The oldest tachyporine rove beetle in amber (Coleoptera,Staphylinidae): A new genus and species from Upper Cretaceous Burmese amber

A new genus and species of extinct rove beetle, Procileoporus burmiticus gen. and sp. n., is described from Upper Cretaceous Burmese amber (Cenomanian; ca. 99 Ma). Due to the condition of the fossil, parts of the body could not be examined, but sufficient characteristics were visible to allow the specimen to be placed within the subfamily Tachyporinae (tribe Tachyporini). Procileoporus is most similar to the extant genus Cileoporus Campbell in having a slender abdomen, but it differs in having much shorter abdominal setae, prominent striated microreticulation on the elytra, non-lobed tergite VIII, and in other details of the male genital segments. This is the first tachyporine rove beetle from Burmese amber and the oldest record of the subfamily in amber. The evolution of sexual dimorphism in the genital segments is briefly discussed.     

The first water measurers from the Lower Cretaceous amber of Spain (Heteroptera,Hydrometridae, Heterocleptinae)

Two fossils belonging to a new genus and species of water measurer (Gerromorpha, Hydrometridae), Alavametra popovi Sánchez-García and Nel gen. n., sp. n., are described as first definitive record of the family in Lower Cretaceous (upper Albian) amber from the Utrillas Group (Peñacerrada I site) in Spain. Although several parts of the specimens are obscured due to preservation, a sufficient number of taxonomical characters are visible to consider adequate placement within Heterocleptinae, including the very long posterior pair of cephalic trichobothria inserted on tubercles and the preapical articulation between the first and second antennal segments. The new fossil taxon is included into a cladistic analysis with extinct and extant hydrometrids, and it results putatively basal among the subfamily Heterocleptinae, suggesting that this clade was already present 105 Ma ago.     

A new genus and species of soldier beetle from Upper Cretaceous Burmese amber (Coleoptera,Cantharidae, Malthininae)

A new Upper Cretaceous genus and species of soldier beetles, Archaeomalthodes rosetta gen. et sp. nov., is described and illustrated from an individual preserved in Upper Cretaceous (Cenomanian, ca. 99 Ma) amber from northern Myanmar. It is undoubtedly placed in extant subfamily Malthininae based on its small-sized body, somewhat abbreviated elytra and fusiform terminal maxillary palpomere, representing the oldest documented occurrence of Malthininae. It suggests that this subfamily is an ancient group, which originated at least in the earliest Late Cretaceous. Our discovery sheds light on the palaeodiversity of Cantharidae in the Late Mesozoic. Together with other previously reported fossil cantharids, it is likely that Malthininae has been fairly diverse during the early evolution of Cantharidae. On the other hand, a morphological similarity between Archaeomalthodes and Recent malthinines and the occurrence of flowering plants in the Burmese amber implies a potential flower-visiting behaviour of this fossil species.     

Evolutionary stasis in enigmatic jacobsoniid beetles

Jacobsoniidae is a small but perplexing beetle family, with unknown phylogenetic relationships to other polyphagan Coleoptera. To date, only a single fossil jacobsoniid has been described, from Eocene Baltic amber (~ 40 Ma). Here, we push back the oldest definitive record of Jacobsoniidae by approximately 60 million years with a new fossil species recovered from mid-Cretaceous (~ 99 Ma) Burmese amber from Myanmar. Remarkably, exploration of the fossil's morphology with confocal laser scanning microscopy revealed that it belongs to an extant genus, Derolathrus. The similarity of the new taxon, Derolathrus abyssus n. sp., to modern congeners provides a striking example of morphological stability over deep evolutionary time—a possible outcome of long-term persistence of mesic microhabitats, a hypothesis we argue is supported by a variety of other Recent, litter-inhabiting arthropod taxa now known to be largely unchanged since the Mesozoic. Many such examples belong to the Staphylinoidea—a hyperdiverse beetle superfamily that dominates contemporary mesic habitats, and with which Jacobsoniidae may have a close phylogenetic relationship.This published work has been registered in ZooBank, http://zoobank.org/urn:lsid:zoobank.org:pub:7C65ACAF-456E-4301-BDD7-0A801768EEB9.     

A new genus of alderflies (Megaloptera: Sialidae) in Upper Cretaceous Burmese amber

A new genus and species of Mesozoic alderfly is described as Haplosialodes liui gen. et sp. nov., and from an adult male preserved in Cretaceous Burmese amber. The new genus is closely related to the genera Haplosialis Navás (Recent fauna of Madagascar), Indosialis Lestage (Recent fauna of Southeast Asia), and Eosialis Nel et al. (Eocene of France), suggesting a possible Early Cretaceous age for the clade that comprises these groups.     

Biting midges of the extinct genus Protoculicoides Boesel from Lower Cretaceous amber of San Just,Spain and new synonymy in recently described fossil genera (Diptera: Ceratopogonidae)

We describe two new species of extinct biting midges in the fossil genus Protoculicoides: Protoculicoides hispanicus Szadziewski and Arillo, sp. nov. and Protoculicodes sanjusti Szadziewski and Arillo, sp. nov., from Albian (101–113 Ma) amber of San Just, Spain. Atriculicoides Remm, 1976 is recognized as a new junior synonym of Protoculicoides Boesel, 1937 (NEW SYNONYM). Devalquia Choufani et al., 2013 is regarded here as a new junior synonym of the extant genus Culicoides Latreille, 1809 (NEW SYNONYM). Metahelea roggeroi Choufani et al., 2013 from Upper Cretaceous French amber, is excluded from the tribe Heteromyiini and placed in the extant genus Stilobezzia Kieffer, 1911, tribe Ceratopogonini: Stilobezzia roggeroi (Choufani et al., 2013), comb. nov. The extinct tribe Atriculicoidini Szadziewski, 1996 is regarded as a new subfamily, Atriculicoidinae, stat. nov., that includes the fossil genus Protoculicoides, with 13 species reported from Albian, Turonian, Cenomanian, Coniacian, Santonian and Campanian ambers (78–113 Ma). Protoculicoides skalskii Szadziewski & Arillo, 1998 from Lower Cretaceous amber of Álava, Spain, Protoculicoides succineus Szadziewski, 1966 from Lower Cretaceous Lebanese amber and Protoculicoides burmiticus Szadziewski & Poinar, 2005 from Upper Cretaceous Burmese amber are transferred to the extinct genus Archiculicoides Szadziewski, 1996, comb. nov. Protoculicoides krzeminskii Choufani et al., 2014 from Lower Cretaceous Lebanese amber is transferred to the extinct genus Archiaustroconops Szadziewski, 1996, comb. nov. The Cretaceous subfamily Atriculicoidinae forms an unresolved trichotomy with the extant subfamilies Forcipomyiinae and Dasyheleinae, both of which date to the Eocene. The fossil record indicates that wings with macrotrichia in biting midges evolved during the mid-Cretaceous greenhouse climate. We suggest that this was an evolutionary adaptation to new atmospheric conditions with higher levels of CO₂ in order for the antennal Johnston's organs of males to receive the vibrational sex signals produced by females during flight.     

A new Late Cretaceous genus and species of polypore fungus beetles (Coleoptera,Tetratomidae) from northern Myanmar

A new polypore fungus beetle is described and illustrated, under the name of Thescelostrophus cretaceus gen. et sp. nov., representing the first documented occurrence of the tribe Eustrophini. The well-preserved specimen was collected from the Upper Cretaceous (Cenomanian, ca. 99 Ma) amber near the Hukawng Valley of northern Myanmar. This fossil species can be assigned to the extant subfamily Eustrophinae based on its elongate oval and strongly narrowed posteriorly body, simple and narrow tarsi, and somewhat clubbed antennomeres. The comparison among the extinct and extant eustrophines supports the previous hypothesis that antennal morphology of early eustrophines was very diverse. Additionally, an overall similarity between Thescelostrophus and extant eustrophines suggests a potential fungivory of this fossil species. Morphological characters preserved in the Burmese amber highlight the diversity of tetratomids during the Late Mesozoic and provide data for future phylogenetic studies of Tetratomidae.     

The first fossil Compsocidae from Cretaceous Burmese amber (Insecta, Psocoptera, Troctomorpha)

The first fossil record of the Compsocidae, Burmacompsocus perreaui gen. et sp. nov., is described from Late Albian Burmese amber. Its strong similarity to the two extant compsocid genera suggests a remarkable morphological stability within this group of 100 Ma. This family, now known only in Central America, was certainly more widespread in the past.     

A new genus of whip-scorpions in Upper Cretaceous Burmese amber: Earliest fossil record of the extant subfamily Thelyphoninae (Arachnida: Thelyphonida: Thelyphonidae)

Mesozoic whip-scorpions are very rare, with only two Cretaceous species known to date. Here we describe a new genus and species of Thelyphonidae, Mesothelyphonus parvus gen. & sp. nov., based on a very well-preserved male in Upper Cretaceous amber from Myanmar. Mesothelyphonus is firmly placed in the extant subfamily Thelyphoninae as supported by the abdominal tergites with a median longitudinal suture. Mesothelyphonus differs from other fossil and recent genera primarily by its very small body size, the absence of ommatoids on abdominal segment XII, and the elongate, slender and toothed patellar apophysis of the male pedipalp. The new discovery represents the oldest definitive fossil record for Thelyphoninae, highlighting the antiquity of the whip-scorpion group.     

A look with μCT technology into a treasure trove of fossils: The first two fossils of the millipede order Siphoniulida discovered in Cretaceous Burmese amber (Myriapoda,Diplopoda)

Millipedes (Diplopoda) are an important fossil group of land arthropods in the Palaeozoic. However, there is a gap in the Mesozoic, with only slightly more than a dozen fossils being known, until the much more recent fossil records mainly from Cenozoic Dominican and Baltic ambers become available. Burmese amber, precisely dated to the Late Cretaceous, is known for an apparently rich but still undescribed millipede fauna, and might represent the ideal bridge to close this gap in the millipede fossil record. In addition, modern micro-computed tomography (μCT) technology allows complex 3D reconstructions of objects fossilized in amber. Here we utilize μCT technology to describe the first millipedes from Burmese amber, which are also the first two fossil representatives of the order Siphoniulida. Siphoniulida, with two known species and just nine recorded specimens, are the rarest and least known of the 16 extant orders of the Diplopoda. Records are known from Sumatra, Guatemala and Mexico. The two new fossils described here represent two distinct species, Siphoniulus muelleri sp. nov. and S. preciosus sp. nov., and indicate a wider distribution of this order in the Cretaceous. The holotype of S. muelleri sp. nov. was well-enough preserved so that characters of the head, such as the incisura lateralis, not investigated before in extant representatives of the order, could be studied. This study highlights the possibilities and challenges provided by μCT technology in investigating Diplopoda fossilized in amber.     

Cretocrenis burmanicus,the first Mesozoic amber inclusion of a water scavenger beetle (Coleoptera: Hydrophilidae)

Cretocrenis burmanicus, gen. et sp. nov. is described from Burmese amber and represents the oldest known amber inclusion of the family Hydrophilidae (Coleoptera: Polyphaga). The new genus resembles the small-bodied modern genera of the tribe Anacaenini and the subfamily Acidocerinae, and the morphology of the venter and male genitalia suggest that it belongs to the Horelophus+Crenitis clade of the tribe Anacaenini. The fossil is described in detail, illustrated, and compared with extant hydrophilid genera.     

Notes on the divergence time of the fern genus Asplenium from fossil and molecular evidence

The extant fern genus Asplenium Linnaeus, 1753 is widely distributed in tropical-temperate regions and shows a high diversity. The oldest fossils assigned to it comprise fronds and spores preserved in situ from the Lower Cretaceous of northeast Asia. However, molecular dating suggests that Asplenium diverged during the Paleocene (∼57.7 Ma). Here we present some explanations for the disparity in fossil and molecular age estimates, and new insights into the origin and evolution of the genus. We suggest that Cretaceous Asplenium most likely represents a stem-group member, and that lineage extinction during the early evolutionary stages of the genus resulted in missing nodes.     

The first fossil of dasycerine rove beetle (Coleoptera: Staphylinidae) from Upper Cretaceous Burmese amber: Phylogenetic implications for the omaliine group subfamilies

The enigmatic staphylinid subfamily Dasycerinae consists of only 17 species within a single extant genus Dasycerus, but it is easily distinguished from other rove beetles by overall, latridiid beetle-like body and extremely slender, verticillate antennae. Direct fossil evidence is lacking for this group. Here, I describe the first fossil of this peculiar subfamily, Protodasycerus aenigmaticus gen. and sp. n., from the Upper Cretaceous Burmese amber. Despite considerable external similarities to extant dasycerine species, this new genus possesses several important morphological differences: a much smaller body size (ca. 1.1 mm), narrowly elongate antennomeres 1 and 2, not strongly transverse metaventrite, elytra striate but not tricostate, and truncate posterior margin of the elytra exposing four abdominal tergites dorsally. The new finding of a Cretaceous representative of the Dasycerinae helps elucidate the origin and early evolution of the omaliine group subfamilies, implying rather close similarities between the Dasycerinae and the monobasic subfamily Neophoninae. Discovery of P. aenigmaticus suggests a rather ancient origin of the subfamily by the Upper Cretaceous.     

New Cretaceous caddisflies from Burmese amber (Insecta,Trichoptera)

Three new caddisflies species are described and illustrated from the mid-Cretaceous Burmese amber: Wormaldia cretacea sp. nov., W. resina sp. nov. (Philopotamidae) and Neureclipsis burmanica sp. nov. (Polycentropodidae). Palerasnitsynus ohlhoffi (Psychomyiidae) is re-described based on new fossils. Wormaldia are common in Burmese amber, and its diversity shows that this genus had very ancient origin and diversified at least during the mid-Cretaceous. N. burmanica sp. nov. is the oldest record of Neureclipsis, revealing this genus originated at least in the mid-Cretaceous. So far, six extinct species representing the small Order Trichoptera have been found in Burmese amber.     

Cretaceous amber inclusions of Spain and Myanmar demonstrate early diversification and wide dispersal of Cephenniitae (Coleoptera: Staphylinidae: Scydmaeninae)

The taxonomic status of previously misplaced species of an ant-like stone beetle from Spanish amber (Albian) is clarified. Specimens of Kachinus magnificus (originally placed as incertae sedis within Scydmaenitae) were re-examined and their characters were found different from those of the type species of Kachinus from Myanmar amber. Consequently, Archeutheia gen. nov. is proposed to accommodate the Spanish species, resulting in Archeutheia magnifica comb. nov. Moreover, in a comprehensive phylogenetic analysis Archeutheia was placed as a sister group to extant Eutheia, within the tribe Eutheiini of Cephenniitae. A specimen of an undetermined genus from Myanmar amber clearly belonging in Cephenniini is also recorded. Both taxa represent the first definite Cretaceous Cephenniitae, a supertribe whose recent members are distributed on all continents but are especially diverse in the Oriental and East Palaearctic regions. This finding demonstrates a diversification of two presently most species-rich tribes of Cephenniitae already in Early Cretaceous. Archeutheia is strikingly similar to the extant species of Eutheia and Veraphis, showing male dimorphic characters (modified protrochanters) and antennal cavities characteristic of Palaearctic Eutheiini. This fact suggests a long morphological stability in the supertribe. A previously proposed hypothesis of an early presence of the Cephenniitae in the Northern Hemisphere is for the first time supported by the fossil record, and the palaeolocalities (western Europe and Southeast Asia) demonstrate a wide distribution of Cephenniitae in the Cretaceous and an early split of its ancestral lineage.     

Contributions of zircon U–Pb geochronology to understanding the volcanic and sedimentary history of some Purāna basins,India

In this century, U–Pb ages of magmatic and detrital zircons, together with a few less accurate but fairly robust ages determined on monazite and baddeleyite, in the Purāna successions in India have established a few firm timelines that constrain the opening, closure, inversion, and provenance of the Purāna basins. The Cuddapah basin opened shortly before ca. 1900 Ma, the Vindhyan basin opened before ca. 1630 Ma, the Khariar basin likely opened ca. 1500 Ma, and the Chhattisgarh basin opened ca. 1400 Ma. The Marwar basin opened after ca. 750 Ma. The Chhattisgarh basin began to invert at ca. 1000 Ma and closed shortly thereafter. The Indravati and the Vindhyan basins closed ca. 1000 Ma. There are no other defensible geochronologic data to adequately constrain the opening and closure of other Purāna basins (e.g., Kaladgi, Badami, Bhima, Kurnool, Mallampalli, Albaka, Ampani, Sabari, and Kolhan). Neither the fossil record nor the biostratigraphy of these basins necessarily correspond to the chronology determined through radiometric measurements.The discovery of ca. 1000 Ma volcanic events in the Indravati and Chhattisgarh basins adds to the growing list of ca. 1000 Ma thermal disturbances in the Indian shield. Most of these events were likely the far field effects of the final assembly of Rodinia.     

An Ichthyornis-like bird from the earliest Late Cretaceous (Cenomanian) of European Russia

Ornithuromorph birds (the clade which includes modern avian radiation) first appeared in the Early Cretaceous in Asia and achieved a great diversity during the latest ages of the Late Cretaceous (Campanian and Maastrichtian). The evolutionary history of orithuromorphs during the first 17 MYAs of the Late Cretaceous (Cenomanian to Santonian ages) remains very poorly known, as the fossil record for this time interval is largely restricted to several isolated finds of the classic avian genus Ichthyornis in North America. Here we describe an isolated distal tibiotarsus of an evolutionary advanced bird, morphologically similar to Ichthyornis, from the middle Cenomanian of Saratov Province, European Russia. This is the first documentation of an Ichthyornis-like bird in the Old World. The find further constitutes only the second pre-Campanian record of the Late Cretaceous Ornithuromorpha in Eurasia, the second record of Cenomanian birds in Russia. This discovery shows that Ichthyornis-like birds enjoyed a wide geographical distribution as early as the beginning of the Late Cretaceous. Given that the earliest and the most primitive ornithuromorph birds are known from Asia, the new find supports a Eurasian origin for Ichthyornithidae.