Kachin Amber Research Articles

Three new lithobiomorphan centipede specimens from mid-Cretaceous Myanmar amber, a clue on the geological record of Lithobiomorpha

Chilopoda, part of Myriapoda, is a species-rich group of ~3300 formally described species. Yet, the phylogenetic relationship of centipedes is not fully clear, and the scarceness of their fossil record, compared to the closely related Diplopoda, is a major challenge for understanding their evolutionary history. Within Chilopoda, Lithobiomorpha is one of the most problematic concerning its fossil record, so far restricted to the Cenozoic (~40 mya) and with a single lithobiomorphan-like specimen from Kachin amber (~100 mya). Here, we report three new exceptionally well-preserved lithobiomorphan specimens from Myanmar amber (~100 mya). These represent the first report of oldest representatives of Henicopidae from the Cretaceous, and with this the oldest definite record of Lithobiomorpha. Two specimens have ten pairs of walking legs (stage IV), and one has a fully developed trunk. These specimens are similar in many aspects to the extant group of Henicopidae and, more precisely, to Lamyctes Meinert, 1868. The specimens seemingly lack ocelli, exhibit ~14 (stage IV) and 24 antenna articles, have 2+2 coxosternite teeth, and present tooth-like setae on their coxosternite margins (=porodont). The fully developed specimen possesses a tibial spinose projection on each tibia of legs 1–11, a blunt projection on the tibia of leg 12, and undivided tarsi on their legs 1–12. With the finding of these specimens, we expand the fossil record of Lithobiomorpha significantly.

Three new species of Multistria from mid-Cretaceous amber of northern Myanmar (Hemiptera: Fulgoromorpha: Mimarachnidae)

The extinct planthopper family Mimarachnidae is well represented in mid-Cretaceous Kachin amber of northern Myanmar. In this study, three new species of mimarachnid planthoppers are described and illustrated from Kachin amber, all belonging to the genus Multistria Zhang, Yao & Pang, 2021. The new species, Multistria irregularis sp. nov., M. juanae sp. nov., and M. fionae sp. nov., are primarily distinguished from each other mostly by tegminal characters, such as the branching pattern of the secondary veinlet meshwork, venation, and the colour patterns, as well as differences in head. The tegminal diagnostic characters of Multistria are briefly examined.

The first record of disruptive colouration in holometabolan larvae from about 100 million-year-old Kachin amber is a lacewing larva with dark stripes on the legs

The first record of disruptive colouration in holometabolan larvae from about 100 million-year-old Kachin amber is a lacewing larva with dark stripes on the legs

A new species of genus Probaisselcana (Orthoptera: Elcanidae) from mid-Cretaceous Kachin amber of northern Myanmar

A new species of genus Probaisselcana (Orthoptera: Elcanidae) from mid-Cretaceous Kachin amber of northern Myanmar

An Enigmatic Cretaceous Beetle in Kachin Amber With Tentative Affinities to Pythidae (Coleoptera: Tenebrionoidea).

Tenebrionoids are not uncommon in late Mesozoic ambers, but their paleodiversity remains poorly explored, partly due to the insufficiently defined families of the extant fauna. Here, we describe and illustrate a new tenebrionoid beetle from mid-Cretaceous Kachin amber, Glyphonotum hsiaoi gen. et sp. nov., which exhibits an unusual form of pronotal sulcus and tarsi. Based on morphological comparison and phylogenetic analyses, we tentatively place Glyphonotum in the extant family Pythidae, representing the first Mesozoic fossil of this family.

New genus of falsiformicid wasps (Hymenoptera, Vespoidea: Falsiformicidae) with brachypterous male from middle Cretaceous Kachin amber in Myanmar

Falsiformicidae is a poorly known extinct family of aculeate wasps. It is known only as inclusions in various Cretaceous ambers. Brachypterous male Falsiformix pedestris Zhang and Rasnitsyn gen. et sp. nov. is described in the family Falsiformicidae based on a unique fossil from the middle Cretaceous Kachin amber. Occurrence and meaning of the male flightlessness in Hymenoptera is discussed. A combination of the flightless males with flying females occurs when mating takes place shortly after the eclosion, before adults disperse from confined space where they developed. An equally rare even if less exotic strategy with males and females both being flightless depends on the female pedestrian habits rather than on the pre-dispersal mating. Wide spatial (Angara Land, Laurussia Land and Gondwana Land) and narrow temporal distribution (Cenomanian and Turonian ages only) indicate Falsiformicidae as a possibly important stratigraphical indicator.

Two new species of the extinct subfamily Alitrepaninae (Coleoptera: Bostrichidae) from the Upper Cretaceous (Cenomanian) Kachin amber in northern Myanmar

Bostrichidae is commonly referred to as auger beetles. Of them, the subfamily Alitrepaninae is the only extinct subfamily of the family Bostirichidae. Here, based on detailed characterization analysis and comparisons with other species of the Alitrepaninae subfamily, we identified two new species of the genus Poinarinius in well-preserved Upper Cretaceous (Cenomanian) amber from northern Myanmar, along with a key to Poinarinius genus. Our new species can be clearly distinguished through the feature of head visible from above, dorsal plate of the pronotum, elytra performance and length of each tarsomere. Our study deepens insight into the adaptive evolution of the subfamily Alitrepaninae regarding feeding habits and resistance, as well as discussed the ecological habits of this taxon in Cretaceous. In summary, our findings will contribute to the understanding of the diversity and evolutionary origin of Bostirichidae.

New mid‐Cretaceous macrothelids showing a similar living mode to extant Macrothelidae (Araneae: Mygalomorphae)

AbstractFive new spider fossils of the family Macrothelidae (Araneae: Mygalomorphae) are described from mid‐Cretaceous Kachin amber, Myanmar. A new genus Acanthomacrothele gen. nov. is established for three new species: Acanthomacrothele pauciverrucae sp. nov., Acanthomacrothele geminata sp. nov., and Acanthomacrothele longicaudata sp. nov. Both male and female specimens of A. pauciverrucae sp. nov. are described, representing a rare case of a fossil spider with both sexes known. We also describe an unidentified juvenile of Macrothelidae to document different developmental stages of Cretaceous species. To test the phylogenetic position of the new fossils, we undertook phylogenetic analyses using both topology‐unconstrained and topology‐constrained methods. Our analyses supported the placement of Acanthomacrothele gen. nov. in Macrothelidae, although its phylogenetic relationship to other genera of Macrothelidae differed among different analytical methods. The fossils documented here have elongated, widely spaced posterior lateral spinnerets, compact rectangular group of eyes on a tubercle, and more spines on male tibia of anterior legs than female, similar to extant macrothelids, suggesting that they probably have similar retreat construction behavior, habitat preference, and mating position to their living relatives.

A New Genus and Species of Dinoderinae Subfamily (Coleoptera: Bostrichidae) from Mid-Cretaceous Kachin Amber of Northern Myanmar

A New Genus and Species of Dinoderinae Subfamily (Coleoptera: Bostrichidae) from Mid-Cretaceous Kachin Amber of Northern Myanmar

A new burmaeshnid dragonfly (Odonata, Anisoptera, Aeshnoptera) from mid-Cretaceous Kachin amber, north Myanmar.

The fifth burmaeshnid dragonfly, Neoaeschna kachinensis gen. et sp. nov., is described based on the basal parts of a pair of fore- and hindwings from Kachin amber, indicating that Burmaeshnidae Huang, Cai, Nel & Bechly, 2017 is the most diverse family of true dragonflies in Kachin amber. The new dragonfly differs from the other genera in having one row of cells present in the postdiscoidal area basal of the midfork, the trigonal planate being obsolete, and one or two crossveins present basal of the CuP-crossing in the submedian space.

Archaic sap beetles (Coleoptera: Nitidulidae) as Cretaceous pollinators

Kateretidae have been considered a family of generalist (as a whole) fossil pollinator beetles after the description of many fossil species in this taxon from the Upper Cretaceous Kachin amber together with pollen grains from their host plant. But the placement of this group of fossils in Kateretidae remained tentative because some definite characters to be observed in the fossils (e.g., maxillae and genitalia) were almost inaccessible by conventional methods. A recent paper proposed to include most of these fossil “kateretid” genera and species in the newly erected family Apophisandridae among Cucujoidea. The description of the two new genera and species Diopsiretes corniger gen. et sp. nov. and Cornuturetes elaphus gen. et sp. nov. from the same deposit, and the use of synchrotron light to describe the first cited species, combined with the examination of new photographic material of the type of Apophisandra ammytae, allowed us to better define this peculiar group of fossils. We attempt to demonstrate their placement in an extinct basal subfamily in Nitidulidae (Apophisandrinae stat. nov.), with some partially shared plesiomorphic characters of both Kateretidae and Nitidulidae: Epuraeinae, and with a series of convergent morphological characters also shared with other extant anthophagous nitidulids including Nitidulinae: Mystropini and Meligethinae. As such, all the fossil species from the Kachin amber initially described in Kateretidae and recently moved to Apophisandridae, should be included in Nitidulidae: Apophisandrinae.

Discovery of new brown lacewings from the mid-Cretaceous Kachin amber highlights the Cretaceous diversity of Hemerobiidae (Insecta: Neuroptera)

Two new genera and two new species of the lacewing family Hemerobiidae, Mischemerobia yumini Chen, Zhuo & Liu gen. et sp. nov. and Pararchaeomegaloma suzheni Chen, Zhuo & Liu gen. et sp. nov., are described from the mid-Cretaceous Kachin amber in northern Myanmar. Mischemerobia Chen, Zhuo & Liu gen. nov. differs from the other genera by the complex configuration of forewing recurrent humeral veinlet, the presence of two forewing ORBs, and the forewing MP distally fused with CuA. Pararchaeomegaloma Chen, Zhuo & Liu gen. nov. can be distinguished from the other genera by the presence of only one forewing ORB, with posterior most branch deeply forked, and the forewing MP forked near wing margin. Our finding provides new evidence for understanding the Cretaceous diversity and early diversification of brown lacewings.

Cretabaltoraea volsella gen. et sp. nov. (Coleoptera: Nitidulidae) from Cretaceous Kachin amber and its relationship with Eocene Baltoraea (Coleoptera: Nitidulidae)

Here we describe Cretabaltoraea volsella Peris, Jelínek & Audisio gen. et sp. nov. of the family Nitidulidae (Coleoptera). As implied by its generic name, the new species is described after a fossil specimen preserved in the Upper Cretaceous Kachin amber from northern Myanmar. This new species is rather similar to the two fossil nitidulid species of Baltoraea Kurochkin & Kirejtshuk, 2010, previously described from the Eocene Baltic amber. The comparison between this group of fossils and the study of Baltoraea simillima Kurochkin & Kirejtshuk, 2010 using CT-scanning suggest that Cretabaltoraea volsella gen. et sp. nov. and the two Baltoraea species should be placed in the extinct Apophisandrinae, a basal subfamily of Nitidulidae which until now only includes a group of Cretaceous fossils from the Kachin amber, described as ancient pollinators of both gymnosperms and basal angiosperms.

A new species of Hadraulacus Li, Shih & Ren, 2023 (Hymenoptera: Praeaulacidae) from mid-cretaceous Kachin amber

A new praeaulacid species, Hadraulacus liae sp. nov., is described and illustrated based on a female specimen from mid-Cretaceous Kachin amber. This new species reinforces the validity of key diagnostic characters used to define the genus Hadraulacus Li, Shih & Ren, 2023, such as the absence of the 2rs-m crossvein in the forewing. However, it also demonstrates that some traits previously considered diagnostic for the genus, like the tibial spur formula (1-1-2), represent mere interspecific variation and have limited taxonomic value. While the discovery of this species adds to the known diversity of Praeaulacidae in the mid-Cretaceous Kachin amber, it also highlights that the diversity of the subfamily Praeaulacinae within this biota remains significantly underestimated.

The third mesomegaloprepid damselfly from the mid-Cretaceous Kachin amber (Odonata: Zygoptera)

Mesomegaloprepus liea sp. nov., the third species of the family Mesomegaloprepidae, is described from mid-Cretaceous Kachin amber. To date, this family is only known from the Cretaceous Burma paleo-island (also referred to as the Burmese terrane), although it probably originated in the Gondwana continent during the early Cretaceous. It possibly knew a phenomenon of endemism diversification.

An unusual Cretaceous beetle with affinity to Anamorphidae (Coleoptera: Coccinelloidea)

Coccinelloid beetles have a sparse fossil record in the Mesozoic. Here, we describe and illustrate an unusual coccinelloid beetle, Yassibum yoshitomii gen. et sp. nov., from mid-Cretaceous Kachin amber. Yassibum stands out within the Coccinelloidea due to its notched profemora and the presence of antennal grooves on the elytral epipleura. Based on our phylogenetic analyses, we suggest that Yassibum is most likely related to the family Anamorphidae. The alternative placements are critically evaluated based on our comparison of the morphology.

Comment on «Microlepia burmasia sp. nov., a new fern species from mid-Cretaceous Kachin amber of norther Myanmar (Dennstaedtiaceae, Polypodiales) » [Cretaceous Research 143 (2023) 105417]

“Microlepia” burmasia is a recently described eupolypod fern from mid-Cretaceous Burmese amber by Long et al. (2023). According to the latest taxonomic system of ferns, “M.” burmasia belongs to the Dennstaedtiaceae, Polypodiales. Discovery of “M.” burmasia means the origin of the genus can be pushed back by at least 99 Ma. The specimen provides new information on the floral diversity of the Kachin amber forest and new insight to the origin of Microlepia and Dennstaedtiaceae (Long et al., 2023). However, a careful review of the illustrations and descriptions of the sporangium and spore in the manuscript showed that the polar axial length and equatorial length of the spores were three to six times that of the spores in the extant and fossil Microlepia species, and nearly the same size as the sporangium, and the sporangium morphology and spore size are very different from that of any other polypod species. In an effort to further investigate the systematic position of “Microlepia” burmasia, its spore morphology and size were compared with those of the entire Dennstaedtiaceae and to all fern families possessing trilete spores. Comparative analyses reveal some similarities only with Anemia subgenus Coptophyllum (Anemiaceae). However, the sporangium morphology of “Microlepia” burmasia does not align with Anemiaceae. Given these discrepancies, it is recommended to reconsider the placement of “Microlepia” burmasia within Polypodiales and its systematic placement needs further study.

The evolutionary history and biogeographical distribution of the Mesozoic relic genus Chilelimnophila (Diptera, Limoniidae)

Abstract This study presents novel findings that expand our understanding of the evolutionary history and diversity of the Limoniidae subfamily Limnophilinae, with a specific focus on the relict genus Chilelimnophila. The family Limoniidae is well documented in the fossil record, with many species considered relicts in the modern fauna. Our study is based on the discovery of the first fossil specimens of Chilelimnophila in both Cretaceous Spanish and Kachin amber. The new materials have allowed the establishment of a new subgenus Chilelimnophila (Ribeironia) Krzemiński, Kania-Kłosok et Arillo, subgen. nov. and three new species: Chilelimnophila (Ribeironia) amorimi Krzemiński, Kania-Kłosok et Arillo, sp. nov., Chilelimnophila (Chilelimnophila) wangi Krzemiński, Kania-Kłosok et Arillo, sp. nov., and Chilelimnophila (Chilelimnophila) parva Krzemiński, Kania-Kłosok et Arillo, sp. nov. This research also significantly extends the stratigraphic range of the genus, providing evidence of its existence dating back to the Early Cretaceous period. The morphology and phylogenetic analysis of Chilelimnophila and related genera within the Limoniidae subfamily Limnophilinae provide valuable insights into the evolutionary relationships of these organisms. Furthermore, our research highlights the unique environmental conditions of Cretaceous Spanish and Kachin amber formations, which differ significantly from the current habitat of these organisms.

A new Darwin wasp (Ichneumonidae: Novichneumoninae) from mid-Cretaceous Kachin amber

A new Darwin wasp (Ichneumonidae: Novichneumoninae) from mid-Cretaceous Kachin amber

First female of Eomeropidae (Mecoptera) from Kachin amber sheds light on morphology and environmental preferences of eomeropids in the Cretaceous

First female of Eomeropidae (Mecoptera) from Kachin amber sheds light on morphology and environmental preferences of eomeropids in the Cretaceous