A new genus of highly specialized ants in Cretaceous Burmese amber (Hymenoptera: Formicidae).

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

Simple SummaryLucanidae (stag beetles) is a small family and one of the most ancient groups within the Scarabaeoidea superfamily. Most adult lucanids exhibit clear sexual dimorphism, with males often having impressive mandibles that are used in fierce competition for mates. Fossils of Lucanidae from the Mesozoic era are rare. In this study, we describe a new lucanid fossil, Prostreptocerus burmiticus Yu & Cai gen. et sp. nov., found in mid-Cretaceous Burmese (Kachin) amber, which shares similar features with the modern Lampriminae. This discovery marks the first fossil record of Lampriminae in mid-Cretaceous amber from northern Myanmar and is the oldest reliable record of the subfamily. The well-developed mandibles and curved claws of Prostreptocerus Yu & Cai provide additional evidence for sexual dimorphism and combat behavior in Mesozoic lucanids. This new taxon also enhances our understanding of early biodiversity and the biogeographic implications of stag beetles.A new stag beetle fossil, Prostreptocerus burmiticus Yu & Cai gen. et sp. nov., is described based on a single male specimen. This is the first representative of the subfamily Lampriminae (Coleoptera: Scarabaeoidea: Lucanidae) from mid-Cretaceous Burmese amber. The new species is distinctive among Lucanidae due to its well-developed, right-angled mandible, frons featuring a pair of large protuberances, a coarse and sparsely punctate elytral disc, and large tubercles on the humeri. Prostreptocerus Yu & Cai is placed within Lampriminae based on several key characteristics. Morphologically, it is most similar to the extant Streptocerus Fairmaire, 1850. The current distribution of Streptocerus and Lampriminae is primarily restricted to the Southern Hemisphere, suggesting that this lineage is ancient and existed on Gondwanaland, which has significant geographical implications. This discovery extends the fossil record of Lampriminae and provides additional evidence for the existence of sexual dimorphism and potential combat behavior in Mesozoic lucanids. Additionally, Electraesalopsis Bai, Zhang & Qiu, 2017, previously placed as Lucanidae incertae sedis, shares many characteristics with Prostreptocerus Yu & Cai and is also assigned to Lampriminae based on a suite of traits.

A new genus and species of parasitic wasps (Hymenoptera: Diapriidae) from Hkamti mid–Cretaceous Burmese amber

A camel spider from Cretaceous Burmese amber

Abstract. An unusually large acariform mite is described as Immensmaris chewbaccei gen. et sp. nov. from the Cretaceous (ca. 100 Ma) Burmese amber of Myanmar. With an idiosoma plus gnathosoma more than a centimetre long, it represents the largest unequivocal fossil mite ever recorded and approaches the maximum size of the largest living Acariformes today. Although some details of the dorsal idiosoma are equivocal, the new fossil appears to belong to Smarididae (Prostigmata: Parasitengona: Erythraeoidea) and also represents the largest erythraeoid mite ever discovered, indicating a clade of giant, possibly arboreal, mites in the Late Cretaceous of southeastern Asia.

Millipedes have been inhabiting the earth for more than 400 my and show a great diversity regarding their morphology and ecology. For a better understanding of the timing and pattern of millipede evolution, Burmese amber offers a unique window into the Cretaceous period, ca. 99 Ma. Here, we describe the first known fossil of the colobognathan order Platydesmida, the species Andrognathus burmiticus n. sp. based on 15 specimens from Cretaceous Burmese amber. We combine classical light-microscopy and modern micro-computer tomography (μCT) with computer aided 3D-reconstructions. These non-invasive techniques allow us to describe the fossil millipedes as detailed as is general practice for extant species, and to grant the scientific community open access to the deposited “Cybertypes”. Based on the combination of unique morphological characters such as surface structures, body type, the unique size and shape of tergite 5, the absence of a hypoproct at the anal segment, and detailed gonopod characteristics, the studied fossils can be placed in the family Andrognathidae and the extant genus Andrognathus, which nowadays is restricted to the eastern USA and Mexico with three extant species. Therefore, the minimum age of the genus Andrognathus is pushed to the Cenomanian, 99 Ma. It can be assumed that the genus was much more diverse and wider distributed in the past and migrated between Asia and America via one of the once existing land bridges. These unique fossils prove the unusual relictual distribution of Andrognathus and can serve as key-fossils for the dating of the diplopod phylogeny.

The click beetles (Elateridae) represent the major and well-known group of the polyphagan superfamily Elateroidea. Despite a relatively rich fossil record of Mesozoic Elateridae, only a few species are described from the Upper Cretaceous Burmese amber. Although Elateridae spend most of their lives as larvae, our knowledge on immature stages of this family is limited, which is especially valid for the fossils. So far, only a single larval click beetle has been reported from Burmese amber. Here, we describe two larval specimens from the same deposit which based on their morphology unambiguously belong to the predominantly Southern Hemisphere subfamily Pityobiinae, being the most similar to the representatives of tribe Tibionemini. However, since the larvae of the closely related bioluminescent Campyloxenini have not yet been described, we place our specimens to Tibionemini only tentatively. One species of Pityobiinae was recently described from Burmese amber based on adults, and we discuss if it can be congeneric with the here-reported larvae. Recent representatives of the Tibionemini + Campyloxenini clade are known from South America and New Zealand, and this group is hypothesized to have a Gondwanan origin. Hence, the newly discovered Burmese amber larvae may further contribute to a recently highly debated hypothesis that biota of the resin-producing forest on the Burma Terrane, which was probably an island drifting northward at the time of amber deposition, had at least partly Gondwanan affinities. The discovery of enigmatic click beetle larvae in the Upper Cretaceous Burmese amber sheds further light on the palaeodiversity and distribution of the relatively species-poor Gondwanan clade of click beetles, which contain a recent bioluminescent lineage, as well as on the taxonomic composition of the extinct Mesozoic ecosystem.

A remarkable diversity of parasitoid beetles (Ripiphoridae) in Cretaceous amber, with a summary of the Mesozoic record of Tenebrionoidea

The first termites in Early Cretaceous (Albian) amber from Spain are described and figured. Morazatermes krishnai Engel and Delclòs, new genus and species, is described from an imago (and wings of a second specimen) preserved in fossiliferous resin from Moraza, Burgos Province. A second termite species, Cantabritermes simplex Engel and Delclòs, new genus and species, is also recorded from the same deposits but is presently known only from the forewing. Similarly, an isolated forewing in amber from San Just, Teruel Province is described as Aragonitermes teruelensis Engel and Delclòs, new genus and species. Lastly, the first termite in Late Cretaceous (Campanian) amber from Grassy Lake, near Medicine Hat, Canada is described from a fragmentary imago lacking wings or much of the body. All of these taxa belong to a primitive grade of unassigned termites between Mastotermitidae and the families Termopsidae, Hodotermitidae, and Archotermopsidae (sensu Engel et al., 2009). Notes are appended on the recently described “Kalotermes” burmensis Poinar, from the latest Albian of Myanmar (Burmese amber), and the species transferred to Kachinitermopsis Engel and Delclòs, new genus, resulting in the new combination, Kachinitermopsis burmensis. These new taxa highlight the diversity of primitive termites during the Cretaceous.

ABSTRACTAn ambrosia beetle described as Palaeotylus femoralis n. gen et sp. belonging to a new subfamily (Palaeotylinae n. subfam.: Coleoptera: Platypodidae) is described from Cretaceous Burmese amber. It differs from other subfamilies by the loose antennal club, 6-articled funicle, coarsely faceted eyes, tibiae with teeth at apex, bilobed meso- and meta-tarsomeres 2 and 3 and tarsomere 1 shorter than tarsomeres 2–4 combined. This is the first described Platypodidae from Burmese amber and the oldest documented ambrosia beetle that demonstrates glandular sac mycangia containing yeast-like propagules and hyphal fragments.

A look with μCT technology into a treasure trove of fossils: The first two fossils of the millipede order Siphoniulida discovered in Cretaceous Burmese amber (Myriapoda, Diplopoda)

New auger beetle (Coleoptera; Bostrichidae) from mid-Cretaceous Burmese amber

Through the ongoing research on Burmese amber, our knowledge about mid-Cretaceous life on an island in the Tethys ocean continuingly increases (Ross, 2019, 2020; Westerwheel et al., 2019), a life that was exotic and highly endemic (Zhang, 2018; Rasnitsyn & Öhm-Kühnle, 2018a). Among its rich biota is the extinct, strictly Cretaceous family Serphitidae of the Hymenoptera, which still is underexplored. Serphitidae are known in Burmese amber in two subfamilies, one of them (Supraserphitinae) is confined exclusively to Burmese amber and recorded just with one genus and, before the present study, two species (Rasnitsyn & Öhm-Kühnle, 2018b, c). Another subfamily, Serphitinae, is known from three genera, with the type genus Serphites Brues, 1937 (Engel, 2015), which is the most diverse serphitid genus in other Cretaceous ambers and most likely in Burmese amber as well. While the description of Burmese Serphitinae needs to be reserved for our future research, the present work is devoted to the recently described genus Supraserphites Rasnitsyn & Öhm-Kühnle, 2018, the only one in the subfamily Supraserphitinae. We are adding two new species to this genus, hereby doubling its numbers.

New soldier beetles (Cantharidae) are described from amber deposits in Burma (Myanmar), the Baltic region and the Dominican Republic. They include the Lower Cretaceous Burmese amber Ornatomalthinus elvirae gen. et sp. n., the Upper Eocene Baltic amber Rhagonycha (s. str.) sucinobaltica sp. n. and the mid-Tertiary Dominican amber Tytthonyx (s. str.) geiseri sp. n. These are the first descriptions of soldier beetles from Burmese and Dominican amber. The new genus Ornatomalthinus in Burmese amber is noted for possessing features similar to lycid beetles (Coleoptera: Lycidae) and for emitting, presumable defensive, secretions from everted thoracic and abdominal vesicles.

Procaeculus coineaui sp. nov. from Cretaceous Burmese amber is described and its phylogenetic position discussed. This fossil taxon is the first caeculid mite known from Burmese amber and constitutes the earliest record of the family. The genus Procaeculus is redefined to include the new fossil species and internal relationships between genera of the family are discussed based on a phylogenetic hypothesis.