Fossil Genus Research Articles

Braconid parasitoids of ants (Hymenoptera, Braconidae, Euphorinae, Neoneurini) from Baltic amber with a discussion of records of fossil larvae parasitizing ant workers

A new record of the fossil genus Elasmosomites Brues, 1933 from Baltic amber with an illustrated description of a new species, E. arkadylelejisp. nov. and the first description of a male of E. primordialis Brues, 1933 are provided. A key to currently known Neoneurini genera is compiled. A new record of fossil braconid larva emerging from an ant worker of Lasius schiefferdeckeri Mayr, 1868 is discussed and a correction to previous determination of ant hosts from amber is included.

Fossil evidence for Paleocene diversification of Araceae: Bognerospadix gen. nov. and Orontiophyllum grandifolium comb. nov.

Nearly 200 araceous leaves and two spadices have been identified among Paleocene fossils from the Blindman River locality near Blackfalds, Alberta, Canada. Although not found in attachment, these probably represent parts of the same extinct plant species. Specimens were studied using light microscopy. Phylogenetic analyses using a morphological matrix of living and fossil Araceae were performed using TNT version 1.5 to help establish relationships of the fossil leaves and spadices within Araceae and to each other. Leaves are simple with a broad petiole, entire margin, and elliptic to ovate or oblong blade with an acute to slightly rounded apex. A multi-veined midrib extends into the basal region of the blade. Parallelodromous primary veins of two orders diverge at acute angles, converging with a submarginal vein or at the apex. Transverse veins are opposite percurrent, producing rectangular to polygonal areoles. Higher-order veins are mixed opposite/alternate. Spadices are cylindrical, with helically arranged, bisexual, perigoniate flowers, each with six free tepals and a protruding style. Fruits are trilocular, with axile placentation and one seed per locule. Leaves are assignable to the fossil genus Orontiophyllum J. Kvaček & S.Y. Sm. as O. grandifolium comb. nov. Spadices are described as Bognerospadix speirsiae gen. et sp. nov. Leaves and spadices each conform to an early-diverging lineage of Araceae, increasing the known diversity of Proto-Araceae (viz., subfamilies Gymnostachydoideae and Orontioideae). Together, they provide strong evidence for extinct Proto-Araceae with novel combinations of characters shortly after the Cretaceous-Paleogene floral transition.

Protomauroania mikhailovia new species of malachite beetles (Coleoptera, Dasytidae) in Rovno amber.

A new species of malachite beetles, Protomauroania mikhailovi Tshernyshev Perkovsky, sp. n. is described from late Eocene Rovno amber. The new beetle is the second species of the Eocene fossil genus Protomauroania Tshernyshev, 2021 that was first recorded in Rovno amber and shows fauna similarity of dasytids in Baltic and Rovno amber. The new species is typical owing to the following characters: antennae with 5-segmented wide club, surface covered with dark-brown long semi-erect thin setae, and the ultimate ventrite (apical sternite) simple, narrow, not depressed. Digital high resolution pictures of the beetle are provided.

Molecules and fossils tell distinct yet complementary stories of mammal diversification

Reconstructing the tempo at which biodiversity arose is a fundamental goal of evolutionary biologists, yet the relative merits of evolutionary-rate estimates are debated based on whether they are derived from the fossil record or time-calibrated phylogenies (timetrees) of living species. Extinct lineages unsampled in timetrees are known to "pull" speciation rates downward, but the temporal scale at which this bias matters is unclear. To investigate this problem, we compare mammalian diversification-rate signatures in a credible set of molecular timetrees (n= 5,911 species, ∼70% from DNA) to those in fossil genus durations (n= 5,320). We use fossil extinction rates to correct or "push" the timetree-based (pulled) speciation-rate estimates, finding a surge of speciation during the Paleocene (∼66-56 million years ago, Ma) between the Cretaceous-Paleogene (K-Pg) boundary and the Paleocene-Eocene Thermal Maximum (PETM). However, about two-thirds of the K-Pg-to-PETM originating taxa did not leave modern descendants, indicating that this rate signature is likely undetectable from extant lineages alone. For groups without substantial fossil records, thankfully all is not lost. Pushed and pulled speciation rates converge starting ∼10 Ma and are equal at the present day when recent evolutionary processes can be estimated without bias using species-specific "tip" rates of speciation. Clade-wide moments of tip rates also enable enriched inference, as the skewness of tip rates is shown to approximate a clade's extent of past diversification-rate shifts. Molecular timetrees need fossil-correction to address deep-time questions, but they are sufficient for shallower time questions where extinctions are fewer.

Tropidogyne euthystyla sp. nov., a new small-flowered addition to the genus from mid-Cretaceous Myanmar amber

Tropidogyne euthystyla, described here, is the fourth species of this fossil genus to have been reported from amber deposits in northern Myanmar. The species are alike in features of the calyx, the shape and venation of the inferior ovary, and the absence of petals. They differ in the number and form of the styles, the lobing of the epigynous disc, and whether the flowers are apparently bisexual or unisexual. In the one species for which several flowers are available for study, T. pentaptera, floral diameters vary from 3.5 to 5.0 mm. The present species, known only from a single flower, is the smallest in the genus, with a floral diameter of only 2 mm. It differs from the 3 previously described species in having 2 stout, erect styles bearing a terminal stigma, whereas the other species have 2 or 3 short or long, arching styles that are decurrently stigmatic along the adaxial surface.

Reconstruction of the evolutionary biogeography reveal the origins and diversification of oysters (Bivalvia: Ostreidae)

Oysters (Bivalvia: Ostreidae Rafinesque, 1815) live in the intertidal and shallow subtidal areas worldwide. Despite their long evolutionary histories, abundant fossil records, global distribution, and ecological significance, a systematic time-dependent biogeographical analysis of this family is still lacking. Using combined mitochondrial (COI and 16S rRNA) and nuclear (18S rRNA, 28S rRNA, H3 and ITS2) gene makers for 80% (70/88) of the recognized extant Ostreidae, we reconstructed the global phylogenetic and biogeographical relationships throughout the evolutionary history of oysters. The result provided a holistic view of the origin, migration and dispersal patterns of Ostreidae. The phylogenetic results and fossil evidence indicated that Ostreidae originated from the circum-Arctic region in the Early Jurassic. The widening of the Atlantic Ocean and changes in the Tethys Ocean further facilitated their subsequent diversification during the Cretaceous and the Palaeogene periods. In particular, Crassostrea and Saccostrea exhibited relatively low dispersal abilities and their major diversifications were consistent with the tectonic events. Environmental adaptations and reproductive patterns, therefore, should play key roles in the formation of oyster distribution patterners, rather than the dispersal ability of their planktonic larvae. The diversity dynamics inferred by standard phylogenetic are consistent with the fossil record, however, further systematic classification, especially for fossil genus Ostrea, would enhance our understanding on extant and fossil oysters. The present study of the historical biogeography of oysters provides new insights into the evolution and speciation of oysters. Our findings also provide a foundation for the assessment of evolutionary patterns and ecological processes in intertidal and inshore life.

New perlid stonefly (Insecta: Plecoptera) from mid-Cretaceous Burmese amber

Billoperla starki gen. et sp. nov., a new extinct stonefly genus and species is described based on a well-preserved male adult in mid-Cretaceous Burmese amber and assigned to the subfamily Acroneuriinae of Perlidae. Its sternum 9 with a triangular hammer, and its epiproct is large, well-developed and upcurved, being distinctive for both the extant and extinct Perlidae. The new fossil genus is diagnostic mainly by the RA vein almost reaching wing apex, tergum 10 unmodified, paraprocts reduced, hammer present, and by the large and apically modified epiproct.

A new unusual Monachinae from the Neogene of the Atlantic Coastal Plain (Maryland, USA)

ABSTRACT To date, for the family Phocidae, only two fossil genera of the subfamily Monachinae (Monotherium and Terranectes) and two fossil genera of the subfamily Phocinae (Prophoca and Leptophoca) have been described from the Western Shore of the Chesapeake Bay (Maryland, USA). This study presents the first description of a new fossil partial seal skull from the St. Mary’s Formation (late Miocene, 8.5–7.5 MYA) in Maryland, USA. The new skull exhibits both primitive and derived features. Morphological assessment of this new skull supports classifying it within the subfamily Monachinae (based on numerous diagnostic characters). However, the presence of unique characters that do not match with any known genera of Monachinae led to the naming of a new genus and species, Magnotherium johnsii. This is now the third taxon of the subfamily Monachinae described from this locality. Some key characters of the Magnotherium johnsii (sp. nov.) skull include the presence of six incisors (similar to seals of the subfamily Phocinae), a long rostrum, and long concavity of the preorbital area of the maxilla.

Phylogeny and biogeography of the enigmatic ghost lineage Cylindrotomidae (Diptera, Nematocera)

Ghost lineages have always challenged the understanding of organism evolution. They participate in misinterpretations in phylogenetic, clade dating, biogeographic, and paleoecologic studies. They directly result from fossilization biases and organism biology. The Cylindrotomidae are a perfect example of an unexplained ghost lineage during the Mesozoic, as its sister family Tipulidae is already well diversified during the Cretaceous, while the oldest Cylindrotomidae are Paleogene representatives of the extant genus Cylindrotoma and of the enigmatic fossil genus Cyttaromyia. Here we clarify the phylogenetic position of Cyttaromyia in the stem group of the whole family, suggesting that the crown group of the Cylindrotomidae began to diversify during the Cenozoic, unlike their sister group Tipulidae. We make a comparative analysis of all species in Cyttaromyia, together with the descriptions of the two new species, C. gelhausi sp. nov. and C. freiwaldi sp. nov., and the revision of C. obdurescens. The cylindrotomid biogeography seems to be incongruent with the phylogenetic analysis, the apparently most derived subfamily Stibadocerinae having apparently a ‘Gondwanan’ distribution, with some genera only known from Australia or Chile, while the most inclusive Cylindrotominae are Holarctic.

Cyst-theca relationships of Spiniferites bentorii, S. hyperacanthus, S. ramosus, S. scabratus and molecular phylogenetics of Spiniferites and Tectatodinium (Gonyaulacales, Dinophyceae)

ABSTRACT It is well known that modern resting cysts with morphologies matching those of species of the fossil genus Spiniferites germinate into motile cells of the genus Gonyaulax. Different Spiniferites species have been connected to a single Gonyaulax species, raising the question of whether they are over-classified. Through germination experiments of cysts with the morphological features of four species of Spiniferites, viz. S. bentorii, S. hyperacanthus, S. ramosus and S. scabratus, we established cyst-theca relationships. Cysts with the morphology of S. bentorii gave rise to vegetative, motile cells of Gonyaulax nezaniae sp. nov., which is characterized by two stout antapical spines. Cysts with S. hyperacanthus and S. ramosus morphologies germinated into Gonyaulax whaseongensis and G. spinifera, respectively. Cysts with S. scabratus morphology lacked a ventral pore and were attributed to Gonyaulax cf. spinifera. Gene sequences for SSU, LSU and/or ITS-5.8S rRNA were obtained from these four species, and from cysts with the morphology of Spiniferites belerius, S. mirabilis, S. lazus, Spiniferites cf. bentorii and Tectatodinium pellitum. The maximum likelihood and Bayesian inference analyses based on LSU and SSU rRNA gene sequences revealed that cysts assignable to Spiniferites formed a polyphyletic group, intermingled with Tectatodinium, Bitectatodinium, Ataxiodinium and Impagidinium, whereas Gonyaulax species appeared as monophyletic. From our results we inferred the phylogenetic positions of S. bentorii, S. mirabilis, S. lazus, S. scabratus, Tectatodinium pellitum and Gonyaulax digitale for the first time, supporting the idea that Spiniferites species are not over-classified and each of them may correspond to different Gonyaulax species.

A new genus and three new species of fossil braconid wasps (Hymenoptera, Ichneumonoidea) from Eocene Baltic and Rovno ambers

AbstractNew parasitoid wasps of the family Braconidae are documented from Eocene Baltic and Rovno ambers. A new fossil genus belonging to the braconid subfamily Exothecinae, Palaeocolastes n. gen., with its type species P. bruesi n. sp., is described and illustrated from Baltic amber. This represents the first reliable fossil record for a member of Exothecinae. Two additional new species from Baltic amber are also described: Ascogaster (Syntaphus) latitibialis n. sp. (Cheloninae) and Meteorus arasnitsyni n. sp. (Euphorinae). Another fossil species, Microtypus eocenus n. sp. (Microtypinae), is described from coeval Rovno amber (Ukraine), representing the first braconid species described from this deposit. A new record of a female of Diospilites brevicornis Brues, 1933 (Diospilitinae) from Baltic amber, together with variation of some diagnostic features of the species and redescription of its subfamily and genus, are also provided.UUID: http://zoobank.org/656cb1a3-b9cf-4696-ae24-0d4df9545101.

Application of neutron tomography in studying new material of Ixostrobus Raciborski from the Middle Jurassic of Inner Mongolia, China

Cone‐producing gymnosperms are important elements of the Mesozoic floras. Studying their cone organizations can potentially help us understand the evolutionary trends of seed plants through time and the origin of angiosperms. In this paper, we present a new and an undetermined species of Ixostrobus Raciborski, a fossil genus representing male cones of the Czekanowskiales from the Middle Jurassic Daohugou locality in Inner Mongolia, China. The holotype specimen of the new species was studied using the neutron tomography (NT) technique. The cone shows higher neutron attenuation than the surrounding matrix. To detect the different organic compounds, a volume rendering of tomographic reconstruction with false colour spectrum of relative neutron attenuation is presented. The highest concentration of organic material is in the axis and some parts of the sacs, the rest of the cone has lower concentration, and the surrounding matrix has the lowest concentration. It seems that the remnant organic materials are regularly differentiated in different parts of the cone probably because of the preservation and different taphonomic process of different type of cells. In addition to revealing more detailed morphological features of the cone by NT reconstruction, the application of NT is potentially important for detecting remnant organic materials preserved in fossil plants.

Brachyphyllum: State of the art and new data regarding B. obesum, the most representative fossil plant in the Araripe Basin, Brazil

Among the rich paleobotanical record of the Araripe Basin, the coniferous fossil taxon Brachyphyllum stands out, found in the Crato, Romualdo, and possibly Ipubi formations. In these units, species Brachyphyllum obesum, Brachyphyllum castilhoi, and Brachyphyllum sattlerae are found, the first being the most common. However, there are still many gaps, especially regarding the paleoecology and parataxonomy of this fossil genus. This study aims to make a broad review of the current stage of knowledge of Brachyphyllum from the Araripe Basin, a very representative taxon of the local palaeoflora. We consider data available in the literature and morpho-anatomical analyses of new specimen using Scanning Electron Microscopy. The specimen analyzed in SEM has tracheids and features typical of Araucariaceae, like biseriate and alternating intervascular pits. However, there is variation in the number of pits per cross-field compared to other specimens. This variation may indicate greater diversity of fossil Brachyphyllum in the Araripe Basin. All species of Brachyphyllum from the Araripe Basin have xeromorphic characteristics, which can be adaptive responses to the conditions of aridity and/or salinity in the Crato and Romualdo formations.

New replacement name for the genus Latitergum Yu, Ślipiński, Leschen, Ren amp; Pang, 2014 (Insecta: Coleoptera: Trogossitidae).

Yu, Ślipiński, Leschen, Ren and Pang (2014) established the trogossitid fossil genus Latitergum with the type species Latitergum glabrum Yu, Ślipiński, Leschen, Ren Pang, 2014 from China (Jiulongshan Formation, Inner Mongolia). So far, this genus includes only type species and it is recorded only from China. It was used as a valid generic name in the family Trogossitidae (Insecta: Coleoptera).

Fossil wood from the Upper Cretaceous crater sediments of the Salpeterkop volcano, North West Province, South Africa

AbstractThe Salpeterkop volcano forms part of what has been referred to as the Upper Cretaceous Sutherland Suite of alkaline rocks, an igneous province composed of olivine melilitites, carbonatites, trachytes and ultramafic lamprophyres. Salpeterkop is a remnant of the summit tuff ring structure that surrounds a crater which is almost 1 km in diameter and is filled with epiclastic strata.Five pieces of silicified wood were collected from the crater filled sediments, sectioned and identified as a new species of Cupressinoxylon, C. widdringtonioides. This is the first example of the fossil genus in South Africa. Only one member of the Cupressaceae s.l. occurs in southern Africa today. From the wide and indistinct growth rings in the fossil wood it can be deduced that the local climate was warm and humid with little or no seasonality, in support of global records of a warm Late Cretaceous. The preservation of the crater further signifies the low level of erosion the region has experienced since its emplacement.

New fossil genus and species of carrion beetle (Coleoptera, Silphidae) from the Lower Cretaceous Jinju Formation, South Korea

• A new fossil genus and species of Silphidae is described from the Jinju Formation. • This fossil can be assigned to Nicrophorinae based on morphological evidence. • Diagnostic differences of the fossil and extant genera of Nicrophorinae are provided. • Primitive characteristics presented in Mesozoic silphids are discussed. A new fossil genus of Silphidae, Cretosaja gen. nov., is described, based on a new fossil species, Cretosaja jinjuensis sp. nov. from the Lower Cretaceous Jinju Formation in South Korea. The association of Cretosaja with Nicrophorinae is discussed on the basis of morphological evidence. Diagnostic differences of the fossil and extant genera of Nicrophorinae are provided. Primitive characteristics presented in Mesozoic silphids are discussed.

A Peculiar New Genus of Bibionomorpha (Diptera) with Brachycera-Like Modification of Antennae from Mid-Cretaceous Amber of Myanmar.

Simple SummaryThe mid-Cretaceous amber of Myanmar (also known as Burmese amber) is almost 100 MYA old and represents an invaluable source of information about the evolution of life in the late Mesozoic. This is particularly true for the early flies (lower Diptera) which underwent rapid radiation during the Cretaceous period. Here we describe a remarkable nematocerous fossil fly which shows a character typical of the flies of the suborder Brachycera—with strongly modified antenna—representing new evidence that such a Brachycera-like modification of the antennae has evolved several times during the evolutionary history of Diptera.A new fossil genus of Bibionidae (Diptera: Bibionomorpha), Burmahesperinus gen. nov., from the mid-Cretaceous Burmese amber, is described and illustrated (type species Burmahesperinus antennatus sp. nov., the other two species included are B. conicus sp. nov. and B. pedicellatus sp. nov.). The new genus is tentatively placed in a new subfamily, Burmahesperininae subfam. nov. of the family Bibionidae. Its possible phylogenetic position is briefly discussed. The new genus, as well as the subfamily, possesses the wing venation similar to the recent genus Hesperinus Walker, 1848, in combination with Brachycera-like modification of both the male and female antenna and the overall habitus typical of fungus gnats (Sciaroidea).

Epidermal features of the floating leaves of Quereuxia angulata (Newberry) Krištofovič, an aquatic angiosperm from the Upper Cretaceous of Northeast China

Quereuxia angulata (Newberry) Krištofovič 1953, an aquatic herbaceous angiosperm with heterophyllous leaves, is a common element of the Late Cretaceous and Paleocene floras in the Northern Hemisphere. The floating leaves are rosulate and compound with many obovate leaflets while the submerged leaves are usually filiform and dichotomously branched. The leaves of Quereuxia are taxonomically difficult to delineate if only based on their gross morphology. Therefore, acquiring their anatomical information of the leaf epidermis is an important line of evidence for the natural classification of this fossil genus. In this report, we examine the epidermal features of well-preserved floating leaves of Q. angulata, collected from the Upper Cretaceous Yong'ancun Formation in Jiayin County, Heilongjiang Province, Northeast China. The leaves are hyperstomatic with brachyparacytic stomata. Both the adaxial and abaxial epidermal cells are usually irregularly pentagonal or hexagonal and sometimes isodiametric in shape. This is the first time that the epidermal features are examined for Quereuxia. The results provide valuable morphological characters in identifying the different species of this extinct genus.

New taxa of extant and fossil primitive moths in South-East Asia and their biogeographic significance (Lepidoptera, Micropterigidae, Agathiphagidae, Lophocoronidae)

We report some surprising recent distributional range extensions of one extant genus and two more families of primitive moths discovered in amber fossils from South-east Asia which were previously only known from Australia and/or the southwestern Pacific, with the possible exception of an undescribed Siberian fossil attributed to Lophocoronidae. During entomological field work in rain forests of central Vietnam a new species of Micropterigidae was discovered. It is described herein as Aureopterix bachmaensis sp. nov. based on male and female specimens collected at light in the Bach-Ma National Park. The identification was corroborated by a molecular analysis. This is the first record of this genus in the Northern Hemisphere, previously thought to be restricted to the Australian Region (including New Caledonia). First results of investigations of Burmese amber inclusions now reveal the presence of the Australian Region families Agathiphagidae and Lophocoronidae in the Cretaceous of Asia. The fossil taxon Agathiphagama perdita gen. nov., sp. nov. is established on the basis of two females and this is assigned to Agathiphagidae. The fossil genus Acanthocorona gen. nov. is established in Lophocoronidae and includes seven species described here as A. skalskiisp. nov., A. bowangisp. nov., A. muellerisp. nov., A. kuranishiisp. nov., A. sattlerisp. nov., A. spiniferasp. nov. and A. wichardisp. nov. The new species can be distinguished by the male genitalia which are illustrated together with wing venation and other morphological characters. The disjunct ranges of these taxa are discussed in a historical biogeographic context. Vicariance and dispersal hypotheses explaining the disjunct pattern are discussed. The discovery of these new species suggests a broader ancestral range of Aureopterix, Agathiphagidae and Lophocoronidae. Their extant ranges may be regarded as remnants or relicts of a wider distribution in the Mesozoic, or at least in the case of Aureopterix they could be the results of recent or ancient dispersal processes, since the calibration of molecular splits does not so far accord with plate tectonics.

Fossils Shed a New Light on the Diversity and Disparity of the Family Limoniidae (Diptera, Nematocera).

Simple SummaryA new established subfamily (family Limoniidae) from Cretaceous Burmese amber shows a unique reduction of radial veins combined with complete set of medial veins. The discovery of this new subfamily contributes to a better understanding of the diversity and disparity of the family, and is important for further research on the evolution of this group of insects.A new subfamily Drinosinae (Diptera, Limoniidae) is established with two fossil genera, Drinosa and Decessia gen. nov. with one new species, Decessia podenasi gen. et sp. nov. from Cretaceous Burmese amber. Additional description of Drinosa prisca is based on new material. A new subfamily shows unique reduction of radial veins combined with complete set of medial veins.