First North American species of the European genus <i>Archaemegaptilus</i> from the Upper Carboniferous Pottsville Formation of northern Alabama (Palaeodictyoptera: Archaemegaptilidae)

Although the major glass-sand deposits of the midwestern United States are of the classic blanket marine sandstone type, throughout the United States and Canada a wide variety of geological types of silica deposits is available as glass-sand sources and potential sources. These include: (I) Unconsolidated sands: (A) Littoral — Cohansey Formation, New Jersey; (B) Alluvial plain — Citronelle Formation, Florida; (C) Marine dunes — Pacific Grove, California; (D) Lake dunes — Redcliff, Alberta; (E) Stream channel — Ravensdale, Washington. (11) Arkosic sands: Idaho Formation, Idaho. (III) Consolidated sandstones and orthoquartzites: (A) Marine and littoral — St. Peter Formation, Oriskany Formation, Potsdam Sandstone; (B) Alluvial — Pottsville Formation, Pennsylvania. (IV) Quartzites: Lorrain–north shore Lake Huron, Ontario; Grenville — Baie Comeau, Quebec. (V) Hydrothermal veins: Quartz Mountain, Washington; Carson City, Nevada. (VI) Tectonically crushed rocks: (A) Sandstone — Moberly Mountain, British Columbia; (B) Quartzite — St. Donat and St. Remi, Quebec. (VII) Weathering products — Oriskany Formation, Goshen, Virginia. Another, nongeological category would be waste sands — leftovers from other mining operations, such as the residual sands from the Fort McMurray, Alberta, tar sands operations. The chief deposits of the north-central United States are the St. Peter (Ordovician) and Sylvania (Devonian) sandstones. The St. Peter is believed to have been derived from Precambrian quartzites of the Canadian Shield (which themselves originally may have been second-generation sandstones), and the Sylvania probably was derived from St. Peter outcrops, making it a third- (or fourth-) generation sandstone.

Regional stratigraphic and sedimentologic studies in the Appalachian fold and thrust belt and Black Warrior foreland basin in Alabama indicate deposition of two converging clastic wedges during Carboniferous time. A northeastward-prograding clastic wedge (Floyd-Pride Mountain-Hartselle-Parkwood) reached Alabama by late Meramecian time; progradation continued with deposition of the Lower Pennsylvanian Pottsville Formation. A southwestward-prograding clastic wedge (Pennington-Pottsville) did not appear in Alabama until latest Mississippian time. The northeastward-prograding wedge indicates a source terrain southwest of the Black Warrior basin and implies orogenesis as a result of convergence along the southern margin of North America. Petrographic data from 79 sandstone and 6 conglomera e samples from the Parkwood and Pottsville Formations in Alabama provide information on the composition of the source rocks and. thus, on the crustal components and tectonic setting of the convergent margin. Foliated quartzmica rock fragments. unstable polycrystalline quartz, pelitic rock fragments, and polycyclic monocrystalline quartz suggest that the largest and/or most proximal source-rock province was a low-grade metamorphic and sedimentary fold-thrust belt. Detrital chert suggests derivation from a subduction complex or from bedded chert incorporated in a fold-thrust belt. Andesitic ± basaltic and dacitic volcanic rock fragments indicate the presence of an arc complex. A complex source terrain produced by juxtaposition of a fold-thrust belt, subduction complex, and arc sugge ts collision of the Alabama promontory of the southern margin of North America with an arc or with a microcontinent and associated continental-margin arc.

Numerical taxonomic studies show that eleven species of Solanum sect. Solanum occur in North America. Five diploid (n = 12) species, S. americanum, S. douglasii, S. interius, S. pseudogracile, and S. ptycanthum are apparently native. A sixth diploid species, S. sarrachoides, is an introduction from South America. Three polyploid species, S. furcatum, S. nigrum, and S. villosum, occur infrequently. Two other polyploid species, S. scabrum and S. retrofiexum, are sometimes cultivated. A notable nomenclatural change, necessitated by a previously selected lectotype for S. americanum, is the use of the name S. americanum for the species previously known as S. nodfiorum. The name S. ptycanthum is now used for the species of the north- eastern United States formerly called S. americanum. Solanum sect. Solanum (also known as the S. nigrum complex) is a cos- mopolitan group of about 30 annual or short-lived perennial, herbaceous species of weeds. A variety of historical and biological factors combine to make the taxonomy of this section difficult (Edmonds 1979a). The use of experimental taxonomic techniques in several regional studies has clarified the taxonomy of this section in much of its range (Edmonds 1972, 1979a; Henderson 1974; Heiser et al. 1979). The present study covers the North American species of the section. Sterility of interspecific hybrids and ease of obtaining hybrids in sect. Solanum make it tempting to attempt to define species on the basis of genetic isolating mechanisms. However, the high frequency of intraspe- cific hybrid sterility and its lack of correlation with morphological diver- gence indicate that hybrid sterility is not useful in delimiting species in this section (Schilling and Heiser 1979). Because the breeding system of most species of sect. Solanum is primarily autogamous (Schilling 1978), there is probably little gene flow between populations with the result that biological species (Mayr 1963) are not present in this section. Hence, although data from crossing studies have been incorporated into this study as phenetic characters, they are not accorded any special signifi- cance as evidence of an isolating mechanism that separates species. To classify species in this section, an operational approach using techniques of numerical taxonomy to discover discontinuities by which species may be recognized has been used.

Allozyme variation and the taxonomy of Wolffiella

Three similar species of Carex sect. Atratae subsect. Atropictae (subsect. nov.) occur in South America, which together may be known as the Carex atropicta complex. All three, similar in habit, grow south of the Tropic of Capricorn, with C. atropicta occurring primarily in Patagonia and Tierra del Fuego, C. malmei in west-central Argentina and adjacent parts of Chile, and C. monodynama (comb. et stat. nov.) in central Argentina. The new subsection is distinguished by: stigmas 2 (infrequently 3); plants commonly with a solitary spike (except in C. atropicta where they are occasional); and margins of the perigynia ciliate-scabrous (but in C. monodynama sparingly so), more or less winged, and generally with a lightcolored strip of varying length that extends from the beak toward the base. Habitats for the three species include moist to wet meadows, swamps, marshes and marshy pasturelands, depressions in moist grassland, grassy hillsides, ravines, banks of streams, and coastal flats bordering the sea. Carex L., with an estimated 1500 to 2000 species, is well represented in both hemispheres, but sectional representation can vary greatly from one hemisphere to another. For instance, sect. Atratae (Kunth) Christ is strongly developed in the mountains and cooler regions of the Northern Hemisphere, particularly in North America and Eurasia (e.g., Charkevicz 1988; Chater 1980; Hermann 1970; Mackenzie 1935; Murray 1969), but is poorly represented in the Southern Hemisphere (Kiikenthal 1909). Previous authors (Barros 1935, 1947; Hauman and Vanderveken 1917; Kalela 1940; Kiukenthal 1899,1909; Leveille 1915; Marticorena and Quezada 1985) have recognized from one to three species, and a varying number of infraspecific taxa, of sect. Atratae in South America. Discrepancies abound regarding their distributions. Also, some validly published names (Kalela 1940) applicable to the South American members of sect. Atratae have not been taken into account by recent authors (e.g., Barros 1947, 1969). In this paper, which is the third in a series of sectional revisions of the Carex flora of South America (Wheeler 1987, 1989b), I treat the South American members of sect. Atratae. As treated here, three species of sect. Atratae occur in South America (table 1): C. atropicta Steudel, C. malmei Kalela, and C. monodynama (Griseb.) G. Wheeler (comb. et stat. nov.). Because the South American members of sect. Atratae differ morphologically in some respects from their counterparts in the Northern Hemisphere, they are here placed in subsect. Atropictae G. Wheeler (subsect. nov.). All members of the new subsection occur south of the Tropic of Capricorn, and only one, C. atropicta, extends as far south as Tierra del Fuego. Habitats include moist to wet meadows, swamps, marshes and marshy pasturelands, depressions in moist grassland, grassy hillsides, ravines, banks of streams, and coastal flats bor-

Insects possess a vast phenotypic diversity and key ecological roles. Several insect species also have medical, agricultural and veterinary importance as parasites and disease vectors. Therefore, strategies to identify potential essential genes in insects may reduce the resources needed to find molecular players in central processes of insect biology. However, most predictors of essential genes in multicellular eukaryotes using machine learning rely on expensive and laborious experimental data to be used as gene features, such as gene expression profiles or protein-protein interactions, even though some of this information may not be available for the majority of insect species with genomic sequences available. Here, we present and validate a machine learning strategy to predict essential genes in insects using sequence-based intrinsic attributes (statistical and physicochemical data) together with the predictions of subcellular location and transcriptomic data, if available. We gathered information available in public databases describing essential and non-essential genes for Drosophila melanogaster (fruit fly, Diptera) and Tribolium castaneum (red flour beetle, Coleoptera). We proceeded by computing intrinsic and extrinsic attributes that were used to train statistical models in one species and tested by their capability of predicting essential genes in the other. Even models trained using only intrinsic attributes are capable of predicting genes in the other insect species, including the prediction of lineage-specific essential genes. Furthermore, the inclusion of RNA-Seq data is a major factor to increase classifier performance. The code, data and final models produced in this study are freely available at https://github.com/g1o/GeneEssentiality/. Supplementary data are available at Bioinformatics online.

Biomechanics of fore wing to hind wing coupling in the southern green stink bug Nezara viridula (Pentatomidae)

About half of the approximately 110 species of Erythrina (Fabaceae: Faboideae), comprising New World species of six sections of subgen. Erythrina, are characterized by tubular flowers in which the standard is elongated and the keel and wings are reduced. These species, which are pollinated predominantly by hummingbirds, have relatively low concentrations of amino acids and high sucrose/hexose ratios in their nectar. In the remaining 12 species that occur in the New World and all but two of those of the Old World, the flowers are more or less gaping, with the standard tending to be ovate or obovate and the keel and wings more or less conspicuously exserted. These species are pollinated predominantly by medium-sized passerine birds; their flowers have relatively high concentrations of amino acids and low sucrose/hexose ratios in their nectar. In the two species of the southern African sect. Humeanae of subgen. Erythrina, the floral morphology resembles that of the New World humingbirdpollinated species. They are pollinated by small sunbirds and white-eyes. Several and perhaps all species of Erythrina have a large gland at the apex of the calyx that secretes nectar; ants, attracted to this nectar, patrol the plants and help to protect them from herbivores. A report of short-styled flowers in E. leptorhiza is reviewed, and papers providing new information on the taxonomy, alkaloids, modes of propagation, and bruchids of Erythrina, included in this symposium, are mentioned. Most of the papers in the present symposium address the pollination relationships of Erythrina, and they add significantly to our body of knowledge concerning this interesting field. The basic division of the genus, from the standpoint of pollination biology, is between those species in which the standard tends to be ovate or obovate, and the keel and wings are more or less conspicuously exserted from the calyx, and those in which the standard is elongated and the keel and wings are reduced. In the first group of species, the corollas are often more or less gaping, the sucrose/hexose ratios are low, and the proportion of amino acids in the nectar is often extremely high. Included here are all species of the genus except some of those of the large subgen. Erythrina, and all species of Erythrina that occur in the Old World except those of the ditypic southern African sect. Humeanae Barneby & Krukoff of subgen. Erythrina. In the second group, comprising six related American sections of subgen. Erythrina and about half of the species of the genus, together with the two species of sect. Humeanae of the same subgenus, the corollas are narrow and tubular. In the American ones, the nectar has high sucrose/hexose ratios, and low proportions of amino acids. Within the Old World, only Erythrina zeyheri Harvey and E. humeana Sprengel (sect. Humeanae) have relatively narrow corollas that correspond to those of the American species of subgen. Erythrina just mentioned. As Jacot

Several Central American species of Piper sect. Macrostachys have obligate associations with ants, in which the ant partner derives food and shelter from modified plant structures and, in turn, protects the plant against fungal infection and herbivory. In addition to these obligate ant-plants (i.e. myrmecophytes), several other species in Piper have resident ants only sometimes (facultative), and still other plant species never have resident ants. Sheathing petioles of sect. Macrostachys form the domatia in which ants nest. Myrmecophytes in sect. Macrostachys have tightly closed petiole sheaths with bases that clasp the stem. These sheathing petioles appear to be the single most important plant character in the association between ants and species of sect. Macrostachys. We examined the structure and variation of petioles in these species, and our results indicate that minor modifications in a small number of petiolar characters make the difference between petioles that are suitable for habitation by ants and those that are not.

Reconstructing ancestral states is a useful method to understand the pathway and patterns of character evolution and to test specific hypotheses within a phylogenetic context. Using a phylogenetic hypothesis of the subgenus Amerallium and related subgenera based on molecular data, we reconstructed the evolutionary history of leaf blade anatomical characters and identified those characters that are most congruent with phylogenetic relationships. Furthermore, we used these character histories to investigate the evolution of terete leaves and explore a possible correlation between environment and leaf anatomy in the North American species. Sixty-seven North American and Old World species were sampled from all major infrageneric taxa and lineages for transectional leaf anatomy. To provide a phylogenetic framework for interpretation, representatives of Old World Amerallium and related subgenera were added to a published data matrix of North American taxa and ITS, ETS, trnL-F, and rpL32-trnL sequences. Four anatomical characters, namely leaf-blade shape in transection, presence versus absence of palisade mesophyll, distribution and orientation of vascular bundles, and position of laticifer cells, were found to be congruent with phylogenetic relationships and useful diagnostic traits within North American species. Character reconstructions show that terete leaves in North American species evolved from flattened leaves via a possible transition from subterete to terete leaves. Furthermore, terete leaves possess traits that are indicative of possible adaptation to xeric environments. The findings from this study provide valuable information for understanding the evolution of leaf-blade anatomy in North American Allium species.

To compare hypothesized species boundaries in Gambelia to patterns of differentiation inferred from morphology and isozymes, we examined nine populations for divergence at 22 isozyme loci and 29 OTU's/populations for morphological divergence using 20 characters. Thirteen quantitative and seven qualitative characters were analyzed using clustering (UPGMA) and ordination (PCA, CVA) methods. Placement of North American shrub snapdragons in Gambelia separate from southern hemisphere species (Galvezia s. str.) was supported by numerous qualitative morphological and genetic differences. Within Gambelia, the pattern of morphological and isozyme variation is most concordant with recognition of two species, G. speciosa and G. juncea, based on the phylogenetic species concept. Each species can be defined by several invariant and unique morphological and isozyme characters. Delimitation of infraspecific taxa in G. speciosa is unwarranted, because no consistent interpopulation differentiation was observed. Recognition of segregate species within the G. juncea complex of Baja California and Sonora also was not supported. No constant morphological differences were observed for either G. glabrata or G. rupicola. Biogeographic and systematic data support hypotheses that the California Island endemic G. speciosa is relictual, that disjunct Sonoran populations of G. juncea were established recently, and that populations of G. juncea from the Cape Region of Baja California have been isolated since the Holocene. Generic and specific delimitation among New World shrub snapdragons are problematic. At the generic level, Munz (1926), Munz and Keck (1959), and Pennell (unpubl. data) treat all New World species in Galvezia Dombey; Rothmaler (1943, 1954) places North American species in two genera (Gambelia Nuttall and Saccularia Kellogg) and South American species in Galvezia; whereas Sutton (1988), in the most recent revision, includes all North American species in Gambelia and the South American and Galapagos species in Galvezia. Delimitation of species is equally unresolved. Two (Munz 1926; Wiggins 1980) to four (Rothmaler 1943; Sutton 1988) North American species commonly are recognized; recent treatments delimit one to three South American species and a Galapagos endemic. Differing treatments of North American taxa primarily reflect disparities in taxonomic rank accorded to the morphological variants of Gambelia juncea (Bentham) Sutton s.l. The present study examines genetic and morphological divergence among North American taxa. The initial taxonomic organization follows Sutton (1988), who delimits four species without infraspecific taxa in Gambelia. The species occur on the California Islands of the southwestern U.S.A. and Mexico, coastal Sonora, and the offshore islands and peninsula of Baja California in Mexico (Fig. 1): G. speciosa Nuttall (southern California Islands), G. juncea (Sonora, Baja California), and two species recognized by Sutton from the Cape Region of Baja California Sur, G. rupicola (Brandegee) Sutton and G. glabrata (Brandegee) Sutton. All species are longlived shrubs with showy red corollas and occur on cliffs and in washes and canyons from sea level to 1500 m. Gambelia speciosa is an island endemic occurring in only a few, small populations on Santa Catalina, San Clemente, and Guadalupe islands. Although G. speciosa is placed alternately in the genera Galvezia, Antirrhinum L., and Maurandya Ortega, Gambelia speciosa has not been submerged in another species and infraspecific variants have not been described. Besides its insular distribution, G. speciosa is differentiated readily from all other shrub snapdragon species by a personate corolla (throat closed by an expanded palate). The other three species recognized by Sutton in Gambelia constitute the G. juncea complex, which is segregated by Rothmaler (1943) into Saccularia. Because of polymorphism in inflorescence pubescence, leaf size and shape, stem and leaf pubescence, and calyx segment shape, taxa in the G. juncea complex are treated vari-

Why red‐dominated autumn leaves in America and yellow‐dominated autumn leaves in Northern Europe?

Classification of freshwater fish in the subfamily Leuciscinae, Cyprinidae is hampered by complexity or lack of morphological diversity. In this study, analyses based on mtDNA sequences were undertaken to clarify phylogenetic relationships among Far Eastern, North American and European species in the Leuciscinae. Evolutionary rate in cytochrome b gene (Cyt-b) and D-loop sequences appear to be almost constant in Leuciscinae. The topology of phylogenetic trees generated by neighbor-joining (NJ) and maximum likelihood (ML) methods based on Cyt-b gene and D-loop sequences was similar. Five major clades, designated clades 1-5, and a minor clade were discriminated. Most of the Far Eastern, North American and European species were included in the major clades. Clade 1, comprised almost entirely of Far Eastern phoxinins, is monophyletic and greatly diverged from the other species of Leuciscinae. From the present phylogenetic relationships and the previous studies, we present the following hypotheses with respect to the evolutionary history of the Far Eastern phoxinins. The Far Eastern species should be classified into Far Eastern-specific genera, although ichthyologists have still insisted that the species should be included in the European genera. The Far Eastern clade 1 consists of two subclades, including genera Pseudaspius-Tribolodon and Far Eastern Phoxinus species. According to our phylogenetic analyses, Pseudaspius leptocephalus and Tribolodon species should be reclassified into the same genus. On the basis of evolutionary rate in Cyt-b gene in Cyprinidae, it is estimated that the Far Eastern lineage diverged approximately 10-14 million years ago (mya) from the common ancestor of Leuciscinae. It is deduced that speciation of the Far Eastern species occurred until approximately 4 mya, in relation to the formation of the Sea of Japan and the Japanese Islands.

Sex determination and the regulation of sexual dimorphism are among the most fascinating topics in modern biology. As the most species-rich group of sexually reproducing organisms on Earth, insects have multiple sex determination systems. Though sex chromosomes and sex-biased genes are well-studied in dozens of insects, their gene sequences are scattered in various databases. Moreover, a shortage of annotation hinders the deep mining of these data. Here, we collected the chromosome-level sex chromosome data of 49 insect species, including 34 X chromosomes, 15 Z chromosomes, 5 W chromosomes and 2 Y chromosomes. We also obtained Y-linked contigs of four insects species—Anopheles gambiae, Drosophila innubila, Drosophila yakuba and Tribolium castaneum. The unannotated chromosome-level sex chromosomes were annotated using a standard pipeline, yielding a total of 123 030 protein-coding genes, 2 159 427 repeat sequences, 894 miRNAs, 1574 rRNAs, 5105 tRNAs, 395 snoRNAs (small nucleolar RNA), 54 snRNAs (small nuclear RNA) and 5959 other ncRNAs (non-coding RNA). In addition, 36 781 sex-biased genes were identified by analyzing 62 RNA-seq (RNA sequencing) datasets. Together with 5707 sex-biased genes from the Drosophila genus collected from the Sex-Associated Gene Database, we obtained a total of 42 488 sex-biased genes from 13 insect species. All these data were deposited into InSexBase, a new user-friendly database of insect sex chromosomes and sex-biased genes. Database URL: http://www.insect-genome.com/Sexdb/.

Phylogenetic Relationships within Diadasia, a Group of Specialist Bees