Allostrophus cretaceus gen. et sp. nov.: A new polypore fungus beetle (Coleoptera, Tetratomidae) from the Cretaceous Myanmar amber

Abstract. Rhopalosomatidae, currently considered the sister group of the Vespidae, are an enigmatic family of aculeate wasps that originated in the Late Jurassic or Early Cretaceous. Despite their considerable age, very few fossils of the family have been reported – all of them in amber (Miocene Dominican, Miocene Mexican, and mid-Cretaceous Burmese ambers). Here we report a new mid-Cretaceous rhopalosomatid wasp, Cretolixon alatum Lohrmann, gen. et sp. nov., from Burmese (Kachin) amber. This new genus has a unique mixture of characters, some of which are only known from the recent brachypterous genus Olixon and others of which are known only from the recent macropterous genera. Thus, Cretolixon Lohrmann, gen. nov. not only provides further evidence for the monophyly of the family but also contributes evidence for the monophyly of the Rhopalosomatinae. Key characters of the family are discussed, and an updated checklist of the world genera and fossil species and occurrences of Rhopalosomatidae is provided. Additionally, a chemical analysis was performed for three of the newly reported fossils as well as for the amber piece containing the rhopalosomatid larva described by Lohrmann and Engel (2017) to ascertain their amber vs. copal nature and their affinities with each other and previously described Burmese amber.

A new genus and species of soldier beetle from Upper Cretaceous Burmese amber (Coleoptera, Cantharidae, Malthininae)

A new polypore fungus beetle species Allostrophus Hsiao, Ślipinski, Yu, Deng and Pang embedded in Upper Cretaceous Burmese amber (Cenomanian, ca. 99 Ma) is described: A. yangi sp. nov.; this new species can be differentiated from its only congener based on its antennomere 11 and fusiform, elongate body. Morphological characters preserved in the inclusion compared to A. cretaceus Hsiao, Ślipinski, Yu, Deng and Pang provide further data for completing the definition of Allostrophus. This new discovery highlights the species diversity of fungivorous beetles during the Cretaceous period, adding evidence that the formerly hypothesized co-diversification between fungus-feeding coleopterans and their food resources originated in the late Mesozoic Era.

Throughout most of the eastern Great Basin major parts of the stratigraphic section have been removed by erosion. In general, effusive volcanic rocks of early Tertiary age overlie strata ranging in age from Precambrian to Permian. Because sedimentary rocks of Mesozoic and early Cenozoic age are generally absent it has been difficult to interpret the geologic history of these eras. Individual units and sequences of the early Tertiary volcanic rocks have been correlated over most of the eastern Great Basin and western Colorado Plateau. These rocks provide a valuable datum for the deciphering of the structural and stratigraphic evolution of the region. Study of the contact relations of the volcanic rocks with older rocks indicates the existence of a linear positive element in western Utah, called herein the Sevier arch, during the late Mesozoic era. The axis of this arch trends generally northeast and is more or less parallel with the axis of the Manhattan geanticline of central Nevada and the early Cordilleran geanticline of eastern Nevada that became positive in Devonian and latest Paleozoic time respectively. The Sevier arch thus appears to be the third of a series of major upwarps developed by eastward progression of Paleozoic and Mesozoic orogenies. It is convenient to describe the tectonic development of the Sevier arch in six stages. Stage I was represented by deposition of Triassic and Jurassic sediments westward as far as the early Cordilleran geanticline. Stage II was initiated by linear uplift of the Sevier arch that extended from west-central Utah into southern Nevada. Material eroded from the arch was transported eastward into the Rocky Mountain seaway to form the thick clastic formations of latest Jurassic(?) and Cretaceous age. Stage III was climaxed by regional thrusting that culminated the upwarping and folding of the previous stage. Highlands produced by this phase of the orogeny extended from southern Nevada northward at least as far as north-central Utah. Erosion of these highlands resulted in deposition eastward of material that formed rocks of latest Cretaceous and early Tertiary age. Stage IV resulted in continued erosion that reduced the region to one of mild topographic relief. In stage V early Tertiary volcanics were deposited over the region as an extensive sheet. In stage VI late Tertiary deformation superimposed the characteristic Basin-and-Range-type structure upon the structural features of late Mesozoic and early Tertiary age.

Spinotoma ruicheni: A new Late Cretaceous genus and species of wedge-shaped beetle from Burmese amber (Coleoptera, Ripiphoridae, Pelecotominae)

A new Late Cretaceous genus and species of polypore fungus beetles (Coleoptera, Tetratomidae) from northern Myanmar

An important intermediate step in the evolution of pincer wasps: an extraordinary new type of chela from mid-Cretaceous Burmese amber (Hymenoptera, Dryinidae)

Pseudoscorpions are amongst the oldest terrestrial lineages but there is a major gap in the fossil record between the oldest fossils from the Devonian (ca. 385 million years ago) and rich fossil communities in amber that mostly originate from the Eocene of Europe. Burmese/Myanmar amber (or Burmite) from the middle Cretaceous preserves a diverse community of pseudoscorpions but these remain poorly documented, despite their exceptional preservation and potential to offer unique insights into evolutionary history. Here we describe a new genus and species of pseudoscorpion with a unique morphology of the chelicerae, Prionochthonius burmiticus gen. et sp. nov., from Burmese amber. Although some key characters remain obscure, the fossil can be confidently attributed to the basal pseudoscorpion family Chthoniidae, but it cannot be assigned to any extant or other fossil genus. Based on trichobothria patterns, it is most similar to extant genera that are found only in the Southern Hemisphere; findings that are in line with previous studies suggesting Gondwanan origins for at least some of the Burmese amber invertebrates. The fossil provides further evidence for a diverse community of litter- and soil-dwelling pseudoscorpions in the Late Cretaceous that comprises many extinct genera but represents many of the modern families. It also suggests that the diversification of chthoniid pseudoscorpions occurred well before the middle Cretaceous, and that the principle gestalt of its members has changed relatively little over time.

Sclerogibbid wasps (Hymenoptera: Chrysidoidea: Sclerogibbidae) are the obligate parasitoids of webspinners (Embiidina) in extant fauna; fossil sclerogibbids are very rare, while fossil webspinners are more abundant. Burmese amber is the oldest Lagerstätte where both diverse webspinners and sclerogibbids are found. In this paper, Sclerogibba cretacica sp. nov. is described from Late Cretaceous Burmese (Myanmar) amber. The new species, assigned to the extant genus Sclerogibba Riggio & De Stefani-Perez, 1888, is the fourth known fossil species of Sclerogibbidae and the first known fossil male of this family. Moreover, this is the first described sclerogibbid wasp from Burmese amber and the first known fossil species of Sclerogibba. Sclerogibba cretacica is similar to extant sclerogibbid wasps with a closed discoidal cell from South-East Asia, but differs in the shape of the discoidal cell and small number of antennomeres (19 only). The phylogenetic significance of this species is discussed. Evolutionary trends in the antennal polymorphism of sclerogibbid wasps since the Cretaceous are outlined. The records of fossil webspinners, their ancestors (Alexrasniidae) and sclerogibbids suggest a Laurasian origin of Sclerogibbidae. The genus Protosclerogibba Olmi, Marletta, Guglielmino & Speranza, 2016 is synonymized with Herpetosphex Arnold, 1940 (Pompilidae) and Protosclerogibba australis Olmi, Marletta, Guglielmino & Speranza, 2016 is synonymized with Herpetosphex staphylinoides Arnold, 1940 (new synonyms).http://zoobank.org/urn:lsid:zoobank.org:pub:8742C684-7937-401C-9958-C6106DB5C378

Ten new Cyphophthalmi specimens (Arachnida: Opiliones) from the Upper Cretaceous (Lower Cenomanian) Burmese amber of northern Myanmar are described. Seven of these are placed in Stylocellidae, the predominant extant family found today in Southeast Asia. Sirocellus iunctus gen. et sp. nov. represents the first fossil with a combination of sironid and stylocellid characters, suggesting a still ongoing transition in some lineages during the Upper Cretaceous. Mesopsalis oblongus gen. et sp. nov. represents a second fossil with elongated ozophores, a character not known from modern species. Leptopsalis breyeri sp. nov. is the first Cretaceous cyphophthalmid assignable to an extant genus. The species Foveacorpus cretaceus gen. et sp. nov. and F. parvus gen. et sp. nov., which cannot be placed in an extant family, show morphological novelties for Cyphophthalmi such as numerous pits covering the whole body. The possible function of these pits is discussed. Three more adult males with unique adenostyles and two juveniles are not formally named but further indicate an already highly diverse cyphophthalmid fauna during the Cretaceous. The total number of named Burmese amber Cyphophthalmi species is raised from one to six, and the total fossil record for this suborder now stands at eight.

Based on a review of troodontid specimens from the territories of the former Soviet Union, including new discoveries from Uzbekistan, two dental morphotypes can be distinguished among Troodontidae from the Cretaceous of Asia: (1) unserrated teeth, present in Mei from Lujiatun (China; Early Cretaceous: Hauterivian-Barremian), an unnamed taxon from Hövöör (Mongolia; Early Cretaceous: Aptian-Albian), Urbacodon itemirensis, gen. et sp. nov. from Itemir and Urbacodon sp. from Dzharakuduk (Uzbekistan; Late Cretaceous: Cenomanian and Turonian, respectively), and Archaeornithoides from Bayn Dzak and Byronosaurus from Ukhaa Tolgod (Mongolia; Late Cretaceous: Campanian); and (2) serrated teeth, present in Sinornithoides from Huamuxiao (China; Early Cretaceous) and Sinornithoides-like taxa from Khamryn Us (Mongolia; Early Cretaceous: Aptian-Albian), Shestakovo (Russia; Early Cretaceous: Aptian-Albian), and Sheikhdzheili (Uzbekistan; Late Cretaceous: Cenomanian); Troodontidae indet. from Kansai (Tajikistan; Late Cretaceous: Santonian) and Alymtau (Kazakhstan; Late Cretaceous: Campanian), Saurornithoides (Mongolia and China; Late Cretaceous: Campanian-Maastrichtian), and Troodon from Kakanaut and Blagoveshchensk (Russia; Late Cretaceous: Maastrichtian).

A blood sucking biting midge from Upper Cretaceous Burmese amber with a key to the determination of fossil species in the relictual genus Leptoconops Skuse (Diptera: Ceratopogonidae)

Marine dinoflagellates from Lower Cretaceous Muling Formation of Jixi Basin, China and their palaeoenvironmental significance

A moss fossil in Burmese amber is described as a new genus and species, Vetiplanaxis pyrrhobryoides. Previously the specimen was misidentified as Hypnodendron, based partially on a misinterpretation of laminar areolation. The age of the Burmese amber is Middle Cretaceous, not Eocene as previously believed, making this one of the best preserved and potentially most informative moss fossils known from the Mesozoic. The specimen has morphological affinities to some Bryalean and proto-pleurocarpous groups, but cannot be securely placed in any extant family.

A new species of minute Scydmaenini (Coleoptera: Staphylinidae: Scydmaeninae) in mid-Cretaceous amber from Myanmar