Review of the El Soplao Amber Outcrop,Early Cretaceous of Cantabria,Spain

<正>El Soplao outcrop,an Early Cretaceous amber deposit recently discovered in northern Spain (Cantabria),has been shown to be the largest site of amber with arthropod inclusions that has been found in Spain so far.Relevant data provided herein for biogeochemistry of the amber,palynology,taphonomy and arthropod bioinclusions complement those previously published.This set of data suggests at least two botanical sources for the amber of El Soplao deposit.The first(type A amber)strongly supports a source related to Cheirolepidiaceae,and the second(type B amber)shows non-specific conifer biomarkers.Comparison of molecular composition of type A amber with Frenelopsis leaves(Cheirolepidiaceae)strongly suggests a biochemical affinity and a common botanical origin.A preliminary palynological study indicates a regional high taxonomical diversity,mainly of pteridophyte spores and gymnosperm pollen grains.According to the preliminary palynological data,the region was inhabited by conifer forests adapted to a dry season under a subtropical climate.The abundant charcoalified wood associated with the amber in the same beds is evidence of paleofires that most likely promoted both the resin production and an intensive erosion of the litter,and subsequent great accumulation of amber plus plant cuticles.In addition,for the first time in the fossil record, charcoalified plant fibers as bioinclusions in amber are reported.Other relevant taphonomic data are the exceptional presence of serpulids and bryozoans on the surfaces of some amber pieces indicating both a long exposure on marine or brackish-water and a mixed assemblage of amber.Lastly,new findings of insect bioinclusions,some of them uncommon in the fossil record or showing remarkable adaptations,are reported.In conclusion,a documented scenario for the origin of the El Soplao amber outcrop is provided.     

A new amber deposit from the Cretaceous (uppermost Albian-lowermost Cenomanian) of southwestern France

A Cretaceous amber deposit has recently been discovered in a quarry of Charente-Maritime (southwestern France), at Cadeuil. This paper presents the sedimentary and palaeoenvironmental settings of the uppermost Albian-lowermost Cenomanian series including the amber deposit. A preliminary analysis of the amber samples reveals diverse fossil arthropods (a few mites and at least 20 insect families within 9 orders), as well as numerous micro-organisms, mainly algae and mycelia. A myceloid colony of bacteria, a flagellate algae and four especially well preserved insects are illustrated (Diptera Dolichopodidae, Diptera Chironomidae, Hymenoptera Parasitica, and Heteroptera Tingidae). The abundance of the limnic micro-organisms is discussed in terms of bloom events. Their relative scarcity in almost all the amber pieces containing fossil arthropods is attributed to differences in the origin of resin: production along trunk and branches for amber with arthropods; production by aquatic roots for amber rich in algae. The absence of pollen and spores in amber is attributed to differences in the respective periods of resin and palynomorph production, which may be related to a seasonal climate during the Albian-Cenomanian transition in Western Europe.     

A look with μCT technology into a treasure trove of fossils: The first two fossils of the millipede order Siphoniulida discovered in Cretaceous Burmese amber (Myriapoda,Diplopoda)

Millipedes (Diplopoda) are an important fossil group of land arthropods in the Palaeozoic. However, there is a gap in the Mesozoic, with only slightly more than a dozen fossils being known, until the much more recent fossil records mainly from Cenozoic Dominican and Baltic ambers become available. Burmese amber, precisely dated to the Late Cretaceous, is known for an apparently rich but still undescribed millipede fauna, and might represent the ideal bridge to close this gap in the millipede fossil record. In addition, modern micro-computed tomography (μCT) technology allows complex 3D reconstructions of objects fossilized in amber. Here we utilize μCT technology to describe the first millipedes from Burmese amber, which are also the first two fossil representatives of the order Siphoniulida. Siphoniulida, with two known species and just nine recorded specimens, are the rarest and least known of the 16 extant orders of the Diplopoda. Records are known from Sumatra, Guatemala and Mexico. The two new fossils described here represent two distinct species, Siphoniulus muelleri sp. nov. and S. preciosus sp. nov., and indicate a wider distribution of this order in the Cretaceous. The holotype of S. muelleri sp. nov. was well-enough preserved so that characters of the head, such as the incisura lateralis, not investigated before in extant representatives of the order, could be studied. This study highlights the possibilities and challenges provided by μCT technology in investigating Diplopoda fossilized in amber.     

The oldest armoured harvestman (Arachnida: Opiliones: Laniatores), from Upper Cretaceous Myanmar amber

The oldest laniatorean harvestman, Petrobunoides sharmai gen. et sp. nov. (Opiliones: Laniatores) is described, from the Upper Cretaceous (lowermost Cenomanian) amber of Myanmar. This is the first fossil Laniatores recovered from Southeast Asia, which is placed in the extant family Epedanidae. It is also the first fossil known within the superfamily Epedanoidea; a relatively derived clade of Laniatores restricted to Southeast Asia today. At ca. 99 Ma, this new amber inclusion is substantially older than the previous oldest record of a member of Laniatores from Baltic amber (ca. 44–49 Ma); however, given the Palaeozoic age of Laniatores implied by molecular data, the new record from Burmese amber is probably still too young for constraining or calibrating the date of cladogenesis for total group Laniatores. Nevertheless, it provides a much better constraint for Epedanoidea, adding the first useful laniatorean fossil to provide an internal calibration point for a clade of Grassatores.     

Spinning with the dinosaurs: the fossil record of spiders

When most people hear the word 'fossil' they tend to conjure up images of giant dinosaurs such as Tyrannosaurus rex or shelled marine invertebrates. Prior to the Hollywood blockbuster movie Jurassic Park , which was based on recreating dinosaurs through extracting their DNA from fossil mosquitoes preserved in amber, few non-palaeontologists would entertain the notion that small, soft-bodied organisms such as insects occur in the fossil record. However, insects and spiders are common as fossils in amber, where they are often preserved with life-like fidelity, and they also occur to a lesser degree in carbonate rocks.     

New species of fossil oribatid mites (Acariformes,Oribatida), from the Lower Cretaceous amber of Spain

Mites are relatively common and diverse in fossiliferous ambers, but remain essentially unstudied. Here, we report on five new oribatid fossil species from Lower Cretaceous Spanish amber, including representatives of three superfamilies, and five families of the Oribatida. Hypovertex hispanicus sp. nov. and Tenuelamellarea estefaniae sp. nov. are described from amber pieces discovered in the San Just outcrop (Teruel Province). This is the first time fossil oribatid mites have been discovered in the El Soplao outcrop (Cantabria Province) and, here, we describe the following new species: Afronothrus ornosae sp. nov., Nothrus vazquezae sp. nov., and Platyliodes sellnicki sp. nov. The taxa are discussed in relation to other fossil lineages of Oribatida as well as in relation to their modern counterparts. Some of the inclusions were imaged using confocal laser scanning microscopy, demonstrating the potential of this technique for studying fossil mites in amber. A table, including all the known Mesozoic oribatid mites preserved in amber, is included.     

A new Burmese amber hawker dragonfly helps to redefine the position of the aeshnopteran family Burmaeshnidae (Odonata: Anisoptera: Aeshnoidea)

The new genus and species Angustaeshna magnifica of Burmaeshnidae is described on the basis of a new fossil from Burmese amber. The genus Cretaeshna from the same amber is transferred from the Telephlebiidae into the Burmaeshnidae. We redefine this last family, no longer considered as the sister group of the Late Cretaceous Enigmaeshnidae, but as putative sister group of the Telephlebiidae in the Aeshnoidea. No known fossil belongs to the Telephlebiidae.     

Colloidal and polymeric nature of fossil amber

Fossilized ambers from several geographical origins, copal from the Kauri pine tree of New Zealand and modern white spruce tree resin have been analyzed by the following analytical techniques: dynamic light scattering, optical and scanning electron microscopy, gel permeation chromatography, IR spectroscopy, rheology and viscometry. The results dispute the prevailing view that amber is largely an insoluble, continuously crosslinked, integral polymer network. Rather, the data indicate that a large portion of amber consists of insoluble though solvent-swellable colloidal particles, ranging from submicron to multimicron in size, which can be dispersed in organic solvents such as N,N-dimethyl-formamide. The presence of colloidal particles in fossil amber, copal and even fresh resin suggests a mechanism for resin exudation involving the presence or formation of discrete ‘packets’ of resin, where the surface of each packet has been modified by the interaction with oxygen and water.     

Beckerite

Beckerite, a minor component of the amber fossil resins of northern Europe, has previously been classified as being mineralogically distinct from common Baltic amber or succinite on the basis of physical properties such as density and chemical properties such as saponification number. We show that beckerite and succinite are spectroscopically identical, according to infrared and carbon-13 nuclear magnetic resonance methods. Following the suggestion of Schubert, we attribute the deviations of beckerite to the presence of low levels of contaminants, such as decomposed wood and insect excrement.     

First definitive fossil agyrtodine beetles: An extant southern hemisphere group recorded from Upper Cretaceous Burmese amber (Coleoptera: Staphylinoidea: Leiodidae)

Mesozoic leiodids are poorly known, and only one definitive leiodid is formally described from Burmese amber. Here we describe and illustrate the second definitive Mesozoic leiodid, Cretagyrtodes glabratus gen. et sp. nov., based on a single specimen from the Upper Cretaceous Burmese amber. The fossil is placed in Agyrtodini (subfamily Camiarinae) after maxillary palpomere 4 as wide as palpomere 3, and procoxal cavities closed behind. Cretagyrtodes is tentatively attributed to the extant “Eupelates group”. The discovery of Cretagyrtodes in Burmese amber suggests that the south hemisphere endemic tribe Agyrtodini is probably an ancient group, which has showed its first appearance before the breakup of Pangaea.     

Frullania pinnata spec. nov. (Frullaniaceae,Porellales), a new leafy liverwort in mid-Cretaceous Burmese amber from Myanmar

An inclusion in Cretaceous amber from Myanmar is described as a new fossil species in the extant liverwort genus Frullania. The name Frullania pinnata is proposed for the taxon that is characterized by entire underleaves paired with a conspicuous pinnate branching pattern, two distinctive and stable morphological features. Entire underleaves are known in several extant Frullania species but had not previously been documented in Frullania in amber. The combination of morphological characters in this new fossil species is unknown in any crown group lineage of Frullania, and may very well represent a stem lineage element of the genus. This discovery is important because it expands our understanding of the diversity of Frullaniaceae in the Burmese amber forest as well as important ramifications for the phylogenetic reconstruction of extant Frullania lineages.     

New fossil booklice from the Cretaceous amber of Myanmar (Psocodea: Troctomorpha: Amphientometae: Manicapsocidae)

Palaeomanicapsocus margoae gen. et sp. nov. and Palaeomanicapsocus fouadi gen. et sp. nov. are characterized, described, illustrated, from the Cretaceous Burmese amber. Their phylogenetic position is discussed. These fossil taxa are the first manicapsocid barklice to be described from the Burmese amber.     

The first record of a bryophyte in Upper Cretaceous amber from Taimyr,northern Siberia: Taimyrobryum martynoviorum gen. et sp. nov. (Bryopsida)

Cretaceous bryophyte fossils are known only from a few localities and only a few are known in ultrastructural fidelity. We describe a fossil moss gametophyte from Upper Cretaceous Taimyr amber and place it in the fossil genus Taimyrobryum martynoviorum gen. et sp. nov. (Bryopsida). Its unbranched, somewhat zig-zagged stems with distantly spaced, spreading, narrowly lanceolate leaves and the unbranched costa match the gross morphology of Dicranidae; however, the uniformly prosenchymatous leaf cells contradict an affiliation to this subclass. The Yantardakh in the Taimyr Peninsula is the fourth and northernmost Cretaceous amber locality yielding inclusions of bryophytes.     

First Psocodean (Psocodea,Empheriidae) from the Cretaceous Amber of New Jersey

<正>Representatives of the extinct psocid family Empheriidae are known from Eocene Baltic amber, Lowermost Eocene French amber(Oise),and Lower Cretaceous Spanish amber(Alava).We report herein the first discovery of an empheriid psocid from the Cretaceous amber of New Jersey as Jerseyempheria grimaldii gen.et sp. nov.The fossil is figured and described.The new species is distinguished from related taxa.A discussion and checklist of Empheriidae are provided.     

First boganiine beetle in mid-Cretaceous amber from northern Myanmar (Coleoptera: Boganiidae)

Cretoboganium gei gen. et sp. nov., a new amber inclusion of the cucujoid family Boganiidae is described and figured based on a well-preserved adult from the mid-Cretaceous Burmese amber (Hukawng Valley, northern Myanmar), some 99 million years ago. Based on the presence of a pair of pronotal callosities, Cretoboganium can be firmly placed in the extant subfamily Boganiinae, a small group currently comprising two small austral genera. Our discovery represents the first fossil record for Boganiinae. It also demonstrates another example that an apparently austral group may have its sister group occurred in today’s northern hemisphere. Together with the other fossil boganiid known from the Middle Jurassic of China, the finding suggests that Boganiidae is an ancient and relict group. Moreover, the present biogeographic distribution of Boganiinae is indicative of an earlier origin of this subfamily, which likely originated before the breakup of the Gondwanan supercontinent.     

A new genus and species of soldier beetle from Upper Cretaceous Burmese amber (Coleoptera,Cantharidae, Malthininae)

A new Upper Cretaceous genus and species of soldier beetles, Archaeomalthodes rosetta gen. et sp. nov., is described and illustrated from an individual preserved in Upper Cretaceous (Cenomanian, ca. 99 Ma) amber from northern Myanmar. It is undoubtedly placed in extant subfamily Malthininae based on its small-sized body, somewhat abbreviated elytra and fusiform terminal maxillary palpomere, representing the oldest documented occurrence of Malthininae. It suggests that this subfamily is an ancient group, which originated at least in the earliest Late Cretaceous. Our discovery sheds light on the palaeodiversity of Cantharidae in the Late Mesozoic. Together with other previously reported fossil cantharids, it is likely that Malthininae has been fairly diverse during the early evolution of Cantharidae. On the other hand, a morphological similarity between Archaeomalthodes and Recent malthinines and the occurrence of flowering plants in the Burmese amber implies a potential flower-visiting behaviour of this fossil species.     

A new compsocid booklouse from the Cretaceous amber of Myanmar (Psocodea: Troctomorpha: Amphientometae: Compsocidae)

Paraelectrentomopsis chenyangcaii gen. et sp. nov. from the Cretaceous Burmese amber is characterized, described, illustrated and its position is discussed. This fossil taxon is the second compsocid barklouce to be described from the Burmese amber and constitute one of the earliest records of the family. A checklist of known Compsocidae is given. Identification keys of all known Compsocidae are provided. A palaeobiogeography scenario is proposed.     

The first record of Cretaceous ground beetle (Coleoptera: Carabidae: Oodini) from Burmese amber

The first fossil Carabidae from Burmese amber is described as new to science, Oodes kachinensis Liu n. sp., based on a single individual preserved in Cretaceous amber from Myanmar. This species is placed in the extant tribe Oodini as supported by several characters: one supraorbital seta at each side of vertex, interval 9 very narrow, stria 8 very deep, epipleuron plica presented, antennomeres 1–3 glabrous and 4–11 densely pubescent. This new species has surprising long legs, indicating most probably it was living on the bank of puddle.     

A plesiomorphic gasteruptiid wasp in Cenomanian amber from Myanmar (Hymenoptera: Gasteruptiidae)

The first definitive Burmese amber fossil of the family Gasteruptiidae s.str. (Evanioidea) is described and figured from a male entombed in amber from the Hukawng Valley, Myanmar. The Cenomanian-aged fossil is plesiomorphic in many respects when compared to the modern subfamilies Hyptiogastrinae and Gasteruptiinae. The genus Hypselogastrion Engel, gen. nov. (type species: Hypselogastrion simplex Engel and Wang, sp. nov.), is segregated into the extinct subfamily Hypselogastriinae Engel, subfam. nov., owing the more enriched wing venation, aulcid-like mesoscutal sculpturing, non-clavate metatibia, and absence of U-shaped notauli. The affinities of H. simplex among other living and fossil Aulaciformes are discussed.     

Hymenoptera (wasps,bees and ants) in mid-Cretaceous Burmese amber: A review of the fauna

The Burmese amber assemblage of Hymenoptera with its 47 constituent families is now the richest in Cretaceous. A collection of Burmite (Burmese amber) from the Hukawng Valley, Myanmar at the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences was examined, revealing that Burmite inclusions contain a very highly diverse hymenopteran fauna with as many as ten families found new for the Burmese fossil assemblage. The mid-Cretaceous hymenopteran fauna of Burmese amber is revised at the family level. A high level of the first family occurrences and endemism is demonstrated suggestive of an insular syndrome affected the mid-Cretaceous Burmese biome, as well as somewhat contradictory features in composition of the hymenopteran families there.