Miocene Dominican Amber Research Articles

Plastome phylogenomics and new fossil evidence from Dominican amber shed light on the evolutionary history of the Neotropical fern genus Pecluma.

Molecular studies based on chloroplast markers have questioned the monophyly of the fern genus Pecluma (Polypodioideae, Polypodiaceae), which has several species of Polypodium nested within it. We explored the delimitation of Pecluma and its biogeographic pattern by evaluating the phylogenetic position of four Polypodium species not sequenced thus far and integrating the first fossil evidence of Pecluma. Using herbarium material, we applied a genome-skimming approach to obtain a phylogenetic hypothesis of Polypodioideae; assessed the combination of character states observed in the fossil from Miocene Dominican amber using a previously published phylogeny of Polypodioideae based on four plastid markers as framework; calculated divergence times; and conducted an ancestral area estimation. Within Polypodioideae, Pecluma was recovered as sister to Phlebodium. Three of the newly sequenced species-Polypodium otites, P. pinnatissimum, and P. ursipes-were recovered with maximum support within the Pecluma clade, whereas P. christensenii remained within Polypodium. The closest combination of character states of the fossil was found within Pecluma. Our biogeographic analyses suggest an Eocene origin of the genus in South America, with several subsequent Oligocene and Miocene colonization events to Mexico-Central America and to the West Indies. Although the circumscription of Pecluma is still challenging, our results elucidate the origin and age of the genus. The newly described fossil, Pecluma hispaniolae sp. nov., supports the hypothesis that the epiphytic communities of the Greater Antilles exhibit a constant generic composition since the Miocene. We propose new combinations (Pecluma otites, Pecluma pinnatissima, and Pecluma ursipes) to accommodate three species previously classified in Polypodium.

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.

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.

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.

A new fossil euphorine genus and species (Hymenoptera, Braconidae) with the longest known ovipositor from Dominican amber

A new genus and species of the braconid subfamily Euphorinae, Palaeorionis longicaudisgen. et sp. nov., is described and illustrated from Miocene Dominican amber. This new genus is characterised by the long and tube-shaped petiole, presence of both radiomedial (2-SR and r-m) veins on the infuscate fore wing and long ovipositor.

A new fossil inchworm moth discovered in Miocene Dominican amber (Lepidoptera: Geometridae)

We report a fossil geometrid moth, a male, virtually complete, preserved in a clear piece of Miocene Dominican amber dating from 19 to 16 Mya. Fore- and hindwings appear partially overlapped, and all body characters are visible externally in dorsal and ventral views, including the outer surface of the valvae of the genitalia. The scale pattern on the wing membrane is preserved, whereas the wing color pattern is not. It belongs to the genus Dolichoneura (Geometridae: Desmobathrinae) and is named Dolichoneura jorelisae Sarto i Monteys, Hausmann, Baixeras and Peñalver sp. n., based on wing features. Because of the poor fossil record of lepidopterans, both in amber and compression rocks, the description of the available well-preserved specimens is of considerable interest for phylogenetic studies. Furthermore, it could also serve for calibrating molecular clocks and for paleobiogeographic inferences.

Revision of recluse spiders (Araneae: Sicariidae: Loxosceles) preserved in Dominican amber and a total-evidence phylogeny of Scytodoidea reveal the first fossil Drymusidae

Recluse or violin spiders in the genus Loxosceles (Scytodoidea: Sicariidae) are a diverse group (~140 extant species) including medically important species and distributed mainly in the Americas, Africa, and the Mediterranean region. In addition, this genus includes three fossil species from Miocene Dominican amber. Here we revise the taxonomy of these fossil species by examining, imaging and re-describing their type specimens. We find that L. defecta Wunderlich, 1988 and L. deformis Wunderlich, 1988 are bona fide members of the genus and report additional characters overlooked in their original descriptions. We further study the holotype of L. aculicaput Wunderlich, 2004 using synchrotron radiation micro-computed tomography to reveal previously unknown morphological details hidden by fissures in the amber. We found several characters inconsistent with Loxosceles but consistent with Drymusa (false violin spiders; Scytodoidea: Drymusidae), such as three claws, well-developed podotarsite, and a broad colulus. This suggests the species is misplaced in Loxosceles. To test this hypothesis, we estimated a total-evidence phylogeny of the superfamily Scytodoidea including extant and fossil taxa, morphological data, traditional molecular markers, and sequences of ultra-conserved elements. The results show unambiguously that L. aculicaput belongs to Drymusa and is a close relative of extant species of the genus inhabiting the Greater Antilles. Therefore, we here transfer this species to Drymusa, establishing a new combination and new family assignment. Drymusa aculicaputcomb. nov. represents the first known fossil Drymusidae and shows that crown members of this genus already existed in the Miocene.

Evolutionary history of interactions among terrestrial arthropods.

The study of terrestrial arthopod fossils preserved with microscopic fidelity in amber and as permineralized replicas has been revolutionized by CT scanning. Fine preservation facilitates phylogenetic interpretation of fossils, but molecular divergence-time models still commonly use insufficient fossil calibrations, skewing estimates away from the direct (i.e.fossil, morphological) evidence. Interactions among terrestrial arthropods (predation, parasitoidism; phoresy, social symbionts) are briefly reviewed from the fossil record. Predation is the oldest and most widespread, originating with arachnids since probably the Silurian. The first phoretic arthropods were probably mites (Acari). Parasitoidism extends to the early Jurassic ~200 mya, with four main episodes proposed by [1•]. 100-myo Burmese amber, the most diverse Cretaceous paleobiota, is unique for our understanding of insect eusociality and interrelationships among terrestrial arthropods. Eusocial insect colonies are ecological sinks for thousands of symbiont species; ages of the major eusocial groups and some of their nest symbionts are discussed. Fossilized arthropod interrelationships in Miocene Dominican amber are presented as visual exemplars.

Synopsis of the wasp genus Clystopsenella Kieffer (Hymenoptera: Scolebythidae).

Scolebythidae are ectoparasitoid wasps which develop gregariously as idiobionts on wood-boring beetle larvae. Among them, the genus Clystopsenella is restricted to the Neotropical region and the eastern coast of Australia. The genus also includes a fossil species, Clystopsenella mirabilis Engel, 2015, from Miocene Dominican amber. In the present study we review the genus Clystopsenella and describe a new species from Costa Rica, Clystopsenella pacifica sp. nov. A key to the extant and extinct species is provided. The type locality of Clystopsenella longiventris Kieffer, 1911 is reinterpreted based on the original labels. The distribution of the genus is mostly confined to woodlands under tropical and subtropical climates. The biology of scolebythids is discussed based on a new host record for C. longiventris.

A new Cryptotermes species (Isoptera: Kalotermitidae) from the Miocene amber of Dominican Republic

Summary. A new fossil kalotermitid species of the genus Cryptotermes is described and illustrated as Cryptotermes pouilloni n. sp. from the Miocene Dominican amber (Dominican Republic). This new species can be differentiated from the other Cryptotermes species, inter alia, by its small size (one of the smallest Cryptotermes species), anterior margin of anteclypeus concave, 15 antennomeres, and forewing RP with five secondary branches reaching wing anterior margin and M joining RP after wing midlength. The new species originates from La Toca mines while the exact origins of the other Dominican fossil Cryptotermes species are unknown. We summarize the Isoptera diversity from Dominican amber and rapidly discuss the impact of inaccurate dating of the Dominican amber on the time divergence estimate of the isopteran constitutive families.

A new biting midge of the genus Forcipomyia Meigen, 1818 from Miocene Ethiopian amber (Diptera: Ceratopogonidae)

Biting midges (Ceratopogonidae) are a relatively well-studied family of nematocerous flies distributed worldwide, including 6,206 extant and 296 fossil species. To date, 1,146 extant and 32 fossil species in the genus Forcipomyia have been recorded in the world (Borkent & Dominiak, 2020). Biting midges of the subgenus Forcipomyia s. str. are indicative of forests because their larvae and pupae usually live under the bark of rotting trees (Szadziewski, 2018). The oldest records of the genus are from the Eocene. Forcipomyia are reported from early Eocene Fushun amber (one species; Hong, 1981; Stebner et al., 2016; Szadziewski, 2018; Krzemiński et al., 2019), early Eocene Cambay amber (unnamed, Stebner et al., 2017), middle Eocene Sakhalin amber (one species, Szadziewski & Sontag, 2013), Eocene Baltic amber from the Gulf of Gdańsk, Rovno and Bitterfeld (21 species; Szadziewski, 1988, Szadziewski, 1993, Sontag & Szadziewski, 2011), Miocene Dominican amber (10 species, Szadziewski & Grogan, 1998) and Miocene Mexican amber (unnamed, Szadziewski & Grogan, 1996).

Clystopsenella australiana sp. nov. (Hymenoptera: Scolebythidae): first species of the genus found outside the Neotropical region

AbstractClystopsenella Kieffer, 1911 is one of four extant genera included in the family Scolebythidae. This wasp family is the smallest within Chrysidoidea with six extant species described so far. To date, there are only two described species in the genus Clystopsenella—the extant Clystopsenella longiventris Kieffer, 1911 and the fossil C. mirabilis Engel, 2015, from Miocene Dominican amber. The extant species is found throughout the neotropics and has been recorded from Brazil, Costa Rica, Colombia, Panama and Belize. Besides this, Clystopsenella had already been recorded in the Australian fauna, indicating that the genus is not strictly Neotropical. In the present work, Clystopsenella australiana sp. nov. is described based on the single specimen ever recorded, which was collected over 100 years ago in Bribie Island, Queensland. The presence of Clystopsenella in Australia adds to the intricate scenario of disjunct distributions within the family and agrees with the restriction of Scolebythidae to warm areas.

Taxonomic description and phylogenetic placement of two new species of Spalangiopelta (Hymenoptera: Pteromalidae: Ceinae) from Eocene Baltic amber.

Spalangiopelta is a small genus of chalcid wasps that has received little attention despite the widespread distribution of its extant species. The fossil record of the genus is restricted to a single species from Miocene Dominican amber. We describe two new fossil species, Spalangiopelta darlingi sp. n. and Spalangiopelta semialba sp. n. from Baltic amber. The species can be placed within the extant genus Spalangiopelta based on the distinctly raised hind margin of the mesopleuron. 3D models reconstructed from µCT data were utilized to assist in the descriptions. Furthermore, we provide a key for the females of all currently known Spalangiopelta species. The phylogenetic placement of the fossils within the genus is analyzed using parsimony analysis based on morphological characters. Phylogenetic and functional relevance of two wing characters, admarginal setae and the hyaline break, are discussed. The newly described Baltic amber fossils significantly extend the minimum age of Spalangiopelta to the Upper Eocene.

The polycentropodid genus <i>Cernotina</i> (Insecta, Trichoptera) in Miocene Dominican amber

Abstract. A new polycentropodid caddisfly species is described from Miocene Dominican amber. The family Polycentropodidae is therefore represented in the Dominican amber with two species belonging to the genus Cernotina: C. pulchra Wichard, 2007, and C. fossilinova sp. nov. The endemic C. danieli Flint & Sykora, 2004, is the only representative of the genus occurring on Hispaniola today and is similar to the two fossil species. On the Caribbean islands altogether six extant species of the genus Cernotina are registered.

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.

Eco-morphological diversity of larvae of soldier flies and their closest relatives in deep time.

Stratiomyomorpha (soldier flies and allies) is an ingroup of Diptera, with a fossil record stretching back to the Early Cretaceous (the Barremian, about 125 MYA). Stratiomyomorpha includes at least 3,000 species in the modern fauna, with many species being crucial for ecosystem functions, especially as saprophages. Larvae of many stratiomyomorphans are especially important as scavengers and saproxyls in modern ecosystems. Yet, fossil larvae of the group are extremely scarce. Here we present 23 new records of fossil stratiomyomorphan larvae, representing six discrete morphotypes. Specimens originate from Cretaceous amber from Myanmar, Eocene Baltic amber, Miocene Dominican amber, and compression fossils from the Eocene of Messel (Germany) and the Miocene of Slovenia. We discuss the implications of these new records for our understanding of stratiomyomorphan ecomorphology in deep time as well as their palaeoecology.

A new macrolepidopteran moth (Insecta, Lepidoptera, Geometridae) in Miocene Dominican amber

A new genus and species of fossil moth, Miogeometrida chunjenshihi Zhang, Shih & Shih, gen. et sp. nov., assigned to Geometridae, is described from Miocene Dominican amber dating from 15–20 Mya. The new genus is characterized by the forewing without a fovea, R1 not anastomosing with Sc, no areole formed by veins R1 and Rs, R1 and Rs1 completely coincident, M2 arising midway between M1 and M3, anal veins 1A and 2A fused for their entire lengths; and the hind wing with Rs running close to Sc + R1 and M2 absent.

A guest from the past: A new genus and a new species of Deraeocorinae (Hemiptera: Heteroptera: Miridae) in Miocene Dominican amber.

The second fossil record of deraeocorine species from Miocene Dominican amber is presented with description of a new taxon, Amberderaeous gigophthalmus gen. and sp. nov. based on a well-preserved specimen. The need for revision of related group Eustictus and a comprehensive study of its tribal placement within Deraeocorinae are discussed.

A New Species of the Weevil Genus Anthonomus Germar, 1817 (Coleoptera: Curculionidae) in Dominican Amber

A new species, Anthonomus aphelomerus Legalov and Poinar, sp. nov. from Early Miocene Dominican amber is described. The new species differs from Anthonomus browni Poinar and Legalov, 2015 in the smaller body size, thinner, weakly curved rostrum and weakly clavate femora; it is differs from Anthonomus clarki Legalov, 2019 in the longer rostrum and slightly convex body; it also differs from Anthonomus cruraluma Poinar and Legalov, 2015 in the profemora with one tooth, and the longer and weaker curved rostrum. A key to species of the genus Anthonomus from Dominican amber is given.