New subfamily of ambrosia beetles (Coleoptera: Platypodidae) from mid-Cretaceous Burmese amber

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 species and diagnostic characters for Panguidae (Hymenoptera, Panguoidea)

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

Re-appraisal of two fossil Frullaniaceae species (Marchantiophyta, Porellales) from the mid-Cretaceous Burmese amber

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

Four fossil ticks (Arachnida: Parasitiformes: Ixodida) are described from mid-Cretaceous (ca. 100 Ma) Burmese amber of Myanmar.Ixodes antiquorumsp. nov. (Ixodidae) is the first Mesozoic record ofIxodesand the oldest representative of the most species-rich extant tick genus. Its affinities appear to lie with modern Australian forms, consistent with the hypothesis that Burmese amber hosted Gondwanan faunal elements. Even more remarkable isKhimaira fossusgen. et sp. nov. which combines a body resembling that of a soft tick (Argasidae) with a basis capitulum more like that of a hard tick (Ixodidae). We refer it to Khimairidae fam. nov. as a possible transitional form between the two main families of ticks alive today. Another member of the extinct Deinocrotonidae is described asDeinocroton copiasp. nov., while the first described adult female forCornupalpatum burmanicumis associated with a dinosaur feather barb.

A new genus and species of Elcanidae (Insecta: Orthoptera) is described from mid-Cretaceous Burmese amber. Elcanonympha diana gen. et sp. nov. is known from a single, complete nymph and is distinguished from other elcanids by the pronotum cut by a single transverse sulcus, the dorsal margin of the metafemoral genicula with a row of prominent apical denticles, and the distal third of the metabasitarsus bearing a row of apically directed scale-like spines on the ventral surface.

Odonatans are rare as amber inclusions, but quite diverse in Cretaceous Burmese amber. In the past two years, over 20 new species have been found by the present authors after studying over 250 odon...

Brachypsectridae is a species-poor elateroid family containing two extant genera with a disjunct distribution range spanning the Nearctic, Palaearctic, Oriental, and Australian regions. Here we describe a second Texas beetle from mid-Cretaceous Burmese amber, Hongipsectra electrella gen. et sp. nov. The new genus can be distinguished from all hitherto known brachypsectrids by the 11-segmented sexually dimorphic antennae with antennomeres 6–10 bilamellate in males and serrate in females, pronotum with a pair of posterolateral carinae and an M-shaped notch in the posterior margin for the reception of a cordiform scutellum. The present discovery adds a fourth genus and eleventh species to Brachypsectridae. Given that two of the known Texas beetle genera are from the Cretaceous Burmese amber, the family probably have been much more widespread and diverse in the Mesozoic than it is today. A key to the extant and fossil genera of Brachypsectridae is provided, along with a list of fossil species.

We describe two caddisflies from mid-Cretaceous Burmese amber, with unusual hair fan modifications on the legs: Cretaganonema dongi nov. gen. et nov. sp. (Calamoceratidae) possesses greatly elongated hind legs with hairtufts at the tarsal apex; Cretahelicopsyche liuyani nov. gen. et nov. sp. (Helicopsychidae) bears a hair-fan on the tibia of the middle legs. The functions of the leg modifications in the fossils are unknown, possibilities are briefly discussed. The species described here represent the third known calamoceratid and the first helicopsychid from the Cretaceous, thus increasing our scant knowledge on the Cretaceous Trichoptera biota and their adaptations.

A new spiny reticulated beetle (Coleoptera: Cupedidae) from Cretaceous Burmese amber

In this article, a new genus with four new species of the family Oedemeridae from mid- Cretaceous Burmese amber are described and illustrated. Ditysparedrus n. gen. differs from other genera of the subfamily in the short ventrite I and pyriform elytra. Key to new species of this genus is given.

The mid-Cretaceous Burmese amber was extensively colonized by marine epibiont communities, including pholadids, corals, oysters, and serpulids. In this study, we report a diverse array of marine organisms that adhered to the amber, forming epibiont communities. Notably, cheilostome bryozoans are documented for the first time as an additional group of colonizing organisms on Burmese amber. These bryozoans formed extensive sheets and proliferated on the amber surface, often encrusting other epilithic taxa such as serpulids and oysters. The encrusting organisms exhibited significant marginal competitive interactions, including overgrowth and stand-off behaviours, as they competed for space. These hard substrate communities display trends similar to those observed in extensive soft substrate communities, resembling many counterparts in both modern and geological records. This discovery provides valuable insights into the composition of epibionts, the sequence of their colonization, and their ecological interactions on Burmese amber. Furthermore, this study indicates that the establishment of epibiont communities on Burmese amber occurred later than the entrapment of bioinclusions but earlier than the deposition of nearshore gravel strata.

A camel spider from Cretaceous Burmese amber