Early Cretaceous Amber Research Articles

First non‐amber Mesozoic pseudoscorpion from Upper Triassic deposits of eastern Europe, with a description of two new fossil subfamilies (Arachnida, Pseudoscorpiones, Feaellidae)

AbstractPseudoscorpiones is one of the oldest arachnid orders, known in the palaeontological record since the Middle Devonian (c. 390 Ma). The following reliable indications of fossil pseudoscorpions occur in Early Cretaceous amber: Lebanese amber (c. 135–125 Ma), Spanish Álava amber (c. 113–100 Ma), Archingeay amber (c. 100 Ma) and Burmese amber (c. 99 Ma). Thus, there is a gap of at least 255–265 myr in the palaeontological record of pseudoscorpions. Therefore, the fossil feaellid pseudoscorpion Archaeofeaella henderickxi gen. et sp. nov., described herein from Triassic deposits of Ukraine (c. 227 Ma) is of exceptional interest. Based on the analysis of previously unknown morphological features for the family Feaellidae, we place A. henderickxi in Archaeofeaellinae subfam. nov. The previously described species Protofeaella peetersae from Burmese amber is placed in Protofeaellinae subfam. nov., based on comparisons with A. henderickxi as more ancient and closer to the basal group, as well with Recent representatives of this family. Based on this new data, we show that the family Feaellidae survived the Triassic break‐up of Pangaea, and its earliest find is associated not with Gondwana, but with Laurasia; thus, the current ‘Gondwanan distribution’ of the family on the continents of the southern hemisphere is a relic of a wider (probably pancontinental) distribution.

A transitional fossil mite (Astigmata: Levantoglyphidae fam. n.) from the early Cretaceous suggests gradual evolution of phoresy-related metamorphosis

Metamorphosis is a key innovation allowing the same species to inhabit different environments and accomplish different functions, leading to evolutionary success in many animal groups. Astigmata is a megadiverse lineage of mites that expanded into a great number of habitats via associations with invertebrate and vertebrate hosts (human associates include stored food mites, house dust mites, and scabies). The evolutionary success of Astigmata is linked to phoresy-related metamorphosis, namely the origin of the heteromorphic deutonymph, which is highly specialized for phoresy (dispersal on hosts). The origin of this instar is enigmatic since it is morphologically divergent and no intermediate forms are known. Here we describe the heteromorphic deutonymph of Levantoglyphus sidorchukae n. gen. and sp. (Levantoglyphidae fam. n.) from early Cretaceous amber of Lebanon (129 Ma), which displays a transitional morphology. It is similar to extant phoretic deutonymphs in its modifications for phoresy but has the masticatory system and other parts of the gnathosoma well-developed. These aspects point to a gradual evolution of the astigmatid heteromorphic morphology and metamorphosis. The presence of well-developed presumably host-seeking sensory elements on the gnathosoma suggests that the deutonymph was not feeding either during phoretic or pre- or postphoretic periods.

Phloem sap in Cretaceous ambers as abundant double emulsions preserving organic and inorganic residues

Fossilized remains preserved in amber provide abundant data on the paleobiota surrounding the resin-producing plants, but relatively scarcer information about the resinous sources themselves. Here, dark pseudoinclusions in kidney-shaped amber pieces from the Early Cretaceous (Albian) amber from Spain are studied. This type of fossilized remain, abundant in Cretaceous ambers, was first interpreted as fossilized vacuole-bearing microorganisms, but later regarded as artifactual and probably secreted by the resinous trees, although their origin remained unclear. Using complementary microscopy (light, electron, confocal), spectroscopy (infrared, micro-Raman), mass spectrometry and elemental analysis techniques, we demonstrate that the pseudoinclusions correspond to droplets of phloem sap containing amber spheroids and preserving both organic and inorganic residues consistent with degraded components from the original sap. The amber pieces containing pseudoinclusions are fossilized, resin-in-sap-in-resin double emulsions, showing banding patterns with differential content of resin-in-sap emulsion droplets. Our findings represent the first time fossilized phloem sap, 105 million years old, has been recognized and characterized, and open new lines of paleontological research with taxonomic, taphonomic, physiological and ecological implications.

Heinrichsia cheilanthoides gen. et sp. nov., a fossil fern in the family Pteridaceae (Polypodiales) from the Cretaceous amber forests of Myanmar

AbstractDivergence time estimates suggest that most clades constituting the fern family Pteridaceae (Polypodiales) were in existence by the Early Cretaceous. However, fossil evidence to corroborate this remains exceedingly rare. Burmese amber is an important source of new information on the radiation of derived fern lineages during the Cretaceous Terrestrial Revolution. This study describes Heinrichsia cheilanthoides gen. et sp. nov., a fern with suggested affinities to Pteridaceae, based on fertile foliage portions preserved in Early Cretaceous (~100 Ma) amber from Myanmar. Heinrichsia cheilanthoides is characterized by a pinnate‐pinnatifid frond that bears apical, marginal sori protected by a pseudoindusium. Sporangia are of the polypod type and contain tetrahedral‐globose, trilete spores with a striate perine. This discovery provides a new calibration point to test and refine molecular clock‐based concepts of the evolutionary history of the Pteridaceae. Heinrichsia cheilanthoides further substantiates the suggestion that the Cretaceous forests of Myanmar were home to a rich fern flora.

<p><strong>A new dustywing (Neuroptera: Coniopterygidae) from the Early Cretaceous amber of Spain</strong></p>

A new Cretaceous dustywing, Soplaoconis ortegablancoi gen. et sp. nov. (Neuroptera: Coniopterygidae), is described from four specimens preserved in Early Cretaceous (Albian, ~105Ma) El Soplao amber (Cantabria, northern Spain). Two additional specimens are assigned to this new taxon. A crossvenational abnormality on an area of diagnostic significance from one of the holotype’s forewings provides a reminder of the importance of not ruling out character plasticity or teratoses when evaluating palaeodiversity. A comment on the possible palaeoecological significance of the co-occurrence as syninclusions of plant trichomes with the holotype of S. ortegablancoi and seven of the eleven described Burmese amber dustywing species is provided.

A mid-Cretaceous embryonic-to-neonate snake in amber from Myanmar.

We present the first known fossilized snake embryo/neonate preserved in early Late Cretaceous (Early Cenomanian) amber from Myanmar, which at the time, was an island arc including terranes from Austral Gondwana. This unique and very tiny snake fossil is an articulated postcranial skeleton, which includes posterior precloacal, cloacal, and caudal vertebrae, and details of squamation and body shape; a second specimen preserves a fragment of shed skin interpreted as a snake. Important details of skeletal ontogeny, including the stage at which snake zygosphene-zygantral joints began to form along with the neural arch lamina, are preserved. The vertebrae show similarities to those of fossil Gondwanan snakes, suggesting a dispersal route of Gondwanan faunas to Laurasia. Finally, the new species is the first Mesozoic snake to be found in a forested environment, indicating greater ecological diversity among early snakes than previously thought.

Mating and aggregative behaviors among basal hexapods in the Early Cretaceous.

Among the many challenges in paleobiology is the inference and reconstruction of behaviors that rarely, if ever, leave a physical trace on the environment that is suitable for fossilization. Of particular significance are those behaviors tied to mating and courtship, individual interactions critical for species integrity and continuance, as well as those for dispersal, permitting the taxon to expand its distribution as well as access new habitats in the face of local or long-term environmental change. In this context, two recently discovered fossils from the Early Cretaceous amber of Spain (ca. 105 mya) give a detailed view of otherwise fleeting ethologies in Collembola. These occurrences are phylogenetically spaced across the class, and from species representing the two major clades of springtails—Symphypleona and Entomobryomorpha. Specifically, we report unique evidence from a symphypleonan male (Pseudosminthurides stoechus Sánchez-García & Engel, 2016) with modified antennae that may have functioned as a clasping organ for securing females during mating on water’s surface, and from an aggregation of entomobryomorphan individuals (Proisotoma communis Sánchez-García & Engel, 2016) purportedly representing a swarming episode on the forest floor. We demonstrate that the mating behavioral repertoire in P. stoechus, which is associated with considerable morphological adaptations, likely implied elaborate courtship and maneuvering for guarantee sperm transfer in an epineustic species. These discoveries reveal significant behaviors consistent with modern counterparts and a generalized stasis for some ancient hexapod ethologies associated with complex mating and courtship and social or pre-social aggregations, so critical to specific constancy and dispersal.

The case of Darwinylus marcosi (Insecta: Coleoptera: Oedemeridae): A Cretaceous shift from a gymnosperm to an angiosperm pollinator mutualism

ABSTRACTAbundant gymnosperm pollen grains associated with the oedemerid beetle Darwinylus marcosi Peris, 2016 were found in Early Cretaceous amber from Spain. This discovery provides confirmatory evidence for a pollination mutualism during the mid Mesozoic for the family Oedemeridae (Coleoptera), which today is known to pollinate only angiosperms. As a result, this new record documents a lateral host-plant transfer from an earlier gymnosperm to a later angiosperm, indicating that pollination of the latter is a derived condition within Oedemeridae. This new fossil record exemplifies one of the 4 ecological-evolutionary pollinator cohorts now known to have existed during the global shift from a gymnosperm to an angiosperm dominated global flora. Currently, all direct evidence for pollination during the 35 million-year interval of the mid Cretaceous gymnosperm-to-angiosperm transition entails recognition of gymnosperm pollen grains on insect mouthparts and other body contact surfaces, while analogous records involving angiosperms are lacking. The gathering evidence indicates that angiosperm pollination was preceded by at least 4 gymnosperm pollination modes that served as a functional and ecological prelude to the rise and expansion of angiosperms.

A new stem-coenagrionoid genus of damselflies (Odonata: Zygoptera) from mid-Cretaceous Burmese amber.

A new genus and species of damselfly, Burmagrion marjanmatoki, gen. et sp. nov., is described from Early Cretaceous Burmese amber. It is attributed to the basal stem group of Coenagrionoidea. The inclusion of five wings from the same species suggests that the amber piece contains the remains of a mating pair of damselflies.

A new genus and species of maimetshid wasps in Lebanese Early Cretaceous amber (Hymenoptera: Maimetshidae)

An interesting new maimetshid wasp is described and figured from the Early Cretaceous of Lebanon. Zorophratra corynetes Engel, new genus and species, differs in several important features from all other Maimetshidae and is classified within its own subfamily, Zorophratrinae Engel, new subfamily. A revised key to the genera of the family is provided, and attempts to incorporate all of those taxa known only as compression fossils. The genera of the family are organized into a revised classification, with the tribe Ahiromaimetshini Engel, new tribe, newly recognized within Maimetshinae, and the genus Turgonaliscus Engel, new genus, described for Turgonalus cooperi Rasnitsyn & Jarzembowski (resulting in Turgonaliscus cooperi, new combination).

Springtails from the Early Cretaceous Amber of Spain (Collembola: Entomobryomorpha), with an Annotated Checklist of Fossil Collembola

ABSTRACT Entomobryomorphan springtails (Hexapoda: Entognatha: Collembola) of the family Isotomidae are the most numerous group of Collembola in Spanish amber, a pattern typical in other studied Cretaceous amber deposits. Here we provide a revision of the Spanish amber springtail fauna, Early Cretaceous (Late Albian) in age, based on 93 specimens sufficiently well preserved to permit specific identification. Three new species are erected within the Isotomidae: Anurophorinae. These are: Burmisotoma spinulifera, new species, Protoisotoma autrigoniensis, new species, and Proisotoma communis, new species. The two former are respectively placed in the Cretaceous genera Burmisotoma Christiansen and Nascimbene (previously known from Cenomanian Burmese amber) and Protoisotoma Christiansen and Pike (in both Burmese and Canadian ambers), while the last species is indistinguishable from the extant, cosmopolitan genus Proisotoma Borner (also recorded in Burmese amber). Low morphological intraspecific variability is de...

A New Bethylid Wasp in Lebanese Early Cretaceous Amber (Hymenoptera: Chrysidoidea), with Comments on other Mesozoic Taxa

ABSTRACT A new genus and species of bethylid wasps is described and figured from a female preserved in Early Cretaceous (Barremian) amber from Lebanon. Holopsenella primotica, new genus and species, is distinguished from other bethylids and segregated into a new subfamily, Holopsenellinae, along with Cretabythus sibiricus Evans in Late Cretaceous (Santonian) Taimyrian amber. Holopsenellines are perhaps basal within the family, representing a stem group to other Bethylidae, and, if so, those features shared with the coeval Lancepyrinae suggest a basal position for that lineage as well. In addition, Lancepyris alavaensis Ortega-Blanco and Engel in Early Cretaceous (Albian) amber from northern Spain is considered generically distinct from the type species of the genus, L. opertus Azevedo and Azar in Lebanese amber, and is transferred to the new genus, Zophepyris, resulting in the new combination, Zophepyris alavaensis (Ortega-Blanco and Engel). The genus Archaepyris Evans, currently considered as incertae se...

Morphologically Specialized Termite Castes and Advanced Sociality in the Early Cretaceous

A hallmark of animals that are eusocial, or those with advanced sociality, is reproductive specialization into worker and queen castes. In the most derived societies, these divisions are essentially fixed and in some arthropods, include further specialization--a tripartite system with a soldier caste that defends the colony. Eusociality has originated numerous times among insects but is believed to have appeared first in the termites (Isoptera), in the Early Cretaceous. However, all termites known from the Cretaceous have, until now, only been winged reproductives (alates and dealates); the earliest soldiers and definitive workers were known from just the Miocene (ca. 17-20 million years ago [mya]). Here, we report six termite species preserved in Early Cretaceous (ca. 100 mya) amber from Myanmar, one described as Krishnatermes yoddha gen. et sp. nov., comprising the worker/pseudergate, winged reproductive, and soldier, and a second species, Gigantotermes rex gen. et sp. nov., based on one of the largest soldier termites yet known. Phylogenetic analysis indicates that Krishnatermes are in the basal "Meiatermes-grade" of Cretaceous termites. Workers/pseudergates of another four species are briefly described, but not named. One of these workers/pseudergates reveals that ants--the most serious enemies of modern termites--lived in close proximity to termites in the Burmese paleofauna. These discoveries demonstrate the Mesozoic antiquity of specialized termite caste systems and corroborate that among all social species, termites probably had the original societies.

A new family of primitive serphitoid wasps in Lebanese amber (Hymenoptera: Serphitoidea)

A new family of serphitoid wasps (Bipetiolarida: Serphitoidea) is described and figured as <strong>Archaeoserphitidae</strong> Engel, new family. The family is based on <em><strong>Archaeoserphites melqarti</strong></em> Engel, new genus and species, preserved in Early Cretaceous amber from Lebanon, and shares with Serphitidae a two-segmented, tubular petiole. <em>Archaeoserphites</em> have several primitive features relative to Serphitidae (<em>e.g</em>., reduced pterostigma, similar to many chalcidoids; a greater number of flagellomeres; a distinct malar sulcus), while simultaneously exhibiting its own derived features (<em>e.g</em>., angulate lower face, with clypeus downward; smaller mandibles; large pronotum; fused propleura). Diagnoses of and keys to the higher taxa of Bipetiolarida are provided, and the subfamily <strong>Microserphitinae</strong> Engel, new subfamily, is established.

A defensive behavior and plant-insect interaction in Early Cretaceous amber – The case of the immature lacewing Hallucinochrysa diogenesi

Amber holds special paleobiological significance due to its ability to preserve direct evidence of biotic interactions and animal behaviors for millions of years. Here we review the finding of Hallucinochrysa diogenesi Pérez-de la Fuente, Delclòs, Peñalver and Engel, 2012, a morphologically atypical larva related to modern green lacewings (Insecta: Neuroptera) that was described in Early Cretaceous amber from the El Soplao outcrop (northern Spain). The fossil larva is preserved with a dense cloud of fern trichomes that corresponds to the trash packet the insect gathered and carried on its back for camouflaging and shielding, similar to that which is done by its extant relatives. This finding supports the prominent role of wildfires in the paleoecosystem and provides direct evidence of both an ancient plant–insect interaction and an early acquisition of a defensive behavior in an insect lineage. Overall, the fossil of H. diogenesi showcases the potential that the amber record offers to reconstruct not only the morphology of fossil arthropods but, more remarkably, their lifestyles and ecological relationships.

An earwig (Insecta: Dermaptera) in Early Cretaceous amber from Spain

The order Dermaptera (earwigs) is recorded for the first time from the Early Cretaceous ambers of Spain.Autrigonoforceps ibericaEngel et Peris gen. et sp. n. is described and figured from a single, putative ♀ preserved in Albian amber from Peñacerrada I. Due to its trimerous tarsi and the absence of ocelli, the placement of the new fossil within the Neodermaptera is clear. Although it seems close to Labiduridae, its confident placement in any family is impossible given the limited visibility of several critical characters. The species is compared with the labiduridMyrrholabiafrom mid-Cretaceous amber of Myanmar.

A new tribe, new genus, and new species of Mordellidae (Coleoptera: Tenebrionoidea) from the Early Cretaceous amber of Spain. ERRATUM CORRIGENDUM

A new tribe, new genus, and new species of Mordellidae (Coleoptera: Tenebrionoidea) from the Early Cretaceous amber of Spain. ERRATUM CORRIGENDUM David Peris a, , Enrico Ruzzier b a Departament d'Estratigrafia, Paleontologia i Geoci encies Marines and Institut de Recerca de la Biodiversitat (IRBio), Facultat de Geologia, Universitat de Barcelona, Marti i Franqu es s/n, Barcelona E-08071, Spain b Department of Life Science, Natural History Museum, Cromwell Rd, London SW7 5BD, United Kingdom

New biting midges from the Cretaceous amber of Lebanon (Diptera: Ceratopogonidae)

SummaryNew Ceratopogonidae from the Early Cretaceous amber of Hammana (Central Lebanon) are studied. Five new species (Lebanoculicoides daheri sp. nov., Protoculicoides krzeminskii sp. nov., Archiaustroconops annae sp. nov., Archiaustroconops hammanensis sp. nov., and Archiaustroconops dominiakae sp. nov.) are characterized, described, illustrated, and compared with other Cretaceous taxa. New keys for species of the three genera Lebanoculioides, Protoculicoides, and Archiaustroconops, but also for all genera of Lebanese fossil biting midges, are proposed.

A rich and diverse tanaidomorphan (Crustacea: Tanaidacea) assemblage associated with Early Cretaceous resin-producing forests in North Iberia: palaeobiological implications

The extinct tanaidomorphan diversity from Early Cretaceous Spanish amber, currently comprising 26 specimens, is reassessed. The fossil family Alavatanaidae Vonk & Schram, 2007, described from Spanish amber, is revised on account of new preparation of type specimens and the discovery of new material. The described tanaidomorphan taxa are classified within the superfamily Paratanaoidea. An emended diagnosis for Alavatanaidae is provided, as well as for the genera Alavatanais Vonk & Schram, 2007 and Proleptochelia Vonk & Schram, 2007, and their respective species Alavatanais carabe Vonk & Schram, 2007 and Proleptochelia tenuissima Vonk & Schram, 2007. Three new species, two of them classified in a new genus each, are described: Alavatanais margulisae Sánchez-García, Peñalver & Delclòs sp. nov., Eurotanais terminator Sánchez-García, Peñalver & Delclòs gen. et sp. nov. and Electrotanais monolithus Sánchez-García, Peñalver & Delclòs gen. et sp. nov. Proleptochelia euskadiensis Vonk & Schram, 2007 is considered a junior synonym of A. carabe, and the genus Proleptochelia, together with its type and only species P. tenuissima, is left without familial placement within Paratanaoidea. Within this superfamily, Alavatanaidae is closely related to Leptocheliidae. Also, morphological variability due to sexual dimorphism in the studied paratanaoids has been determined. Multiple lines of taphonomic and palaeobiological evidence indicate that the Spanish amber tanaids were most likely inhabitants of wet or moist forest floors.http://zoobank.org/urn:lsid:zoobank.org:pub:DC943B18-A01C-412C-8378-C644FEFDA716

Diverse scelionid wasps in Early Cretaceous amber from Spain (Hymenoptera: Platygastroidea)

Diverse scelionid wasps in Early Cretaceous amber from Spain (Hymenoptera: Platygastroidea)