Dominican Amber Research Articles

Notes on Chisosa (Araneae, Pholcidae), with the description of a new species from Mexico.

The genus Chisosa Huber, 2000 previously included only three species of small to tiny North American and Caribbean spiders that are rare in collections and poorly studied. Originally placed in the subfamily Ninetinae, Chisosa is currently considered a representative of Arteminae, close to the North American genus Physocyclus Simon, 1893. This placement has been suggested by molecular data, and it affects the interpretation of morphological characters that were originally thought to support the monophyly of Chisosa: they are shared with Physocyclus and thus plesiomorphic for Chisosa. Here we describe a new species from Mexico, C. calapa sp. nov., and restudy in detail the morphology (incl. ultrastructure) of the type species C. diluta (Gertsch & Mulaik, 1940) and of C. caquetio Huber, 2019, based on newly collected material. We document further similarities with Physocyclus but find only weak morphological support for the monophyly of Chisosa (body size reduction and short legs). In addition, we document surprisingly large genetic distances among C. caquetio specimens from Curaao (>14% CO1 K2P distances), possibly indicating species limits. Finally, we propose that the Dominican amber genus Serratochorus Wunderlich, 1988, based on a single male specimen, is also phylogenetically close to Chisosa and should be included in future studies on these enigmatic spiders.

The second treehopper species in Miocene Dominican amber (Hemiptera: Membracidae)

Summary Stylocentrus pouilloni n. sp., the second species from the mid-Miocene Dominican amber, is described. This new occurrence is important as it enriches the incomplete fossil record of Membracidae, a morphologically highly diversified family among Cicadomorpha, and corroborates the hypothesis of an early divergence of Stegaspidinae within Membracidae.

A new species of the genus Cheiloceps Uhler, 1895 (Hemiptera: Fulgoromorpha: Issidae) from the Dominican amber.

A new species of the planthopper genus Cheiloceps Uhler, 1895 (Issidae, Issinae, Thioniini), Cheiloceps magnifrons sp. nov., is described from the Dominican amber. Issidae fossils are briefly discussed.

Impact of increasing morphological information by micro-CT scanning on the phylogenetic placement of Darwin wasps (Hymenoptera, Ichneumonidae) in amber

The correct interpretation of fossils and their reliable taxonomic placements are fundamental for understanding the evolutionary history of biodiversity. Amber inclusions often preserve more morphological information than compression fossils, but are often partially hidden or distorted, which can impede taxonomic identification. Here, we studied four new fossil species of Darwin wasps from Baltic and Dominican amber, using micro computed tomography (micro-CT) scans and 3D reconstructions to accurately interpret and increase the availability of morphological information. We then infer their taxonomic placement in a Bayesian phylogenetic analysis by combining morphological and molecular data of extant and fossil Darwin wasps and evaluate the impact and usefulness of the additional information from micro-CT scanning. The results show that although we gained significant morphological information from micro-CT scanning, especially concerning measurements and hidden dorsal and ventral structures, this did not impact subfamily-level placement for any of the four fossils. However, micro-CT scanning improved the precision of fossil placements at the genus level, which might be key in future dating and diversification analyses. Finally, we describe the four new fossil species as Rhyssa gulliveri sp. nov. in Rhyssinae, Triclistus levii sp. nov. in Metopiinae, Firkantus freddykruegeri gen. et. sp. nov. in Pimplinae and Magnocula sarcophaga gen. et sp. nov. in Phygadeuontinae. The first two species are the first known representatives of the subfamilies Rhyssinae and Metopiinae in amber.

First pyraloid (Insecta, Lepidoptera) caterpillar from Dominican amber

Only three fossils in the Pyraloidea (Insecta, Lepidoptera) have been confirmed to date, two adults and one larva. The first confirmed larva, in the subfamily Pyraustinae (Crambidae), was described from Baltic amber. Recently, another pyraloid larva from Dominican amber has come to our attention. We describe this second confirmed larval fossil as Penestola wichardi Solis, Léger & Neumann, sp. nov., based on larval morphological characters, such as setal patterns and the shape of their sclerotized bases or pinacula, and place it in the subfamily Spilomelinae (Crambidae).

A new species and new combination in the planthopper genus Cheiloceps Uhler (Hemiptera: Fulgoroidea: Issidae) from Miocene Dominican amber

Cheiloceps arachnophila sp. nov. (Hemiptera: Fulgoroidea: Issidae) is described and illustrated based on a well-preserved adult male, representing the second species of Issidae known from Early Miocene (Burdigalian) Dominican amber. The only previously described issid from Dominican amber is transferred from Thionia Stål to Cheiloceps Uhler: Cheiloceps douglundbergi (Stroiński & Szwedo) comb. nov. Comparative notes on Cheiloceps and Thionia are provided.

‘Dawn’ hexapods in Cenozoic ambers (Diplura: Campodeoidea)

Abstract Diplura are an ancient group of basal (apterygote) hexapods that thrive in various cryptic terrestrial habitats. Despite an ancient origin that extends at least to the Devonian period, the dipluran fossil record is exceedingly sparse. Here, we document five very rare fossil specimens of the family Campodeidae in amber from the Miocene of the Dominican Republic and the Eocene of the Baltic region. Microscopic preservation in amber provides unique detail for taxonomic placement of small, delicate, soil- and leaf litter-dwelling organisms like these. New taxa include the following: in Lepidocampinae, Lepidocampa glaesi sp. nov. (in Dominican amber); and in Campodeinae, Litocampa eobaltica sp. nov. (in Baltic amber) and Rostricampa engeli gen. et sp. nov. (in Dominican amber). Rostricampa has an extraordinary rostrum formed by sclerotized extensions of the clypeus and, probably, the labium, unique among diplurans. These new taxa provide rare additional data on the fossil record of the earliest diverging lineages of the hexapods and shed light on their evolution and ecology.

New records of assassin bugs (Hemiptera: Heteroptera: Reduviidae) for the Dominican Republic

The Hispaniolan fauna of Reduviidae is only partially known, as it has never been the subject of a comprehensive taxonomic or faunistic inventory. These species belong to Neotropical genera that have Caribbean, Central and South American distributions. In this contribution new records are given for 14 species of assassin bugs belonging to six subfamilies. Among these, seven species are first records from the Dominican Republic and the island of Hispaniola: Bactrodes spinulosus Stål, 1862 (Bactrodinae), Lophoscutus rideri Kormilev, 1988, Lophoscutus rugosipes (Guérin-Méneville, 1857) both belonging to Phymatinae, Leogorrus pallipes Stål, 1872 (Reduviinae), and the Saicinae species Oncerotrachelus nasutus (Bergroth, 1913), Tagalis drakkar Varela & Melo, 2017 and Tagalis grossi Gil-Santana, 2011. With these new records the reported extant fauna of Hispaniolan Reduviidae reaches a total of 46 documented species, which are classified in 25 genera and 10 subfamilies. Additionally, 13 fossil species have been reported from the Dominican amber.

The first neotropical ground beetle (Coleoptera, Carabidae) from the Eocene of Ukraine: finding the first Old World ant nest beetle related to Eohomopterus in the Rovno amber

ABSTRACTThe first record of the tribe Paussini Latreille is reported based on a specimen from late Eocene Rovno amber. It is the first known close relative of the genus Eohomopterus (subtribe Carabidomemnina) in the Old World. The recent and Neogene distribution of Eohomopterus is Neotropical, with extant representatives in Ecuador, Brazil and the West Indies, and extinct species in Dominican and Mexican amber. The occurrence of the Neotropical Carabidomemnina in Rovno amber and the presence of the Oriental Protopaussini in Dominican amber are of significant interest as evidence of the probable transarctic migrations of their ant host in the early Eocene.

Paraphloeostiba dominicana sp. nov.: The first omaliine rove beetle from Dominican amber (Coleoptera: Staphylinidae: Omaliinae)

Paraphloeostiba dominicana Shavrin & Jenkins Shaw, sp. nov. from mid-Miocene Dominican amber is described and illustrated. It represents the first species of the rove beetle subfamily Omaliinae from this Neotropical fossil deposit and represents a genus that is not known among the extant fauna of the Neotropics. The new species, embedded within a large piece of amber, was scanned using X-ray micro-computed tomography (μCT), to enable the study of its morphology, including the male genitalia (aedeagus). Based on the revealed characters, the new species is compared with extant and extinct species of the genus Paraphloeostiba Steel, 1960 whose wide extant distribution is confined to the (sub)tropical zones of the world except the Neotropical region and whose fossil record is otherwise known from two species preserved in Eocene Baltic amber from Denmark and Russia. The systematic placement of the genus within the tribe Omaliini, its current and historical ecology and biogeography, as well as the probability that it will be found in the recent Neotropical fauna among the unrevised and undescribed species of Omaliinae are discussed.

Revision of Bethylinae from Dominican amber, with description of a new genus (Hymenoptera, Bethylidae)

Fossil species of bethyline wasps from Dominican amber are revised. Based on a cladistic analysis of female morphological data we recognize a new genus and species, †Crassibethylus dominicanusgen. et sp. nov., which came out as sister group of the clade Odontepyris + Prosierola. We also transfer to Bethylidae a fossil taxon originally described in Sclerogibbidae, placing †Pterosclerogibba Olmi as a new junior synonym under Goniozus Förster, in the new combination †Goniozus antiquus (Olmi). Additionally, the third species of Bethylinae known from Dominican amber, †Goniozus respectus Sorg, is diagnosed and illustrated with color images of the holotype. An identification key to the species of Bethylinae from Dominican amber is provided.

Fossil diversity in ‘dawn’ hexapods (Diplura: Projapygoidea), with direct evidence for being chemically predaceous in the Cretaceous

Abstract Diplurans are among the earliest hexapods in the geological record. These primitively wingless relatives of insects are infrequently encountered despite being pervasive in soil habitats. Two groups have disparate adaptations for hunting, one mechanical and the other chemical, in Japygoidea and Projapygoidea, respectively. Here, we report three genera (two new) and four species of fossil Projapygidae preserved in Mesozoic and Cenozoic ambers: Electroprojapyx alchemicus gen. et sp. nov. in mid-Cretaceous Myanmar amber, and Symphylurinopsis punctatus gen. et sp. nov. and two species (unnamed) of Symphylurinus in Miocene Dominican amber. The exceptionally preserved specimens possess cerci that are morphologically specialized for expelling a glandular substance on prey. The new Cretaceous E. alchemicus is a stem group to all living species of the family and provides conclusive Mesozoic evidence for a rare type of predation involving offensive (vs. defensive) secretions. The specimen was fossilized in a preying-and-spraying position with its presumptive meal, a Symphypleona springtail (Collembola), reflecting the behavioural predatory repertoire of modern relatives. Apart from one Cenozoic species, these rare specimens represent the only fossil record of the family Projapygidae. Our findings demonstrate that these basal hexapods were predators of small arthropods of ancient forest soils and enrich our understanding of palaeoecological associations and behavioural strategies paramount for the survival of species.

Deep time extinction of largest insular ant predators and the first fossil Neoponera (Formicidae: Ponerinae) from Miocene age Dominican amber

BackgroundPonerine ants are almost exclusively predatory and comprise many of the largest known ant species. Within this clade, the genus Neoponera is among the most conspicuous Neotropical predators. We describe the first fossil member of this lineage: a worker preserved in Miocene-age Dominican amber from Hispaniola.ResultsNeoponera vejestoria sp. nov. demonstrates a clear case of local extinction—there are no known extant Neoponera species in the Greater Antilles. The species is attributable to an extant and well-defined species group in the genus, which suggests the group is older than previously estimated. Through CT scan reconstruction and linear morphometrics, we reconstruct the morphospace of extant and fossil ants to evaluate the history and evolution of predatory taxa in this island system.ConclusionsThe fossil attests to a shift in insular ecological community structure since the Miocene. The largest predatory taxa have undergone extinction on the island, but their extant relatives persist throughout the Neotropics. Neoponera vejestoria sp. nov. is larger than all other predatory ant workers known from Hispaniola, extant or extinct. Our results empirically demonstrate the loss of a functional niche associated with body size, which is a trait long hypothesized to be related to extinction risk.

Headspace solid-phase microextraction comprehensive 2D gas chromatography-time of flight mass spectrometry (HS-SPME-GC × GC-TOFMS) for origin traceability of the genus Hymenaea resinites.

Differentiating the chemical compositions of resinite (amber, copal, and resin) is very crucial for determining the botanical origin and chemical compositions of the fossilised amber and copal. This differentiation also assists in understanding the ecological functions of resinite. Headspace solid-phase microextraction-comprehensive two-dimensional (2D) gas chromatography-time-of-flight mass-spectroscopy (HS-SPME-GC × GC-TOFMS) was firstly proposed and utilised in this research to investigate the chemical components (volatile and semi-volatile compositions) and structures of Dominican amber, Mexican amber, and Colombian copal for origin traceability, which were all produced by trees belonging to the genus Hymenaea. Principal component analysis (PCA) was used to analyse the relative abundances of each compound. Several informative variables were selected, such as caryophyllene oxide, which was only found in Dominican amber, and copaene, which was only found in Colombian copal. 1H-Indene, 2,3-dihydro-1,1,5,6-tetramethyl- and 1,1,4,5,6-pentamethyl-2,3-dihydro-1H-indene were abundantly present in Mexican amber, which were the critical fingerprints for the origin traceability of amber and copal produced by trees from the genus Hymenaea of various geological places. Meanwhile, some characteristic compounds were closely related to the invasion of fungi and insects; their links with ancient fungi and insect categories were also decoded in this study and these special compounds could be used to further study the plant-insect interactions.

Scorpions trapped in amber: a remarkable window on their evolution over time from the Mesozoic period to present days.

This synoptic review aims to bring some general information on fossil scorpions, namely those trapped in amber - fossilized resin - ranging from Lower Cretaceous through the Palaeocene and up to the Miocene. The question to be addressed is how the study of these fossils can be connected with possible present scorpionism problems. A precise knowledge of these ancient lineages provides information about the evolution of extant lineages, including the buthoids, which contain most known noxious species. Among the Arthropods found trapped in amber, scorpions are considered rare. A limited number of elements have been described from the Late Tertiary Dominican and Mexican amber, while the most ancient Tertiary amber from the Baltic region produced more consistent results in the last 30 years, primarily focusing on a single limited lineage. Contrarily, the Cretaceous amber from Myanmar, also called Burmite, has yielded and continues to yield a significant number of results represented by several distinct lineages, which attest to the considerable degree of diversity that existed in the Burmese amber-producing forests. As in my previous similar contributions to this journal, the content of this note is primarily addressed to non-specialists whose research embraces scorpions in various fields such as venom toxins and public health. An overview knowledge of at least some fossil lineages can eventually help to clarify why some extant elements associated with the buthoids represent dangerous species while others are not noxious.

Phylogeny, diversity and biogeography of flightless amphi-Pacific lymantine weevils (Coleoptera: Curculionidae: Molytinae)

We use DNA sequence data to generate the first phylogenetic hypothesis for the weevil tribe Lymantini. These are leaf litter inhabiting beetles generally regarded as restricted to the New World and taxonomically arranged in two subtribes, 11 genera and some 150 named species. An additional genus of questionable affinities to the tribe, Devernodes Grebennikov, 2018, has five described species in Southeastern Asia. All these beetles are flightless and some have eyes reduced in size or absent, traits normally associated with limited dispersal capacity. We performed a phylogenetic analysis of 153 terminals (50 of them belong to Lymantini representing Devernodes and all but three named genera) based on 4,174 bp alignment of one mitochondrial (cox1) and two nuclear fragments (ITS2 and 28S). We find that both Lymantini subtribes Lymantina and Caecossonina are monophyletic, the latter sister to the amphi-Atlantic tribe Anchonini. The Asian genus Devernodes is deeply nested among American Lymantina. The clade of Anchonini plus Lymantini is consistently recovered outside of the CCCMS clade of “higher” weevils (Curculioninae, Conoderinae, Cossoninae, Molytinae and Scolytinae). We hypothesize that the polished head capsule of adult beetles is an apomorphy of Anchonini and Lymantini, the 8-segmented antennal funicle is an apomorphy of Anchonini plus Caecossonina. We attribute the origin of the currently observed amphi-Pacific distribution of Lymantina to normal ecological dispersal facilitated by the warmer periods of the Cenozoic such as the Eocene, and by presently submerged Arctic land bridges. Using parsimony we hypothesize a North American origin for the Anchonini plus Lymantini crown group, as well as that of Lymantina. We argue that Bronchotibia adunatus Poinar & Legalov, 2021, a Dominican amber adult weevil fossil, is not a member of Lymantini and re-classify it as Curculionidae incertae sedis. We present an image gallery of 28 Lymantini specimens to document the morphological diversity of the tribe. We hypothesize the existence of unnamed American genera of Lymantina and make public the DNA-barcode dataset of 89 Lymantini specimens.

Fossil History of Ambrosia Beetles (Coleoptera; Platypodidae) with Description of a New Genus from Dominican Amber

The fossil record of ambrosia beetles is summarized and a new genus and species in the subfamily Mecopelminae, Gongyloceria dominicana gen. et sp. nov. is described. The new genus differs from the extant genus Mecopelmus Blackman, 1944, possessing weakly elongated tarsi, finely faceted eyes, a scape not reaching the posterior margin of the eye, coarsely sculptured pronotum and elytra, and a larger body size. It is the first Miocene record of the Mecopelminae. The genus Xyleborites Wickham, 1913, placem. n. is transferred from the Scolytidae to the Platypodidae. A list of the fossil Platypodidae, including a key to the subfamilies and tribes of ambrosia beetles, is presented. Xyleborites longipennis Wickham, 1913 and Gongyloceria dominicana sp. nov. may have been related to Paullinieae recorded from the late Eocene and the early Miocene of North and Central America. Distribution maps with fossil records for ambrosia beetles are included.

Fossil history of bark-beetles (Coleoptera: Scolytidae) with descriptions of two new species

ABSTRACT The presence of fossil bark beetles from the early Cretaceous to the Miocene is discussed. Changes in the diversity of this group over time are presented. Assumptions about trophic relationships are given. Two new species, Hylastes perkovskyi n. sp. from the tribe Hylastini and Chramesus boninoi n. sp. from the tribe Hylesinini, are described, respectively, from Eocene Rovno and Miocene Dominica amber. These are the first records of the genera Hylastes in Rovno amber and Chramesus in Dominican amber.

First record and two new species of the genus Trichomyia (Diptera: Psychodidae) from the Lower Miocene Dominican amber

Trichomyia (Septemtrichomyia) grimaldii sp. nov. and Trichomyia (Trichomyia) fudalai sp. nov. from the Lower Miocene Dominican amber are characterised, described, illustrated and their taxonomic position discussed. These fossils constitute the first record of the Trichomyiinae and increase the knowledge on the biodiversity of the biological inclusions from the Dominican amber. Chresonymy and subgeneric division of the genus Trichomyia are presented and briefly discussed.

A New Tytthonyx LeConte (Coleoptera: Cantharidae) from Dominican Amber, with Notes on Diagnostic Characters of West Indian Cantharids with Short Elytra

Tytthonyx milleri Ivie, Fanti, and Ferreira, new species (Cantharidae, Tytthonyxini) is described from Miocene Dominican amber. The new species is compared with the other two described fossil taxa of the genus, as well as two additional, undescribed Dominican amber cantharid species, and their morphology is discussed. A comparison of extant and fossil Tytthonyx LeConte and Caccodes Sharp is given.