Amber Inclusions Research Articles

The first Mesozoic puppet beetle (Coleoptera: Tenebrionoidea: Aderidae) from mid-Cretaceous amber of northern Myanmar

Grzymalia wukong gen. et sp. nov. is described as the first named representative of Aderidae from the Mesozoic amber deposits, based on a single adult beetle inclusion in mid-Cretaceous Kachin amber, northern Myanmar (ca. 99 Ma). The new genus resembles several extant representatives of the tribe Euglenesini, with such characters as uniseriate elytral pubescence, fully visible from above the head; a subquadrate pronotum; and the general ratio and form of antennomeres. The new genus differs from other members of the tribe in having a complete suture between abdominal ventrites I and II, as well as sparse and long setae along the entire length of its metafemoral inner edge. The fossil is provisionally attributed to Euglenesini; however, the single known female specimen doesn't allow a formal and indisputable tribal placement without the study of a conspecific specimen of the opposite sex.

Re-appraisal of lacewing mimicry of liverworts from the mid-Cretaceous Kachin amber, Myanmar with a description of Selaginella cretacea sp. nov. (Selaginellales, Selaginellaceae)

A unique case of liverwort mimesis in lacewing larvae of Phyllochrysa huangi has been reported from the mid-Cretaceous Kachin amber, Myanmar. However, we caution to take this interpretation for granted because of the still incomplete assessment of the plant diversity preserved in the Kachin amber inclusions. Our re-examination of the plant fossils regarded as models for Phyllochrysa huangi received evidence for a new species of the lycophyte genus Selaginella, namely S. cretacea sp. nov., and two indeterminate species of Selaginella, besides four species of the leafy liverwort family Frullaniaceae, including Frullania baerlocheri, F. kachinensis, F. partita, and Protofrullania cornigera. Careful morphological comparison recovered that the flat larvae of Phyllochrysa huangi closely match the dorsiventrally complanate strobili of Selaginella subgenus Stachygynandrum (lycophytes) represented by S. cretacea sp. nov. In turn, the larval morphology did not show obvious similarities with the shoots of the leafy liverworts. In the context of the improved taxonomic survey of the plant inclusions, it is evident that the so-called liverwort mimesis in Cretaceous lacewing larvae was actually lycophyte mimesis. The larvae of Phyllochrysa huangi provided the earliest evidence of a putative extinct Phyllochrysa-Selaginella mimetic system.

About this title - Mesozoic Biological Events and Ecosystems in East Asia

Mesozoic Biological Events and Ecosystems in East Asia covers a wide range of topics, encompassing palaeoenvironments, palaeoecosystems and important vertebrate, invertebrate and plant fossils, some found in amber with excellent preservation of delicate morphological features. Fifty-three authors from a number of different disciplines – geochronology, palaeontology, stratigraphy, sedimentology, tectonics and geochemistry – contribute to the 18 articles in the volume. Well-preserved fossils and rocks continue to be found from marine and terrestrial sediments across East Asia. Over some years, the palaeontological and geological evidence discovered from this region has significantly improved our understanding of Mesozoic environments. In discussing feathered dinosaurs, primitive birds, early mammals, diverse insects, amber inclusions, the oldest-known flowers and research utilizing new, advanced methods, this volume explores Earth's history in even greater detail. What other exciting discoveries are waiting to be unveiled in the future?

Organic inclusions in Brazilian Cretaceous amber: The oldest ostracods preserved in fossil resins

Fossil resins and ostracods are well-known in Brazilian Cretaceous sedimentary Basins, especially in the Araripe Basin. The present work reports several ostracods encapsulated in an amber sample recovered from limestones of the Crato Formation (Araripe Basin, Northeastern Brazil). The amber was analyzed under optical and eletronic microscopy revealing several ostracod specimens. Considering the general morphology, the recovered specimens were attributed to the freshwater to brackish genera Pattersoncypris Bate, 1972 and Damonella Anderson, 1966 in the superfamily Cypridoidea. Additionally, palynological analyses of the limestone rock around the amber demonstrate the predominance of pollen grains of the Classopolis genus, produced by conifers of Cheirolepidiaceae family, suggesting this family as possible botanical source of the fossil resin. The proposed interpretation for this preservation is as follow: (i) the lake level variations transported the ostracods to the margin; (ii) drops of resin exuded from the trunk fell to the margin on the dead ostracods; (iii) the exposed resin underwent polymerization preserving the ostracods; (iv) and finally, the amber was preserved in the laminated calcareous deposit. The record described here provides a detailed study of organisms fossilized in Brazilian amber as well as it reports the oldest record of ostracods enclosed in fossil resins (Aptian age).

A tardigrade in Dominican amber.

Tardigrades are a diverse group of charismatic microscopic invertebrates that are best known for their ability to survive extreme conditions. Despite their long evolutionary history and global distribution in both aquatic and terrestrial environments, the tardigrade fossil record is exceedingly sparse. Molecular clocks estimate that tardigrades diverged from other panarthropod lineages before the Cambrian, but only two definitive crown-group representatives have been described to date, both from Cretaceous fossil deposits in North America. Here, we report a third fossil tardigrade from Miocene age Dominican amber. Paradoryphoribius chronocaribbeus gen. et sp. nov. is the first unambiguous fossil representative of the diverse superfamily Isohypsibioidea, as well as the first tardigrade fossil described from the Cenozoic. We propose that the patchy tardigrade fossil record can be explained by the preferential preservation of these microinvertebrates as amber inclusions, coupled with the scarcity of fossiliferous amber deposits before the Cretaceous.

Discovery of a new genus and species of Dryinidae (Hymenoptera: Chrysidoidea) from Kachin (Myanmar) amber: Rasnitsynum burmense gen. et sp. nov.

Dryinidae (Hymenoptera: Chrysidoidea) are parasitoids, and often also predators, of leafhoppers, planthoppers and treehoppers (Hemiptera: Auchenorrhyncha) (Guglielmino et al., 2013; Olmi et al., 2020b). Fossils of Dryinidae are known both as inclusions in amber and as compression fossils (Perkovsky et al., 2019; Olmi et al., 2010, 2020b; Martynova et al., 2020). Among the amber deposits, those situated in Myanmar are the richest. Mid-Cretaceous Burmese amber from Kachin State is known in fact to include Dryinidae belonging to the following subfamilies and genera: Anteoninae: Burmanteon Engel, 2003 (one species); Burmadryininae: Burmadryinus Olmi, Xu & Guglielmino, 2014 (one species); Dryininae: Dryinus Latreille, 1804 (12 species) (Martynova et al., 2020); Hybristodryinus Engel, 2005 (17 species) (Perkovsky et al., 2019; Tribull et al., 2020; Olmi et al., 2021; Wang et al., 2021); Pseudodryinus Olmi, 1991 (one species); Palaeoanteoninae: Palaeoanteon Olmi, 2000 (one species) (Perkovsky et al., 2020a); Raptodryininae: Raptodryinus Olmi, Perkovsky, Martynova, Contarini, Bückle, Guglielmino, 2020 (one species).

International Palaeoentomological Society—20 years after

Fossilised insects probably brought man’s attention since the prehistory, since first amber with an insect entombed in resin was found. Amber was collected and used by humans first in the Upper Paleolithic period, perhaps as long ago as 20,000 years (Beck et al., 2009; Burdukiewicz, 2009; Płonka & Kowalski, 2017). The written testimonies on amber inclusions goes back to Ancient Rome (Plinius Secundus, 77). During 17th and 18th centuries the inclusions in amber were noted by philosophers (Bacon, 1638), their values discussed and illustrated (e.g., Sendel, 1742) and their importance to understanding the history of life pointed (Kant in Hagen, 1821). Shortly after Linnaeus “Systema Naturae” editions, the first research using binomial names for insect included in the copal was published (Bloch, 1776) and Pleistocene record of Recent beetle was noted by Fabricius (1775). Notes and information on fossil insects from imprints and amber were presented by Lang (1708), Bertrand (1763), Linnaeus (1778) and Volta (1796). The first regular description of beetle inclusion in Baltic amber came from Gravenhorst (1806) and works of de Serres (1828, 1829) seems to be the first with more detailed overview and description of insects as adpression fossils. Therefore, human’s palaeoentomological interests predates official beginning of modern taxonomy and palaeoentomology as science is as old as modern entomology (Azar et al., 2018).

Looking back at the latest 20 years

Twenty years ago the International Palaeoentomological Society was founded in Kraków during the 2nd Congress on Palaeoentomology (5th–9th September, 2001). This congress was preceded by a world conference in Moscow, 1998 (which was afterwards given the formal numbering as first), and World Congress on Amber Inclusions in Vitoria-Gasteiz, Basque Country, Spain, 1998. Later, Brazilian Symposium on Palaeoarthropodology in Ribeirão Preto, Brazil held for the first time in 2000, took place. The event in Kraków attracted a record number of 120 participants. We were quite aware that this frequency in 2001 was partially caused by the curiosity of the country which for long time was behind the iron curtain. Literally most of the countries were represented; from USA to China, from Russia to South Africa, as you may notice from the list of 53 founding members, below, who also provided the starting Society with first donations.

Breathing colour into fossils: A tomographic system for reconstructing the soft tissue microstructure of amber inclusions

Limited photon flux from the specimen using laser scanning microscopy during very short pixel dwell time often leads to insufficient signal-to-noise ratios (SNR). Increasing the SNR is invariably accompanied with a high power density, which may cause thermal damage to valuable specimens, for instance, the amber fossil record which provides an unparalleled insight into the history of terrestrial ecosystems over the past 230 million years. Here we describe an optimised high-resolution three-dimensional (3D) imaging strategy termed high dynamic range, colour structured illumination microscope (HDR-C-SIM) that overcomes the limitation of laser scanning confocal microscopy as well as the state-of-the-art micro-CT techniques for the study of amber inclusions. We demonstrate the utility of our new system for studying Mesozoic amber inclusions, which are difficult to image due to the optical properties of fossilised resin and the fossil's variable nature of preservation. Also, the HDR-C-SIM system was able to image the structural colours of cuckoo wasps preserved in mid-Cretaceous Burmese amber. By enabling palaeontologists to non-destructively study the nanostructures of organisms preserved in amber, HDR-C-SIM unlocks a new source of information about the palaeoecology of ancient ecosystems and holds promise for the non-destructive imaging of heat-sensitive samples in other fields.

Liverworts from Cretaceous amber

DNA-based analyses as well as the fossil record indicate that liverworts date back to the early Paleozoic, but diverse specimens of lifelike three-dimensional fossils only occur as amber inclusions from the mid-Cretaceous onwards. Some Albian–Cenomanian ambers preserve elements of a diverse biota that existed during the rise of angiosperms, a time of fundamental change in terrestrial ecosystems that likely affected epiphytic taxa. Recent analyses have provided important insight into the phylogenetic diversification and morphological evolution of liverworts. They suggest that the mid- to Late Cretaceous was a transitional time with a significant species turnover. Here, we review all currently recognized leafy liverwort species from Cretaceous ambers based on the examination of previously described fossil specimens as well as newly discovered amber inclusions. Our survey includes a determination key. The study of 26 new fossils from Kachin amber, including fertile material, enabled us to emend descriptions for Frullania cretacea, F. baerlocheri, and Protofrullania cornigera. Mid-Cretaceous Frullaniaceae often possess some characters and character combinations that are absent in extant representatives, substantiating the assumption of a lineage turnover in the Cretaceous. Among the new fossils is Radula heinrichsii sp. nov., which expands the number of Cretaceous, amber-preserved liverwort species to eight.

Terrestrial Isopods from Spanish Amber (Crustacea: Oniscidea): Insights into the Cretaceous Soil Biota

Terrestrial isopods (Crustacea: Oniscidea) are a model group for studying the colonization of land. However, their fossil record is remarkably scarce and restricted to amber inclusions, and therefore amber deposits represent valuable windows to their past diversity and morphology. Here we present a new collection of 11 terrestrial isopod specimens preserved in Albian-aged amber from the Peñacerrada I outcrop, northern Spain, which collectively represent the most thoroughly documented fauna of Mesozoic Oniscidea. The three new genera and species identified belong to three of five major groups of the Oniscidea: Eoligiiscus tarraconensis, new genus and species (Ligiidae), Autrigoniscus resinicola, new genus and species (Synocheta: Trichoniscidae), and Heraclitus helenae, new genus and species (Crinocheta: Detonidae?). These taxa significantly expand the known fossil record of Oniscidea and demonstrate that considerable cladogenesis had already transpired by the Albian. The assemblage represents the earliest-known diversification of Oniscidea, extending direct evidence of terrestrialization in the group back to the late Early Cretaceous. These new taxa exhibit some characteristics that may inform hypotheses relating to general patterns of terrestrial isopod evolution. A discussion is provided about different aspects of the paleoecology and biology of the fossils compared to the Recent fauna. The new species indicate that Cretaceous isopods were a group of considerable adaptive diversity, exhibiting innovations analogous to what Recent isopods would exhibit 105 million years later.

Central nervous system of a 310-m.y.-old horseshoe crab: Expanding the taphonomic window for nervous system preservation

Abstract The central nervous system (CNS) presents unique insight into the behaviors and ecology of extant and extinct animal groups. However, neurological tissues are delicate and prone to rapid decay, and thus their occurrence as fossils is mostly confined to Cambrian Burgess Shale–type deposits and Cenozoic amber inclusions. We describe an exceptionally preserved CNS in the horseshoe crab Euproops danae from the late Carboniferous (Moscovian) Mazon Creek Konservat-Lagerstätte in Illinois, USA. The E. danae CNS demonstrates that the general prosomal synganglion organization has remained essentially unchanged in horseshoe crabs for >300 m.y., despite substantial morphological and ecological diversification in that time. Furthermore, it reveals that the euarthropod CNS can be preserved by molding in siderite and suggests that further examples may be present in the Mazon Creek fauna. This discovery fills a significant temporal gap in the fossil record of euarthropod CNSs and expands the taphonomic scope for preservation of detailed paleoneuroanatomical data in the Paleozoic to siderite concretion Lagerstätten of marginal marine deposits.

Application of confocal laser scanning microscopy to the study of amber bioinclusions

Confocal laser scanning microscopy is an essential analytical tool in biological, biomedical, and material sciences, integrating microscope manufacturing technology, optical-electronic technology, and computer technology. In the last decade, confocal laser scanning microscopy has been successfully applied to the study of amber bioinclusions. Enhanced signal to noise ratios, resolution power, capability of optical sectioning, three-dimensional reconstruction, and better performance when imaging thicker samples provide a great deal of valuable and detailed morphological information about amber fossils. We briefly discuss the practical applications of CLSM in amber studies and compare it with other imaging methods commonly used in the field, including bright-field microscopy, wide-field fluorescence microscopy, and micro-computed tomography. A general procedure for imaging amber inclusions with CLSM is provided, with a focus on pretreatments and image processing.

Wanted, tracked down and identified: Mesozoic non-biting midges of the subfamily Chironominae (Chironomidae, Diptera)

AbstractHere we provide evidence for the presence of non-biting midges of the subfamily Chironominae in the Mesozoic, based on descriptions of exceptionally rare amber inclusions. The subfamily has already been reported, but based on a single and unspecified record from Late Cretaceous Taimyr amber (~84 Mya). That record is here revised and confirmed. Moreover, a new find in Burmese amber locates the temporal boundary of the subfamily back to the mid-Cretaceous (probably ~100 Mya). We describe two new genera assigned to the tribe Pseudochironomini: Mesoacentron gen. nov. with the species Mesoacentron kaluginae sp. nov. (Taimyr amber) and Palaeocentron gen. nov. with the species Palaeocentron krzeminskii sp. nov. (Burmese amber), the oldest known representative of the subfamily. The systematic position of the new taxa is discussed, and a key to the identification of adult males of extinct and extant Pseudochironomini genera is presented. Insights in the phylogeny and diversification tempo of the Chironominae and Pseudochironomini in the past are also provided.

A new March fly Protopenthetria skartveiti gen. nov. et sp. nov. (Diptera, Bibionidae, Plecinae) from mid-Cretaceous Burmese amber

Bibionidae, also called March flies, is a widespread group of Nematocera and their fossils are very abundant in lacustrine deposits especially in the Oligocene and Miocene, but records as amber inclusions in the Mesozoic are quite rare. Here, we describe a new genus and species of March fly, Protopenthetria skartveiti gen. et sp. nov. from mid-Cretaceous Burmese amber. The new genus and species described and illustrated based on a well-preserved male specimen. A key to all known genera and species of Bibonidae from Burmese amber is given. The discovery of Protopenthetria skartveiti gen. nov. et sp. nov. provides evidence about the morphology of Bibionidae in the Mesozoic and illustrates the high diversity of the Burmese amber biota.

First freshwater gastropod preserved in amber suggests long-distance dispersal during the Cretaceous Period

AbstractBurmese amber continues to provide unique insights into the terrestrial biota inhabiting tropical equatorial forests during mid-Cretaceous time. In contrast to the large amount and great diversity of terrestrial species retrieved so far, aquatic biota constitute rare inclusions. Here we describe the first freshwater snail ever preserved in amber. The new speciesGalba primasp. nov. belongs in the family Lymnaeidae, today a diverse and near globally distributed family. Its inclusion in terrestrial amber is probably a result of the amphibious lifestyle typical of modern representatives of the genus. The finding of a freshwater snail on the Burma Terrane, back then an island situated at some 1500 km from mainland Asia, has implications for the dispersal mechanisms of Mesozoic lymnaeids. The Cenomanian species precedes the evolution of waterfowl, which are today considered a main vector for long-distance dispersal. In their absence, we discuss several hypotheses to explain the disjunct occurrence of the new species.

A New Ant Species of the Genus Pheidole Westwood, 18391 from Miocene Mexican Amber

A fossil species of Pheidole Westwood, 1839 (Formicidae, Myrmicinae) was described based on an amber inclusion found in the Miocene strata at Chiapas, southwestern Mexico. It was named Pheidole pauchil sp. nov., which is the first described species of the genus in Mexican amber. This broadens our understanding of the diversity of Pheidole in the Miocene in the southernmost part of North America.

New taxa of extant and fossil primitive moths in South-East Asia and their biogeographic significance (Lepidoptera, Micropterigidae, Agathiphagidae, Lophocoronidae)

We report some surprising recent distributional range extensions of one extant genus and two more families of primitive moths discovered in amber fossils from South-east Asia which were previously only known from Australia and/or the southwestern Pacific, with the possible exception of an undescribed Siberian fossil attributed to Lophocoronidae. During entomological field work in rain forests of central Vietnam a new species of Micropterigidae was discovered. It is described herein as Aureopterix bachmaensis sp. nov. based on male and female specimens collected at light in the Bach-Ma National Park. The identification was corroborated by a molecular analysis. This is the first record of this genus in the Northern Hemisphere, previously thought to be restricted to the Australian Region (including New Caledonia). First results of investigations of Burmese amber inclusions now reveal the presence of the Australian Region families Agathiphagidae and Lophocoronidae in the Cretaceous of Asia. The fossil taxon Agathiphagama perdita gen. nov., sp. nov. is established on the basis of two females and this is assigned to Agathiphagidae. The fossil genus Acanthocorona gen. nov. is established in Lophocoronidae and includes seven species described here as A. skalskiisp. nov., A. bowangisp. nov., A. muellerisp. nov., A. kuranishiisp. nov., A. sattlerisp. nov., A. spiniferasp. nov. and A. wichardisp. nov. The new species can be distinguished by the male genitalia which are illustrated together with wing venation and other morphological characters. The disjunct ranges of these taxa are discussed in a historical biogeographic context. Vicariance and dispersal hypotheses explaining the disjunct pattern are discussed. The discovery of these new species suggests a broader ancestral range of Aureopterix, Agathiphagidae and Lophocoronidae. Their extant ranges may be regarded as remnants or relicts of a wider distribution in the Mesozoic, or at least in the case of Aureopterix they could be the results of recent or ancient dispersal processes, since the calibration of molecular splits does not so far accord with plate tectonics.

A Miocene pyrgodesmid millipede (Polydesmida: Pyrgodesmidae) from Mexico.

A new fossil species of pyrgodesmid millipede (Polydesmida: Pyrgodesmidae) placed in the genus Myrmecodesmus Silvestri, 1910 is described. The type materials are two amber inclusions, male and female specimens that come from Miocene strata in Chiapas, Mexico. Myrmecodesmus antiquus sp. nov. has collum with 10 dorsal tubercles; without porosteles or ozopores; legs of the rings 2–9 with a short projection on the prefemur in both the female and male. Myrmecodesmus antiquus sp. nov is the first fossil record of the genus Myrmecodesmus. This is a New World taxon that belongs to the pantropical family Pyrgodesmidae. Thus, Myrmecodesmus antiquus sp. nov expands the range of the genus to the Miocene tropics in Middle America.

Taxonomic revision of fossil Psilodercidae and Ochyroceratidae spiders (Araneae: Synspermiata), with a new species of Priscaleclercera from mid-Cretaceous Burmese amber, northern Myanmar

Psilodercidae contains some 200 known extant species of small spiders that live in tropical rainforests and caves and is mainly restricted to the Oriental biogeographic realm. Interestingly, at least ten different fossil species have been described from inclusions in Upper Cretaceous Burmese amber. This suggests the family has been diversifying in the region for at least ~100 million years. In this paper, we revise the taxonomy of fossil species of this family and the closely related Ochyroceratidae, based on the re-examination of type specimens of described species. We find that ten Cretaceous species described in the psilodercid genera Priscaleclercera and Aculeatosoma are valid, and present new illustrations of their type material. The genus Propterpsiloderces apparently does not belong to Psilodercidae, but rather to a family representing a stem lineage within Scytodoidea. Ochyroceratidae is represented in the fossil record by a single ochyroceratine genus from Miocene Dominican amber, Arachnolithulus. The original combination of the extant species Leclercera spinata Deeleman-Reinhold, 1995 is reinstated by transferring it from Priscaleclercera, leaving this latter genus as a strictly fossil taxon. Finally, we present the description of a hitherto unknown species of Priscaleclercera from mid-Cretaceous Burmese amber, Priscaleclercera christae sp. nov., bringing the total number of congeners to ten. By studying its morphological features, we argue that Priscaleclercera is a crown-group Psilodercidae, closely related to the Althepus–Leclercera lineage. The high species diversity of Priscaleclercera indicates that Psilodercidae was already a diverse component of the Oriental tropical forests during the Cretaceous.