Amber Research Articles

Synchrotron X-ray imaging of a dichasium cupule of Castanopsis from Eocene Baltic amber.

The Eocene Baltic amber deposit represents the largest accumulation of fossil resin worldwide, and hundreds of thousands of entrapped arthropods have been recovered. Although Baltic amber preserves delicate plant structures in high fidelity, angiosperms of the "Baltic amber forest" remain poorly studied. We describe a pistillate partial inflorescence of Castanopsis (Fagaceae), expanding the knowledge of Fagaceae diversity from Baltic amber. The amber specimen was investigated using light microscopy and synchrotron-radiation-based X-ray micro-computed tomography (SRμCT). The partial inflorescence is a cymule, consisting of an involucre of scales that surround all four pistillate flowers, indicating a dichasium cupule. Subtending bracts are basally covered with peltate trichomes. Flowers possess an urecolate perianth of six nearly free lobes, 12 staminodia hidden by the perianth, and a tri-locular ovary that is convex-triangular in cross section. The exceptional three-dimensional preservation suggests that the fossil belongs to the extant East Asian genus Castanopsis. The amber inclusion represents the first record of Castanopsis from Baltic amber and the first pistillate inflorescence of Fagaceae from Eurasia. The partial female inflorescence reported here provides an important addition to acorns of Castanopsis described from middle Eocene strata of Europe. Furthermore, the intercontinental distribution of Castanopsis in the Eocene is confirmed. The amber fossil also broadens the picture of the Baltic amber source area, indicating oligotrophic, sandy, bog-like habitats. Finally, this study underscores the great benefit of SRμCT as a powerful tool to investigate plant inclusions from amber in a nondestructive way.

Next ones to fill the gap—first tanaupodids (Trombidiformes: Prostigmata, Tanaupodidae) from Baltic amber with notes on extant genera and species

Propolyssenia gen. nov. with Propolyssenia wohltmanni sp. nov., based on larva, and Eothrombium fortesambiense sp. nov. based on active postlarval form, are described from Baltic amber. The new genus shares some characters with the extant Polydiscia and Lassenia. The new species are among the three fossil amber representatives of Tanaupodidae known to date. The present-day fauna of Tanaupodidae is revisited.

Amber fossils reveal the Early Cenozoic dipterocarp rainforest in central Tibet

The palaeoenvironmental reconstruction of central Tibet is key to understanding the uplift history of the Tibetan Plateau, which had a profound influence on Cenozoic global climate and biotic change. Here we report an amber layer from the lower part of the Dingqing Formation (late Oligocene) in Lunpola of central Tibet, which is the first record of amber from Tibet. Herein we find that Lunpola amber is derived from dipterocarp trees, as determined by gas chromatography-mass spectrometry, which are restricted to and dominant in Asian rainforest nowadays. This amber forest represents the northernmost dipterocarp forest and is consistent with the hypothesis of out-of-India dispersal of Asian dipterocarps. The Lunpola amber most probably was derived from the lower part of the Niubao Formation (early–middle Eocene) and suggests a tropical/subtropical wet forest was present in central Tibet at least before the late Oligocene (probably early–middle Eocene).

Editing of Genomic TNFSF9 by CRISPR-Cas9 Can Be Followed by Re-Editing of Its Transcript.

The CRISPR-Cas system is a well-established RNA-guided DNA editing technique widely used to modify genomic DNA sequences. I used the CRISPR-Cas9 system to change the second and third nucleotides of the triplet TCT of human TNSFSF9 in HepG2 cells to TAG to create an amber stop codon. The TCT triplet is the codon for Ser at the 172nd position of TNSFSF9. The two substituted nucleotides, AG, were confirmed by DNA sequencing of the PCR product followed by PCR amplification of the genomic TNFSF9 gene. Interestingly, sequencing of the cDNA of transcripts of the edited TNFSF9 gene revealed that the TAG had been re-edited to the wild type triplet TCT, and 1 or 2 bases just before the triplet had been deleted. These observations indicate that CRISPR-Cas9-mediated editing of bases in target genomic DNA can be followed by spontaneous re-editing (correcting) of the bases during transcription.

A primitive triatomine bug, Paleotriatoma metaxytaxa gen. et sp. nov. (Hemiptera: Reduviidae: Triatominae), in mid-Cretaceous amber from northern Myanmar

The present study describes a primitive kissing bug (Hemiptera: Reduviidae: Triatominae) in mid-Cretaceous amber from northern Myanmar. The fossil, which is described as Paleotriatoma metaxytaxa gen. et sp. nov., contains a predominance of features of the Triatominae as well as some characters of the Reduviinae and is considered an intermediate fossil representing an early progenitor of the Triatominae. Based on the present distribution of the Triatominae and recent studies indicating that Burmese amber fossils could have originated in Gondwana, it is proposed that Paleotriatoma metaxytaxa is a Gondwanan lineage that evolved in the mid-Cretaceous. The specimen contains developing trypanosome flagellates in its hindgut, suggesting that early triatomines could have been vectoring pathogenic protozoa to vertebrates some 100 Ma.

Mites as fossils: forever small?

ABSTRACTSmallness being in the essence of a mite, the question is whether it has always been so during the geological history of Acari. Here I assemble measurements of over 260 published mite fossils, distributed from the Early Devonian (410 mya) to the end of the Neogene (5 mya), and compare them to the data available for their extant relatives. A number of fossils are reconsidered: reports of the Ordovician Brachypylina and Permian Astigmata have to be excluded from the fossil record; Jurassic fossils of Trhypochthoniidae (Nothrina) are reconsidered as Neoliodidae (Brachypylina) and Desmonomata (Brachypylina or Nothrina).Based on these data, mites began small. From the oldest, Paleozoic, fossils through the Jurassic, Sarcoptiformes show a positive size trend, which then ceases. The smallest mites, are recovered from the Triassic amber. Cretaceous amber fossils show wide size range, which further increases through the Cenozoic. Fossils of mites tend to fall within size ranges of their extant relatives mostly on the smaller side of those ranges. Paleozoic fossils, however, tend to be on the larger side of their relatives’ size range. What can be called a “Jurassic anomaly” – a set of much larger-than-extant fossils currently attributed to Cymbaeremaeidae – calls for further study.

World’s oldest baby snake found preserved in amber

World’s oldest baby snake found preserved in amber

A mini-snake in amber is the oldest — and youngest — ever found

A mini-snake in amber is the oldest — and youngest — ever found

Analysis of gases in fossil amber

Fossilized tree resin, commonly known as amber, has long served as a robust source of paleobiologic information via the preservation of embalmed invertebrates. Another more radical idea is that gas bubbles enclosed in fossil amber may represent ancient air trapped at the time the original resin was exuded from its host tree. Alternatively, gas trapped in ancient amber may instead represent contamination by modern air. Here, we analyze gaseous inclusions from ambers sampled worldwide spanning the Cretaceous, Eocene, Eocene–Oligocene, Eocene–Miocene, U. Oligocene–Miocene, and modern. After careful consideration of a number of possible explanations, we suggest the gas inclusions may represent, at least in part, ancient air.

Unlocking preservation bias in the amber insect fossil record through experimental decay.

Fossils entombed in amber are a unique resource for reconstructing forest ecosystems, and resolving relationships of modern taxa. Such fossils are famous for their perfect, life-like appearance. However, preservation quality is vast with many sites showing only cuticular preservation, or no fossils. The taphonomic processes that control this range are largely unknown; as such, we know little about potential bias in this important record. Here we employ actualistic experiments, using, fruit flies and modern tree resin to determine whether resin type, gut microbiota, and dehydration prior to entombment affects decay. We used solid phase microextraction gas chromatography-mass spectrometry (SPME GC-MS) to confirm distinct tree resin chemistry; gut microbiota of flies was modified using antibiotics and categorized though sequencing. Decay was assessed using phase contrast synchrotron tomography. Resin type demonstrates a significant control on decay rate. The composition of the gut microbiota was also influential, with minor changes in composition affecting decay rate. Dehydration prior to entombment, contrary to expectations, enhanced decay. Our analyses show that there is potential significant bias in the amber fossil record, especially between sites with different resin types where ecological completeness and preservational fidelity are likely affected.

"Controversies in digital ethics," edited by Amber Davisson and Paul Booth

Book review of Amber Davisson and Paul Booth. Controversies in Digital Ethics. New York, NY: Bloomsbury, 2016. $130.00 (392p) ISBN 978-1-50131-056-0.

Physicochemical Stability of 5 mg/mL Pediatric Prednisone Oral Suspension in Syrspend® SF PH4

Abstract Background Prednisone is a corticosteroid used in several inflammatory diseases and cancers. In France, no available prednisone drinkable formulation exists. Instead, an oral syrup of prednisone with ethanol, sodium benzoate and simple syrup is produced. However, sodium benzoate can induce neonatal icterus and alcohol is not authorized for children below 3 years of age. The aim of this study was to determine the stability of 5 mg/mL prednisone oral suspension in a commercial compounding excipient: Syrspend® SF PH4. Methods Three batches of oral suspensions were prepared, using micronized prednisone and Syrspend® SF PH4. They were packaged in amber glass vials and stored at room temperature. On day 0, 1, 4, 10, 30, 60 and 90, we observed physical and chemical stability (pH measurement, osmolality measurement, residual concentrations of prednisone and degradation product identification). A stability indicating method was developed using high performance liquid chromatography with Ultraviolet detection at 254 nm. Results Prednisone concentrations remained stable within ± 5 % of nominal values for 60 days. No degradation product and change of physicochemical properties were detected. Conclusion This study showed that 5 mg/mL prednisone oral suspension in Syrspend® SF PH4 is stable for 60 days, at room temperature and protected from light.

Puyehuemyia chandleri, gen. nov., sp. nov. (Diptera: Opetiidae): Remnant of a Cretaceous Biota in Chile

The first Opetiidae known from the Southern Hemisphere is described—Puyehuemyia chandleri, gen. nov., sp. nov.—based on a female specimen collected in Valdivian forest in the Province of Osorno, south Chile. The Palearctic species Opetia nigra Meigen was also studied, allowing detailed comparisons. Features of the antenna, mouthparts, wing, and terminalia allowed the issue of the position of the family within the Eremoneura to be revisited. The inclusion of Opetiidae in the Platypezoidea is corroborated, possibly in a clade also including Lonchopteridae and Phoridae. The 3-articled condition of the styluslike arista in Puyehuemyia corroborates the hypothesis that the 2-articled condition in Opetia is independently derived, as it is in the Empidoidea and many schizophorans. Puyehuemyia chandleri has female terminalia typical of parasitoid groups, as does Opetia, although their life history is not known. Described Platypezoidea Cretaceous amber fossils are reviewed, and Lonchopterites is considered to be sister to the crown group of Opetiidae. The presence of an Early Cretaceous biogeographical layer in the Valdivian forest, associated with plant and animals disjunct from New Zealand, and similar to the beech forests in the Northern Hemisphere, is discussed.

Origin of spiders and their spinning organs illuminated by mid-Cretaceous amber fossils.

Understanding the genealogical relationships among the arachnid orders is an onerous task, but fossils have aided in anchoring some branches of the arachnid tree of life. The discovery of Palaeozoic fossils with characters found in both extant spiders and other arachnids provided evidence for a series of extinctions of what was thought to be a grade, Uraraneida, that led to modern spiders. Here, we report two extraordinarily well-preserved Mesozoic members of Uraraneida with a segmented abdomen, multi-articulate spinnerets with well-defined spigots, modified male palps, spider-like chelicerae and a uropygid-like telson. The new fossils, belonging to the species Chimerarachne yingi, were analysed phylogenetically in a large data matrix of extant and extinct arachnids under a diverse regime of analytical conditions, most of which resulted in placing Uraraneida as the sister clade of Araneae (spiders). The phylogenetic placement of this arachnid fossil extends the presence of spinnerets and modified palps more basally in the arachnid tree than was previously thought. Ecologically, the new fossil extends the record of Uraraneida 170 million years towards the present, thus showing that uraraneids and spiders co-existed for a large fraction of their evolutionary history.

The Last to Let Go by Amber Smith

The Last to Let Go by Amber Smith

A new stingless bee from the tertiary amber of the Dominican Republic (Hymenoptera; Meliponini)

Se describe una nueva meliponida fosil, Trigona (Liotrigona) dominicana. Esta abeja fosil se relaciona a tres especies africanas modernas y pudo haber pertenecido a un grupo grande y extendido durante el Oligoceno, que sirviera de tronco ancestral a todas las demas Hypotrigona tanto del Viejo Mundo como de la America.

Cretaceous fossil gecko hand reveals a strikingly modern scansorial morphology: Qualitative and biometric analysis of an amber-preserved lizard hand

Gekkota (geckos and pygopodids) is a clade thought to have originated in the Early Cretaceous and that today exhibits one of the most remarkable scansorial capabilities among lizards. Little information is available regarding the origin of scansoriality, which subsequently became widespread and diverse in terms of ecomorphology in this clade. An undescribed amber fossil (MCZ R–190835) from mid-Cretaceous outcrops of the north of Myanmar dated at 99 Ma, previously assigned to stem Gekkota, preserves carpal, metacarpal and phalangeal bones, as well as supplementary climbing structures, such as adhesive pads and paraphalangeal elements. This fossil documents the presence of highly specialized adaptive structures. Here, we analyze in detail the manus of the putative stem Gekkota. We use morphological comparisons in the context of extant squamates, to produce a detailed descriptive analysis and a linear discriminant analysis (LDA) based on 32 skeletal variables of the manus. The comparative sample includes members of 15 extant squamate families (Agamidae, Dactyloidae, Iguanidae, Leiosauridae, Liolaemidae, Polychrotidae, Tropiduridae, Diplodactylidae, Eublepharidae, Gekkonidae, Phyllodactylidae, Sphaerodactylidae, Gymnophthalmidae, Teiidae, and Scincidae). Although the fossil manus is qualitatively more similar to that of members of Gekkota, the LDA analysis places it in a morphozone shared by Gekkota and Scincomorpha. This result is particularly interesting, given that despite the presence of paraphalangeal structures had only been reported in extant geckos of the families Gekkonidae and Phyllodactylidae, the usage of an adhesive subdigital system to climb originated independently in Gekkota, Scincidae, and Dactyloidae.

Concealed Androconial Scales in Metalmark Butterflies (Lepidoptera: Riodinidae): New Insights from Confocal Laser Scanning Microscopy

Abstract Confocal scanning microscopy is widely used in the biological sciences—from tissue protein expression to the study of fossil amber inclusions. However, it is rarely used in insect taxonomy despite its unique feature for the examination of structural detail in small samples. In this study, we use confocal laser scanning microscopy (CLSM) to image certain poorly studied male secondary sexual organs, namely androconial scales, in a group of riodinid butterflies (Lepidoptera: Riodinidae). This group shows cryptic and mimetic morphology, so pheromones are thought to play an important role in mate choice. We found significant interspecific structural differences in androconial patches. The use of CLSM provides a simple, nondestructive and highly effective method to examine complex morphological characters, which could be applied to other structures and taxa across Lepidoptera and other insects.

The fossil history of pseudoscorpions (Arachnida: Pseudoscorpiones)

Abstract. Pseudoscorpions, given their resemblance to scorpions, have attracted human attention since the time of Aristotle, although they are much smaller and lack the sting and elongated tail. These arachnids have a long evolutionary history but their origins and phylogenetic affinities are still being debated. Here, we summarise their fossil record based on a comprehensive review of the literature and data contained in other sources. Pseudoscorpions are one of the oldest colonisers of the land, with fossils known since the Middle Devonian (ca. 390 Ma). The only arachnid orders with an older fossil record are scorpions, harvestmen and acariform mites, plus two extinct groups. Pseudoscorpions do not fossilise easily, and records from the Mesozoic and Cenozoic consist almost exclusively of amber inclusions. Most Mesozoic fossils come from Archingeay and Burmese ambers (Late Cretaceous) and those from the Cenozoic are primarily from Eocene Baltic amber, although additional fossils from, for example, Miocene Dominican and Mexican ambers, are known. Overall, 16 of the 26 families of living pseudoscorpions have been documented from fossils and 49 currently valid species are recognised in the literature. Pseudoscorpions represent a case of morphological stasis and even the Devonian fossils look rather modern. Indeed, most amber fossils are comparable to Recent groups despite a major gap in the fossil record of almost 250 Myr. Baltic amber inclusions indicate palaeofauna inhabiting much warmer climates than today and point to climatic shifts in central Europe since the Eocene. They also indicate that some groups (e.g. Feaellidae and Pseudogarypidae) had much wider Eocene distributions. Their present-day occurrence is relictual and highlights past extinction events. Faunas from younger tropical amber deposits (e.g. Dominican and Mexican amber) are comparable to Recent ones. Generally, there is a strong bias in the amber record towards groups that live under tree bark, whereas those from litter habitats are underrepresented. We also discuss challenges in interpreting fossils: their cryptic morphology warranting novel techniques of morphological reconstruction, the massive gap in the fossil record between the Palaeozoic and Mesozoic, and problems with the classification of (historically) old amber material. Finally, we discuss aspects of the palaeoecology and biology of the fossils compared with the Recent fauna, such as phoresy.

The identity of giant black flies (Diptera: Simuliidae) in Baltic amber: insights from large-scale photomicroscopy, micro-CT scanning and geometric morphometrics

Black fly adults are minute insects with marked structural homogeneity. This is problematic for the study of fossils, wherein only external structural characters are available for study, thus impeding taxonomic studies and phylogenetic inference. This paper provides a template for future palaeontological research on small, structurally homogeneous, organisms such as black flies, by using cutting-edge tools including large-scale digital microscopy, 3D images derived from micro-CT scanning and geometric morphometrics. These tools reveal difficult-to-observe structures and provide a more objective means for the analysis of character states. We used this approach to study ‘giant’ black flies preserved in Baltic amber of Eocene age. We describe, for the first time, a male plus five additional female specimens of giant black flies from Baltic amber. We discuss the relationships of these fossil flies to each other and to extant (i.e. North American) members of the genus Ectemnia. The male and all females in this study, except Ectemnia lithuanica Yankovsky & Bernotiene, 2005, are confirmed as morphologically consistent with Ectemnia. We further speculate about possible host preferences, way of life and propose best practices for future taxonomic studies on amber fossils.