New tribes of the superfamily Curculionoidea (Coleoptera) in Burmese amber

Two new tribes in the Curculionoidea are described as the Anchineini Poinar and Legalov, n. trib. (Ithyceridae: Carinae) and Paleocryptorhynchini Poinar and Legalov, n. trib. (Curculionidae: Erirhininae). The genus Anchineus Poinar and Brown, 2009, n. placem. is transferred from the subfamily Curculioninae of the family Curculionidae to the subfamily Carinae of the family Ithyceridae. The genus Paleocryptorhynchus Poinar, 2009, n. placem. is transferred from the subfamily Cryptorhynchinae to the subfamily Erirhininae. The placement of the genus Mesophyletis Poinar, 2006 in the family Ithyceridae was confirmed. http://www.zoobank.org/urn:lsid:zoobank.org:pub:0C0039DD-7BC6-4A54-9282-F43C5606D68B     

Burmese amber: evidence of Gondwanan origin and Cretaceous dispersion

Abstract

Burmese amber is an extremely important source of mid-Cretaceous plant and animal remains with over 870 species of organisms, ranging from protozoa to vertebrates, described from this source. The amber mines are located on the West Burma Block that according to geologists was originally part of Gondwana. The present study introduces some angiosperms and insects in Burmese amber whose closest extant relatives have a Gondwanan distribution and there is no previous evidence of a Laurasian distribution. Based on this evidence, it is proposed that organisms in Burmese amber represent a selection of tropical to subtropical life forms that inhabited the interconnected continents of Gondwana in the Early Cretaceous. Based on the fossil record of angiosperms and their diversity in Burmese amber, the West Burma Block could not have rafted from Gondwana to SE Asia before the Early Cretaceous.     

Paleoleishmania proterus n. gen., n. sp., (Trypanosomatidae: Kinetoplastida) from Cretaceous Burmese amber

A trypanosomatid (Trypanosomatidae: Kinetoplastida) associated with a blood-filled female sand fly in Cretaceous Burmese amber, is described in the new genus and species, Paleoleishmania proterus. The genus Paleoleishmania is established as a collective genus for digenetic fossil trypanosomes associated with sand flies. Amastigotes, promastigotes and paramastigotes are described. Paleoleishmania proterus is the first fossil kinetoplastid and provides a minimum age for the digenetic Trypanosomatidae. Its discovery indicates that vector-borne pathogens had been established by the Early Cretaceous.     

New genus of fossil apoid wasps (Hymenoptera,Apoidea) from the Cretaceous amber of Myanmar

The new genus 2Burmasphex is proposed for two fossil species, 2Burmasphex sulcatus sp. nov. and 2Burmasphex pilosus sp. nov., described from Myanmar Cretaceous amber. It exhibits many plesiomorphic features in relation to the extant Apoidea and is here provisionally allocated in the extinct family 2Angarosphecidae.     

A new genus of nemonychid weevil from Burmese amber (Coleoptera,Curculionoidea)

The first fossil nemonychid (Nemonychidae) in Burmese amber, belonging to the subfamily Rhinorhynchinae, is described and figured as Burmonyx zigrasi Davis & Engel, gen. n. and sp. n. While this specimen also comprises the first definitive record of the subfamily in the Asian continent, other compression fossils exist at least from the Yixian Formation of China and the Karatau site of Kazakhstan which may also deserve placement within this group. Although several important areas of the body are obscured by the shape and fragmented condition of the amber piece, a sufficient number of features are visible to consider adequate placement within Rhinorhynchinae, including the fairly strongly punctate elytral striae and appendiculate, nearly bifid pretarsal claws.     

Vetuformosa buckleyi n. gen., n. sp. (Ephemeroptera: Baetidae; Vetuformosinae n. subfam.), a new subfamily of mayflies in Early Cretaceous Burmese amber

A new subfamily, genus and species of mayflies, Vetuformosa buckleyi n. gen., n. sp. (Ephemeroptera: Baetidae; Vetuformosinae n. subfam.), are described as the first representative of the family Baetidae from Early Cretaceous Burmese amber. The female fossil is characterised by unusually long antennae, two pairs of gonostyli representing a primitive appendiculate ovipositor, sensory patches on sternites 8, 9 and 10, protuberances on the egg chorion and the absence of a costal projection on the hind wing. This is the first documentation of such long antennae and a primary ovipositor in the Ephemeroptera.     

Burmaphlebia reifi gen. et sp. nov., the first anisozygopteran damsel-dragonfly (Odonata: Epiophlebioptera: Burmaphlebiidae fam. nov.) from Early Cretaceous Burmese amber

A new family, genus and species of damselfly, Burmaphlebia reifi gen. et sp. nov. (Burmaphlebiidae fam. nov.), is described as the second fossil odonate from Early Cretaceous Burmese amber. Its phylogenetic position is discussed and the fossil is attributed to a new family at the base of the anisozygopteran grade, probably closely related to the Recent relict group Epiophlebiidae. It is the first record of the ‘anisozygopteran’ grade from amber and the smallest known representative of this group.http://zoobank.org/6EFE7288-BD89-42F9-BFA5-804CE6B904A6     

Electraesalopsis beuteli gen.& sp.nov., the first lucanid beetle from the Cretaceous Burmese amber (Coleoptera: Scarabaeoidea)

The first stag beetle found in Cretaceous Myanmar amber,Electraesalopsis beuteli Bai,Zhang & Qiu gen.& sp.nov.,is described and illustrated on the basis of one well-preserved specimen.This specimen provides more detailed morphological characters compared with compression fossils,e.g.the highly setose antennae and the punctured elytra.However,the systematic position of the new genus is still questionable and we provisionally place it as Lucanidae incertae sedis.In addition,the discovery ofElectraesalopsis Bai,Zhang & Qiu gen.nov.also indicates that there is very high biodiversity in Burmese amber.The new discoveries in future studies on Burmese amber will provide more information and improve our knowledge of biogeography and early evolution of the Lucanidae.     

The early evolution of feathers: fossil evidence from Cretaceous amber of France

The developmental stages of feathers are of major importance in the evolution of body covering and the origin of avian flight. Until now, there were significant gaps in knowledge of early morphologies in theoretical stages of feathers as well as in palaeontological material. Here we report fossil evidence of an intermediate and critical stage in the incremental evolution of feathers which has been predicted by developmental theories but hitherto undocumented by evidence from both the recent and the fossil records. Seven feathers have been found in an Early Cretaceous (Late Albian, ca 100 Myr) amber of western France, which display a flattened shaft composed by the still distinct and incompletely fused bases of the barbs forming two irregular vanes. Considering their remarkably primitive features, and since recent discoveries have yielded feathers of modern type in some derived theropod dinosaurs, the Albian feathers from France might have been derived either from an early bird or from a non-avian dinosaur.     

Protoresinacarus brevipedis gen. n., sp. n. from Early Cretaceous Burmese amber: the first fossil record of mites of the Family Resinacaridae (Acari: Heterostigmata: Pyemotoidea)

A new genus and species of mites, Protoresinacarus brevipedis gen. n., sp. n. (Acari: Heterostigmata: Pyemotoidea), is described from Early Cretaceous Burmese amber. This represents the first fossil record of a member of the family Resinacaridae. It is represented by 21 phoretic females adjacent to an adult mantidfly (Neuroptera: Mantispidae). This is the first record of phoresy of pyemotid mites on members of the insect order Neuroptera. The fossil mites differ from extant members of the family in possessing distinctly shorter legs I, which do not reach beyond the apex of the gnathosoma, and by the long setae v ₁, v ₂ and c ₂.     

The first cupedine beetle from Burmese amber (Coleoptera: Cupedidae)

A rare archaic beetle, Mallecupes qingqingae gen. et sp. n., (Insecta: Coleoptera: Archostemata: Cupedidae) is described from mid-Cretaceous Burmese amber. It shows affinity with Paracupes found in South America today and ‘Paracupes’ found in North America during the Cretaceous. Archostemata are diverse in Burmese amber.     

Emergence of a superradiation: pselaphine rove beetles in mid‐Cretaceous amber from Myanmar and their evolutionary implications

Pselaphinae is an exceptionally species‐rich, globally distributed subfamily of minute rove beetles (Staphylinidae), many of which are inquilines of social insects. Deducing the factors that drove pselaphine diversification and their evolutionary predisposition to inquilinism requires a reliable timescale of pselaphine cladogenesis. Pselaphinae is split into a small and highly plesiomorphic supertribe, Faronitae, and its sister group, the ‘higher Pselaphinae’ – a vast multi‐tribe clade with a more derived morphological ground plan, and which includes all known instances of inquilinism. The higher Pselaphinae is dominated by tribes with a Gondwanan taxonomic bias. However, a minority of tribes are limited to the Nearctic and Palearctic ecozones, implying a potentially older, Pangaean origin of the higher Pselaphinae as a whole. Here, I describe fossils from mid‐Cretaceous (～99 million years old) Burmese amber that confirm the existence of crown‐group higher pselaphines on the Eurasian supercontinent prior to contact with Gondwanan landmasses. Protrichonyx rafifrons gen. et sp.n. is placed incertae sedis within the higher Pselaphinae. Boreotethys gen.n. , erected for B. grimaldii sp.n . and B. arctopteryx sp.n. , represents an extinct sister taxon and putative stem group of Bythinini, a Recent tribe with a primarily Holarctic distribution. The Laurasian palaeolocality of the newly described taxa implies that higher pselaphines are indeed probably of Jurassic, Pangaean extraction and that the Laurasian‐Gondwanan tribal dichotomy of this clade may have developed vicariantly following Pangaean rifting. Higher pselaphines probably predate the earliest ants. Their physically protective morphological ground plan may have been a preadaptation for myrmecophily when ants became diverse and ecologically ubiquitous, much later in the Cenozoic. This published work has been registered in ZooBank, http://zoobank.org/urn:lsid:zoobank.org:pub:36E3FE2A-B947-422D-89CA-0EF43B99C382 .     

Heinrichsia cheilanthoides gen. et sp. nov., a fossil fern in the family Pteridaceae (Polypodiales) from the Cretaceous amber forests of Myanmar

Divergence time estimates suggest that most clades constituting the fern family Pteridaceae (Polypodiales) were in existence by the Early Cretaceous. However, fossil evidence to corroborate this remains exceedingly rare. Burmese amber is an important source of new information on the radiation of derived fern lineages during the Cretaceous Terrestrial Revolution. This study describes Heinrichsia cheilanthoides gen. et sp. nov., a fern with suggested affinities to Pteridaceae, based on fertile foliage portions preserved in Early Cretaceous (~100 Ma) amber from Myanmar. Heinrichsia cheilanthoides is characterized by a pinnate‐pinnatifid frond that bears apical, marginal sori protected by a pseudoindusium. Sporangia are of the polypod type and contain tetrahedral‐globose, trilete spores with a striate perine. This discovery provides a new calibration point to test and refine molecular clock‐based concepts of the evolutionary history of the Pteridaceae. Heinrichsia cheilanthoides further substantiates the suggestion that the Cretaceous forests of Myanmar were home to a rich fern flora.     

The hatching mechanism of 130‐million‐year‐old insects: an association of neonates,egg shells and egg bursters in Lebanese amber

Hatching is a pivotal moment in the life of most animals. Diverse chemical, behavioural and mechanical methods have evolved in metazoans to break the egg membranes. Among them, many arthropod and vertebrate embryos hatch using ephemeral, frequently convergent structures known as egg bursters. However, the evolutionary processes by which hatching mechanisms and related embryonic structures became established in deep time are poorly understood due to a nearly complete absence from the fossil record. Herein we describe an exceptional c. 130‐million‐year‐old association in Lebanese amber composed of multiple neonate green lacewing larvae, Tragichrysa ovoruptora gen. et sp. nov. (Neuroptera, Chrysopoidea), and conspecific egg remains. Egg bursters with a serrated blade bearing a short process are attached to three longitudinally split egg shells. Embryos of extant green lacewing relatives (Chrysopidae) utilize this egg burster morphotype to open a vertical slit on the egg, after which the burster is moulted and left joined to the empty egg shell. Additionally, the new larval species has extremely elongate dorsal tubercles, an adaptation to carry exogenous debris for protection and camouflage also known from other Cretaceous chrysopoids but absent in modern relatives. The present discovery demonstrates that the hatching mechanism of modern green lacewings was established in the chrysopoid lineage by the Early Cretaceous and proves through direct fossil evidence how some morphological traits related to hatching and linked behaviours, at least in insect embryos, have been subject to a high degree of evolutionary conservatism.     

A new species of Zorotypus (Insecta,Zoraptera, Zorotypidae) and the earliest known suspicious mating behavior of Zorapterans from the mid‐cretaceous amber of northern Myanmar

A new species of the insect order Zoraptera, Zorotypus pusillus, sp. n., is described and illustrated based on two ill‐preserved specimens in mid‐Cretaceous amber from the Hukawng Valley in northern Myanmar. Compared with known extinct zorapterans, the new species possesses eight‐segmented antennae and can be readily distinguished from all other extinct and recent members of the order in the presence of a shallow groove connecting two antennal sockets and by unique spination of the metafemur and metatibia. The earliest known suspicious mating behavior of Zoraptera, the intromittent organ of the fossil zorapterans, the egg, and the earliest known basal plate of the male genitalia are briefly discussed. The genitalia of new species are used as an intromittent organ in the majority of mating patterns among living zorapterans. The mating patterns (a copula is performed by males and females) of the most extant species have been present since at least the mid‐Cretaceous. A shared similar aedeagal structure in the new species and in the most extant species suggests an analogous mating behavior.     

Predatory behaviour of the social orb-weaver spider,Geratonephila burmanica n. gen., n. sp. (Araneae: Nephilidae) with its wasp prey,Cascoscelio incassus n. gen., n. sp. (Hymenoptera: Platygastridae) in Early Cretaceous Burmese amber

The present work shows predatory behaviour of the social orb-weaver spider, Geratonephila burmanica n. gen., n. sp. (Araneae: Nephilidae) against a parasitic wasp, Cascoscelio incassus n. gen., n. sp. (Hymenoptera: Platygastridae) in Early Cretaceous Burmese amber. An adult male and juvenile of G. burmanica in the same web provide the first fossil evidence of sociality in spiders. The spider is characterised by a pedipalp with a hemispherical tegulum, a subtegulum curved at 180°and an apical spiralled embolas-conductor bent approximately 45°at midpoint. The male wasp is characterised by an ocellar tubercle, 12-segmented antennae with a feeble five-segmented clava, thick sensilla trichodea curvata with rounded ends on the claval antennomeres, a short uncus, a short post-marginal vein and a nebulose radial sector (Rs) vein extending from the uncus to the costal margin of the forewing. This is the first fossil evidence of spider sociality and a fossil spider attacking prey trapped in its web.     

Palaeoecology of the mid‐Cretaceous siphonate bivalve genus Goshoraia (Mollusca,Veneridae) from Japan

Abstract: The mid‐Cretaceous bivalve Goshoraia Tamura, 1977, endemic to Japan, is an early example of shallow‐marine siphonate bivalves of the family Veneridae Rafinesque, 1815. Three species, including one new, are here described: Goshoraia minor Tashiro and Kozai, 1989 (Aptian), G. crenulata (Matsumoto, 1938; Albian–lower Cenomanian) and G. maedai sp. nov. (middle to ?upper Cenomanian). The habitats of Goshoraia have been extensively compared with those of common Cretaceous, nonsiphonate burrowers, such as trigoniids, which range from tidal flat and shoreface to shelf environments. Depth of burial, which can be estimated from the extent of the pallial sinus, increases from the ancestral G. minor to its descendants G. crenulata and G. maedai sp. nov., documenting that the ability to burrow within this genus improved in time. These morphological and palaeoecological changes may be related to the Mesozoic marine revolution during the mid‐Cretaceous.     

Genome‐wide set of SNPs reveals evidence for two glacial refugia and admixture from postglacial recolonization in an alpine ungulate

Past glaciation events have played a major role in shaping the genetic diversity and distribution of wild sheep in North America. The advancement of glaciers can isolate populations in ice‐free refugia, where they can survive until the recession of ice sheets. The major Beringian refugium is thought to have held thinhorn sheep (Ovis dalli) populations during times of glacial advance. While isolation in the major refugium can account for much of the genetic and morphological diversity seen in extant thinhorn sheep populations, mounting evidence suggests the persistence of populations in smaller minor refugia. We investigated the refugial origins of thinhorn sheep using ~10 000 SNPs obtained via a cross‐species application of the domestic sheep ovine HD BeadChip to genotype 52 thinhorn sheep and five bighorn sheep (O. canadensis) samples. Phylogenetic inference revealed a distinct lineage of thinhorn sheep inhabiting British Columbia, which is consistent with the survival of a group of thinhorn sheep in a minor refugium separate from the Beringian refugium. Isolation in separate glacial refugia probably mediated the evolution of the two thinhorn sheep subspecies, the white Dall's sheep (O. d. dalli), which persisted in Beringia, and the dark Stone's sheep (O. d. stonei), which utilized the minor refugium. We also found the first genetic evidence for admixture between sheep from different glacial refugia in south‐central Yukon as a consequence of post glacial expansion and recolonization. These results show that glaciation events can have a major role in the evolution of species inhabiting previously glaciated habitats and the need to look beyond established refugia when examining the evolutionary history of such species.