Amber Research Articles

Cretaceous amber fossils highlight the evolutionary history and morphological conservatism of land snails

Other than hard bones and shells, it is rare for soft tissues to fossilize, but occasionally they are well-preserved in amber. Here, we focus on both modern and fossilized species of the land snail superfamily Cyclophoroidea. Phylogenetic relationships within the Cyclophoroidea were previously studied using extant species, but timing of divergence within the group remains unclear. In addition, it is difficult to observe morphological traits such as the chitinous operculum and periostracum of fossil snails due to their poor preservation potential. Here we describe nine species including a new genus and five new species of well-preserved fossil cyclophoroideans from the mid-Cretaceous Burmese amber. These fossils include not only the shell, but also the chitinous operculum and periostracum, soft body, and excrements. We present the first estimation of divergence time among cyclophoroidean families using fossil records and molecular data, suggesting extreme morphological conservatism of the Cyclophoroidea for nearly 100 million years.

The first amber caridean shrimp from Mexico reveals the ancient adaptation of the Palaemon to the mangrove estuary environment

The aquatic and semiaquatic invertebrates in fossiliferous amber have been reported, including taxa in a wide range of the subphylum Crustacea of Arthropoda. However, no caridean shrimp has been discovered so far in the world. The shrimp Palaemon aestuarius sp. nov. (Palaemonidae) preserved in amber from Chiapas, Mexico during Early Miocene (ca. 22.8 Ma) represents the first and the oldest amber caridean species. This finding suggests that the genus Palaemon has occupied Mexico at least since Early Miocene. In addition, the coexistence of the shrimp, a beetle larva, and a piece of residual leaf in the same amber supports the previous explanations for the Mexican amber depositional environment, in the tide-influenced mangrove estuary region.

Diverse new tropical land snail species from mid-Cretaceous Burmese amber (Mollusca: Gastropoda: Cyclophoroidea, Assimineidae)

The amber fossil record of land snails is poorly studied, with few described species relative to other invertebrate groups (e.g., insects and chelicerates). Recently discovered land snail amber fossils from Myanmar present an important opportunity to understand the tropical land snail fauna of the Cretaceous, which was a time when many terrestrial invertebrates were rapidly diversifying. We describe 12 new land snail species in 3 families from mid-Cretaceous Burmese amber: Eotrichophorus kachin gen. et sp. nov., Perissocyclos kyrtostoma gen. et sp. nov., Macropupina electricus gen. et sp. nov., Paleodiplommatina spelomphalos gen. et sp. nov., Xenostoma lophopleura gen. et sp. nov. and Assiminea striatura sp. nov. and six species of uncertain taxonomic affinity. We also discuss the fossil history of the Cyclophoroidea. We report the first mid-Cretaceous land snail species with periostracal hairs and discuss their adaptive significance, as well as the general paleoecology of Burmese mid-Cretaceous tropical land snails.

Amber.

David Grimaldi introduces amber and the fossils contained therein.

Abstract 2566: CYT01B suppresses RAD51 focus formation and induces replication catastrophe following AID induced DNA damage

Activation Induced Cytidine Deaminase (AID) is a DNA-directed cytidine deaminase that plays a critical role in somatic hypermutation and immunoglobulin class switching in activated B- lymphocytes. AID is often ectopically expressed and promotes genomic hypermutation in a range of lymphoid malignancies. Deamination of genomic cytidines results in point mutations, single strand DNA breaks (SSB), and double strand DNA breaks (DSB). The resulting DNA damage stress leads to an obligate dependency on homologous recombination for cellular survival. RAD51 is a critical component of the homologous recombination pathway, forming nucleoprotein filaments at sites of DNA damage or replication fork stalls. RAD51 mediates homologous DNA strand exchange to promote recombinational repair of breaks and damaged replication forks. We have previously shown that RAD51 depletion leads to accumulation of DNA breaks, and ultimately cell death, in AID expressing cells. We now describe the mechanism of action for a novel small molecule, CYT01B, that targets RAD51 mediated recombination. Treatment of AID-expressing cells with CYT01B, attenuates RAD51 focus formation, reduces the nuclear concentration of RAD51, and promotes RAD51 protein degradation. CYT01B reduces homologous recombination activity in cells, culminating in cytologically visible chromosome fragmentation following DNA damage. Finally, CYT01B treated cells undergo replication catastrophe associated with caspase 3/7 activation and persistent PCNA nuclear signal. We conclude that CYT01B is a novel homologous recombination inhibitor, and propose a new synthetic lethality mechanism, induced by CYT01B, mediated by DNA replication stress and replication catastrophe. Citation Format: Melinda Day, Amber Cyr, Tyler Maclay, Kevin Mills. CYT01B suppresses RAD51 focus formation and induces replication catastrophe following AID induced DNA damage [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2566.

Celebrating Research Devoted to Seed‐Free Land Plants

Celebrating Research Devoted to Seed‐Free Land Plants

Fungi trapped in amber—a fossil legacy frozen in time

Amber is an exceptional organic mineral found all over the world that occasionally contains fossilised organisms. The physical and chemical characteristics of amber pose a challenge when looking for microfossils, such as microfungi. However, also, macrofungi are rarely found in amber, probably because of their ephemeral nature. Yet, in the course of this review, 137 records of non-lichnenised fungi and 182 of lichens were found, the earliest reaching back to the eighteenth century. The findings range from the Carboniferous (ca. 310 Ma) to the Upper Miocene (ca. 10 Ma). About 10% were macrofungi, the rest microfungi (Ascomycetes, Deuteromycetes) or lichens. Identification poses problems due to the fragmentary remains which, as a rule, are inaccessibly entombed in fossilised resin. Most non-lichenised taxa per Ma were, according to this review, recovered from Neogene deposits, whilst lichens showed a marked diversity surge during the Palaeogene. Overall, the record of fungal fossils in amber seems to mirror the diversity patterns through deep time. Nevertheless, the few records from the Palaeozoic and the Lower to Mid-Mesozoic call for the development of additional tools for detection and identification.

Revisión de las avispas figítidas fósiles (Insecta: Hymenoptera: Cynipoidea) descritas de depósitos de compresión durante la primera mitad del siglo XX

En la presente investigación se revisan los holotipos de las avispas fósiles del Cenozoico atribuidas a la familia Figitidae, las cuales fueron descritas en la primera mitad del siglo XX por Charles T. Brues y Georg Statz provenientes de los yacimientos de Florissant (EE.UU.) y Rott-am-Siebengebirge (Alemania), respectivamente. Se proponen los siguientes cambios taxonómicos: Palaeogronotoma? sola (Brues) n. comb., Aulacidea rotundata (Statz) n. comb., A. plana (Statz) n. comb. y A. spiniger (Statz) n. comb. Los cambios taxonómicos para las tres últimas especies indicadas han implicado su emplazamiento en el género actual Aulacidea, de la familia Cynipidae, y por lo tanto no pertenecen a la familia Figitidae como se consideró originalmente en 1938. La revisión de una especie fósil originalmente descrita en 1919, conservada en ámbar báltico, muestra que posee un conjunto único de caracteres para la familia Cynipidae, permitiendo la descripción de una nueva tribu: Kinseycynipsini n. tribe. Se hacen indicaciones taxonómicas referidas a otras tres especies de cinípidos fósiles. La adscripción taxonómica correcta de las especies fósiles de figítidos y cinípidos descritas hace alrededor de un siglo es importante para entender la evolución de estas dos familias de cinipoideos, las cuales desempeñan un importante papel ecológico en los ecosistemas terrestres actuales. También se proporcionan listas actualizadas de las especies fósiles de figítidos y cinípidos conocidas.

Troubled treasure.

Mined in a conflict zone and sold for profit, fossils in Burmese amber offer an exquisite view of the Cretaceous—and an ethical quandary.

A new species of Notaepytus Skelley, 2009 (Coleoptera: Erotylidae: Tritomini)from Dominican amber.

Notaepytus quisqueya sp. nov. (Erotylidae: Erotylinae: Tritomini), is described here from Dominican amber and is the second amber fossil description for the family from the West Indies (Hispaniola). An emended key and a checklist to all known species of Notaepytus are presented.

Ambarticus myanmaricus gen. et sp. nov., the first diving beetle from mid-Cretaceous amber of northern Myanmar (Coleoptera, Dytiscidae, Dytiscinae)

Ambarticus myanmaricus gen. et sp. nov. is described from mid-Cretaceous amber of Myanmar based on examination of a single female specimen, and represents the unique taxon inclusion of fossils of the family Dytiscidae (Coleoptera: Adephaga) from Oriental Region. A new tribe, Ambraticini trib. nov. is established. The new taxon is assigned to subfamily Dytiscinae. This description represents one of a limited number of diving beetle taxa described from fossiliferous amber and is currently the oldest known fossil assigned to Dytiscinae. Key morphological characters of the new taxon are illustrated, and compared with tribes of Dytiscinae.

Baltic amber Staphylinini (Coleoptera: Staphylinidae: Staphylininae): a rove beetle fauna on the eve of our modern climate

AbstractCenozoic climate cooling, particularly during the Eocene, has drastically shaped modern biological assemblages through a shift from an equable greenhouse to a polarized icehouse. Present-day Europe lies in a highly seasonal and temperate area that strongly embodies this modern icehouse climate. Baltic amber provides a Middle Eocene snapshot of the European fauna before this large-scale change. Here, we focused on the rove beetle tribe Staphylinini and conducted a comprehensive phylogenetic study of all known Baltic amber fossils in a total-evidence phylogenetic framework that integrates morphology with molecular data from six gene fragments. Based on our well-resolved topology, we propose the following: †Baltognathina subtrib. nov., Afroquediina subtrib. nov., Antimerina subtrib. nov., †Baltognathus aenigmaticus gen. et sp. nov., †Eolophorus gen. nov., †Laevisaurus robustus and †Laevisaurus gracilis gen. et spp. nov., †Hemiquedius europaeus sp. nov. and †Bolitogyrus fragmentus sp. nov. †Quedius cretaceus is placed as junior synonym of †Cretoquedius infractus. The earliest definitive fossils of Quediina are reported herein from the Eocene. The Staphylinini fauna of Middle Eocene Europe combined thermophilic, freeze-intolerant lineages with freeze-tolerant, temperate lineages and, unlike most other staphylinid or beetle lineages, all have since become extinct in the Palaearctic region.

Gecko Adhesion in Space and Time: A Phylogenetic Perspective on the Scansorial Success Story.

An evolutionary perspective on gecko adhesion was previously hampered by a lack of an explicit phylogeny for the group and of robust comparative methods to study trait evolution, an underappreciation for the taxonomic and structural diversity of geckos, and a dearth of fossil evidence bearing directly on the origin of the scansorial apparatus. With a multigene dataset as the basis for a comprehensive gekkotan phylogeny, model-based methods have recently been employed to estimate the number of unique derivations of the adhesive system and its role in lineage diversification. Evidence points to a single basal origin of the spinulate oberhautchen layer of the epidermis, which is a necessary precursor for the subsequent elaboration of a functional adhesive mechanism in geckos. However, multiple gains and losses are implicated for the elaborated setae that are necessary for adhesion via van der Waals forces. The well-supported phylogeny of gekkotans has demonstrated that convergence and parallelism in digital design are even more prevalent than previously believed. It also permits the reexamination of previously collected morphological data in an explicitly evolutionary context. Both time-calibrated trees and recently discovered amber fossils that preserve gecko toepads suggest that a fully-functional adhesive apparatus was not only present, but also represented by diverse architectures, by the mid-Cretaceous. Further characterization and phylogenetically-informed analyses of the other components of the adhesive system (muscles, tendons, blood sinuses, etc.) will permit a more comprehensive reconstruction of the evolutionary pathway(s) by which geckos have achieved their structural and taxonomic diversity. A phylogenetic perspective can meaningfully inform functional and performance studies of gecko adhesion and locomotion and can contribute to advances in bioinspired materials.

Ancient amino acids from fossil feathers in amber

Ancient protein analysis is a rapidly developing field of research. Proteins ranging in age from the Quaternary to Jurassic are being used to answer questions about phylogeny, evolution, and extinction. However, these analyses are sometimes contentious, and focus primarily on large vertebrates in sedimentary fossilisation environments; there are few studies of protein preservation in fossils in amber. Here we show exceptionally slow racemisation rates during thermal degradation experiments of resin enclosed feathers, relative to previous thermal degradation experiments of ostrich eggshell, coral skeleton, and limpet shell. We also recover amino acids from two specimens of fossil feathers in amber. The amino acid compositions are broadly similar to those of degraded feathers, but concentrations are very low, suggesting that much of the original protein has been degraded and lost. High levels of racemisation in more apolar, slowly racemising amino acids suggest that some of the amino acids were ancient and therefore original. Our findings indicate that the unique fossilisation environment inside amber shows potential for the recovery of ancient amino acids and proteins.

Throscidae (Coleoptera) relationships, with descriptions of new fossil genera and species.

Two new Throscidae genera from Baltic amber are described: Tyrannosthroscus n..gen. (type species Tyrannothroscus rex n.sp.) and Pseudothroscus n. gen. (type species Pseudothroscus balticus n. sp.). Four species are described from Baltic amber: Tyrannothroscus rex n. sp., Pseudothroscus balticus n. sp., Potergus superbus n. sp. and Trixagus parvulus n. sp. Pactopus burmensis n. sp. is described from Burmese amber. A phylogenetic analysis of the known throscid genera is performed. Aulonothroscus Horn and Trixagus Kugelann are shown to be sister-groups, the sister-group of this clade is the genus Pactopus Horn and the sister group of these three genera is the genus Potergus Bonvouloir. The oldest previously known throscids were species belonging to the genera Rhomboaspis Kirejtshuk Kovalev and Potergosoma Kirejtshuk Kovalev, both from Lebanese Amber, 125-135 Mya. The present analysis shows that the extinct Baltic amber genera Jaira Muona and Pseudothroscus belong to clades at least as old as the Lebanese fossils. The Burmese amber fossil Pactopus burmensis, 99 Mya, is considerably older than any of the previously known species belonging to the four extant genera: Pactopus, Potergus, Aulonothroscus or Trixagus. At least three throscid lineages are now known to have gone extinct. Both the Pactopus and Potergus lineages are more than 99 milion years old, whereas the Aulonothroscus and Trixagus lineages extend at least to the Baltic amber, 50 million years ago. The presence of Jaira in Baltic amber shows that that lineage persisted at least 80 million years before going to extinction.

The paralic Albian–Cenomanian Puy-Puy Lagerstätte (Aquitaine Basin, France): An overview and new data

The Puy-Puy quarry at Tonnay-Charente (Charente-Maritime, SW France) is a sand quarry exposing a 9-m-thick series of latest Albian–earliest Cenomanian (mid-Cretaceous) age. The uppermost Albian deposits consist of lignitic clay containing fossiliferous amber. The lowermost Cenomanian sand deposits alternate with clay intercalations containing plant remains. One of these clay levels, named P1, shows an outstanding accumulation of conifer and angiosperm macrofossils including delicate reproductive structures such as flowers. Plant remains are associated with invertebrates such as insects (Odonata, Dictyoptera, Diptera), crustaceans (Mecochirus sp.), putative brachiopods (aff. Lingula sp.), and worms. A few vertebrate remains such as shark egg capsules (Palaeoxyris sp.) and a feather are present in the fossil assemblage, as well as an enigmatic specimen tentatively interpreted as a cephalochordate or a petromyzontiform. Various ichnofossils occur in abundance, such as crustacean coprolites and burrows (Ophiomorpha isp.), insect coprolites (Microcarpolithes hexagonalis), and leaf herbivory, galls and mines. The sediments have been deposited in a coastal, calm and brackish area.

A New Species of the Family Smicripidae (Coleoptera: Cucujoidea) from Rovno Amber

Smicrips fudalai sp. nov. described herein from Late Eocene Rovno amber. It is the first palmetto beetle from Ukraine, whereas the extant Smicrips species are common in the tropics and subtropics of the New World. The new species differs from all extinct species in narrower head (the head with eyes not wider than the pronotum), slender legs, non-dilated tibia without spurs, and elytra that leave only the pygidium exposed. This is the third Eocene European palmetto beetle species, but no fossil smicripids remain to be unknown from Dominican and Mexican amber or other New World fossil localities yet (extant species from Mexico and Hispaniola are known). The Early Cenozoic Smicripidae of the New World were perhaps related not to the macrothermal communities, but to the upper microthermal to lower mesotermal communities. The tarsal formula 5–5–5 is characteristic of both Eocene and Cretaceous representatives of the family.

Tracking the Connection between Disorder and Energy Landscape in Glasses Using Geologically Hyperaged Amber.

Fossil amber offers the unique opportunity to investigate an amorphous material that has been exploring its energy landscape for more than 110 million years of natural aging. By applying different X-ray scattering methods to amber before and after annealing the sample to erase its thermal history, we identify a link between the potential energy landscape and the structural and vibrational properties of glasses. We find that hyperaging induces a depletion of the vibrational density of states in the terahertz region, also ruling the sound dispersion and attenuation properties of the corresponding acoustic waves. Critically, this is accompanied by a densification with structural implications different in nature from that caused by hydrostatic compression. Our results, rationalized within the framework of fluctuating elasticity theory, reveal how upon approaching the bottom of the potential energy landscape (9% decrease in the fictive temperature) the elastic matrix becomes increasingly less disordered (6%) and longer-range correlated (22%).

Amber Fang: Hunted by Arthur Slade

Amber Fang: Hunted by Arthur Slade

In Memoriam to Jochen Heinrichs (1969–2018)

This special issue of Bryophyte Diversity and Evolution is dedicated to Jochen Heinrichs (1969–2018) in commemoration of his outstanding contributions to bryology. His work spanned a diverse spectrum of topics that will be reflected in this special issue by 10 research papers. Therein, and in honor of Jochen, the moss genus Jochenia gen. nov. (Schlesak et al. 2018), the liverwort species Frullania heinrichsii sp. nov. (Atwood et al. 2018), as well as the liverwort amber fossil Geocalyx heinrichsii sp. nov. (Katagiri 2018) are introduced to the scientific community.