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1.
Michel Martin 《Geobios》1980,13(3):437-440
The Morrocan continental upper Trias (Argana valley, Western Atlas) has yielded Mauritanichthys rugosus n. gen. et n. sp. This redfieldiid is very similar to Lasalichthys (upper Trias, Texas). That fact recalls that no deep and broad ocean separated Morroco from North America. This discovery shows, too, that the conditions of deposition were very similar in those two regions. 相似文献
2.
Anna J. Phillips Renzo Arauco-Brown Alejandro Oceguera-Figueroa Gloria P. Gomez María Beltrán Yi-Te Lai Mark E. Siddall 《PloS one》2010,5(4)
Background
Leeches have gained a fearsome reputation by feeding externally on blood, often from human hosts. Orificial hirudiniasis is a condition in which a leech enters a body orifice, most often the nasopharyngeal region, but there are many cases of leeches infesting the eyes, urethra, vagina, or rectum. Several leech species particularly in Africa and Asia are well-known for their propensity to afflict humans. Because there has not previously been any data suggesting a close relationship for such geographically disparate species, this unnerving tendency to be invasive has been regarded only as a loathsome oddity and not a unifying character for a group of related organisms.Principal Findings
A new genus and species of leech from Perú was found feeding from the nasopharynx of humans. Unlike any other leech previously described, this new taxon has but a single jaw with very large teeth. Phylogenetic analyses of nuclear and mitochondrial genes using parsimony and Bayesian inference demonstrate that the new species belongs among a larger, global clade of leeches, all of which feed from the mucosal surfaces of mammals.Conclusions
This new species, found feeding from the upper respiratory tract of humans in Perú, clarifies an expansion of the family Praobdellidae to include the new species Tyrannobdella rex n. gen. n.sp., along with others in the genera Dinobdella, Myxobdella, Praobdella and Pintobdella. Moreover, the results clarify a single evolutionary origin of a group of leeches that specializes on mucous membranes, thus, posing a distinct threat to human health. 相似文献3.
J. Juget 《Hydrobiologia》1987,155(1):107-118
Two new stygobiont species of Rhyacodrilinae (Tubificidae, Oligochaeta), Rhyacodrilus amphigenus, sp. n., and Rhizodriloides phreaticola, g. n., sp. n. are described from the phreatic and hyporheic waters of the alluvial plain of the French upper Rhôone. Further information is given about the distribution of the genera Rhyacodrilus and Rhizodriloides in France and ecological features of several species according to their rate of endemicity and a typological classification of the epigeous and subterranean aquatic environment. 相似文献
4.
Peter M. Galton 《Geobios》1980,13(3):451-457
The holotype of the nodosaurid ankylosaur Dracopelta zbyszewskii n. gen. and n. sp. is described from the Kimmeridgian(Upper Jurassic) of Ribomar on the west coast of Portugal. This is the first Upper Jurassic ankylosaur to be described that is represented by articulated bones. The specimen consists of a partial rib cage with thirteen dorsal vertebrae and five different types of dermal armor, two of wich show a partial overlap between adjacent plates. 相似文献
5.
Representatives of the Nautiloculina population of the Berriasian-Upper Albian Pyrenean upper platform series (Navarro-Languedocian and Catalonian Pyrenees) and Subalpine ranges (Vercors) have been collected and studied. We are led to distinguish two species: one of them, N. cretaceaPeybernes, is the largest of all known Nautiloculina; it does not seem to exist beyond the upper Bedoulian. The other, N. bronnimanni n. sp., occurs up to the top of the Upper Albian; it is distinguished from the former by its smaller size, its depressions at the level of axis of coiling, and its depressed sutures. 相似文献
6.
Enrique Bernárdez 《Annales de Paléontologie》2018,104(3):175-181
Truyolsodontos estauni n. gen., n. sp. is described based on fossil teeth from the middle and upper Cenomanian of northern Spain. The species Protoscyliorhinus magnusLandemaine, 1991 is withdrawn from the genus Protoscyliorhinus and placed in this new one. For the new genus, the new family Truyolsodontidae is proposed. 相似文献
7.
A new subspecies of the Amur grayling is described, the yellow-spotted grayling Thymallus grubii flavomaculatus ssp. n. populating the upper reaches of large tributaries of the Lower Amur basin and some rivers flowing to the Tatar Strait, the Sea of Okhotsk, and the Sea of Japan. From nominative subspecies T. g. grubii populating the basin in the upper reaches of the Amur and from other representatives of the genus Thymallus, this subspecies differs in the dorsal fin pattern whose principal trait is a yellow spot on the last two-five interray membranes, in the body coloration, and in some morphological characters. The yellow-spotted grayling in the upper reaches of tributaries sympatrically coexists with the Lower Amur grayling Thymallus sp. No specimens with intermediate characters are found. The sympatric forms spawn at different times, thus being isolated reproductively. Isolation of the yellow-spotted grayling as a subspecies of the Amur grayling T. grubii is confirmed by the results of molecular-genetic investigations. 相似文献
8.
Selective Somatic Elimination of NICOTIANA GLUTINOSA Chromosomes in the F(1) Hybrids of N. SUAVEOLENS and N. GLUTINOSA
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The F1 hybrids of Nicotiana suaveolens (subgenus Petunioides, 2n = 32) and N. glutinosa (subgenus Tabacum, 2n = 24), were examined during their development, from seedlings to mature plants. It was observed that in the hybrids, there was a progressive change of dominant N. glutinosa morphological characteristics towards those of N. suaveolens, in leaf shape, stem, flower color and branching pattern. A study of mitotic chromosomes in the root-tips and in very young anthers of the mature plants indicated a significantly high average frequency of aberrant mitotic anaphases (bridges and fragments, 12% and 11% respectively). As a consequence of this phenomenon, variability in the number and size of chromosomes was observed in the PMC's and in mitotic metaphases (29-24 chromosomes). In order to establish whether the N. glutinosa chromosomes were preferentially lost, a karyological study of the parents and their F1 hybrids was carried out and it was established that the F1 hybrids were losing N. glutinosa chromosomes preferentially. A mechanism was suggested for the loss of these chromosomes by means of a chromatid type of breakage-fusion-bridge cycle (b-f-b cycle) and initiation of the b-f-b cycle in the hybrid due to an interaction of the regulatory mechanism of DNA replication in the haploid genomes of the parental species. However, loss of these chromosomes owing to interaction of certain genes from the two parental species cannot be ruled out. 相似文献
9.
《Revue de Micropaléontologie》2015,58(3):185-216
Three sections of the Gachal Formation, Tang-e Vaveila, Rahdar, and Bakhshi, located in the Kalmard area near the Tabas town (Central Iran) are revised. Tang-e Vaveila is dated as latest Tournaisian (upper MFZ8) to early Viséan (upper MFZ9); Rahdar is latest Tournaisian (latest MFZ8); and Bakhshi exposes the whole early Viséan (lower and upper MFZ9) succession. The upper MFZ8 subzone is indicated by the presence of Eoparastaffellina ex gr. rotunda; the lower MFZ9 subzone by the appearance of Eoparastaffella ex gr. simplex, and the upper MFZ9 subzone by the more or less concomitant appearances of Eostaffella and Lapparentidiscus. Among the foraminiferal assemblages, the endothyroids and loeblichioids are diversified, whereas the eoparastaffellins, tournayelloids and lituotubelloids remain rare. Regionally, the tetrataxins are interesting, because five species of Tetrataxis succeed one another across the MFZ9 biozone. Rich populations of Eotextularia were also observed. Incertae sedis algae are relatively diversified with the classical moravamminales and aoujgaliales. An interesting true alga is mentioned, but left in open nomenclature, as Epimastoporeae indet. Among the other microfossils, Cryptophyllus, Hamulusella?, Draffania, and hexaphyllids are noteworthy. The new taxa are: Eoparastaffellinae n. subfam., Endolaxina paralaxa n. sp., and Vissarionovella? iranica n. sp. 相似文献
10.
Martin Sorg 《Pal?ontologische Zeitschrift》1986,60(3-4):277-284
Passaloecus microceras n. sp. from baltic amber (upper Eocene) andP. munax n. sp. from amber of Bitterfeld (lower Miocene) are described and their position within the genusPassaloecus Shuckard is discussed. 相似文献
11.
The holotype of the prosauropod dinosaur Blikanasaurus cromptoni n. gen. and n. sp., a partial hindlimb, is described from the lower Elliot Formation (= Red Beds) (upper Carnian or lower Norian; Upper Triassic) of Herschel district, Transkei, South Africa. The new prosauropod family Blikanasauridae is characterized by a hindlimb that is extremely stocky, especially the metatarsus, with the distal tarsals medially situated. Blikanasaurus was an early experiment in the direction of heavily-built, quadrupedal saurischians, but it was not on the evolutionary line that gave rise to the Sauropoda. 相似文献
12.
Arabella T. Morris Doron Lancet Israel Pecht David Givol Raymond A. Dwek 《International journal of biological macromolecules》1980,2(1):39-44
The binding of the haptens DnpOH, Dnp-lysine and Dnp-aspartate to the mouse myeloma IgA protein was studied using 1H 270 MHz nuclear magnetic resonance spectroscopy. The n.m.r. difference spectra showed fewer resonance perturbed than expected. This is explained in terms of chemical exchange between the T and R states of the protein as described by the kinetic scheme of Lancet and Pecht (Lancet, D. and Pecht, I. Proc. Natl Acad. Sci. USA 1976, 73 3549 53). Large upfield chemical shifts were observed on the resonances of the hapten DnpOH on binding to M460. These are interpreted as indicating an aromatic environment for the Dnp ring. In contrast, the Dnp-aspartate resonances were not shifted at all, as would be expected from the observed rate constants using the kinetic scheme. The shifts observed on the hapten Dnp-lysine were much smaller than those observed for DnpOH. A range of possible values of the shifts were calculated for the T and R states, for Dnp-lysine and DnpOH. For both haptens the combining site environment differed between the T and R conformational states of M460, suggesting that the conformational change involves the combining site. 相似文献
13.
The Afrotropical flea beetle genus Notomela Jacoby, 1899 is reviewed. Notomela
joliveti
sp.n. from Principe Island is described. The following new synonymies are established: Notomela
cyanipennis Jacoby, 1899 = Notomela
viridipennis Bryant, 1941, syn. n. = Notomela
cyanipennis
macrosoma Bechyné, 1959, syn. n. In addition, the new combination is established: Notomela
fulvofasciata Jacoby, 1903 is transfered to Amphimela [Amphimela
fulvofasciata (Jacoby, 1903), comb. n.]. Micrographs of male and female genitalia, scanning electron micrographs of some diagnostic morphological characters, a key to identification, and distributional data for all species of Notomela, are provided. 相似文献
14.
The mesic Caspian (Hyrcanian) forest and ecotone communities provide a marked contrast to the arid and semiarid landscapes associated with most of the territory of Iran. To date, the ecological characteristics of these habitats, threatened and of conservation importance, have been little studied. Accordingly, ecological profiles of some important plant species of these communities have been assessed along two altitudinal gradients (300–2300 m a.s.l.). Vegetation and soils were sampled every 100 m in elevation, with the data subsequently analyzed using TWINSPAN and corrected frequency (CF) analyses. Relationships between soil variables (subdivided into three classes, the lowest, the middle and the upper third of all values) and herbaceous and shrub species (presence/absence data) were analyzed by the polythetic divisive classification method. 379 plant species and eleven soil variables – N, P, K, CaCO3, EC, pH, organic matter, C/N ratio and percentage of sand, clay and silt – were considered. The ecological profile method was used to evaluate the affinity and significance of associations between the probability of species’ occurrence and topsoil characteristics found by the polythetic method. Five vegetation groups were identified: two groups, with Acer campestre and Quercus macranthera in the tree layer and Veronica mazanderanae and Phuopsis stylosa as herbs, were restricted to forest-steppe ecotones and the upper mountain areas. Three groups, with Acer velutinum, Ruscus hyrcanus, Carpinus betulus, Danae racemosa, Fagus orientalis and Aruncus vulgaris as indicator species, occurred in the forest itself. Of the 42 plant species assessed as being of particular importance, 13 had significant relationships with eight soil factors. Thus, certain species, including endemic plant species of restricted distribution and conservation importance, can be used as indicators of particular soil conditions in the Hyrcanian forest area. 相似文献
15.
Joseph R. Thomasson 《American journal of botany》1983,70(3):435-449
Silicified achenes and some perigynia of four new sedges are described from the late middle or late Miocene Ash Hollow (Clarendonian or Hemphillian) and early middle Miocene Sheep Creek (Late Hemingfordian) Formations of Nebraska. Carex graceii, sp. n., Cyperocarpus terrestris, sp. n., and Cyperocarpus pulcherrima, sp. n., were collected from strata in Garden and Antelope Counties and Cyperocarpus eliasii, sp. n., was collected from strata in Sioux County. Certain of the newly discovered taxa exhibit considerable anatomical detail of the pericarp wall of the achene. In two taxa, Carex graceii and Cyperocarpus pulcherrima, the achene pericarp exhibits four topographic regions: a cuticle, an outer layer of pentagonally to hexagonally shaped epidermal cells containing silica bodies, a middle layer of sclerenchyma cells, and an inner layer of sclerenchyma cells whose long axes are perpendicular to the long axes of the cells of the middle layer. Similar pericarp anatomy was found in Cyperocarpus terrestris except that the inner layer was not observed. In the fourth taxon, Cyperocarpus eliasii, only an outer epidermal layer of elongate cells with small protuberances is preserved. The ultrastructure of the pericarp of the fossil taxa is similar to that of living forms. Associated flora and fauna indicate widespread savanna environments with significant riparian elements. This is the first systematic treatment of sedges from the Miocene of North America. 相似文献
16.
Chromosome numbers are reported for 20 collections of Mongolian plants representing 19 taxa. The first chromosome records are reported forArabidopsis mongolica (2n=16),Caragana pygmaea (2n=16),Isatis costata var.leiocarpa (2n=28),Lophanthus chinensis (2n=18) andStevenia cheiranthoides (2n=32). Counts partly differing from those previously recorded are given forBatrachium trichophyllum subsp.trichophyllum (2n=32+0-2B, 36+6B),Cuscuta chinensis (2n=60),Dracocephalum fragile (2n=72) andErysimum flavum (2n=14). Chromosome numbers of the following taxa were confirmed:Astragalus monophyllus (2n=16),Erodium stephanianum (2n=16),Gastrolychnis apetala (2n=24),Geum aleppicum (2n=42),Linum baicalense (2n=18),Rorippa palustris (2n=32),Rubia cordifolia subsp.pratensis (2n=22),Schizonepeta multifida (2n=12),Tribulus terrestris (2n=36) andVicia cracca (2n=14). Taxonomic remarks onArabidopsis mongolia, Erysimum flavum, Stevenia cheiranthoides andVicia cracca are added. A new combinationArabidopsis mongolica (Botsch.)Měsí?ek & Soják is proposed. 相似文献
17.
A new gavialid from the Upper Miocene (“Huayquerian”) of Urumaco (western Venezuela) is described as Hesperogavialis cruxenti n. gen., n. sp. It is the only known South American gavialid in which, as in the Gavialidae from the Indian region, the nasals do not come into contact with the premaxillae. This ressemblance with the gavials of India is interpreted as a result of convergent evolution. 相似文献
18.
《Palaeoworld》2022,31(1):86-92
Arrow-shaped P1 elements of Dollymae are characteristic for the Tournaisian conodont faunas worldwide but the phylogeny of this conodont remains obscure and its origin is cryptic. Dollymae peregrina n. sp., from the upper Famennian (upper expansa Zone) strata in the Holy Cross Mountains (central Poland), is the oldest representative of the Dollymae lineage. The morphology of the new species’ P1 element shows primitive features in comparison to other members of this genus and is transitional in the number of element processes. Thus D. peregrina n. sp. is most probably ancestral to the remaining species. The genus appears to be monophyletic, probably rooted in Pelekysgnathus within the Icriodontidae. 相似文献
19.
《Palaeoworld》2022,31(1):131-139
The Dawenkou Basin is a Cenozoic terrestrial fault basin in Shandong Province, East China, containing abundant mineral resources, especially gypsum. Recently a borehole was drilled in this basin unearthing the upper and middle members of the Dawenkou Formation. From the upper member, well-preserved ostracodes were discovered, which are entirely non-marine taxa including species of Eucypris, Caspiolla, Candona and Candoniella. Based on the new material, a new species Candona dawenkouensis n. sp. was erected. The ostracode assemblage biostratigraphically indicates an age of middle Eocene to Oligocene of the upper member of the Dawenkou Formation and the strata bearing mineral resources (mainly gypsum) of the middle member of the Dawenkou Formation is likely early Eocene. 相似文献
20.
Xinpeng Fan Xiangrui Chen Weibo Song Khaled A.S. Al-Rasheid Alan Warren 《European journal of protistology》2010,46(3):212-220
Two new marine scuticociliates, Sathrophilus planus n. sp. and Pseudoplatynematum dengi n. sp., isolated from coastal waters of Qingdao, northern China, were investigated using live observation and silver impregnations. Sathrophilus planus can be recognized by its elongate and conspicuously flattened body, ca. 16 somatic kineties, single postoral kinety, extremely elongated first kinety row of membranelle 1, and its marine habitat. Among these features, the structure of membranelle 1 is the most characteristic and enables this species to be easily distinguished from its congeners. Pseudoplatynematum dengi is characterized by the following features: cell surface conspicuously strengthened and notched; prominent spines both at anterior and posterior ends of cell; membranelles 1 and 2 three-rowed, membranelle 3 single-rowed; paroral membrane composed of two parts, anterior end of upper part extending to about level of membranelle 2; ca. 20 somatic kineties, one postoral kinety; single prolonged caudal cilium; contractile vacuole caudally positioned. The diagnosis of the genus Pseudoplatynematum was renewed to include some new characteristics revealed by silver impregnation methods. 相似文献