Amber Inclusions Research Articles

Fossil arachnids from the earliest Miocene Foulden Maar Fossil-Lagerstätte, New Zealand

Selden, P.A. & Kaulfuss, U., 28 May 2018. Fossil arachnids from the earliest Miocene Foulden Maar Fossil-Lagerstätte, New Zealand. Alcheringa 43, 165–169. ISSN 0311-5518.Fossil Arachnida from New Zealand are extremely rare and represented by some unidentifiable amber inclusions only. The first fossil arachnids from New Zealand to be described in detail are presented here, based on four compression fossils from the earliest Miocene Fossil-Lagerstätte at Foulden Maar, South Island. Two specimens are referred to Arachnida incertae sedis and Araneomorpha incertae sedis, respectively, whereas two specimens are mygalomorph spiders. One of these is placed in the Rastelloidina clade of Mygalomorphae, probably in the Idiopidae, which is represented in New Zealand by the extant Cantuaria.P.A. Selden* [selden@ku.edu] Paleontological Institute and Department of Geology, University of Kansas, Lindley Hall, 1475 Jayhawk Boulevard, Lawrence, KS 66045, USA; U. Kaulfuss [uwe.kaulfuss@otago.ac.nz] Department of Geology, University of Otago, PO Box 56, Dunedin, New Zealand. *Also affiliated with: Natural History Museum, London, UK.

Exceptionally well-preserved dragonflies (Insecta: Odonata) in Mexican amber

Zheng, D., Nel, A., Jarzembowski, E.A., Chang, S.-C., Zhang, H. & Wang, B., 25 May 2018. Exceptionally well-preserved dragonflies (Insecta: Odonata) in Mexican amber. Alcheringa 43, 157–164.Dragonflies (odonatans) are comparatively rare as amber inclusions, and most are not well preserved on account of their size. Here, we report a single piece of Mexican amber with one complete dragonfly and two damselflies. The dragonfly is attributed to the extant gomphid Erpetogomphus Selys Longchamps, and the damselflies belong to the extant coenagrionid Argia Rambur. Both genera are nowadays distributed widely in Mexico. The new discovery dates the origins of these two genera to the Miocene at least.Daran Zheng [dranzheng@gmail.com], Edmund A. Jarzembowski* [jarzembowski2@live.co.uk] Haichun Zhang [hczhang@nigpas.ac.cn] and Bo Wang† [bowang@nigpas.ac.cn] State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, 39 East Beijing Road, Nanjing 210008, PR China; André Nel [anel@mnhn.fr] Institut de Systématique, Évolution, Biodiversité, ISYEB-UMR 7205-CNRS, MNHN, UPMC, EPHE, Muséum national d’Histoire naturelle, Sorbonne Universités, 57 rue Cuvier, CP 50, Entomologie, F-75005, Paris, France; Daran Zheng, Su-Chin Chang [suchin@hku.hk] Department of Earth Sciences, The University of Hong Kong, Hong Kong Special Administrative Region, PR China. *Also affiliated with Department of Earth Sciences, The Natural History Museum, London SW7 5BD, UK. †Also affiliated with Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, PR China.

Arthropods in modern resins reveal if amber accurately recorded forest arthropod communities

Amber is an organic multicompound derivative from the polymerization of resin of diverse higher plants. Compared with other modes of fossil preservation, amber records the anatomy of and ecological interactions between ancient soft-bodied organisms with exceptional fidelity. However, it is currently suggested that ambers do not accurately record the composition of arthropod forest paleocommunities, due to crucial taphonomic biases. We evaluated the effects of taphonomic processes on arthropod entrapment by resin from the plant Hymenaea, one of the most important resin-producing trees and a producer of tropical Cenozoic ambers and Anthropocene (or subfossil) resins. We statistically compared natural entrapment by Hymenaea verrucosa tree resin with the ensemble of arthropods trapped by standardized entomological traps around the same tree species. Our results demonstrate that assemblages in resin are more similar to those from sticky traps than from malaise traps, providing an accurate representation of the arthropod fauna living in or near the resiniferous tree, but not of entire arthropod forest communities. Particularly, arthropod groups such as Lepidoptera, Collembola, and some Diptera are underrepresented in resins. However, resin assemblages differed slightly from sticky traps, perhaps because chemical compounds in the resins attract or repel specific insect groups. Ground-dwelling or flying arthropods that use the tree-trunk habitat for feeding or reproduction are also well represented in the resin assemblages, implying that fossil inclusions in amber can reveal fundamental information about biology of the past. These biases have implications for the paleoecological interpretation of the fossil record, principally of Cenozoic amber with angiosperm origin.

First amber inclusion of a glaresid beetle from the Upper Cretaceous of Myanmar (Coleoptera: Scarabaeoidea)

Glaresis burmitica sp. nov., the first amber inclusion of Glaresidae is described and figured based on a well preserved adult from the Upper Cretaceous Burmese amber. Glaresis burmitica differs from all extant and extinct congeners by its small body size, non-grooved pronotum, teeth on protibial outer margin, and unmodified outer margins of meso- and metatibia. The discovery of Glaresis burmitica from the Late Cretaceous suggests that the extant genus Glaresis is an ancient lineage, and its external morphologies changed very little through a long geological time. Together with previous findings in the Lower Cretaceous of northeastern China, it also highlights the palaeodiversity of the peculiar family Glaresidae.

Chrysidid wasps (Hymenoptera: Chrysididae) from Cretaceous Burmese amber: Phylogenetic affinities and classification

Representatives of chrysidid wasps are described for the first time from inclusions in Late Cretaceous Burmese amber. Five new genera and new species are described and illustrated: †Auricleptes nebulosus gen. et sp. nov., †Azanichrum pilosum gen. et sp. nov., †Bohartiura glabrata gen. et sp. nov., †Burmasega ammirabilis gen. et sp. nov., and †Miracorium tetrafoveolatum gen. et sp. nov. We coded 49 morphological characters for species representing the subfamilies Amiseginae, Loboscelidiinae, Cleptinae and Chrysidinae. The cladistic analysis recovered the following relationships: Cleptinae + (†Auricleptes + (†Burmasega + (†Miracorium + ((Loboscelidiinae + Amiseginae) + ((†Azanichrum + †Bohartiura) + (†Palaeochrum Krombein + (extant Chrysidinae)))))). In light of the cladistic results, we discuss the implications of characters for the interpretation of phylogenetic relationships within the family, and explore the main morphological changes occurred during the diversification of the chrysidid wasps.

Amber inclusions from New Zealand

Terrestrial ecosystems of the long-isolated former Gondwanan landmass of New Zealand are hotspots of modern global biodiversity, based on the level of endemism and distinctiveness of the biota. However, little is known of the evolutionary history of the rarely preserved but diverse, distinctive, fragile, mainly soft-bodied organisms such as arthropods and fungi that comprise 95% of biodiversity in forest ecosystems. Our discovery of fossils preserved in Oligocene/Miocene amber of araucarian origin reveals a diverse invertebrate and fungal biota and complex ecological networks. These fossils comprise 10 orders and approximately 20 families of terrestrial arthropods and include representatives of Pseudoscorpiones, Acari, Araneae, Collembola, Hemiptera, Psocoptera, Hymenoptera, Coleoptera, Lepidoptera and Diptera, together with nematodes, mold fungi and araucarian wood. Ecologically the fossils encompass predators such as spiders with web remains, soil and bark mites, detritivores, parasites, fungivores and decomposers, fungi that grew on solidified resin flows, as well as predatory fungi. This study reports the first major amber deposit with an abundance of biological inclusions from the Southern Hemisphere and the only Cenozoic one of verified araucarian origin. These fossils expand the global record and evolutionary history of many arthropod and fungal groups, providing insights into mid-Cenozoic araucarian forest ecosystems and resolving controversial issues around the antecedents of the modern New Zealand terrestrial biota.

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.

Description of the first flightless platynine ground beetle preserved in Baltic amber (Coleoptera: Carabidae)

Species of the megadiverse ground beetle tribe Platynini occur on all continents except Antarctica. It has been long recognized that platynine beetles were preserved in the Eocene Baltic amber. However, thus far only a single Eocene fossil has been described to the species level. In the present paper, a new species of Platynini known only as an amber inclusion fossil is described and imaged using light microscopy and micro X-ray computed tomography. Since this species cannot be assigned to any of the recently described genera, the monotypic genus Praeanchodemus gen. n., with the type species P. punctaticeps sp. n., is erected. There is some evidence from external morphology that Praeanchodemus gen. n. is part of a lineage comprising the recent genera Paranchodemus, Rhadine, and Tanystoma. However, since some synapomorphies were not found, the true relationships of the fossil taxon remain moot.

Eoplaytpus jordali gen.n. et sp.n., the first described Platypodinae (Coleoptera: Curculionidae) from Baltic amber

The first platypodine beetle from Baltic amber, Eoplatytpus jordali gen.n. et sp.n., is described from two specimens. The species shares diagnostic characters with Tesserocerini and a phylogeny reconstructed with morphological and DNA data groups the species with Mitosoma, Cenocephalus, and Chaetastus. The species lacks mesepisternal and mesonotal carinae and has an antennal club wider than long, which is a unique combination of generic characters. Furthermore, the species provides an additional calibration point for dating of platypodine phylogenies. It corroborates the molecular dating of the Mitosoma + Cenocephalus + Chaetastus clade at approximately 50 mya. Finally, the rarity of platypodine Baltic amber inclusions is discussed.

A well-preserved true dragonfly (Anisoptera: Gomphides: Burmagomphidae fam. nov.) from Cretaceous Burmese amber

Amber inclusions have been studied for several centuries, but true dragonflies are extremely rare, with only several poorly preserved wings recorded. In Burmese amber, odonatans are relatively diverse, but true dragonflies are still rare. An excellently preserved true dragonfly, Burmagomphides electronica Zheng, Nel & Wang gen. et sp. nov., representing the new family Burmagomphidae Zheng, Nel & Wang fam. nov., is described here from Cretaceous Burmese amber. This is the first well-preserved true dragonfly with complete wings in this amber. It is attributed to the clade Oligophlebiata because it has symmetrical RP branches at the midfork and a well-developed trigonal planate as in the clade Hagenioidea, and the vein CuAa distinctly shortened with reduced pectinate branching as in Brevicubitalia; it differs, however, from the latter two in having a narrow hind wing base.http://zoobank.org/urn:lsid:zoobank.org:pub:9E2B3C24-B4D7-43E5-B013-32245D301167

Mesostictinae subfam. nov., an archaic group of platystictid damselflies (Odonata: Zygoptera) from mid-Cretaceous Burmese amber

Odonatans are quite rare in the fossil record compared with the other insects, especially in Cretaceous amber inclusions. The extant family Platystictidae is one of the most diverse Zygoptera, but short of fossil records. In this paper, a new species, Mesosticta davidattenboroughi sp. nov., is described from mid-Cretaceous Burmese amber, representing the third-known fossil species of Platystictidae. Mesosticta davidattenboroughi sp. nov. has a long IR1 beginning one cell distal of the base of RP2, confirming the previous attribution of Mesosticta Huang, Azar, Cai & Nel, 2015 to Platystictidae. It differs from other species of Mesosticta in having a long IR1 and a basally crossed subdiscoidal cell. The fossil genus Mesosticta shares the diagnostic characters of the modern platystictid genera, viz. a basally recessed ‘CuP’ (shared by all species), a very long IR1 (only in Mesosticta davidattenboroughi sp. nov.), and a specialized subdiscoidal area mostly rhomboidal in shape (only in Mesosticta electronica Zheng, Zhang, Chang & Wang, 2016). Based on the platystictid damselflies from Burmese amber, a new subfamily Mesostictinae subfam. nov. is established. Mesostictinae subfam. nov. represents the first fossil group of modern platystictid damselflies, documenting the appearance of Platystictidae as early as mid-Cretaceous. It differs from modern Platystictidae by the presence of fewer postnodal and postsubnodal crossveins, a short MP, the base of RP2 being nearer to the subnodus and the nodus lying more distally.http://zoobank.org/urn:lsid:zoobank.org:pub:6669DBCD-F2EF-4C84-9623-BD33142AD36B

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.

Cretaceous inclusions in Burmese amber throw a new light on the evolution of the Meropeidae (Mecoptera)

The family Meropidae is a small, strongly relict group of scorpionflies (Mecoptera), comprising six species: three fossil and three recent ones. A characteristic feature of the family is the forceps of the male genitalia which resemble the cerci of Dermaptera. A male of a recently described Cretaceous species Burmomerope clara Zhao and Wang, 2016 is herein described for the first time based on a well-preserved fossil from Burmese amber of mid-Cretaceous age. Another specimen, a well preserved female of. B. clara enables the description of additional characters of the body which allows an emended diagnosis of this species to be made. Based on the new specimens, a phylogenetic analysis of the family Meropeidae was made and the phylogenetic relationships within the family are discussed.

Abundant assemblage of Ostracoda (Crustacea) in Mexican Miocene amber sheds light on the evolution of the brackish-water tribe Thalassocypridini

Amber inclusions of fully aquatic animals are rare, most of them isolated specimens of water-bound insect larvae. In contrast, we here describe an ample, speciose fauna of 262 fully aquatic individuals of Ostracoda (Crustacea) from Mexican amber of Early Miocene age. This fauna was trapped whilst under water swimming around trunks of resin-producing trees in a brackish lagoon. Ostracod crustaceans are typically around a millimeter in length, and are known for their mostly well-calcified bivalved carapaces that account for their unparalleled fossil record in arthropods. However, in the Chiapas amber we found representatives of the tribe Thalassocypridini, which are characterised by lightly calcified carapaces and therefore lack a substantial fossil record. Embedded in amber, this ‘drawback’ becomes a clear benefit because the unobstructed view onto the appendages otherwise hidden in the carapace allowed us to identify nine ostracod species, six of them new to science. The exceptional number of individuals permitted insights into population composition, reproduction, taphonomy and into micro-environmental parameters of the amber’s place of formation. Based on ecological data available for Recent Thalassocypridini species, we posit that this tribe reached a peak radiation in open lagoonal settings during the Miocene, and shifted towards anchialine environments by the Recent.http://zoobank.org/lsid:zoobank.org:pub:3C93A06B-F86B-404F-985D-139897F97EF3

Hepatics from Rovno amber (Ukraine), 6. Frullania rovnoi, sp. nov.

A fossil species of the extant liverwort genus Frullania Raddi is described and illustrated, based on a single inclusion in a piece of Rovno amber (Ukraine) that shares its age with Late Eocene Baltic amber, its northern contemporary. Frullania rovnoi is characterised by leaves with a rounded dorsal lobe and the absence of ocelli. The ventral lobe is inflated and forms a saclike lobule, which is bell-shaped and somewhat constricted above the mouth. The bifid underleaves have several blunt teeth or angulations along the shoulder. The Rovno fossil differs sufficiently from morphologically similar species preserved in Baltic and Bitterfeld amber as to be described as new to science. The shape of the lobules and underleaves, as well as the absence of ocelli, indicate an affiliation to F. sect. Australes, hitherto represented in Eocene amber inclusions solely by F. schumannii (Casp.) Grolle. The Rovno fossil is distinguished from extant species of F. subg. Australes and from F. schumannii by having roughly and irregularly dentate-angulate underleaf margins.

Discovery of a new Mesozoic species of the ancient genus Lepicerus (Coleoptera: Myxophaga: Lepiceridae), with implications for the systematic placement of all previously described extinct ‘lepiceroids’

†Lepicerus mumia Jałoszyński & Yamamoto, sp. nov. is described based on a Cenomanian Myanmar amber inclusion. This is the third known and the best preserved fossil of ‘lepiceroid’ myxophagan beetles, making it possible to carry out a more detailed comparative study than previously published findings. Detailed analyses of diagnostic characters given by previous authors for †Haplochelus (†Haplochelidae) and †Lepichelus (= Lepiceroides) (Lepiceridae) led to conclusions that some features might have been misinterpreted, others do not differ from those in Lepicerus, and the remaining morphological structures can be regarded as variable within one genus. Consequently, Haplochelus and Lepichelus are placed as junior synonyms of Lepicerus, and the synonymy between Haplochelidae and Lepiceridae, previously suggested by other authors, is maintained. Lepicerus mumia, although classified in the extant genus, shows an unusual, presumably ancestral myxophagan character state, a partly divided protarsus, with a distinctly demarcated, enlarged and curved tarsomere 1. The presence of a crust partly covering the body of L. mumia suggests a similar biology as that of two extant species that live near river banks among other semiaquatic arthropods.

The oldest fossil mushroom.

A new fossil mushroom is described and illustrated from the Lower Cretaceous Crato Formation of northeast Brazil. Gondwanagaricites magnificus gen. et sp. nov. is remarkable for its exceptional preservation as a mineralized replacement in laminated limestone, as all other fossil mushrooms are known from amber inclusions. Gondwanagaricites represents the oldest fossil mushroom to date and the first fossil mushroom from Gondwana.

Another amber first: A tiny tetraphalerin beetle (Coleoptera: Archostemata) in Myanmar birmite

A new tetraphalerin beetle, Tetraphalerus lindae sp. nov. (Insecta: Coleoptera: Archostemata) is described from mid-Cretaceous Burmese amber from northern Myanmar. This is the first species of this Jurassic-recent genus of archaic beetles to be described from amber inclusions, and is the first tetraphalerin cupedid from Burmese amber. This small, unusual Cretaceous Tetraphalerus is considered to belong to the T. bruchi species group of this now relict South American genus.

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.

Diverse early dwarf mistletoes (Arceuthobium), ecological keystones of the Eocene Baltic amber biota.

Extant dwarf mistletoes (Arceuthobium M. Bieb., Viscaceae) are hemiparasites with complex roles in nature. They are one of the most severe pests in northern hemisphere conifer forests, but they also enhance the structural complexity and species diversity of the forests. Here, we describe the first pre-Miocene macrofossils of dwarf mistletoes. The fossils from Eocene Baltic amber provide new insights into the morphological evolution of the Arceuthobium lineage and its paleobiogeography. The amber inclusions were investigated with light microscopy and compared with extant Viscaceae and to historic descriptions of lost Baltic amber fossils with affinities to Viscaceae. Six fossil species of the Arceuthobium lineage, A. johnianum comb. nov., A. mengeanum comb. nov., A. conwentzii sp. nov., A. groehnii sp. nov., A. viscoides comb. nov. and A. obovatum sp. nov., occurred in source forests of Baltic amber, representing the oldest macrofossil evidence of dwarf mistletoes. They share morphological features of their bracts, internodes, fruits, and stomata with extant Arceuthobium. Differences from extant dwarf mistletoes, such as the perianth merosity, the nonfusion of squamate bracts and presence of oblanceolate expanded leaves, indicate their affiliation to an ancient lineage of the genus. The occurrence of six species of dwarf mistletoes in a single amber deposit suggests Arceuthobium was a keystone taxon of the Baltic amber source area. As in extant conifer forests, they probably influenced the structural complexity of the forest, not only leading to more open woodlands but also increasing species diversity, at least at a microhabitat scale.