Coleoptera), and scorpionflies (Mecoptera). The Tongchuan entomofauna is near the Ladinian-Carnian boundary in age, providing a calibration date for correlation to contemporaneous biotas. Our findings confirm that the clade Holometabola, comprising most of the modern-day insect species, experienced extraordinary diversification in the Middle-Late Triassic. Moreover, our results suggest that the diversification of aquatic insects (a key event of the "Mesozoic Lacustrine Revolution") had already begun by the Middle Triassic, providing new insights into the early evolution of freshwater ecosystems.

Revision of the Scytinopteridae (Hemiptera: Cicadomorpha: Scytinopteroidea) of the Queensland Triassic.

The extinct hemipteran family Scytinopteridae, the presumed ancestors of the Heteroptera, was a small but widely distributed element of the Triassic insect fauna of Queensland. A total of 28 tegmina have been collected at six sites (Gayndah, Esk, Mount Crosby, Riverview, Denmark Hill and Dinmore) in five Middle or Late Triassic Formations. The specimens are remarkably uniform in both wing shape and basic venation, and the generally weakly developed venation of the apical area of the tegmen is rarely clearly preserved. Some consistent variations in tegmen size and in minor venational characters, however, have enabled the identification of six and possibly seven species in three genera, acknowledging of course, the somewhat artificial nature of fossil insect species based solely on isolated wings. Mesoscytina Tillyard, 1919 (= Triassoscarta Tillyard, 1919, syn. nov.), comprising Mesoscytina australis Tillyard, 1919 (= Mesoscytina affinis Tillyard, 1919, syn. nov., = Triassoscarta subcostalis Tillyard, 1919, syn. nov.) (Denmark Hill, Esk), Mesoscytina fistulae sp. nov. (Mount Crosby, Gayndah), Mesoscytina woodsi sp. nov. (Gayndah), and Mesoscytina magna sp. nov. (Dinmore), is distinguished by the combination of the R more or less straight distally and M with three apical branches. The monotypic Eurymelidium Tillyard, 1919, with type species Eurymelidium australe Tillyard, 1919 (Denmark Hill, Dinmore), has R sinuous and M with two apical branches, and the monotypic Apheloscyta Tillyard, 1922, with type species Apheloscyta mesocampta Tillyard, 1922 (Denmark Hill, Riverview) has R more or less straight and M with two apical branches. Three poorly preserved and thus unidentifiable scytinopterid tegmina from Esk, similar in size to Mesoscytina fistulae, are designated as Esk species A.

Revision of the Dysmorphoptilidae (Hemiptera: Cicadomorpha: Prosboloidea) of the Queensland Triassic-Part 2.

The extinct hemipteran family Dysmorphoptilidae was a major component of the Triassic insect fauna of Queensland preserved at the Denmark Hill, Dinmore, Mount Crosby and Gayndah fossil insect sites. A total of 13 species have now been identified, of which eight species in five genera were examined in the first part of this revision. This second part revises the remaining five species in three genera. Eoscartoides Evans, 1956 (= Mesonirvana Evans, 1956, syn. nov.), comprising Eoscartoides bryani Evans, 1956 (= Mesonirvana abrupta Evans, 1956, syn. nov.) (Mount Crosby), Eoscartoides orthocladus (Tillyard, 1922) comb. nov. (Denmark Hill), and Eoscartoides dmitryi sp. nov. (Dinmore), is distinguished by a strongly developed arc-like strigil in the basal costal space, a very short stem of RA, and a deeply forked M1+2. The monotypic Eoscarterella Evans, 1956, with type species Eoscarterella media Evans, 1956 (Mount Crosby), has a strongly lobate tegmen with peculiar surface sculpture and M1+2 simple. Eoscartoides and Eoscarterella differ from most dysmorphoptilids in having more or less lobate tegmina with even margins (without the antero-apical emargination so typical of the family), as well as the early entry of RA1 into the costal margin and the associated extensive and antero-apically positioned RA2. These characters are also shared with two other dysmorphoptilids, the Australian Permian Belmontocarta Evans and an unnamed Triassic species from Kyrgyzstan, and the four thus form a distinct subgroup within the family. On the other hand, the monotypic Trifidella Evans, 1956 (= Alotrifidus Evans, 1956, syn. nov.), with type species Trifidella perfecta Evans, 1956 (= Alotrifidus interruptus Evans, 1956, syn. nov.) (Mount Crosby), is a more typical dysmorphoptilid with a distinct emargination, RA entering the margin much more apically, and RA2 of limited extent. Trifidella is presumably the sister of the Queensland Triassic Dysmorphoptiloides Evans, sharing the basal fusion of M and CuA.

Taphonomic biases in the insect fossil record: shifts in articulation over geologic time

AbstractInsect taphonomy is a topic that has drawn interest because of its potential biases on diversity patterns and the ecological information recorded by ancient insect faunas. Other than the onset of common amber fossilization in the Cretaceous, very little is known about long-term trends in the nature and quality of insect preservation and, as a result, the effects of taphonomic biases are poorly constrained. We assembled a database of nearly 7000 Carboniferous–Pliocene insect adpression (compression and impression) species from the primary literature to assess changes in insect taphonomy over time and test biotic and environmental controls on preservation. We grouped the fossils into 10-Myr bins and scored preservation of holotype specimens as either articulated bodies or isolated wings; articulated specimens with a body implied a generally higher quality of preservation. Paleozoic and Triassic insect holotypes are known overwhelmingly from isolated wings (only 12% articulated bodies), but our database shows a significant increase in the percentage preserved as articulated bodies, to more than 70%, beginning about 160 Myr ago in the Late Jurassic. This transition could reflect variations in the robustness of different insect orders and shifts in the taxonomic composition of insect faunas, but all the major orders in the database exhibit significant increases in articulation. Instead, a shift to increased preservation in lacustrine paleoenvironments, which contain a greater proportion of articulated body fossils, explains most of the trend. The pronounced Late Jurassic increase in articulation has implications for evolutionary and ecological reconstructions, for example, suggesting that preserved insect diversity may be biased downward in the earlier part of their history when articulation was poor.

Endophytic oviposition on leaves from the Late Triassic of northern Chile: Ichnotaxonomic, palaeobiogeographic and palaeoenvironment considerations

This paper reports the first record of Triassic insect oviposition scars from southern South America. Oviposition scars are found on Late Triassic leaves and leaf fragments from Heidiphyllum elongatum (Morris) Retallack and Pseudoctenis harringtoniana Bonetti, from the La Ternera Formation, and Taeniopteris sp. B from the Las Breas Formation, in northern Chile. The morphology of these fossil traces is described in detail and comparisons are made with other worldwide records. The identified scars from the Triassic of Chile are: Paleoovoidus contactus nov. isp., P. megaovoidius nov. isp., and P. rectus Vasilenko. Additionally, P. midribus nov. isp., P. marginatus nov. isp., and P. suboppositus nov. isp. are established, based upon a detailed analysis of descriptions in the literature. A synthesis of the fossil record and ichnotaxonomic considerations is given. The five new ichnotaxa are defined based on characters suggested by previous authors, with the objective of standardizing the different schemes under a single binomial ichnotaxonomical proposal, including most records from the Carboniferous to the Cenozoic, and establishing corresponding synonymy. Ichnofossils from the Triassic of Chile are tentatively assigned to the order Odonatoptera based upon morphological characteristics of scars on their host plants, and palaeoenvironmetal interpretations.

The Earliest Evidence of Holometabolan Insect Pupation in Conifer Wood

BackgroundThe pre-Jurassic record of terrestrial wood borings is poorly resolved, despite body fossil evidence of insect diversification among xylophilic clades starting in the late Paleozoic. Detailed analysis of borings in petrified wood provides direct evidence of wood utilization by invertebrate animals, which typically comprises feeding behaviors.Methodology/Principal FindingsWe describe a U-shaped boring in petrified wood from the Late Triassic Chinle Formation of southern Utah that demonstrates a strong linkage between insect ontogeny and conifer wood resources. Xylokrypta durossi new ichnogenus and ichnospecies is a large excavation in wood that is backfilled with partially digested xylem, creating a secluded chamber. The tracemaker exited the chamber by way of a small vertical shaft. This sequence of behaviors is most consistent with the entrance of a larva followed by pupal quiescence and adult emergence — hallmarks of holometabolous insect ontogeny. Among the known body fossil record of Triassic insects, cupedid beetles (Coleoptera: Archostemata) are deemed the most plausible tracemakers of Xylokrypta, based on their body size and modern xylobiotic lifestyle.Conclusions/SignificanceThis oldest record of pupation in fossil wood provides an alternative interpretation to borings once regarded as evidence for Triassic bees. Instead Xylokrypta suggests that early archostematan beetles were leaders in exploiting wood substrates well before modern clades of xylophages arose in the late Mesozoic.

The beginning of the ‘Age of Dinosaurs’: a brief overview of terrestrial biotic changes during the Triassic

ABSTRACTThe first appearance of dinosaurs during the early Late Triassic coincided with marked faunal changes in terrestrial ecosystems. Most of the major groups of extant tetrapods (or their proximate sister-taxa), including mammaliaforms, crocodyliform archosaurs, lepidosaurs and turtles, also first appeared in the fossil record during the Late Triassic. On the other hand, a number of Palaeozoic ‘holdovers’, such as procolophonid parareptiles, dicynodont therapsids and many groups of temnospondyls, vanished near or at the end of the Triassic. The tempo and mode of this faunal turnover have long been debated, but there has been growing acceptance of a rather sudden event, although the precise dating of such an event remains controversial. However, new discoveries have cast doubt on this assumption. The persistence of non-dinosaurian dinosauromorphs alongside dinosaurs well into Norian times hints at a more protracted turnover. New data on Triassic insect assemblages indicate that turnover among insects may also have been more protracted and possibly not co-incident with the faunal changes among tetrapods. Future work directed toward improved absolute age assessments for major faunal assemblages will be critical for a better understanding of the transition from therapsid-dominated to dinosaur-dominated communities during the early Mesozoic.

First Late Triassic Record of a Paleoentomofauna from South America (Malargüe Basin, Mendoza Province, Argentina)

Abstract:Late Middle Triassic to early Late Triassic insects from Argentina have been previously described from the Bermejo and Cuyana Basins where they have been recovered from the Ischichuca‐Los Rastros and Potrerillos‐Cacheuta Formations, respectively. The insect fauna discussed herein was collected during field studies in 1986/1987 from the Llantenes section (Norian to Rhaetian? Late Triassic), which is situated in the Malargüe Basin in southern Mendoza province. The insect remains were found in the upper part of the Llantenes section (Llantenes Formation), which is built up of two coarsening‐upwards cycles reflecting a deltaic progradation of a fluvial into a lacustrine environment (lower part), succeeded by repeated progradations into a floodplain‐dominated environment (upper part; with finds of insects, conchostracans, fish remains, plant fragments, and drifted logs). The new finds represent the youngest Triassic insect records described from Argentina and even from South America in its entirety. There is only one contemporaneous fossil assemblage in Gondwana: in the Clarence/Moreton Basin (Aberdare Conglomerate; Late Norian) in Australia. The new Triassic insects include an impression of an isolated Mecopterida‐like wing (Mendozachorista volkheimeri gen. et sp. nov.; Mendozachoristidae fam. nov.), coleopteran elytra of the Permosynidae (Ademosyne rosenfeldi sp. nov. and Ademosyne llantenesensis sp. nov.) and other isolated body fragments. This new Late Triassic entomofauna from Argentina is of considerable importance in the reconstruction of the biotic recovery of continental environments in Gondwana after the catastrophic mass extinction at the P/T boundary.

On Permian and Triassic insect faunas in relation to biogeography and the Permian-Triassic crisis

On Permian and Triassic insect faunas in relation to biogeography and the Permian-Triassic crisis

On Permian and Triassic insect faunas in relation to biogeography and the Permian-Triassic crisis

The taxonomic diversity dynamics of pterygote insects in the Permian and Triassic at the family/age level are considered. Different metrics of taxonomic diversity are compared. Biogeographic and taphonomic aspects of changes in the composition of insect faunas in the Permian and about the P-T transition are discussed. Some changes in the Permian insect faunas are of a biogeographic nature and do not indicate global changes in diversity. Insects with aquatic immatures were rather common in the Permian and Early Triassic, but these immatures are well represented in only few localities.

Cladotypic taxonomy applied: titanopterans are orthopterans

The Linnaean taxon Titanoptera is a distinctive Triassic insect order the origin of which is uncertain. Forewing venation patterns of the Permian Linnaean subfamily Tcholmanvissiinae (Orthoptera) and of the Titanoptera are re-investigated. The comparative analysis supports the view that the morphology of the latter group is derived from that of the former. As a consequence, the order Titanoptera is to be included within the subfamily Tcholmanvissiinae. A cladotypic taxonomy is developed in order to avoid the confusion inherent to taxonomic rearrangements associated with rank-based taxonomy. The following hierarchy is proposed: (Archaeorthoptera nom. Béthoux & Nel, 2002a, dis.-typ.n. (Pantcholmanvissiida nom. n., dis. Béthoux & Nel, 2002b, typ.n. (Tcholmanvissiidae nom. Zalessky, 1934, dis. Sharov, 1968, typ.n. (Tcholmantitanopterida nom.-dis.-typ.n. (Tcholmanvissiella nom. Gorochov, 1987, dis.-typ.n. (Titanopterida nom.-dis.-typ.n. (Gigatitanidae nom. Sharov, 1968, dis. -typ.n.))))))). This fi rst application of cladotypic taxonomy unveiled several practical aspects of this system. A system governing the adaptation of pre-occupied taxon names is developed based on various cases of character state formulations; the issue of the occurrence of Linnaean suffi xes and of the preservation of Linnaean binominals within a cladotypic taxonomy are discussed; the capacity to handle the ancestor ‘species’ vs. apomorphy-less sister-species issue by the various nomenclatural systems is discussed.

A new Triassic insect fauna from Cerro Bayo, Potrerillos (Mendoza Province, Argentina) with descriptions of new taxa (Insecta: Blattoptera and Coleoptera)

Martins-Neto, R.G., Gallego, O.F. & Zavattieri, A.M., June, 2007. A new Triassic insect fauna from Cerro Bayo, Potrerillos (Mendoza Province, Argentina) with descriptions of new taxa (Insecta: Blattoptera and Coleoptera). Alcheringa 31, 199‐213. ISSN 0311-5518. This contribution describes new fossil insect taxa from the early Late Triassic Potrerillos Formation (lower section), at quebrada del puente, Cerro Bayo, Mendoza Province, Argentina. A new family, three new genera, and four new species of Blattoptera are described: Anablatta compacta gen. et sp. nov., Potrerilloblatta stipanicici gen. et sp. nov. (Subioblattidae Schneider), Delpuenteblatta dangeloi gen. et sp. nov. and Lariojablatta neiffi sp. nov. (Delpuenteblattidae fam. nov.); and a new coleopteran species, Delpuentesyne menendezi sp. nov. (Permosynidae Tillyard). These findings extend the stratigraphic distribution of the typical Triassic coleopteran taxa. The new assemblage shares the genus Lariojablatta with the Los Rastros fauna. The Blattoptera and Coleoptera genera differ from those typical of the Australian and South African Triassic biota (Ademosyne for Coleoptera and Triassoblatta and Samaroblatta for Blattoptera) and appear to be endemic to Argentina (Delpuentesyne, Potrerilloblatta and Delpuenteblatta).

Triassic Insects of Queensland. I. Eoses, a Probable Lepidopterous Insect from the Triassic Beds of Mt. Crosby, Queensland.

Triassic Insects of Queensland. I. Eoses, a Probable Lepidopterous Insect from the Triassic Beds of Mt. Crosby, Queensland.