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1.
A new species of Veturius (Veturius) Kaup from southern Colombia, Putumayo, lowland forests, is described and illustrated. V. paya n. sp. belongs to the South American “cephalotes” species group and is sister species of V. cephalotes (Le Peletier & Serville, 1825). Both species are distinguished by few characters of the head and thorax. They seem to be allopatric close to the western distributional limits of V. cephalotes. The endemism of V. paya n. sp. corresponds to a geographic vicariance in the axis of the Amazon Basin. An overview is given on the phylogeny and the chorology of the completed “cephalotes” species group. 相似文献
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A new species of amphistome digenean from the stomach and intestine of Podocnemis expansa (Pelomedusidae), of the tropical rain forest, from the State of Pará, Brazil, is described and allocated to a new genus ( Oriximinatrema noronhae ). The new species is characterized by the presence of an esophageal bulb, an esophageal extension uncovered by an extension of the pharyngeal sacs, a well-developed cirrus sac, post-bifurcal genital sucker, a ventro-terminal acetabulum with an anterior lip, and medium-sized eggs. This is the first report of a Dadayiinae trematode infecting a reptilian host. 相似文献
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Hong De-Yuan 《植物分类学报:英文版》1980,18(4):473-475
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A new genus and species of a basal testudinoid turtle of the family “Lindholmemydidae,” Paramongolemys khosatzkyi gen. et sp. nov., is described based on shell material from the Naranbulak Formation (Upper Paleocene) of the Naran Bulak and Khaychin-Ula IE localities (Mongolia). Material of this species includes some specimens previously described as Mongolemys tatarinovi. 相似文献
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Alexandre Antonelli 《BMC biology》2009,7(1):82
Background
The tendency of animals and plants to independently develop similar features under similar evolutionary pressures - convergence - is a widespread phenomenon in nature. In plants, convergence has been suggested to explain the striking similarity in life form between the giant lobelioids (Campanulaceae, the bellflower family) of Africa and the Hawaiian Islands. Under this assumption these plants would have developed the giant habit from herbaceous ancestors independently, in much the same way as has been suggested for the giant senecios of Africa and the silversword alliance of Hawaii. 相似文献6.
Alexandre Antonelli 《BMC biology》2009,7(1):1-21
Background
Understanding stem cell differentiation is essential for the future design of cell therapies. While retinoic acid (RA) is the most potent small molecule enhancer of skeletal myogenesis in stem cells, the stage and mechanism of its function has not yet been elucidated. Further, the intersection of RA with other signalling pathways that stimulate or inhibit myogenesis (such as Wnt and BMP4, respectively) is unknown. Thus, the purpose of this study is to examine the molecular mechanisms by which RA enhances skeletal myogenesis and interacts with Wnt and BMP4 signalling during P19 or mouse embryonic stem (ES) cell differentiation.Results
Treatment of P19 or mouse ES cells with low levels of RA led to an enhancement of skeletal myogenesis by upregulating the expression of the mesodermal marker, Wnt3a, the skeletal muscle progenitor factors Pax3 and Meox1, and the myogenic regulatory factors (MRFs) MyoD and myogenin. By chromatin immunoprecipitation, RA receptors (RARs) bound directly to regulatory regions in the Wnt3a, Pax3, and Meox1 genes and RA activated a β-catenin-responsive promoter in aggregated P19 cells. In the presence of a dominant negative β-catenin/engrailed repressor fusion protein, RA could not bypass the inhibition of skeletal myogenesis nor upregulate Meox1 or MyoD. Thus, RA functions both upstream and downstream of Wnt signalling. In contrast, it functions downstream of BMP4, as it abrogates BMP4 inhibition of myogenesis and Meox1, Pax3, and MyoD expression. Furthermore, RA downregulated BMP4 expression and upregulated the BMP4 inhibitor, Tob1. Finally, RA inhibited cardiomyogenesis but not in the presence of BMP4.Conclusion
RA can enhance skeletal myogenesis in stem cells at the muscle specification/progenitor stage by activating RARs bound directly to mesoderm and skeletal muscle progenitor genes, activating β-catenin function and inhibiting bone morphogenetic protein (BMP) signalling. Thus, a signalling pathway can function at multiple levels to positively regulate a developmental program and can function by abrogating inhibitory pathways. Finally, since RA enhances skeletal muscle progenitor formation, it will be a valuable tool for designing future stem cell therapies. 相似文献7.
Juan C. Paggi 《Hydrobiologia》1989,182(3):239-248
A new species of Ilyocryptus Sars from several localities in River Paraná basin, is described and figured. By the presence of a lateral process on the
valves I. paranaensis n.sp. resembles I. cornutus Mordukhai-Boltovskoi & Chircova, but it shows several morphological differences in the shape and the armature of the postabdomen
and in the antennal formula. 相似文献
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《Geobios》2020
A new species, Phoenicopsis anadyrensis Nosova, is described based on the leaf morphology and cuticle features from the Maastrichtian–Danian Rarytkin Formation, Chukotka, North-East of Russia. It is characterized by hypostomatic leaves with stomatal bands on the abaxial side, undulate anticlinal epidermal cell walls and papillae on the epidermal cells and on the subsidiary cells of the stomata. The new species is the youngest reliable representative of the genus Phoenicopsis. This record extends the stratigraphic range of Phoenicopsis from its previously known latest records in the early Campanian up to Maastrichtian–Danian. The persistence of the genus Phoenicopsis up to the Cretaceous–Paleogene boundary is most likely related with vicinity to mountain floras associated with Late Cretaceous and Paleogene volcanic uplands. 相似文献
11.
A new species attributed to the genus Parvifuzia Guo & Ren, 2011, Parvifuzia peregrinasp. n., is described from the Middle Jurassic Jiulongshan Formation of Daohugou Village, Inner Mongolia, China. This new species, with apex of wing almost reaching the end of the abdomen and forewing venation with 30-32 veins at margin, broadens the diversity of Parvifuzia. This new species, with strongly curved cerci, could tightly clasp female and complete copulation more efficiently, same as other members of the family Fuziidae. 相似文献
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Ronald Sluys Anno Faubel Sanjeevi Rajagopal Gerard van der Velde 《Helgoland Marine Research》2005,59(4):310-314
A new species of polyclad flatworm, Imogine necopinata Sluys, sp. nov., is described from a brackish habitat in The Netherlands. Taxonomic affinities with Asian species and the
ecology of the animals suggest that the species is an introduced, exotic component of the Dutch fauna. The new species belongs
to a group of worms with species that are known to predate on oysters. 相似文献
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Hippia packardii (Morrison) and Hippia insularis (Grote) are moved to the genus Elasmia Möschler as comb. n. Elasmia cave Metzler, sp. n. is described from New Mexico and Texas, and Elasmia mandela santaana Metzler & Knudson, ssp. n. is described from Texas and Oklahoma. A key to the species of Elasmia of southwestern U.S. is provided. Adult male and female moths of Elasmia from southwestern U.S. and their genitalia are illustrated. 相似文献
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Gabrel Lio Federico L. Agnolín Rubén Juarez Valieri Leonardo Filippi Diego Rosales 《Historical Biology》2016,28(6):835-841
Peirosauridae is composed of mid- to large-sized terrestrial mesoeucrododylian crocodyliforms distributed throughout Gondwanan landmasses. Here we describe a new peirosaurid that comes from the upper levels of the Portezuelo Formation (Turonian–Coniacian, Upper Cretaceous) from Loma de la Lata, Neuquén Province, Argentina. This specimen consists of some associated bones belonging to a single individual. In order to facilitate comparisons, we recognise two different peirosaurid morphotypes based on skull shape: broad- and narrow-snouted taxa. The new taxon may be related to broad-snouted taxa, especially Gasparinisuchus peirosauroides. The new taxon here reported has strong heterodont dentition when compared with other peirosaurids. As in related forms, the fourth dentary tooth is caniniform, very large, acute and transversely compressed (much more than other peirosaurids), and the anterior dentary teeth have less globular, sharp serrated crowns. Large interalveolar spaces are present between both mandibular and maxillary teeth, a trait only observed on the new taxon. With this addition, we elevate the number of Patagonian peirosaurids to four. Moreover, it represents together with Lomasuchus palpebrosus the second peirosaurid species described for the Portezuelo Formation. 相似文献
18.
André Nel 《法国昆虫学会纪事》2013,49(1):23-29
A new deposit of Lower Cretaceous amber, found in Charente-Maritime (SW France) has yielded an important entomofauna with numerous arthropod associations characteristic of moist ground. We describe a new species of Dolichopodidae: ‘Microphorinae’(Diptera: Empidoidea), Microphorites deploegi n. sp. on the basis of seven male and female specimens of exceptional state of preservation. This genus was previously only known from Lebanese amber of the Lower Cretaceous. The present discovery supports a reconstruction of the palaeoenvironment as a sandy beach along the sea, under a warm climate. 相似文献
19.
Eudorylaimus shirasei sp. nov. is described as the seventh member of the genus in the Antarctic region. The specimens were found among green algae
collected near the Molodezhnaya Station of Russia, and in moss from Cape Ryugu on the Prince Olav Coast, East Antarctica.
This species resembles E. similis (de Man, 1876), E. coniceps Loof, 1975 and E. imitatoris Gagarin, 1982, but differs from them in the shape of the tail and some other characteristics on the lip region, odontostyle,
spicules and precloacal supplements. It is also similar to three species known from females, E. eremitus (Thorne, 1939), E. jurassicus (Altherr, 1953) and E. altherri Tjepkema et al., 1971, but differs in the features of the body length, lip region, amphids, odontostyle and vulva. The present
species has multinucleate intestinal cells, which have not been so far reported in Eudorylaimus. It is possible that the multinucleation of intestinal cells has been overlooked in the previously known species of the genus.
Received: 11 April 1995/Accepted: 19 June 1995 相似文献
20.
Kesran Akın 《Zoology in the Middle East.》2016,62(1):61-63
A new species in the family Pyralidae is described: Megasis kocaki sp. n., of which the adult, head and the male genitalia are illustrated. The new species is compared with the closely allied Megasis hyrcanella Ragonot, 1893.
http://www.zoobank.org/urn:lsid:zoobank.org:pub:0136DD7F-0E91-4114-9B3B-A42E6114A985 相似文献