A new damselfly (Odonata: Zygoptera: Platystictidae) from mid-Cretaceous Burmese amber

The genus Mesosticta Huang, Azar, Cai et Nel, 2015 was established based on the wing bases of two damselflies from mid-Cretaceous Burmese amber. Here we describe a new well-preserved platystictid damselfly, Mesosticta electronica sp. nov., with complete forewings and hindwings. The diagnosis of Mesosticta is revised and augmented in this paper. Mesosticta electronica sp. nov. differs from Mesosticta burmatica Huang, Azar, Cai et Nel, 2015 in having the arculus slightly distal of Ax2, a free subdiscoidal cell, the hindwing AA ending on the middle area of the posterior side of the discoidal cell, and the base of RP2 being three or four cells distal of the subnodus. The new discovery adds to the diversity of damselflies in mid-Cretaceous Burmese amber and puts the origin of Platystictidae to at least the mid-Cretaceous.     

Burmadysagrioninae,a new subfamily (Odonata: Zygoptera: Dysagrionidae) from mid-Cretaceous Burmese amber

A new subfamily, Burmadysagrioninae Zheng, Wang and Nel, subfam. nov., for the genus and species Burmadysagrion zhangi Zheng, Wang and Nel, gen. et sp. nov. is described from mid-Cretaceous Burmese amber. This is the third dysagrionid damselfly from the Mesozoic and the second one from Burmese amber. The new specimen has a unique discoidal cell with the anterior and posterior sides not parallel, and the basal side longer than the distal side, unlike the typical ‘sieblosiid-dysagrionine’ type. It differs from other dysagrionid damselflies by the presence of a simple wing venation, the vein IR1 originating below the pterostigma and a special discoidal cell.     

Electrodysagrion lini gen. et sp. nov., the oldest Dysagrionini (Odonata: Zygoptera: Dysagrionidae) from mid-Cretaceous Burmese amber

The dysagrionid damselflies are relatively diverse in Burmese amber, with two genera already recorded. A new dysagrionid damselfly, Electrodysagrion lini Zheng, Nel and Wang, gen. et sp. nov., corresponding to the oldest record of the tribe Dysagrionini, is described herein. It has the unique ‘sieblosiid-dysagrionine’ type of discoidal cell. It differs from other genera of Dysagrionini in having no antenodal crossveins distal of Ax2, Arc aligned with Ax2, and only one row of cells in the cubito-anal area below the nodus. This find puts the origin of Dysagrionini back to at least the mid-Cretaceous.     

The first aeshnoid dragonfly (Odonata: Anisoptera: Telephlebiidae) from mid-Cretaceous Burmese amber

A new true dragonfly, Cretaeshna lini gen. et sp. nov., is described based on a forewing from mid-Cretaceous Burmese amber. Cretaeshna is probably a member of Telephlebiidae: Telephlebiinae, but differs from the latter in having a weakly-defined IR1 and a short pterostigma. Cretaeshna lini is the first aeshnid dragonfly to be found as an amber inclusion and the third Cretaceous true dragonfly recorded in amber. Our find augments the diversity of Mesozoic true dragonflies, and enhances our understanding of the palaeogeographic distribution of aeshnid dragonflies.     

The first hangingfly from mid-Cretaceous Burmese amber (Mecoptera: Bittacidae)

The Bittacidae (hangingflies) were abundant and widespread during the Mesozoic, but much of their diversity falls within the Jurassic whereas in the Cretaceous they are less common. A new bittacid, Burmobittacus jarzembowskii gen. et. sp. nov., is described from mid-Cretaceous amber from northern Myanmar. This new find is the first bittacid from Burmese amber and also the first Mesozoic bittacid preserved in amber. The new genus is distinguished from all known bittacids in having a long and narrow wing with Rs arising from R and forking very early (in the basal one-fourth of the wing), resulting in the stem of Rs being very short (about 1/8th of the length of Rs₁₊₂), and stems of the main branches of Rs (Rs₁₊₂ and Rs₃₊₄) being unusually long.     

A new earwigfly from mid-Cretaceous Burmese amber (Mecoptera: Meropeidae)

A new species of Meropeidae (earwigfly) is described and figured based on an exceptionally well-preserved individual in mid-Cretaceous amber from Myanmar. Burmomerope clara Zhao and Wang, sp. nov. is distinguished from the type species B. eureka Grimaldi and Engel, 2013 by presence of broader wings with six longitudinal veins in radial sector and seven in medial field, CuA with two terminal branches, and long setae on the anterior margin of the wing. A detailed comparison of the forewings venation in all fossil and extant species is given. The new find is the third fossil species of Meropeidae and also the first fossil female to be described. The female genital structure of B. clara sp. nov. is remarkably similar to that of extant species, revealing 100 million years of morphological conservatism, and thus highlighting the antiquity of the group.     

First fossil Coloninae from Upper Cretaceous Burmese amber (Coleoptera: Staphylinoidea: Leiodidae)

Fossil leiodids are sparse, and they are confined to the Cenozoic. Here we describe and illustrate the first definitive Mesozoic leiodid, Colonellus burmiticus sp. nov., based on two well-preserved adults from the Upper Cretaceous Burmese amber. The fossil is firmly placed in the extant Coloninae based on multiple synapomorphies, such as antennae with normal-sized antennomere 8 and abdominal intersegmental membranes with “brick-wall” pattern. It can be further assigned to the extant genus Colonellus (subgenus Pentacolonellus) by its five-segmented antennal club. The discovery suggests that Colonellus is an ancient group, originating no later than the mid-Cretaceous.     

The first Mesozoic palmetto beetle (Coleoptera: Smicripidae) in Upper Cretaceous Burmese amber

Fossil smicripid beetles are very rare. Here we describe and figure the first Mesozoic representative of Smicripidae. Smicrips cretacea sp. nov., a new species belonging to the extant Smicrips LeConte is preserved in the Upper Cretaceous amber from northern Myanmar. Our discovery suggests that Smicrips is an ancient group, originating at least in the earliest Late Cretaceous. Together with other two fossil Smicrips species from the Eocene of Europe, it reinforces the hypothesis that the Recent distribution of Smicripidae is relict, and the family was more widespread in the Mesozoic and early Cenozoic than it is in the Recent.     

Mesomegaloprepidae,a remarkable new damselfly family (Odonata: Zygoptera) from mid-Cretaceous Burmese amber

Mesomegaloprepus magnificus gen. et sp. nov. (Odonata: Zygoptera) is described from more than 14 specimens in eight pieces of mid-Cretaceous (earliest Cenomanian, ca. 99 Ma) amber from Myanmar. Possible phylogenetic affinities with the Neotropical Latibasaliidae, Thaumatoneuridae, and Pseudostigmatinae are discussed, and a relationship with Pseudostigmatinae considered as possible, but because of conflicting evidence separate family status as Mesomegaloprepidae fam. nov. is tentatively preferred. The remarkable degree of homoplastic conflict in the wing venational similarities indicates that these represent relatively weak evidence for phylogenetic relationships. The palaeoecology, including sexual dimorphism in wing colouration, of the new taxon is discussed, and the large number of inclusions explained with possible breeding behaviour in association with water-filled tree holes (phytotelmata) of the amber tree, similar to extant Pseudostigmatinae. The position of all alleged fossil Thaumatoneuridae are discussed and revised: Eothaumatoneura ptychoptera Pongracz, 1935 from the Eocene Geiseltal locality is restored in Thaumatoneuridae. Cretaceous Euarchistigma and Paleogene Eodysagrion are tentatively retained as subfamilies Euarchistigmatinae and Eodysagrioninae in Thaumatoneuridae. Paleogene Dysagrioninae and Petrolestinae are removed from Thaumatoneuridae and attributed to a restored family Dysagrionidae, and Paleocene Latibasaliidae is transferred from Amphipterygoidea to Epallagoidea.     

Hymenoptera (wasps,bees and ants) in mid-Cretaceous Burmese amber: A review of the fauna

The Burmese amber assemblage of Hymenoptera with its 47 constituent families is now the richest in Cretaceous. A collection of Burmite (Burmese amber) from the Hukawng Valley, Myanmar at the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences was examined, revealing that Burmite inclusions contain a very highly diverse hymenopteran fauna with as many as ten families found new for the Burmese fossil assemblage. The mid-Cretaceous hymenopteran fauna of Burmese amber is revised at the family level. A high level of the first family occurrences and endemism is demonstrated suggestive of an insular syndrome affected the mid-Cretaceous Burmese biome, as well as somewhat contradictory features in composition of the hymenopteran families there.     

The first fossil Compsocidae from Cretaceous Burmese amber (Insecta, Psocoptera, Troctomorpha)

The first fossil record of the Compsocidae, Burmacompsocus perreaui gen. et sp. nov., is described from Late Albian Burmese amber. Its strong similarity to the two extant compsocid genera suggests a remarkable morphological stability within this group of 100 Ma. This family, now known only in Central America, was certainly more widespread in the past.     

The earliest Attagenus species (Coleoptera: Dermestidae: Attageninae) from Upper Cretaceous Burmese amber

A new species belonging to the extant dermestid genus Attagenus, Attagenus burmiticus sp. nov., is described and illustrated based on a well-preserved specimen from the Upper Cretaceous Burmese amber. The discovery suggests that Attagenus is an ancient group, originating as early as in the mid-Cretaceous. Along with another species of Attagenus known from the Upper Cretaceous New Jersey amber, it implies that Attagenus were widespread in the Mesoozic.     

New taxa of unusual Dilaridae (Neuroptera) with siphonate mouthparts from the mid-Cretaceous Burmese amber

Cretadilar olei gen. et sp. nov. and Burmopsychops groehni sp. nov. (Neuroptera: Dilaridae) are described from the Late Cretaceous (earliest Cenomanian/late Albian) Burmese amber. Their dilarid affinities are supported by two autapomorphies of the family: the reduction of the ligula and the presence of pectinate antennae in males. They are considered to belong to two new subfamilies, Cretanallachiinae subfam. nov. and Cretadilarinae subfam. nov., respectively. These subfamilies are easily distinguished from other dilarids (Dilarinae, Nallachiinae, and Berothellinae) by possessing siphonate mouthparts; however they strongly differ from each other. In particular, the broad gonocoxites 9 of Cretanallachiinae females are not fused to form a distinct ovipositor, and bear long gonostyli, whereas a distinct saber-like ovipositor (short, lacking gonostyli) is present in Cretadilarinae. It is assumed that Cretanallachiinae primarily fed on pollen and Cretadilarinae on the nectar of flowers.     

The first araripeneurine antlion in Burmese amber (Neuroptera: Myrmeleontidae)

Burmaneura minuta gen. et sp. nov., the first araripeneurine antlion in amber, is characterized, described and compared with the modern and Mesozoic Myrmeleontidae. The precise position of the fossil within this group is debatable. Interestingly, despite a rather rich fossil record, all Mesozoic Myrmeleontidae belong to subfamilies that are not recorded in the Cenozoic, although this might merely reflect the artificiality of the classification as the extinct groups may be paraphyletic with respect to their younger counterparts (e.g., Araripeneurinae may very well be nothing more than a stem group of no classificatory value).     

First definitive fossil agyrtodine beetles: An extant southern hemisphere group recorded from Upper Cretaceous Burmese amber (Coleoptera: Staphylinoidea: Leiodidae)

Mesozoic leiodids are poorly known, and only one definitive leiodid is formally described from Burmese amber. Here we describe and illustrate the second definitive Mesozoic leiodid, Cretagyrtodes glabratus gen. et sp. nov., based on a single specimen from the Upper Cretaceous Burmese amber. The fossil is placed in Agyrtodini (subfamily Camiarinae) after maxillary palpomere 4 as wide as palpomere 3, and procoxal cavities closed behind. Cretagyrtodes is tentatively attributed to the extant “Eupelates group”. The discovery of Cretagyrtodes in Burmese amber suggests that the south hemisphere endemic tribe Agyrtodini is probably an ancient group, which has showed its first appearance before the breakup of Pangaea.     

A new twisted-wing parasitoid from mid-Cretaceous amber of Myanmar (Strepsiptera)

A second Mesozoic twisted-wing parasite (Strepsiptera) is described and figured based on an exceptionally well-preserved male in mid-Cretaceous (Cenomanian) amber from northern Myanmar. Phthanoxenos nervosus Engel and Huang, gen. et sp. nov., is distinguished from other strepsipteran lineages, particularly the contemporaneous Cretostylops engeli Grimaldi and Kathirithamby, also in Burmese amber, and Protoxenos janzeni Pohl et al. in mid-Eocene Baltic amber, and assigned to a new family, Phthanoxenidae Engel and Huang, fam. nov. Phthanoxenos exhibit features indicative of a more primitive phylogenetic position than Cretostylopidae but still more derived than Protoxenidae. Brief remarks are made on the geological history of the Strepsiptera.     

First boganiine beetle in mid-Cretaceous amber from northern Myanmar (Coleoptera: Boganiidae)

Cretoboganium gei gen. et sp. nov., a new amber inclusion of the cucujoid family Boganiidae is described and figured based on a well-preserved adult from the mid-Cretaceous Burmese amber (Hukawng Valley, northern Myanmar), some 99 million years ago. Based on the presence of a pair of pronotal callosities, Cretoboganium can be firmly placed in the extant subfamily Boganiinae, a small group currently comprising two small austral genera. Our discovery represents the first fossil record for Boganiinae. It also demonstrates another example that an apparently austral group may have its sister group occurred in today’s northern hemisphere. Together with the other fossil boganiid known from the Middle Jurassic of China, the finding suggests that Boganiidae is an ancient and relict group. Moreover, the present biogeographic distribution of Boganiinae is indicative of an earlier origin of this subfamily, which likely originated before the breakup of the Gondwanan supercontinent.     

The oldest osoriine rove beetle from Cretaceous Burmese amber (Coleoptera: Staphylinidae)

A remarkable new genus and species, Mesallotrochus longiantennatus n. gen. n. sp., is described and figured based on a well-preserved individual in the lowermost Upper Cretaceous (Cenomanian) amber from Myanmar. Mesallotrochus is placed in the extant tribe Thoracophorini based on its general habitus, including the protibia with inner edge straight, without ctenidium, exposed protrochantins, open procoxal cavities, and more or less flatted body. Mesallotrochus is separated from other allied genera by the long antennae, very long maxillary palpomere 4, contiguous procoxae, and well-developed anterolateral pronotal angles. The new discovery of the oldest Osoriinae from about 99 million years not only suggests the antiquity of the subfamily, but also bears significant biogeographic implications.     

First record of the family Scolebythidae (Hymenoptera) in mid-Cretaceous amber from Myanmar

Two new genera and species belonging to the family Scolebythidae are described from mid-Cretaceous amber of Myanmar, Cursoribythus silvestris and Siccibythus musculosus. These taxa are introduced into the current phylogenetic tree of the family, in order to analyze their relationships and observe their impacts on our understanding of the family. The implication of the findings (this is the first record of the family in the Cretaceous amber deposits of Myanmar) are discussed.     

A remarkable evanioid wasp in mid-Cretaceous amber from northern Myanmar (Hymenoptera: Evanioidea)

A remarkable new wasp of the superfamily Evanioidea (Apocrita: Evaniomorpha) is described and figured from a female preserved in mid-Cretaceous amber from the Hukawng Valley of northern Myanmar. Othniodellitha mantichora Engel and Huang, gen. et sp. nov., is characterized by its unique combination of primitive and derived features in mesosomal and metasomal construction and wing venation, along with its peculiarly blocky head with a prominent facial horn, clypeal projection, and massive, squared mandibles, among other traits. The genus is placed in the new family, Othniodellithidae Engel and Huang, fam. nov., and is among the lower Evanioidea and distinguished from the Praeaulacidae and other Mesozoic evanioid families.