New genera and species of Ripipterygidae (Orthoptera, Tridactyloidea) from mid-Cretaceous Kachin amber

New genus and species of syspastoxyelid sawflies (Insecta, Hymenoptera) from the mid-Cretaceous Kachin amber with a review of the family Syspastoxyelidae

The genus Hirsuticyclus Neubauer, Xing and Jochum, 2019 was the first record of an exceptionally preserved land snail with dense periostracal hairs from mid-Cretaceous Kachin (Burmese) amber. Here, we document four newly-discovered shells from Kachin amber, one belonging to the type species Hirsuticyclus electrum Neubauer, Xing and Jochum, 2019 and the remaining three shells belonging to a new species, Hirsuticyclus canaliculatus sp. nov. Well-preserved morphological characteristics of these two species could be clearly demonstrated under light microscopy combined with modern micro-CT scans with computer 3D reconstructions. Our new material of the type species amends the generic diagnosis based on a better-preserved shell including the peristome and operculum. The new species shows distinctive shell characteristics such as numerous spiral keels and a flaring, folded peristome interrupted by two canals. These excellently preserved fossils contribute to our understanding of the morphological diversity and evolution of these ancient members of cyclophoroids.

Earliest fossil record of Tachyporini rove beetles in mid-Cretaceous Kachin amber from northern Myanmar (Coleoptera: Staphylinidae: Tachyporinae)

A new genus and two new species of the planthopper family Mimarachnidae are described based on two specimens trapped in mid-Cretaceous (early Cenomanian) Kachin amber from northern Myanmar. Morphology maps of the tegmen and hind wing, as well as keys for identification of the new species, are provided. Our new fossils not only increase the diversity of planthoppers from the mid-Cretaceous Kachin amber deposits, but also indicate that the ScP + RA and RP may simplify and the MP terminal branches become more abundant in described mimarachnids. Wenqian Wang* [wangwenqian2@lyu.edu.cn], Yan Zheng [zhengyan536@163.com], Xiaohui Cui [cuixiaohui@lyu.edu.cn] and Jun Chen [rubiscada@sina.com], Institute of Geology and Paleontology, Linyi University, Linyi, 276000, China. De Zhuo [zhuode113@163.com], Beijing Xiachong Amber Museum, 9 Shuanghe Middle Road, Beijing 100023, China. Cihang Luo [chluo@nigpas.ac.cn], State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China.

Giants trapped in resin: new material of Sinoalidae in mid-Cretaceous Kachin amber from northern Myanmar (Insecta, Cicadomorpha)

A new genus and species of Perforissidae (Hemiptera: Fulgoromorpha) from mid-Cretaceous Kachin amber

The fossil record of stag beetles (Lucanidae), especially in Mesozoic amber, is sparse. Four additional fossil lucanids preserved in mid-Cretaceous Kachin amber from northern Myanmar are here reported. All of these species are included in the primitive subfamily Aesalinae, and have been identified as: Protonicagus mandibularissp. nov. (tribe Nicagini); Cretognathus minutissimusgen. et sp. nov. (tribe Ceratognathini); Ceratognathini gen. et sp. indet. 1 (provisional assignment); and Ceratognathini gen. et sp. indet. 2 (provisional assignment). Except for Protonicagus mandibularissp. nov., the stag beetles appear to be connected to the continent of Gondwana, as with the Kachin amber paleofauna. More interestingly, these species have significantly smaller bodies than the extant species, with three of them measuring less than 3 mm, which makes them the smallest known species of Lucanidae. This finding is congruent with a trend toward miniaturization in several unrelated lineages of Kachin amber beetles, and it shows hidden paleodiversity of stag beetles during the Cretaceous.

Two new genera and species of false click beetles are described and illustrated from mid-Cretaceous Kachin amber. Yallmoleia arriagavarelai gen. et sp. nov. differs from similar species that have basally closed lateral antennal grooves on the hypomeron primarily by the absence of elytral striae and the morphology of antennae and legs. Xanrofeurya tomaszewskae gen. et sp. nov. is distinctive among Eucnemidae from Kachin amber in having basally open lateral antennal grooves on the hypomeron, and differs from extant species with this feature by its antennal morphology. Muonabuntor grandinotalis Li et al. and Jenibuntor pusillus Muona, previously described from Kachin amber, are transferred into Euryptychus LeConte as Euryptychus grandinotalis comb. nov. and Euryptychus pusillus comb. nov. Sieglindea antiqua Muona, which was claimed to originate from Kachin amber, is instead suggested to be from Eocene Baltic amber.

The earliest fossil record of the extant rove beetle genus Phloeocharis from mid-Cretaceous Kachin amber of northern Myanmar and its biogeographic implications (Coleoptera: Staphylinidae: Phloeocharinae)

The family Pupinidae (Gastropoda: Caenogastropoda: Cyclophoroidea) from mid-Cretaceous Kachin amber

New Lineaburmops fossils (Araneae: Lagonomegopidae) with contrasting color patterns from mid-Cretaceous Kachin amber, northern Myanmar

First mid-Cretaceous nogodinid planthopper (Hemiptera: Fulgoromorpha: Fulgoroidea) from Kachin amber with an extant relative from the Neotropics

A new genus and species of family Mimarachnidae (Hemiptera: Fulgoromorpha: Fulgoroidae) from mid-Cretaceous Kachin amber, northern Myanmar

Two new members of Tridactylidae Brull, 1835 are described based on specimens found in mid-Cretaceous Kachin amber from Northern Myanmar. Duappendactylus melanocephalus gen. et sp. nov. is assigned to the family based on its two-segmented cerci and inflated mesotibia. It is similar to Birmitoxya Gorochov, 2010 by its lack of (visible) paraproctal processes and the presence of an elongated, upward-facing subgenital plate, but differs from that genus in several other aspects of its morphology. Additionally, we describe Hiemalidactylus eileenae gen. et sp. nov. based on a well preserved, presumably nymphal specimen. It is assigned to Tridactylidae based on the two-segmented cerci and the inflated mesotibia. Like the two aforementioned genera, Hiemalidactylus does not have cerciform paraproctal processes. However, this genus differs from Birmitoxya and Duappendactylus by not having an elongated subgenital plate. Instead, the paraproct is elongated and reaches almost the length of the basal segment of the cercus. These new species of Tridactylidae raise the diversity of this family known from Kachin amber to nine genera and eleven species.

The family Perlidae is a diverse group of stoneflies frequently found in Mid-Cretaceous Kachin amber from northern Myanmar. However, no detailed descriptions of genuine perlid larvae from amber specimens have been reported. In this study, the first well-preserved genuine stonefly larva from Kachin amber is described and classified within the Perlidae. Morphological analysis reveals its closest affinity to larvae of the extant genus Caroperla Kohno, 1946 (subfamily Acroneuriinae, tribe Kiotinini), yet highlights unique traits suggesting affiliation with an undescribed lineage. Phylogenetic and morphospace analyses based on larval morphology consistently recover this fossil in an intermediate phylogenetic position, raising questions about the monophyly of subfamilies and tribes within Perlidae. Notably, the specimen exhibits functional adaptations such as predatory mouthparts and chloride cell-bearing gills identical to modern Perlidae, indicating morphological stasis since the mid-Cretaceous. This discovery not only underscores the critical role of amber in preserving aquatic immature stages but also provides novel insights into the evolutionary trajectories and ecological resilience of perlid larvae in ancient freshwater ecosystems.