Burmostrichus brunneus gen. nov., sp. nov. from Mid-Cretaceous Burmese amber, with other taxonomic notes on the family Bostrichidae (Coleoptera)

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

A new species and diagnostic characters for Panguidae (Hymenoptera, Panguoidea)

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.

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 species of the extinct family Minlagerrontidae (Insecta: Hemiptera: Cicadomorpha) from mid-Cretaceous Burmese amber

Two new genera of Apsilocephalidae from mid-Cretaceous Burmese amber

A new species of fossil cockroach, Fragosublattapectinatagen. et sp. nov., is described from mid-Cretaceous Burmese amber. The new species is assigned to the family Corydiidae based on the following combination of characters: pronotum with tubercles, tegmina obovate with smallish anal region and spinules on the antero-ventral margin of the front femur (type C1). The new species is the second reported cockroach with ramified antennae. This finding broadens the diversity of Blattodea in mid-Cretaceous Burmese amber and provides further evidence of convergent evolution for antennal structures among different insect lineages.

Predation is a major driving force for the evolution of functional forms. Avoidance of visual predators has resulted in different kinds of anti-predator defences, such as: camouflage, crypsis, disruptive coloration, and masquerade or mimesis. Camouflage is one of the forms involving shape, colouration, structure and behaviour when the visual pattern and orientation of an animal can determine whether it lives or dies. Inferring the behaviour and function of an ancient organism from its fossilised remains is a difficult task, but in many cases it closely resembles that of its descendants on uniformitarian grounds. Here we report and discuss examples of morphological and behavioural traits involving camouflage named recently as a flatoidinisation syndrome, shown by the inclusion of a planthopper in mid-Cretaceous Burmese amber. We found a new genus and species of an extinct Cretaceous planthopper family Mimarachnidae showing peculiar complex morphological adaptations to camouflage it on tree bark. Due to convergence, it resembles an unrelated tropiduchid planthopper from Eocene Baltic amber and also a modern representatives of the planthopper family Flatidae. Flattening of the body, the horizontal position of the tegmina at repose, tegmina with an undulating margin and elevated, wavy longitudinal veins, together with colouration and more sedentary behavioral traits enable these different insects to avoid predators. Our discovery reveals flatoidinisation syndrome in mid-Cretaceous Burmese amber which may provide insights into the processes of natural selection and evolution in this ancient forest.

Tihelka, E., Huang, D. & Cai, C. 4 October 2019. First false darkling beetle from mid-Cretaceous Burmese amber (Coleoptera: Melandryidae). Alcheringa 44, 169–175. ISSN 0311-5518 The false darkling beetles (Melandryidae) are a small but morphologically diverse and taxonomically problematic family belonging to the polyphagan superfamily Tenebrionoidea. The Mesozoic record of Melandryidae is sparse, with only three described species. A new genus and species, Longicrusa jaracimrmani gen. et sp. nov., is described here from the mid-Cretaceous Burmese amber (ca 99 Ma), representing the oldest false darkling beetle described to date. The modified maxillary palpi of L. jaracimrmani gen. et sp. nov. suggest that the species probably fed on fungi, and its prominent pectinate spurs indicate that the ability to jump had already developed in false darkling beetles by the mid-Cretaceous. A checklist of fossil melandryid beetles is provided. Erik Tihelka [erik.tihelka@hartpury.ac.uk], Department of Animal Science, Hartpury College, Hartpury GL19 3BE, UK; Diying Huang [dyhuang@nigpas.ac.cn], State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing, PR China; Chenyang Cai* [cycai@nigpas.ac.cn], State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, and Centre for Excellence in Life and Paleoenvironment Chinese Academy of Sciences, Nanjing 210008, PR China. *Also affiliated with: School of Earth Sciences, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK.

The first ground cricket (Orthoptera: Trigonidiidae: Nemobiinae) from mid-Cretaceous Burmese amber

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 new mid-Cretaceous fossil genus of stonefly (Plecoptera: Perlidae) from the Burmese amber

New data on embiids (Insecta: Embiodea) from mid-Cretaceous Burmese amber, with description of new genus and two new species

The diagnosis of Palaeodysagrion cretacicus Zheng et al., 2016 is revised based on the description of a new specimen from mid-Cretaceous Burmese amber. Previously, only a fragmentary wing base was known from the holotype. The new specimen shows the complete wing venation of fore- and hind wings as well as large parts of the body anatomy. The new information proves that Palaeodysagrion youlini Zheng et al., 2017 has a very different venation and does not belong to the same genus. Therefore, a new genus Pseudopalaeodysagrion gen. nov. is erected for this species. Concurring with the results of Archibald et al. (2021), the "dysagrionine" taxa from Burmese amber are transferred from Dysagrionidae to Burmadysagrionidae stat. nov.

A new sinoalid froghopper in mid-Cretaceous Burmese amber, with inference of its phylogenetic position (Hemiptera, Cicadomorpha)