mid-Cretaceous Myanmar Amber Research Articles

Investigation of Cretodorus (Hemiptera: Fulgoromorpha: Mimarachnidae) based on new adult and nymph fossils from mid-Cretaceous Myanmar amber

Here we report a new species, Cretodorus lijuanae sp. nov., of extinct Mimarachnidae from mid-Cretaceous amber of northern Myanmar. C. lijuanae sp. nov. was described based on one adult and three nymphal fossils. The new adult specimen exhibits the diagnostic features of Cretodorus and possesses a unique number and arrangement of sensory pits in the pronotum: nine sensory pits on one side, with five sensory pits between median and pronotal carinae and four sensory pits between lateral carina and margin, which is consistent in the nymphs. We also conduct morphometric analyses of forewings of all known species of Cretodorus, demonstrating that morphometrics are effectively discriminative for identifying Cretodorus fossils featuring few longitudinal veins and minimal differences in venation. Additionally, we report the nymphal fossils of Mimarachnidae for the first time. Three nymphal fossils, preserved in the same piece of amber alongside the adult specimen, exhibit the same nodule pattern on the thoracic notum in dorsal view, suggesting a feature linking adult and nymph of Mimarachnidae. These new specimens show morphological characteristics of the different developmental stages of C. lijuanae sp. nov., increasing the diversity of the Mimarachnidae in mid-Cretaceous amber from Myanmar. The preservation of three nymphs of the same age with an adult in the same piece of amber likely indicates aggregation behaviour in Mimarachnidae.

A new genus of beaded lacewings (Neuroptera: Berothidae) from the mid-Cretaceous Myanmar amber

A new genus of beaded lacewings (Neuroptera: Berothidae) from the mid-Cretaceous Myanmar amber

The oldest fossil record of Philopotinae (Diptera: Acroceridae) from the mid-Cretaceous amber of Northern Myanmar

A new genus and species of Acroceridae Leach, 1815, Burmophilopota wintertoni gen. et sp. nov., is identified from mid-Cretaceous Burmese amber, representing the oldest member of Philopotinae Schiner 1868. Based on morphological comparisons, Burmophilopota wintertoni gen. et sp. nov. most likely represents a stem group of the Philopotinae. The new material with well-preserved details of mouthparts and complete wing venation suggests that the new species could possibly be a pollinator for the angiosperms. This finding enhances our understanding of early origin and evolution of pollinating flies during the Mesozoic period.

One New Genus and Four New Species of Beaded Lacewings (Neuroptera: Berothidae) from Upper Cretaceous Myanmar Amber.

In recent years, as more and more fossil species of berothids from Myanmar have been reported, the species and morphological diversity of Berothidae continues to increase. Herein, one new species of Berothidae, Aggregataberotha paucipunctata sp. nov., and one new genus, Sejunctaberotha gen. nov., with three new species (Sejunctaberotha sphaerica gen. et sp. nov., Sejunctaberotha tenuis gen. et sp. nov. and Sejunctaberotha transversa gen. et sp. nov.) are described from mid-Cretaceous Myanmar amber. A. paucipunctata sp. nov. is assigned to Aggregataberotha Wang, Huang & Wang, 2022, based on the characteristics of the similar female terminalia and wing venation, but can be different from A. punctate regarding the pale pterostigma and a few detailed features of wing venation. Additionally, representatives of Sejunctaberotha gen. nov. are remarkably different from the representatives of the other genera within Berothidae in the configuration of wing venation. For example, Sejunctaberotha gen. nov. has simple subcostal veinlets, obviously free Sc and RA at the apex present both in fore- and hindwings, a single ra-rp crossvein connecting the RA with RP3, a single rp-m crossvein locating before the origin of the MP, a simple CuP and no gradate veins. Interestingly, in one of the specimens of Sejunctaberotha gen. nov., a pair of spherical bulges was found at the end of the antennae. The new genus Sejunctaberotha gen. nov. suggests that Berothidae had a higher potential diversification during the Mesozoic Era.

A New Fossil of Cystodium (Cystodiaceae) from the mid-Cretaceous Myanmar amber

The only known fossil of Cystodium (Cystodiaceae) is C. sorbifolioides from mid-Cretaceous Myanmar amber. Here we describe a new fossil species of Cystodium, C. parasorbifolium, also from amber collected in Myanmar. This new species belongs to Cystodium based on pinnate fertile lamina segments, terminal sori protected by a reflexed lobe of the lamina (outer or false indusium), free veins, vertical annuli interrupted at the stalk, trilete spores, and striate perines. It differs from C. sorbifolioides by reflexed ovate-conical indusia and spores with clear striate perines. This new fossil species suggests that Cystodium was more diverse in the forests of Myanmar during the Cretaceous.

Two new species and new material of the family Evaniidae (Hymenoptera: Evanioidea) from the mid-Cretaceous amber of Northern Myanmar

Two new species, Sorellevania rara Li, Shih & Ren, sp. nov. and Iberoevania nova Li, Shih & Ren, sp. nov., and a new specimen of Cretevania bechlyi Jennings, Krogmann & Mew, 2013 are described and illustrated respectively from two male and one female specimens preserved in the mid-Cretaceous Kachin amber. Sorellevania rara sp. nov. is the third species of the genus Sorellevania Engel, 2006. The placement of the new specimen in the latter genus is supported by its small body size, its elbowed antenna, and its forewing venation (e.g., the shape of the medial cells). Iberoevania nova sp. nov. is assigned to Iberoevania based on its forewing with five enclosed cells, the crossveins 2r-m, and 2m-cu absent while 1rs-m is present, and its long petiole (about half the length of the gaster). A map of the deposits yielding Evaniidae during the Cretaceous and a histogram of Evaniidae species and genus diversity during the Cretaceous and Cenozoic are provided.

A new genus and species of the Nabidae (Hemiptera, Heteroptera, Cimicomorpha) from mid-Cretaceous amber of Northern Myanmar

A new genus and species of fossil Nabidae, Feroculipodus obtusidentatus gen. et sp. nov., is described from mid-Cretaceous amber, which represents the second fossil record of Nabidae from Myanmar and is classified under the subfamily Prostemmatinae. The new species is distinguished from other nabids based on the pronotum not clearly divided into an anterior and a posterior part, fore femur with an obtuse angular process on the ventral surface, basal cell on membrane absent. Research on the newly discovered fossil specimen as a source of character information, provides us with a new perspective to analysis the phylogenetic relationships of Nabidae through external morphological characters.

Discovery of the rove beetle subfamily Trichophyinae (Coleoptera: Staphylinidae) in Upper Cretaceous Taimyr amber, Siberia, Russia

The monogeneric rove beetle subfamily Trichophyinae (genus Trichophya) is reported from Upper Cretaceous Taimyr amber from Yantardakh in northern Siberia. The Taimyr specimen of Trichophya is assigned to the “pilicornis species-group” which contains the majority of extant species. It is differentiated from the single known trichophyine fossil Trichophya minor Yamamoto and Newton, 2021 from ca. 99 Ma mid-Cretaceous Myanmar amber, which is placed in the “antennalis species-group” together with one recent species. Together with Trichophya minor, our newly discovered fossil Trichophya species demonstrates that the two morphologically different recent Trichophya species groups were already present far back in time. The taxonomy, biogeography and paleoecology of the Taimyr amber Trichophya is placed in the context of the known morphology, distribution and habitat requirements of the extant species.

When the past meets the present: the oldest known Bibioninae, and the youngest known Cretobibioninae (Diptera, Bibionidae) from mid-Cretaceous Myanmar amber.

The Diptera family Bibionidae has a rich fossil record from the Tertiary, however little is known about this family in the Mesozoic. Recently, a number of specimens have been found in mid-Cretaceous Myanmar amber, dating from about 99 MYr BP. I report the finding of the oldest known member of the recent subfamily Bibioninae, as well as the youngest known member of the Cretaceous subfamily Cretobibioninae.The Cretobibioninae is represented by Cretobibio burmiticus sp. n., which suggests a wide, possibly cosmopolitan distribution of the recently discovered subfamily Cretobibionidae, the Bibioninae by Protodilophus semispinosus gen. et sp. n. The latter species is probably related to the recent and Tertiary genus Dilophus, but displays some plesiomorphic traits related to the more recent taxa.

Atypical 'long-tailed' cockroaches arose during Cretaceous in response to angiosperm terrestrial revolution.

Typical cockroaches are flat, broad, with large pronotum and wings covering the body. This conserved morphotype dates back to the Carboniferous, during which the ancestral cockroaches, or roachoids, originated. On the other hand, the ovipositor of cockroaches gradually reduced during the Mesozoic, coupled with a major shift of reproductive strategy. By the Cretaceous, long external ovipositors became rare, most cockroaches used very short or even hidden internal ovipositors to fabricate egg cases (oothecae), which is an innovation for egg protection. Here, we describe two cockroaches from mid-Cretaceous Myanmar amber: Ensiferoblatta oecanthoides gen. et sp. nov. (Ensiferoblattidae fam. nov.) and Proceroblatta colossea gen. et sp. nov. They are slim, elongate, fusiform, with longitudinal pronotum, and have long external ovipositors. The combination of these traits represents a unique morphotype, which resembles crickets and katydids (Ensifera) more than general cockroaches. Ensiferoblatta and Proceroblatta may be arboreal, feeding on and/or laying eggs into certain angiosperms that newly emerged. Their open habit causes latent impairment to viability, and may contribute to their extinction. These new taxa are the youngest members of the ancient, extinct group of cockroaches, namely Eoblattodea, which are characterized by long ovipositors. We speculate that the extinction of certain gymnosperm hosts almost ended the 200-My triumph of Eoblattodea. Despite an attempt to adapt to angiosperm hosts, Ensiferoblatta, Proceroblatta and suchlike cockroaches as an evolutionary dead end failed to save Eoblattodea from extinction. The lack of protection for eggs (maternal care in particular) might accelerate the extinction of Eoblattodea as a whole.

Fossil diversity in ‘dawn’ hexapods (Diplura: Projapygoidea), with direct evidence for being chemically predaceous in the Cretaceous

Abstract Diplurans are among the earliest hexapods in the geological record. These primitively wingless relatives of insects are infrequently encountered despite being pervasive in soil habitats. Two groups have disparate adaptations for hunting, one mechanical and the other chemical, in Japygoidea and Projapygoidea, respectively. Here, we report three genera (two new) and four species of fossil Projapygidae preserved in Mesozoic and Cenozoic ambers: Electroprojapyx alchemicus gen. et sp. nov. in mid-Cretaceous Myanmar amber, and Symphylurinopsis punctatus gen. et sp. nov. and two species (unnamed) of Symphylurinus in Miocene Dominican amber. The exceptionally preserved specimens possess cerci that are morphologically specialized for expelling a glandular substance on prey. The new Cretaceous E. alchemicus is a stem group to all living species of the family and provides conclusive Mesozoic evidence for a rare type of predation involving offensive (vs. defensive) secretions. The specimen was fossilized in a preying-and-spraying position with its presumptive meal, a Symphypleona springtail (Collembola), reflecting the behavioural predatory repertoire of modern relatives. Apart from one Cenozoic species, these rare specimens represent the only fossil record of the family Projapygidae. Our findings demonstrate that these basal hexapods were predators of small arthropods of ancient forest soils and enrich our understanding of palaeoecological associations and behavioural strategies paramount for the survival of species.

Two new species of heptageniids (Insecta, Ephemeroptera) with long antennae from mid-Cretaceous Myanmar amber

The extant heptageniids are known as flat-headed mayflies in larval stage and mainly living in fast flowing streams. Heptageniidae is one of the most diverse family of Ephemeroptera, however, fossil Heptageniidae in Mesozoic are scarce, obscure the early evolution of this family. Herein, we report one new genus and two new species of Heptageniidae from mid-Cretaceous Myanmar amber. Longiheptagenia gen. nov. is diagnosed by the course of thoracic sutures and characteristics of venation, especially lateroparapsidal sutures are not distinctly curved laterally and without cross-veins in anal field of forewings and small number of cross-veins in the hind wings. Both of the male and female of Longiheptagenia elegantula gen. et sp. nov. are described based upon medial depression of furcasternum mesothorax narrowed anteriorly, the 5th tarsomeres longer than 1st tarsomeres in forelegs, the length proportion of tarsomeres is same in mid- and hind leg, several cross-veins and the pattern of male genitalia which is distinctly distinguished from the male of Longiheptagenia bipartita sp. nov., these findings enrich the diversity of Cretaceous Heptageniidae, moreover, provide comprehensive morphological characters to enhance our understanding of basal Heptageniidae.

A new praeaulacid genus with a new species in Praeaulacidae (Hymenoptera: Evanioidea) from mid-Cretaceous Myanmar amber

A new fossil praeaulacid wasp, Hadraulacus perrarus Li, Shih and Ren gen. et sp. nov., is described and figured from mid-Cretaceous Myanmar amber. The new genus is established based on the following characters: antenna with more than 25 antennomeres; metasoma distinctly longer than mesosoma with the first metasomal segment forming a long petiole; legs long and thin, with tibia spurs 1-1-2, claw with one small subbasal tooth; forewing with 1cu-a postfurcal, 1m-cu shorter than 1-M and 2m-cu, 2r-m absent, 3r-m present, 2 + 3rm nearly trapezoidal, and 1m-cu in contact with 2 + 3rm by a short section of M. In addition, this mid-Cretaceous praeaulacid wasp was preserved together with a cicada nymph, likely the result of an accidental assemblage.

A new genus of net-winged midges (Diptera: Blephariceridae) from mid-Cretaceous amber of Myanmar

Blephariceridae, or net-winged midges, are a small group of highly specialized flies with immatures adapted to torrential streams. The family is known since the Jurassic, but the fossil record is very poor, as is typical of rheophiles. Up to now, only four species of three Mesozoic genera have been described, all of them from Asia. This paper provides a description of a male of Zwickina minaevi gen. et sp. nov. (Blepharicerinae), from mid-Cretaceous Burmese amber of northern Myanmar, and a brief discussion of the phylogenetic position of the new taxon. A key for identification of adults of extinct blepharicerid genera is included.

A New Genus and Species of the Suborder Trogiomorpha (Insecta, Psocodea) from Mid-Cretaceous Amber of Myanmar.

We established a new genus with a new species Brachyantennum spinosum Liang et Liu, gen. et sp. nov. from mid-Cretaceous Burmese Kachin amber. It is tentatively placed into the suborder Trogiomorpha, based on the strong external valve, the reduced dorsal and ventral valve, and the short subgenital plate covering the basal part of the external valve. This new genus is apparently close to the family Cormopsocidae, based on the well-developed and very long hindwing Sc vein. However, its familial placement is ambiguous and it can be excluded from the established families of Trogiomorpha by the presence of the tarsal ctenidiobothria on the mid- and hindleg.

A New Genus of Sap Beetles (Coleoptera: Nitidulidae) from Mid-Cretaceous Amber of Northern Myanmar.

Nitidulidae is the most diverse family of the recently recognized superfamily Nitiduliodea, but Mesozoic nitidulids that are critical for understanding their early diversification are sparse. Here, we report a new genus and species of Nitidulidae, Protonitidula neli gen. et sp. nov., that was recovered from mid-Cretaceous amber in northern Myanmar. The new genus is distinguished from all members of the extant nitidulid subfamilies most prominently by the loose antennal club and the absence of subantennal grooves. Protonitidula neli can be excluded from the closely related Kateretidae and classified into Nitidulidae by the broad and apically expanded prosternal process, although it has many pleisiomorphic characters.

A new wasp genus of Cirrosphecidae (Hymenoptera: Apoidea) from mid-Cretaceous amber of northern Myanmar

A new apoid genus with one new species Heterosphex wuni Li, Rosa, Melo and Shih gen. et sp. nov. is described in Cirrosphecidae based on a male wasp from mid-Cretaceous Myanmar (Burmese) amber. The new taxon is placed in Cirrosphecidae due to its swollen, ring-like metanotum with anterior margin surrounding the scutellum; omaular sulcus and omaular carina absent; propodeum short, with rounded edges and distinctly slanted; metapostnotum extending as a narrow triangle onto posterior surface of propodeum; notaulus not indicated; claws with subapical teeth; and mid tibia with one spur. A key for genera and species of Cirrosphecidae is provided. Up to date, all taxa in Cirrosphecidae are known only from mid-Cretaceous Myanmar amber.

First Member of 'Higher Endomychidae' (Coleoptera: Coccinelloidea) from the Mid-Cretaceous Amber of Myanmar and New Insights into the Time of Origin of the Handsome Fungus Beetles.

Simple SummaryWe discovered an extinct handsome fungus beetle almost 100 million years old embedded in amber from Myanmar. Comparing and analyzing the characteristics of its body with those of other beetles of this family living today, we were able to find out which ones could be their closest relatives. What we discovered suggests that our beetle, representing a new genus and species, is a part of a group called “Higher Endomychidae”. This group shares some features with members of the family Coccinellidae, the well-known ladybugs or ladybirds. Our finding supports the hypothesis that handsome fungus beetles (family Endomychidae) originated at least at the beginning of the Cretaceous period, and most probably in the Jurassic, coinciding with the heyday of dinosaurs on earth.A new genus and species of the family Endomychidae (Coleoptera: Coccinelloidea): Cretostenotarsus striatus Tomaszewska, Szawaryn and Arriaga-Varela gen. et sp. nov. are described, diagnosed and illustrated from the mid-Cretaceous amber from northern Myanmar. To test the systematic placement of the new extinct genus and species within the family, a phylogenetic analysis was conducted. A dataset of 38 morphological characters scored for 29 species (including the new fossil taxon), members of Endomychidae sensu stricto and representatives of Coccinelloidea as outgroups were analyzed using maximum parsimony. The results of the analysis indicate unequivocally that Cretostenotarsus striatus is a member of the Stenotarsus clade within a monophyletic ‘endomychine complex’ sensu Robertson et al. (2015), which corresponds to ‘Higher Endomychidae’ sensu Tomaszewska (2005). The present discovery confirms at least the Jurassic origin of Coccinelloidea and indicates a much older origin of Endomychidae than previously hypothesized.

Validation of the previously published name Endobeuthos paleosum, a fossil flower in mid-Cretaceous Myanmar amber

The name Endobeuthos paleosum, previously published in this journal, was invalid due to the lack of a designation of one of the illustrations as the holotype specimen and the others as paratypes. This oversight is here corrected and the taxon name properly validated.

A New Subgenus and Species of Priochirus from Mid-Cretaceous Kachin Amber (Coleoptera: Staphylinidae: Osoriinae).

Simple SummaryDespite the extant diversity of the rove beetle subfamily Osoriinae, its fossil record remains meagre. The present study reports a new species Priochirus (Eopriochirus) trisclerite subgen. et sp. nov. from Kachin amber (mid-Cretaeous: Cenomanian, ca. 99 Ma). The discovery not only enriches the fossil record of Osoriinae but adds to our understanding of its ancient origin and diversification. With new species described in the present paper, 3 species of osoriines are known from Mesozoic Kachin amber.As one of the largest families of beetles (Coleoptera), the Staphylinidae (rove beetles and their relatives) are rich not only in extant species but also in a comparatively robust fossil record. Despite this preponderance of available fossil material, fossils of the diverse subfamily Osoriinae remain rare. Here, we describe a new ososriine species, Priochirus trisclerite sp. nov., from the mid-Cretaceous amber of Myanmar. The new specimen is similar to the only other definitive fossil of the genus, Priochirus thayerae Yamamoto 2019, and both are placed in the extinct subgenus Eopriochirus subgen. nov. The new species differs noticeably in a number of morphological details in relation to the submentum, gular sutures and protibial crenulae. The new fossil provides further evidence for understanding the radiation of staphylinoid beetles.