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1.
In this paper, we study a sample of cranial, mandibular and dental remains of two species of the machairodontine felid genus Machairodus from the Early Vallesian (MN 9, around 10 Ma) site of Los Valles de Fuentidueña (Segovia, Spain): the tiger-sized Machairodus aphanistus, and the smaller and more primitive M. alberdiae; a species which is only known from this site. The fossils of these two sympatric populations are compared with the most abundant samples of M. aphanistus from the Late Vallesian (MN 10), younger sites of Batallones-1 and Batallones-3 (Torrejón de Velasco, Madrid, Spain). The results support the specific separation of M. alberdiae from M. aphanistus based on several differences in teeth size and proportions. Besides this, we observed differences among the analysed samples of M. aphanistus, indicating a differentiation between the older and more primitive form from Los Valles de Fuentidueña, and the younger and more derived one from the two Batallones sites. These differences fit well with the morphological evolution of this lineage towards the more derived Turolian Amphimachairodus giganteus. Finally, a relatively structured, patched habitat, combining the presence of open landscapes with shrubby and wooded areas, is inferred to explain the sympatric distribution of these two large machairodontines in Los Valles de Fuentidueña. 相似文献
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A fossil tracksite of Lower Miocene age discovered near Salinas de Añana, Alava (Spain), has rendered an exceptionally well-preserved assemblage of vertebrate ichnites. The site shows a high proportion of carnivore tracks (3 out of 5 mammal ichnospecies) and a high number of individual trackways (15), some including over 50 consecutive footprints. The carnivore ichnites are classified as Felipeda lynxi Panin & Avram, 1962, Felipeda parvula ichnosp. nov. and Canipeda longigriffa Panin & Avram, 1962, and they are attributed to a felid, an undetermined small aeluroid, and a herpestid, respectively. The long trackways allow determination of gaits, which include lateral sequence walks and diagonal sequence trots, and of speed, which ranges from 0.4 to 1.4 m/s. Froude numbers range between 0.1 and 0.8, agreeing with gait interpretations and speed calculations. The felid trackways provide the first known evidence of group traveling in fossil cats. The herpestid footprints show modern-grade adaptations for terrestrial locomotion and digging. 相似文献
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A new species ofCestrum from the Cordillera de Mérida in Trujillo state is described and illustrated.Cestrum darcyanum, morphologically similar toC. microcalyx Francey, is distinguished by dendritic pubescence on its branchlets and leaves, larger corolla, stamens distended and geniculate
above their point of adnation to the corolla, and larger calyx. A key is provided for species of VenezuelanCestrum possessing dendritic pubescence. 相似文献
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A new Eocaiman (Alligatoridae,Crocodylia) from the Itaboraí Basin,Paleogene of Rio de Janeiro,Brazil
André E.P. Pinheiro Daniel C. Fortier Diego Pol Diógenes A. Campos Lílian P. Bergqvist 《Historical Biology》2013,25(3):327-337
A new small species of Eocaiman is described on the basis of three anterior left mandibular rami and one isolated tooth. The specimens came from the middle-upper Paleocene Itaboraí Basin (Rio de Janeiro State, Brazil; Itaboraian South American Land Mammal Age). The new taxon differs from the other two Eocaiman species, such as its small size, likely participation of the splenial in the mandibular symphysis, a reduced angle between the longitudinal axis of the symphysis and the mandibular ramus, and enlarged ninth and tenth dentary teeth (in addition to the large first and fourth dentary teeth). The participation of the splenial in the mandibular symphysis is a unique character among caimanines (with the only possible exception being Tsoabichi greenriverensis). The new taxon provides new information on the taxonomic and anatomical diversity of the genus Eocaiman, a taxon of prime importance to understand the evolutionary origins of caimans given its position as the basalmost member of Caimaninae. Furthermore, the new taxon has a relatively small body size in comparison with other species of Eocaiman, a case paralleled by other Itaboraian reptilian groups (e.g. snakes), suggesting that this ecosystem provides critical data to test the relationship between reptilian body size and climate. http://zoobank.org/83636F22-D121-4A77-9141-BE68987B6CBF 相似文献
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The golden mussel, Limnoperna fortunei, is an invasive freshwater bivalve. Since its introduction to Argentina, it had caused damage to the native fauna as well as economic damage to industries of the region. Here, we describe the growth of L. fortunei in a natural temperate environment in Argentina. Age was estimated according to the modal progression method. The constants in the von Bertalanffy growth model were adjusted by an iterative algorithm. Three annual cohorts had similar growth rates. The estimated t
0 for each cohort showed a temporary displacement in relation to the spawning period. 相似文献
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John A. Raven 《Plant Ecology & Diversity》2013,6(3):477-485
Summary The life cycle of the Batrachospermales (freshwater florideophyte red such as Batrachospermum, Lemanea) is a shortened variant of the ‘normal’ marine florideophyte life cycle. The perennial Chantransia diploid phase is microscopic and encrusting. Each winter it produces one or more semi-erect haploid gametophytes by vegetative meiosis. Gamete production and fertilization is followed by production of diploid carposporophytes; these produce diploid carpospores which disperse, and regenerate the Chantransia phase. The question of the extent to which the Chantransia phase contributes resources to the gametophyte was approached by physiological-hydrodynamic modelling. These computations suggest that the photosynthetic rates in situ on an area basis are 20 times greater for the gametophyte than the Chantransia phase; this agrees with the observed ratios of peak biomass. The conclusion is that the Chantransia phase has a negligible role in provisioning the growing gametophyte, and that the role of the Chantransia phase is to occupy space with living biomass throughout the year, including exposure at summer drawdown, and (perhaps) by dispersal via production of monospores. A similar conclusion is arrived at on the basis of biomass data for the role of the perennial ‘mushroom’ phase of the semelparous marine Fucalean brown alga Himanthalia elongata in relation to the short-lived but much larger reproductive receptacles. 相似文献
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- 1.1. The specific activity of Na-K ATPase was determined from the microsomal preparation of gills dissected from adult Macrobrachium rosenbergii.
- 2.2. Maximal ATPase activity was achieved at a substrate concentration of 0.5 mM ATP.
- 3.3. Optimal enzyme activity was obtained at pH of 7.5.
- 4.4. The Arrhenius plot of Na-K ATPase activity revealed a marked discontinuity at 30°C. “Mg” ATPase activity did not exhibit a marked discontinuity.
- 5.5. The Ea for Na-K ATPase and “Mg” ATPase was 14.6 kCal/mole and 9.31 kCal/mole respectively. Q10 values for Na-K ATPase was 2.34 and for “Mg” ATPase 1.65.
- 6.6. ATPase activity and gill homogenate protein concentration exhibited a linear relationship up to 130 μg protein/ml.
- 7.7. Na-K ATPase activity was inhibited by 10−3 M ouabain. It was equally inhibited by the removal of K+ from the reaction medium.
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Pharyngodon medinae García-Calvente, 1948 (Nematoda: Pharyngodonidae) is redescribed from Podarcis pityusensis (Bosca, 1883) (Sauria: Lacertidae) of the Balearic Islands (Spain) and confirmed as a member of the genus Skrjabinodon Inglis, 1968. A systematic review of S. medinae and closely related species is also given. Parathelandros canariensis is referred to Skrjabinodon as a new combination and Parathelandros Magzoub et al., 1980 is dismissed as a junior homonym of Parathelandros Baylis, 1930. 相似文献
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Sid Ahmed Hammouda Dietrich Kadolsky Mohammed Adaci Fateh Mebrouk Mustapha Bensalah M’hammed Mahboubi Rodolphe Tabuce 《Pal?ontologische Zeitschrift》2017,91(1):85-112
Terrestrial gastropods occur in many North African localities in Eocene continental deposits. Here we analyse the faunal assemblage from the Hamada de Méridja Formation in southwestern Algeria, dated as Early to Middle Eocene on the basis of charophytes. The assemblage consists of three closely related species that to date have been classified either in the extant Madagascan genus Leucotaenius v. Martens, 1860, or in the SW European Eocene genera Romanella Jodot, 1957 and Vicentinia Jodot, 1957. This is rejected for shell morphological and phylogeographical reasons, and a new classification as Maghrebiola gen. nov. is proposed. Maghrebiola is tentatively placed in the South American family Strophocheilidae, as species from the Early Eocene Itaboraí Basin of Brazil, currently placed in the genus Eoborus Klappenbach and Olazarri, 1970 in the family Strophocheilidae, superfamily Acavoidea, have a very similar shell habitus. This record possibly extends the known geographical range of the Strophocheilidae into the African continent during the Eocene. Immigration of this stock into North Africa during the Cretaceous via a still existing plate connection is assumed. An attribution of Maghrebiola to the African family Achatinidae is unlikely for shell morphological reasons despite certain habitus similarities, although the Priabonian genera Arabicolaria and Pacaudiella from Oman most likely belong into this family, and not to the Vidaliellidae as originally proposed. Possible causes for the very low diversity of the assemblage are mainly unfavourable living conditions, i.e. a relatively dry climate resulting in sparse vegetation and only occasional presence of water bodies, which may have had increased salinities, accounting for the lack of freshwater mollusks. The absence of any competing large gastropods may possibly have facilitated high intraspecific variability leading to sympatric occurrence of three closely related species, due to the animals occupying a wide range of available ecological niches. As the species discussed here have also been attributed to the genera Romanella and Vicentinia in the Vidaliellidae, we provide an appendix with annotated characterisations of most genera of the Vidaliellidae and list the nominal species assigned to them. This family is tentatively placed in the South American superfamily Orthalicoidea; its stock would have similarly immigrated from South America, but have successfully colonized mainly SW Europe, with only one Eocene species [Romanella kantarensis (Jodot, 1936)] recognized in Algeria. 相似文献
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The present study analyzes the behaviour ofAlnus andBetula pollen in the atmosphere of the town of Santiago de Compostela (N.W. Spain) from January 1993 to December 1995. The main
pollination period of both taxa is identified for each sampling year, which, in the case ofAlnus, took place in January and February and, forBetula, during April.Alnus andBetula pollen are found in very high quantities in the atmosphere of Santiago de Compostela, representing 5% and 12% respectively
of the total annual pollen that was counted. We studied the correlation between pollen content each year for both taxa and
the main meterological parameters (average, maximum and minimum temperatures, precipitation and hours of sunshine). Finally,
we analyzed the diurnal behaviour model for each taxon. ForAlnus, the maximum concentrations were found around 20:00 h, while, in the case ofBetula, the main pollen concentration took place between 15:00 h and 20:00 h in 1993 and 1994, and at 00:00 h in 1995. 相似文献
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The male of Brumptomyia angelae, sp. nov., a new species of Phlebotominae (Diptera, Psychodidae) of the Atlantic forest of the state of Paraná, Brazil, is described and illustrated. This new taxon is closely related to Brumptomyia ortizi Martins, Silva & Falc?o 1971, Brumptomyia nitzulescui (Costa Lima, 1932), and Brumptomyia troglodytes (Lutz, 1922). The male genitalia of these three latter species have also been drawn. 相似文献
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Population density (number of propagules/l) of Pythium in the irrigation water has been studied in the reservoirs of the Poniente Almeriense (Almería, Spain). These reservoirs are habitually used in the watering of the greenhouse crops of the district. From October 1994 to August 1997, 17 sampling campaigns were carried out, 23 reservoirs were visited and three of them were sampled during three years. 300 ml of superficial water were sampled and analyzed in the laboratory by means of filtration with paper Whatman number 1, placed on Ponchet selective medium and incubated at 20 degrees C. Data of the physical-chemical characteristics of the water (temperature, pH, CE, anions and cations) were taken. The geographical and seasonal distributions of the population were correlated with the analyzed characteristics. The more frequent densities were among 0-100 propagules/l. A population's seasonality was observed, with a maximum in winter and a minimum in summer. When Cl- concentration was higher, the number of propagules/l was smaller. 相似文献
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The entire skeleton ofTephrinectes sinensis, the single representative of a monotypic genus, is described in detail. The apomorphic characters observed suggest that
the sister group ofT. sinensis is a clade composed of the Poecilopsettinae, Rhombosoleinae, Samarinae, Achiridae, Soleidae and Cynoglossidae, taxa which
share an anteriorly-inclined second neural spine the distal portion of which overlies the cranium. This supports the removal
ofT. sinensis from its former position in the Paralichthyidae. 相似文献
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A new species of Kritskyia inhabits the urinary bladder of the "curimba", Prochilodus lineatus in the floodplain of the high Paraná river. The new species resembles others members of Kritskyia in the following features: haptor lacking anchors and with 14 hooks marginal, posterior male copulatory organ non articulated with the accessory piece and vagina a sclerotized tube. However, it differs from the known species mainly by the shape of the copulatory complex. This is the third endoparasitic monogenean species reported from freshwater Neotropical fish. 相似文献
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W. C. Osman Hill 《Zoomorphology》1969,65(3):274-286
Musculature innervated by the N. facialis inTheropithecus gelada (Rüppell) is patterned on broad lines in agreement with related genera of catarrhine monkeys, but presents some specializations and divergences in detail. Noteworthy is the extension to the labial margins superficially of the combined levator labii superioris and zygomaticus in the upper and the pars mandibularis of trachelo-platysma in the lower lip. A specialization of the medial fibres of levator labii superioris forms a sling-like structure within the upper lip and serves to implement the lip-flip gesture characteristic of the genus. Its antagonist is the orbicularis oris. Special features of all other facialis muscles are considered.Abbreviations
ABD
Anterior belly of digastricus
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AE
Arteria facialis
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ALS
Arteria labialis superior
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ANL
Arteria lateralis nasi
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AP
Auricularis posterior
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APA
Arteria auricularis posterior
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AS
Arteria auricularis superior
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A.Se.
Arteria septi nasi
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A.Sy.
Arteria symphysialis
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BP
Buccal pouch
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LAO
Depressor anguli oris
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FTA
Fronto-temporo-auricularis
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GLI
Glandulae labialis inferiores
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GLS
Glandulae labialis superioris
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LAO
Levator anguli oris
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LG
Artery to labial glands
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LLAN
Levator labii superioris alaeque nasi
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LLS
Levator labii superioris
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M
Masseter
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MM
Musculus mentalis
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NP
Notoplatysma
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O
Occipitalis
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OO
Orbicularis oris
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O.Oc
Orbicularis oculi
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P
Procerus
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SH
Sterno-hyoideus
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TP
Trachelo-platysma
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VL
Vena labialis communis
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VP
Venous plexus of dorsum nasi
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ZM
Zygomaticus minor
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Zy
Zygomaticus 相似文献