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.     

Diverse fossil amoebae in German Mesozoic amber

Fossil amoebae are very rare, although their evolutionary history extends back into the Proterozoic. The Cenomanian amber of Schliersee (southern Germany) is very rich in micro-organisms and contains the highest diversity of fossil freshwater rhizopods (Gymnamoebia and Testacealobosia) yet discovered. Altogether seven testate amoebae and one gymnamoebian species are recorded from this Mesozoic amber. The four newly discovered taxa described in this paper can be assigned to the extant species Centropyxis delicatula , Centropyxis hirsuta , Phryganella acropodia and Phryganella paradoxa . Over 200 individuals of Phryganella paradoxa are preserved. Together with their syninclusions, the amoebae are species of limnetic or limnetic–terrestrial microcoenoses. The presence of 100-myr-old fossils with extant representatives suggests evolutionary stasis of these freshwater amoebae. However, not all modern testacean families have been recorded from Mesozoic limnetic habitats. Our experimental studies verify that naked and testate amoebae can be embedded in resins.     

Variations of Mesozoic feathers: Insights from the morphogenesis of extant feather rachises

The rachises of extant feathers, composed of dense cortex and spongy internal medulla, are flexible and light, yet stiff enough to withstand the load required for flight, among other functions. Incomplete knowledge of early feathers prevents a full understanding of how cylindrical rachises have evolved. Bizarre feathers with unusually wide and flattened rachises, known as “rachis-dominated feathers” (RDFs), have been observed in fossil nonavian and avian theropods. Newly discovered RDFs embedded in early Late Cretaceous Burmese ambers (about 99 million year ago) suggest the unusually wide and flattened rachises mainly consist of a dorsal cortex, lacking a medulla and a ventral cortex. Coupled with findings on extant feather morphogenesis, known fossil RDFs were categorized into three morphotypes based on their rachidial configurations. For each morphotype, potential developmental scenarios were depicted by referring to the rachidial development in chickens, and relative stiffness of each morphotype was estimated through functional simulations. The results suggest rachises of RDFs are developmentally equivalent to a variety of immature stages of cylindrical rachises. Similar rachidial morphotypes documented in extant penguins suggest that the RDFs are not unique to Mesozoic theropods, although they are likely to have evolved independently in extant penguins.     

Fossil amoebae (Hemiarcherellidae fam. nov.) from Albian (Cretaceous) amber of France

Abstract: Two extraordinarily well‐preserved testate amoebae are described from Late Albian age amber from south‐western France. The specimens are attributed to a new family, the Hemiarcherellidae fam. nov., and are described as Hemiarcherella christellae gen. et sp. nov. The amoebae described herein originate from highly fossiliferous amber pieces. Based on syninclusions, Hemiarcherella christellae was a soil‐dwelling organism, probably an active bacterivore. This taxon represents the third species of testate amoebae described from mid‐Cretaceous French amber. Analysis of this fossil amoeba fauna illustrates the uniqueness of mid‐Cretaceous French amber deposits. Indeed, most amoebae found in amber have been assigned to modern species, corroborating the hypothesis of morphological stasis in different microbial lineages. However, the well‐preserved amoebae fauna found in French amber can be distinguished clearly from modern species and help us to better understand the fossil record of these organisms.     

A new Early Cretaceous snakefly (Raphidioptera: Mesoraphidiidae) from El Soplao amber (Spain

A virtually complete specimen of the family Mesoraphidiidae (Insecta: Raphidioptera) is described as Cantabroraphidia marcanoi n. gen., n. sp. It was found in early Albian amber from a new deposit named El Soplao within the Las Peñosas Fm. in northwestern Cantabria (Spain). It has been compared to all adult fossils placed in the Mesozoic family Mesoraphidiidae. Some taxonomical comments are provided, and we propose to restore the genus Yanoraphidia Ren 1995 and the combination Yanoraphidia gaoi Ren 1995 stat. rest., provisionally retained in the family Mesoraphidiidae.     

The colour of fossil feathers

Feathers are complex integumentary appendages of birds and some other theropod dinosaurs. They are frequently coloured and function in camouflage and display. Previous investigations have concluded that fossil feathers are preserved as carbonized traces composed of feather-degrading bacteria. Here, an investigation of a colour-banded feather from the Lower Cretaceous Crato Formation of Brazil revealed that the dark bands are preserved as elongate, oblate carbonaceous bodies 1-2mum long, whereas the light bands retain only relief traces on the rock matrix. Energy dispersive X-ray analysis showed that the dark bands preserve a substantial amount of carbon, whereas the light bands show no carbon residue. Comparison of these oblate fossil bodies with the structure of black feathers from a living bird indicates that they are the eumelanin-containing melanosomes. We conclude that most fossil feathers are preserved as melanosomes, and that the distribution of these structures in fossil feathers can preserve the colour pattern in the original feather. The discovery of preserved melanosomes opens up the possibility of interpreting the colour of extinct birds and other dinosaurs.     

A new genus of sphaeropsocid bark lice from the Early Cretaceous amber of Lebanon (Psocodea: Sphaeropsocidae)

A new genus and species of sphaeropsocid bark louse is described and figured from a single individual in Early Cretaceous amber from Hammana, central Lebanon. Asphaeropsocites neli gen. n., sp. n. is the second sphaeropsocid described from Lebanese amber. Like Sphaeropsocites lebanensis Grimaldi & Engel 2006, it has a basal phylogenetic position within Sphaeropsocidae, and adds evidence that these insects were once widespread and global, in the past. The new species is distinguished from related taxa, and a discussion and checklist of sphaeropsocids are provided.     

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.     

New biting midges from the Cretaceous amber of Lebanon (Diptera: Ceratopogonidae)

New Ceratopogonidae from the Early Cretaceous amber of Hammana (Central Lebanon) are studied. Five new species (Lebanoculicoides daheri sp. nov., Protoculicoides krzeminskii sp. nov., Archiaustroconops annae sp. nov., Archiaustroconops hammanensis sp. nov., and Archiaustroconops dominiakae sp. nov.) are characterized, described, illustrated, and compared with other Cretaceous taxa. New keys for species of the three genera Lebanoculioides, Protoculicoides, and Archiaustroconops, but also for all genera of Lebanese fossil biting midges, are proposed.     

Latest occurrences of the Mesozoic family Elcanidae (Insecta: Orthoptera), in Cretaceous amber from Myanmar and Spain

Mesozoic orthopterans of the family Elcanidae are reported (as nymphs) in amber, from the latest Albian-Cenomanian of northern Myanmar and the Albian of northern Spain. Four distinct new species in two new genera occur, Burmelcana longirostris n. gen, n. sp. in amber from Myanmar and Hispanelcana arilloi n. gen, n. sp., H. alavensis n. sp. and H. lopezvallei n. sp. from Spanish amber. Detailed preservation reveals the fine structure of the tibial spurs and spines that are so distinctive to Elcanidae, as well as details of the abdominal styli, cerci, tarsomeres, and mouthparts. Elcanidae and their stem group, Permelcanidae, are known from the Early Permian to the Early Cretaceous (Aptian), so the amber fossils represent the latest known occurrence of this clade.     

Two new non-biting midges from the Early Cretaceous Lebanese amber (Diptera: Chironomidae)

Abstract

Two chironomid flies, Ziadeus kamili n. gen., n. sp. and Paicheleria magnifica n. gen., n. sp., respectively attributed to the recent subfamilies Tanypodinae and Prodiamesinae, are described from the Early Cretaceous Lebanese amber. Although very old, this non-biting midge fauna was very diverse with no less than 11 genera and species. However, it was also strongly different from the recent faunas for the complete absence of the Chironominae, that is today the dominant subfamily. The development of the modern chironomid fauna occurred during the Late Cretaceous and/or the Early Paleogene, but when and how?     

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.     

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.     

A fossil brain from the Cretaceous of European Russia and avian sensory evolution

Fossils preserving traces of soft anatomy are rare in the fossil record; even rarer is evidence bearing on the size and shape of sense organs that provide us with insights into mode of life. Here, we describe unique fossil preservation of an avian brain from the Volgograd region of European Russia. The brain of this Melovatka bird is similar in shape and morphology to those of known fossil ornithurines (the lineage that includes living birds), such as the marine diving birds Hesperornis and Enaliornis, but documents a new stage in avian sensory evolution: acute nocturnal vision coupled with well-developed hearing and smell, developed by the Late Cretaceous (ca 90Myr ago). This fossil also provides insights into previous 'bird-like' brain reconstructions for the most basal avian Archaeopteryx--reduction of olfactory lobes (sense of smell) and enlargement of the hindbrain (cerebellum) occurred subsequent to Archaeopteryx in avian evolution, closer to the ornithurine lineage that comprises living birds. The Melovatka bird also suggests that brain enlargement in early avians was not correlated with the evolution of powered flight.     

Palaeobiology of tanaidaceans (Crustacea: Peracarida) from Cretaceous ambers: extending the scarce fossil record of a diverse peracarid group

Diverse assemblages of tanaidacean peracarid crustaceans from western Tethyan continental deposits suggest that the group was relatively common in or around ancient resin‐producing forests. Here we report the results of an examination of 13 tanaidacean specimens from three Cretaceous (Albian to Turonian) French amber deposits. Two new species of the fossil family Alavatanaidae are placed in the previously described Early Cretaceous genus Eurotanais: Eurotanais pyrenaensis sp. nov. from Cenomanian Pyrenean amber (Fourtou, Aude) and Eurotanais seilacheri sp. nov. from Turonian Vendean amber (La Garnache, Vendée). The remaining specimens are placed in three newly erected genera and species (but family incertae sedis): Arcantitanais turpis gen. et sp. nov. from Albian–Cenomanian Charentese amber (Archingeay, Charente‐Maritime), and Tytthotanais tenvis gen. et sp. nov. and Armadillopsis rara gen. et sp. nov. from Pyrenean amber. These are the first formally described fossils that might be related to the paratanaoidean families Nototanaidae and Paratanaidae, sharing with these some putatively derived features and providing possible evidence for the antiquity and morphological stability of these families and the suborder Tanaidomorpha. The distinctive features and character combinations of these fossil taxa are discussed in connection with possible relationships to the living lineages of tanaidaceans. Propagation phase‐contrast X‐ray synchrotron microtomography was used to obtain high‐quality 3D images for some fossils. A discussion is provided on the putative palaeobiology of tanaidaceans and the French resiniferous forest ecosystem. The discovery of these new tanaidaceans extends the palaeogeographical distribution and stratigraphical range of the family Alavatanaidae and sheds new light on the palaeoecology and diversity of tanaidaceans in pre‐angiospermous woodlands.     

The oldest psyllipsocid booklice, in Lower Cretaceous amber from Lebanon (Psocodea, Trogiomorpha, Psocathropetae, Psyllipsocidae)

Libanopsyllipsocus alexanderasnitsynigen. et sp. n., of Psyllipsocidae is described and figured from the Lower Cretaceous amber of Lebanon. The position of the new taxon is discussed and the fossil is compared to other psyllipsocids. The species represents the earliest record of the family Psyllipsocidae.     

A new Lower Cretaceous bird from China and tooth reduction in early avian evolution

A new avian genus and species, Zhongjianornis yangi gen. et sp. nov., is reported from the Lower Cretaceous lacustrine deposits of the Jiufotang Formation in Liaoning, northeast China. The new taxon is characterized by possessing the following combination of features: upper and lower jaws toothless, snout pointed, humerus with large and robust deltopectoral crest, second phalanx of the major manual digit longer than the first phalanx, unguals of the alular and major digits of similar length and significantly shorter than the corresponding penultimate phalanges, tibiotarsus slender and more than twice the length of the tarsometatarsus, and metatarsal IV longer than the other metatarsals. Phylogenetic analysis indicates that Zhongjianornis is phylogenetically basal to Confuciusornis and the dominant Mesozoic avian groups, Enantiornithes and Ornithurae, and therefore provides significant new information regarding the diversification of birds in the Early Cretaceous. It also represents the most basal bird that completely lacks teeth, suggesting that tooth loss was more common than expected in early avian evolution and that the avian beak appeared independently in several avian lineages, most probably as a response to selective pressure for weight reduction. Finally, the presence of a significantly enlarged humeral deltopectoral crest suggests that Zhongjianornis shares with other basal birds such as Jeholornis, Sapeornis and Confuciusornis a distinctive mode of adaptation for flight contrasting with that seen in more advanced birds, which instead possess an elongated sternum and a prominent keel.