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.

A new species of Cretodorus (Hemiptera: Fulgoromorpha: Fulgoroidea: Mimarachnidae) from Upper Cretaceous amber of northern Myanmar

New araripeneurids (Insecta: Neuroptera) from Upper Cretaceous amber of northern Myanmar

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.

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

A new genus of ants, Zigrasimecia Barden and Grimaldi, is described for a new and uniquely specialized species, Z. tonsora Barden and Grimaldi n.sp., preserved in Cretaceous amber from Myanmar. The amber is radiometrically dated at 99 myo. Zigrasimecia is closely related to another basal genus of ants known only in Burmese and French Cretaceous amber, Sphecomyrmodes Engel and Grimaldi, based in part on the shared possession of a comb of pegs on the clypeal margin, as well as mandible structure. Highly specialized features of Zigrasimecia include extensive development of the clypeal comb, a thick brush of setae on the oral surface of the mandibles and on the labrum, and a head that is broad, flattened, and which bears a crown of blackened, rugose cuticle. Mouthparts are hypothesized to have functioned in a unique manner, showing no clear signs of dentition representative of "chewing" or otherwise processing solid food. Although all ants in Burmese amber are basal, stem-group taxa, there is an unexpected diversity of mouthpart morphologies and probable feeding modes.

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

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 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)

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.

Insight into fossil fauna of terrestrial Parasitengona mites (Trombidiformes: Prostigmata) – The first representatives of Erythraeina Welbourn, 1991 and Trombidiina Welbourn, 1991 in Burmese amber

Summary A second camel spider (Arachnida, Solifugae) from the Late Cretaceous (c. 99 Ma) Burmese amber of Myanmar is described. It is referred to Cushingia cf. ellenbergeri Dunlop et al., 2015. This extinct species is of uncertain familial affinities, but noticeable are similarities to the modern genus Dinorhax Simon, 1879, which is today the only camel spider recorded from Southeast Asia. The present specimen differs from the original holotype in some characters. For example, the number of malleoli strongly suggests that the present specimen is a juvenile, and thus potentially provides valuable data about intraspecific variation within this fossil species.

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.

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

The oldest armoured harvestman (Arachnida: Opiliones: Laniatores), from Upper Cretaceous Myanmar amber