Longitudinal Costae Research Articles

European net-winged beetles of the Pyropterus clade, with the description of Gomezzuritus gen. nov. (Coleoptera: Lycidae)

We simultaneously considered morphology and molecular phylogeny to modify the generic classification of the ‘pyropterine clade’ (Lycidae, Erotinae, Dictyopterini). To place species previously included in Benibotarus Kôno, 1932 in reciprocally monophyletic genera, we propose Gomezzuritus gen. nov. with the type-species Dictyopterus alternatus Fairmaire, 1856. Further, we transfer Gomezzuritus alternatus (Fairmaire, 1856) comb. nov., G. longicornis (Reiche, 1878) comb. nov., and G. rubripes (Pic, 1897) comb. nov. from Benibotarus to Gomezzuritus gen. nov. The pyropterine clade contains five genera in the Palaearctic region: Pyropterus Mulsant, 1838, Gomezzuritus gen. nov., Helcophorus Fairmaire, 1891, Greenarus Kazantsev, 1995, and Benibotarus Kôno, 1932. The arrangement of longitudinal elytral costae proved misleading for consideration of relationships. Two genera in distant positions share only four primary costae (Pyropterus and Helcophorus), and three similarly distant genera share the shortened primary costa 3, resulting in three primary and four secondary longitudinal costae (Gomezzuritus, Greenarus, and Benibotarus). The larva of Gomezzuritus alternatus is described in detail, and it is compared with the larvae of other Dictyopterini, including the presumed larva of G. longicornis.

THE LAGENID BENTHIC FORAMINIFERAL GENUS WIGNALLYIA ALY AND ITS MEMBERS IN THE TETHYS

Three species of the Eocene Lagenid benthic foraminiferal genus Wignallyia Aly are known from the Northern and Southern Tethys. The genus Wignallyia is characterized by its elongate test, involute earlier chambers and covered by beaded tubercles, and followed by uniserial globular chambers with longitudinal costae covered the surface, ended by a terminal circular aperture with thickened lip on a short neck. These species are: Wignallyia hewaidyi, W. infracompressa and W. behmi. The first two species are common in many sites in Egypt (Beni Suef area in Nile Valley, Fayoum area, southeast Cairo), and also are recorded in Poland and Hungary. The third one W. behmi is recorded in Italy, France, Swiss, Austria, Italy, Poland, Hungary and Slovenia (Northern Tethys), as well as in Egypt and the United Arab Emirates, UAE (Southern Tethys). The taxonomic consideration, stratigraphic implication of the erected taxa, and paleogeographic distribution of the identified species on both sides of the Tethys are also presented and discussed.

Morphological and molecular reinvestigation of acanthoecid species II. – Pseudostephanoeca paucicostata (Tong et al., 1998) gen. et comb. nov. (= Stephanoeca diplocostata var. paucicostata Throndsen, 1969) including also the description of Pseudostephanoeca quasicupula sp. nov. and Stephanoeca ellisfiordensis sp. nov.

The present study has revealed morphological differences of species assigned to the acanthoecid choanoflagellate genus Stephanoeca based on the relative position of transverse and longitudinal costae in the anterior lorica chamber. A detailed re-examination of published material of S. paucicostata Tong et al., 1998 combined with new data has shown that the species characteristic, a double transverse costa, is clearly located outside of the longitudinal costae excluding this taxon from an affiliation to Stephanoeca sensu stricto, confirmed also by molecular data of a clonal culture from Kos Islands, Greece. Two specimens of S. paucicostata with only a single, interiorly positioned transverse costa, namely from Marchant et al. (1987) and Nitsche et al. (2011) were erroneously assigned to this species. These facts have here led to the establishment of a new genus, Pseudostephanoeca with its type species P. paucicostata, and the description of S. ellisfiordensis for the two specimens mentioned above, corroborated by new material from Antarctica. In addition, two specimens previously assigned to S. cupula have been shown to share the core characteristic of Pseudostephanoeca with exteriorly positioned transverse elements. This has led to the description of the new species P. quasicupula including also new material from Iceland.

New genus of erotine net-winged beetles, Damzenium gen. nov. (Coleoptera: Lycidae), from Eocene Rovno amber.

A new genus and a new species of erotine net-winged beetles, Damzenium rivnense gen., sp. nov., are described from late Eocene Rovno amber of Ukraine. The new taxon is placed in the tribe Erotini (Lycidae: Erotinae) based on the general appearance, structure of pronotal carinae and elytral costae. Its elytral primary costa 3 is very stout and forms the humeral edge. Primary costa 4 is weak and we have not been able to clearly identify regular four rows of cells in the wide external interstice. Similar modification of elytral longitudinal costae is known from the related tribe Dictyopterini. This discovery increases the number of Baltic and Rovno amber taxa of Lycidae to six genera and seven species. Remarkably, five genera and six species of these belong in the subfamily Erotinae, which has never been reported from other amber deposits. This quite species-poor group of net-winged beetles is still represented almost exclusively in the Holarctic fauna.

A new species group defined in Lycocerus Gorham (Coleoptera, Cantharidae), with description of a new species from Xizang, China

The Lycocerus varipubens species-group is defined to accommodate three previously described species and a new species from the Himalayan area, including L. varipubens, L. semiextensus, L. purpurascens comb. nov. & stat. reinst. and L. zayuensis sp. nov. L. purpurascens, originally described in Cantharis and first combined in Lycocerus here, is reinstated as a valid specific name to replace L. rubrispinis syn. nov., which is a replacement name for Cantharis rubripennis. Meanwhile, L. rubrispinis becomes a junior synonym of L. purpurascens. L. varipubens species-group could be distinguished from all other groups by the combination of following characters, the filiform antennae, pronotum wider than long, reddish-brown elytra with weakly or moderately developed longitudinal costae, all pro- and meso-outer claws each with a digtiform tooth in both sexes, and spermatheca with three spiral tubes. The species descriptions are provided with habitus photos, aedeagi, abdominal sternites VIII and reproductive systems of female. L. purpurascens and L. varipubens are recorded to China for the first time. In addition, a morphological phylogenetic analysis shows that the L. varipubens group is sister to L. purpureus group. A distribution map and a key to the species of this species-group are also provided. http://www.zoobank.org/urn:lsid:zoobank.org:pub:7C82B6E4-9A71-4893-AD97-5692839D2236

Siliceous microfossils as a potential age marker for the early Hirnantian Mass Extinction horizon in South China

Abundant cone-shaped siliceous microfossils have been recovered from Upper Ordovician black shales of the Wufeng Formation in South China. They occur in the Hirnantian Metabolograptus extraordinarius Biozone. An investigation of their internal structure conducted using focused ion beam-scanning electron microscope (FIB-SEM) and transmitted light microscope shows that the specimens are possibly composed of three parts: cephalis, thorax and foot. Robust, longitudinal costae are developed, sometimes branching at the thorax. The geological distribution of these microfossils in South China indicates that they occurred in a restricted epicontinental sea on the Upper Yangtze Platform, which was connected to the open ocean in the north. It seems likely that these microfossils have a limited temporal range relative to the Late Ordovician Mass Extinction (LOME) in the early Hirnantian. In the absence of coeval graptolites or other index fossils, their occurrence therefore provides an age marker for the LOME, and has utility for future shale gas exploration in the Wufeng Formation. Xuejin Wu [xjwu@nigpas.ac.cn], State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing, 210008, PR China; University of Science and Technology of China, Hefei, 230026, PR China; *Hui Luo* [huiluo@nigpas.ac.cn], State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing, 210008, PR China; *Yuandong Zhang [ydzhang@nigpas.ac.cn], State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing, 210008, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China; Chao Li [chaoli@nigpas.ac.cn], State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, PR China.

Loricate choanoflagellates (Acanthoecida) from warm water seas. VI. Pleurasiga Schiller and Parvicorbicula Deflandre

The loricate choanoflagellate genera Pleurasiga and Parvicorbicula are taxonomically ambiguous. Pleurasiga because of the uncertainty that relates to the true identity of the type species, and Parvicorbicula because too many newly described species over time have been dumped here in lack of better options. While all species currently allocated to the genus Pleurasiga (with the exception of the type species) are observed in our samples from the global warm water belt, the genus Parvicorbicula is represented by just a few and mostly infrequently recorded taxa. Two new species, viz. Pl. quadrangiella sp. nov. and Pl. minutissima sp. nov., are described here. While the former is closely related to Pl. echinocostata, the latter is reminiscent of Pl. minima. Core species of Pleurasiga and Parvicorbicula deviate from the vast majority of loricate choanoflagellates in having both the anterior and the mid-lorica transverse costae located exterior to the longitudinal costae. In Pl. quadrangiella there is no mid-lorica transverse costa but rather a small posterior transverse costa located inside the longitudinal costae. In Pl. minutissima the mid-lorica transverse costa has extensive costal strip overlaps which reveal patterns of costal strip junctions that deviate from the norm.

Loricate choanoflagellates (Acanthoecida) from warm water seas. II. Bicosta, Apheloecion, Campyloacantha, Crucispina, Calliacantha and Saroeca

The main outcome of this and subsequent papers is to provide a baseline survey of heterotrophic protist diversity from warm water marine ecosystems, exemplified by loricate choanoflagellates (Acanthoecida). Genera in focus here (i.e. Bicosta, Apheloecion, Campyloacantha, Crucispina, Calliacantha and Saroeca) possess anterior spines or projections and a posterior pedicel, and have 0, 1 or 2 transverse costae. Longitudinal costae are, with the exception of Campyloacantha, external to transverse costal elements across all genera examined here. We describe here Apheloecion eqpacia sp. nov. and Calliacantha magna sp. nov., both of which are so far distributionally confined to warm water habitats. A ‘form A’ of Bicosta minor is introduced to facilitate the distinction between B. minor sensu stricto and a presumed warm water adapted variant with a posterior lorica chamber twist of the longitudinal costae.

New species of Diatrichalus (Coleoptera: Lycidae) from New Guinea and the Moluccas.

The recently collected material of Diatrichalus Kleine, 1926 from New Guinea and the Moluccas was studied. Four new species are described: D. buruensis sp. n., D. manokwarensis sp. n., D. mindikensis sp. n., and D. robustus sp. n. The diagnostic morphological characters are described in detail and illustrated. New records of previously described species are reported from several localities in New Guinea and D. mancus (Kleine, 1926) is for the first time reported from the Australian continent. Some Diatrichalus have similar male genitalia and are considered as closely related. Despite supposed relationships, they differ in the presence of secondary elytral longitudinal costae, which have been traditionally used for the delimitation of genera in net-winged beetles.

Beetles (Coleoptera) of Peru: A Survey of the Families. Lycidae Laporte, 1836

Diversity in Peru: 1 subfamily, 6 tribes, 23 genera, and 126 species. Recognition: Lycidae, or net-winged beetles, have adults mostly about 4–28 mm long and often brightly colored (Bocak and Bocakova, 2008). Their aposematic colors, tendency to aggregate, and spontaneous bleeding are attributed to their chemical defenses; some may be involved in mimicry complexes. The six tribes of Peruvian lycids have mostly yellow and dark brown coloration. One of the most frequent of the various color patterns is the cross pattern (elongate dark brown cross on yellow to red background), or yellow coloration forming transverse or longitudinal stripes. The Lycidae are soft-bodied as they have thin, weakly sclerotized cuticle. The adult body is dorsoventrally flattened and head sometimes elongate forming a rostrum in floricolous taxa. The pronotum often bears costae forming areolae and the flexible elytra are reinforced by longitudinal costae and distinct reticulate cells— thus, their common name as net-winged beetles. Among related soft-bodied elateroid beetles, the Lycidae can be distinguished by elongate trochanters with femoral articulation distally, while the trochanters of Lampyridae and Cantharidae are small with femoral articulation oblique. Other morphological features (Bocak and Bocakova, 1990; Bocakova, 2003) of lycid adults are: head prognathous to hypognathous, partly covered by pronotum, antennae 11-segmented, filiform to flabellate, mandibles arcuate, pronotum oblong to trapezoidal, scutellum rectangular, slightly emarginate distally. The elytra are mostly parallel, sometimes widened posteriorly (Calopteron), each elytron with 3–9 longitudinal costae, legs compressed, trochanters elongate to triangular, tarsal segments 3–4 lobed, abdomen with 7 (males) and 8 (females) visible sterna, male genitalia mostly trilobate, parameres shortened (as long as K–2/3 of phallus in Calopterini, Neolycus), or absent (Plateros), female genitalia with coxites mostly separate, paraproctal baculi mostly rod-like, sometimes widened and fused basally, styli setose. Lycid larvae are flattened, with the middle part of abdomen sometimes widened (Lycini). Their body is weakly sclerotized, similar to the adults; the head is prognathous, partly retracted into pronotum, and sometimes elongate (Lycini). Stemmata are absent or reduced to one stemma on each side of the head. The antenna is 2-segmented (while 3-segmented in larvae of Lampyridae), mandibles falciform, entire mandible cleft longitudinally; sometimes with paired urogomphi (Bocak and Matsuda, 2003).

Stephanoeca arndti spec. nov. – First cultivation success including molecular and autecological data from a freshwater acanthoecid choanoflagellate from Samoa

Until recently acanthoecid choanoflagellates have been described only from marine and brackish waters. Here I describe a distinct, strictly freshwater acanthoecid species from Samoa based on its morphology, ecology and molecular biological data (partial Small Subunit rDNA). The lorica of the species is characterised by two extensions at the posterior chamber which are used for attachment to the substratum. The posterior chamber is constructed of irregularly arranged costae. The anterior chamber consists of four transverse costal rings and 14–18 longitudinal costae. Despite its sturdy appearance, the lorica was extremely sensitive to water turbulence and movements of the water. The species showed a salinity tolerance of 0.5 practical salinity units with reduced growth rates and a temperature tolerance range of 20–34°C. According to the morphology, phylogenetic analysis, and autecology of the species it was classified as a member of the genus Stephanoeca.

Two remarkable new species of Prothemus Champion from China and Thailand, with comments on their systematic status (Coleoptera, Cantharidae)

Two remarkable new cantharid species were described, Prothemus laticornis sp. n. (CHINA: Yunnan) and Prothemus lycoceroides sp. n. (THAILAND: Chiang Dao), and provided with illustrations of aedeagi, ultimate abdominal sternites and antennae of both sexes. Their systematic status was discussed, because they differed from all other species of Prothemus in the dilated and/or serrate antennae and elytra with distinct longitudinal costae and longer pubescence.

Costal strip production and lorica assembly in the large tectiform choanoflagellate Diaphanoeca grandis Ellis

Diaphanoeca grandis posseses a voluminous flask-shaped lorica comprising an outer layer of 12 longitudinal costae and an inner layer of four transverse costae. The cell is suspended just above the centre of the lorica chamber by tentacles that are attached to the anterior transverse ring. The component costal strips are superficially similar although four different strip categories can be distinguished on the basis of length and morphology. Costal strips are produced ‘upside-down’ within the parent cell and accumulated in a close-packed horizontal ring at the top of the inner surface of the collar. The order in which costal strips are produced is consistent, starting with those for the transverse rings, basal to anterior, and then the longitudinal costae, again with the posterior first and the anterior later. Cell division is of the classical tectiform variety with the juvenile cell being inverted and pushed backwards out of the parent lorica. Lorica assembly entails firstly the rotation of the anterior vertical strips so they become horizontal and then their movement backwards under the posterior layer of longitudinal strips. From this time onwards, lorica assembly proceeds in a standard manner with the lorica-assembling tentacles providing a forward and left-handed rotational movement.

Choanoflagellate Lorica Construction and Assembly: The Tectiform Condition. Volkanus costatus (= Diplotheca costata)

The tectiform choanoflagellate Volkanus costatus (=Diplotheca costata) possesses a lorica comprising an outer layer of 14-18 longitudinal costae and three transverse costae. Six categories of costal strips can be distinguished on the basis of morphology. Costal strips are deposited intracellularly, upside-down, starting with the transverse costae, posterior to anterior, and then longitudinal costae, again posterior to anterior. Strips are exocytosed from the cell anteriorly and stored horizontally at the top of the collar. Cytokinesis involves inversion of the juvenile cell which is then pushed backwards into the accumulation of strips thereby restoring the normal relationship between costal strips and cell. Once free of the parent, the juvenile assembles its lorica by a forward and left-handed rotational movement. Whilst individual stages in costal strip production, storage and lorica assembly are the same in tectiform and nudiform species, nevertheless the overall procedure in tectiform species is complicated by inversion of the strip producing apparatus and cytokinesis. One explanation for this increase in complexity is that a single regulatory change has caused the coincidental inversion of costal strip production, storage and cytokinesis. The consequences of this change bequeathed tectiform cells with two important evolutionary advantages. One was the immediate inheritance by the juvenile of a lorica following division and the second was the development of transverse costae, which are mechanically superior to the helical costae of nudiform species. The outcome of these changes probably accounts for the major radiation of tectiform species within the marine environment.

Choanoflagellate Lorica Construction and Assembly: The Nudiform Condition. II. Acanthoeca spectabilis Ellis

Acanthoeca spectabilis is one of the most common loricate choanoflagellates found in marine biofilms everywhere. However, it is special for two reasons; firstly, it is probably the most distinctive member of the small nudiform clade of loricate choanoflagellates. Secondly, the lorica chamber of Acanthoeca comprises a closely wound left-handed coil of costae that is unique amongst choanoflagellates. Mathematical analysis of the lorica chamber shows that the helical costae undergo two turns. This species, more than any, demonstrates that the helical coiling of costae can only be achieved by a rotational movement generated by the cell during lorica assembly. Comparison of the lorica morphology of Acanthoeca with that of the closely related genus Polyoeca indicates that the helical costae of Acanthoeca are probably homologous with the outer longitudinal costae of Polyoeca. This is unusual because helical costae are usually the innermost layer of costae. However, since there is no 'true' inner layer in the chamber of Acanthoeca the outer layer of costae are adjacent to the cell surface and therefore available for coiling. In contrast to tectiform choanoflagellates, which number more than one hundred species and inhabit a wide variety of microniches, the six known extant nudiform species must either represent a minor evolutionary development or be the remnants of a previously more extensive radiation.

A new genus, Helgoeca gen. nov., for a nudiform choanoflagellate

A new genus, Helgoeca gen. nov., has been designated to accommodate a nudiform loricate choanoflagellate (American Type Culture Collection strain ATCC 50073) that was incorrectly attributed to the tectiform genus Acanthoecopsis (= Acanthocorbis). The first indication that this species might be nudiform came from a four-gene phylogeny of the choanoflagellates which recovered ATCC 50073 within a strongly supported monophyletic clade comprising two other nudiform taxa. Fortunately an isolate of the species in question was available from the ATCC and when observed in rapidly growing culture it was immediately apparent that this species divided with the production of ‘naked’ motile cells; a typically nudiform character. The beaker-shaped lorica of this species consists of an outer layer of approximately 11 longitudinal costae, which terminate anteriorly as spines, and an equal or larger number of helical costae, with a left-handed conformation, each of which terminates anteriorly adjacent to the base of a spine. The pattern of costae in this species is indistinguishable from that of Acanthocorbis nana Thomsen and for this reason A. nana has been transferred to the new genus Helgoeca gen. nov., as the type species.

Pleuroceratos burmiticus, n. gen., n. sp. (Coleoptera: Silvanidae) from Early Cretaceous Burmese Amber

A new genus and species of cucujoid beetle, Pleuroceratos burmiticus Poinar and Kirejtshuk in the Oryzaephilus generic complex of Silvanidae, is described from Early Cretaceous Burmese amber. The new genus is characterized by the head, pronotum and elytra bearing a series of longitudinal costae, large, protruding round eyes, long tri-quadri-dentate mandibles, elongate trochanters, contiguous procoxae, 11- segmented antenna with 3-segmented symmetrical, abrupt, loose club bearing a sensory extension on apical segment, 5 subequal, freely movable, abdominal segments, and elytra covering most of the abdomen. This is the first description of a Mesozoic member of the family Silvanidae.

Choanoflagellate Lorica Construction and Assembly: The Nudiform Condition. I. Savillea Species

The lorica of Savillea spp. (Choanoflagellida) comprises a two layered arrangement of siliceous costae, the inner layer consists of helical costae and the outer layer longitudinal. In Savillea micropora, the helical costae, in a left-handed conformation, undergo 1.5 turns and extend from a short distance above the base of the lorica to the anterior opening. In S. parva the helical costae undergo two turns from base to anterior opening. Ratios of the numbers of helical to longitudinal costae vary from 1:1 in S. parva to 1:1-1:4 in S. micropora. Cell division in Savillea is of the nudiform type, whereby a cell divides to produce a 'naked' flagellated juvenile that swims away from the parent lorica, settles on to a surface and produces a complete set of costal strips. The first formed strips are those that will form the longitudinal costae, this is followed by the slightly thicker strips which will form the inner helical costae. Lorica assembly occurs as a single continuous process and is mediated by the forward movement of the collar tentacles and a rotational movement by the cell. The longitudinal and helical costae are thereby moved in this one combined movement to their respective positions. The longitudinal costae must rotate freely during assembly whilst the helical costae are held at their front end by the respective longitudinal costae and their rear end on the surface of the cell sheath. The concluding inference, based on lorica construction, that there must be a rotational as well as the observed forward movement during lorica assembly is of seminal importance to understanding the basic pattern of lorica construction and the mechanism of lorica assembly in all choanoflagellates.

Revision of the subgenus Neosynaptops Voss of Euops Schoenherr (Coleoptera, Curculionoidea, Attelabidae) from the Papuan region

The subgenus Neosynaptops Voss of Euops Schoenherr is revised. It contains two previously described species, E. cupreosplendens Macleay and E. viridiceps Voss, plus seven new ones: E. doertheae sp. n., E. gladiator sp. n., E. paraviridiceps sp. n., E. punctaticeps sp. n., E. similis sp. n., E. waigeoensis sp. n. and E. wapogae sp. n. A lectotype is designated for E. viridiceps Voss. The species are described and the characters relevant for their identification, especially the male genitalia, are illustrated. A key to the species is provided. Three distinct types of proventriculi found in species of Neosynaptops are illustrated. A cladistic analysis is performed which confirms the monophyly of Neosynaptops. The most important apomorphies are the punctate‐rugose sculpture of the gena and the longitudinal costae on the ventral surface of the rostral base. The group is restricted to New Guinea and some small neighbouring islands.

MORPHOLOGY OF OESTRUPIA ZACHARIASII AND ITS TRANSFER TO BIREMIS

Light and scanning electron microscopical studies of the rare freshwater taxon Oestrupia zachariasii from Lake Hovsgol, Mongolia, clearly indicate that this taxon does not have features characteristic of Oestrupia, but belongs within the genus Biremis as B. zachariasii (Reichelt) Edlund, Andresen & Soninkhishig comb. nov. Biremis has internal poroid cribral plates covering marginal chambered striae that open externally by two foramina, one on the valve face and one on the valve mantle. In contrast, Oestrupia is characterized by Pinnularia/Caloneis-type alveolate striae opening internally by large internal foramina and interrupted by longitudinal costae. Biremis zachariasii also has a longitudinal row of occluded areolae on each side of the axial area, similar to some specimens of B. ambigua. Oestrupia zachariasii var. undulata is separable from the nominate variety as a shape series and is similarly proposed for transfer to Biremis as B. undulata(Schulz) Andresen, Edlund & Soninkhishig comb, et stat. nov. As currently understood, Biremis includes both marine and freshwater taxa, whereas the removal of B. zachariasii and B. undulata leaves Oestrupia as a primarily marine/brackish genus.