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Tytuł:
80 lat gdyńskiej miejskiej komunikacji zbiorowej
Eighty anniversary of public transport in Gdansk
Autorzy:
Wyszomirski, O.
Józefowicz, M.
Powiązania:
https://bibliotekanauki.pl/articles/192663.pdf
Data publikacji:
2010
Wydawca:
Stowarzyszenie Inżynierów i Techników Komunikacji Rzeczpospolitej Polskiej
Tematy:
transport pasażerski
transport zbiorowy
komunikacja miejska
passengers transport
public transport
city transport
Opis:
Historia miejskiej komunikacji zbiorowej przedstawiona w ostatnich ośmiu dekadach. Podjęte aspekty: system zarządzania komunikacją, funkcjonujące przedsiębiorstwa przewozowe oraz tabor autobusowy i trolejbusowy.
The history of city public transport presented in last eight decades. The considered aspects: the system of transport management, the transport operators, the bus and trolleybus fleet.
Źródło:
Transport Miejski i Regionalny; 2010, 3; 2-8
1732-5153
Pojawia się w:
Transport Miejski i Regionalny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Bioremediation Study of Raw and Treated Crude Petroleum Oil Polluted Soil with Aspergillus niger and Pseudomonas aeruginosa
Autorzy:
Ojewumi, M. E.
Anenih, E. V.
Taiwo, O. S.
Adekeye, B. T.
Awolu, O. O.
Ojewumi, E. O.
Powiązania:
https://bibliotekanauki.pl/articles/124955.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
bioremediation
Aspergillus niger
Pseudomonas aeruginosa
pollution
Opis:
This study was conducted to investigate the degree of bioremediation that would occur in the samples of soil polluted with raw and treated crude petroleum (oil) with the aid of Aspergillus niger (fungi) and Pseudomonas aeruginosa (bacteria). This was achieved by monitoring the Organic carbon content in the soil over 45 days and pH over 25 days. Four systems of 500 g soil were polluted with 40 g treated crude petroleum, while four systems were contaminated with 40 g raw crude petroleum. The eight systems were labeled accordingly. Two systems for raw crude control and treated crude control (RCC and TCC) were left as control, two systems for raw crude Aspergillus niger and treated crude Aspergillus niger (RCA and TCA) were treated with Aspergillus niger only, two systems for raw crude Pseudomonas aeruginosa and treated crude Pseudomonas aeruginosa (RCP and TCP) were treated with Pseudomonas aeruginosa only and the last two systems for raw crude Aspergillus niger and Pseudomonas aeruginosa (RCAP and TCAP) were treated with both Pseudomonas aeruginosa and Aspergillus niger. At the end of the bioremediation period, the results obtained showed that the pH was not particularly a solid parameter to estimate the degree of bioremediation. This is because a proper trend in the results obtained could not be determined. Additionally, it was observed that Aspergillus niger (fungi) and Pseudomonas aeruginosa (bacteria) alone and separate remediate raw crude polluted soil better than treated crude polluted soil. This was determined by the TOC (Total Organic Carbon) values on the 45th day of the experiment.
Źródło:
Journal of Ecological Engineering; 2018, 19, 2; 226-235
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A comparative study of the antioxidant activity and phytochemical composition of leaves extract between three varieties of date palm tree
Autorzy:
Eddine, L. S.
Ladjel, S.
Mohamed, O. M.
Powiązania:
https://bibliotekanauki.pl/articles/412430.pdf
Data publikacji:
2013
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Phoenyx dactylifera
polyphenol
DPPH radical-scavenging activity
reducing power
antimicrobial
south Algeria
Opis:
The date palm (Phoenyx dactylifera) consisted, for the people of southern Algeria, as tree of providence. Dates and their extracts are also used for many centuries as a medicine against allergy, inflammation, constipation and gastro-protective; they also have a high antibacterial and antioxidant activity. However, no studies are conducted to evaluate the extract from the leaves of date palm (Phoenyx dactylifera) in point of view of phytochemical composition, antimicrobial and the antioxidant activity. In this study, we have determined the phenolic compounds, antioxidant and antimicrobial activity of methanolic extracts from three varieties of leaves tree. According to the results the leaves extracts have very important values for polyphenols (215.24 to 156.46 mg GAE / g DW) and high antioxidant activity (324. 45 to 206.21 mg GAE / g DW), Diphenyl-1 picrylhydrazyl radical-scavenging activity (IC50 = 2.98 to 4.83 μg / ml); also the three extracts reveal a considerable antimicrobial potency and antifungal considerable activity, the diameter of inhibition is 35.2 to 39.5 mm (concentration 50 mg/ml) for Candida albicans ATCC 90026.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2013, 9, 2; 162-171
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A conceptual scheme for modelling forestry and LUC CO2 emissions in Ukraine
Autorzy:
Turkovska, O.
Gustil, M.
Powiązania:
https://bibliotekanauki.pl/articles/411128.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Oddział w Lublinie PAN
Tematy:
LULUCF
CO2 emissions
Ukraine
information technology
modeling
Opis:
A number of global land-use change and forest management models for studying CO2 emissions in land-use change and forestry, in particular: G4M, GLOBIOM, Land- SHIFT, GTM and GCOMAP are considered. The main issues and features of forestry in Ukraine (e.g. illegal forest harvesting, lack of reliable and consistent data on forestry, difference between concepts of Ukrainian and international legislation in forestry) are analyzed. A conceptual scheme for modelling forestry and land-use CO2 emissions in Ukraine is developed.
Źródło:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes; 2013, 2, 1; 57-62
2084-5715
Pojawia się w:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Cretaceous mammal from Tanzania
Autorzy:
Krause, D W
Gottfried, M.D.
O'Connor, P.M.
Roberts, E.M.
Powiązania:
https://bibliotekanauki.pl/articles/23042.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
mammal
Gondwana
Cretaceous
Mammalia
Africa
Tanzania
Gondwanatheria
paleontology
Opis:
We report here the discovery of a Cretaceous mammal from the “Red Sandstone Group” of southwestern Tanzania. This specimen is one of only a very few Cretaceous mammals known from Gondwana in general and Africa in particular. The specimen consists of a short, deep left dentary that bore a large, procumbent central incisor, and five single−rooted, hypsodont cheek−teeth. The specimen is very tentatively identified as a sudamericid, and thus may represent the first African record of an enigmatic clade of mammals, the Gondwanatheria, which is otherwise known from the Late Cretaceous and Paleogene of several other Gondwanan landmasses. Unfortunately, the precise age of the specimen could not be determined. If it is pre−Campanian and if its identity as a sudamercid is corroborated through subsequent discoveries, it represents the earliest known gondwanatherian. If the specimen is from the Campanian or Maastrichtian, and again assuming its identification is correct, it has the potential to refute a recently formulated biogeographic hypothesis predicting the absence of certain terrestrial and freshwater vertebrate taxa, including gondwanatherians, in Africa (i.e., those that evolved elsewhere on Gondwana after Africa became an isolated landmass).
Źródło:
Acta Palaeontologica Polonica; 2003, 48, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A disaggregated measures approach of poverty status of farming households in Kwara State, Nigeria
Zdezagregowane pomiary ubóstwa wśród gospodarstw rolnych w stanie Kwara w Nigerii
Autorzy:
Akinsola, G.O.
Adewumi, O.M.
Ayinde, O.E.
Powiązania:
https://bibliotekanauki.pl/articles/43550.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Przyrodniczy w Poznaniu. Wydawnictwo Uczelniane
Tematy:
poverty
measurement
agriculture
household
poverty status
Kwara State
Nigeria
Opis:
In a bid to strengthen the agricultural sector in Nigeria, the Kwara State Government invited thirteen Zimbabwean farmers to participate in agricultural production in Kwara State in 2004. The main objective of this study therefore was to examine the effect of the activities of these foreign farmers on local farmers’ poverty status. A questionnaire was administered on the heads of farming households. A total of 240 respondents were used for the study, which was comprised of 120 contact and 120 non-contact heads of farming households. The analytical tools employed included descriptive statistics and the Foster, Greer and Thorbecke method. The result indicated that the non-contact farming households are poorer than the contact farming households. Using the disaggregated poverty profile, poverty is most severe among the age group of above 60 years. The intensity of poverty is also higher among the married group than the singles. Based on the education level, poverty seems to be most severe among those without any formal education. It is therefore recommended that a minimum of secondary school education should be encouraged among the farming households to prevent higher incidence of poverty in the study area.
W ramach starań o wzmocnienie sektora rolniczego w Nigerii w 2004 roku władze stanu Kwara zaprosiły trzynastu zimbabweńskich rolników do udziału w stanowej produkcji rolnej. Głównym celem badania była analiza wpływu działalności zagranicznych rolników na poziom ubóstwa wśród rolników lokalnych. Kwestionariusz skierowano do osób zarządzających gospodarstwami rolnymi. W badaniu udział wzięło 240 respondentów, w tym 120 mających styczność z działalnością zagranicznych rolników i 120 takich, którzy nie mają z nią styczności. Wykorzystano następujące narzędzia analityczne: statystykę opisową oraz metodę Fostera-Greera-Thorbecka. Zgodnie z uzyskanymi wynikami gospodarstwa rolne pozostające poza enklawą zagranicznych rolników były biedniejsze niż te w jej zasięgu. Według zdezagregowanego pomiaru ubóstwa bieda mocno dotyka osoby z grupy wiekowej powyżej 60 lat. Intensywność ubóstwa jest wyższa także u osób w związku małżeńskim niż stanu wolnego. Ubóstwo wydaje się również bardziej dotkliwe wśród osób nieposiadających oficjalnego wykształcenia. Zaleca się zatem wsparcie uzyskiwania minimalnego wykształcenia średniego przez pracowników gospodarstw rolnych, by zapobiec poszerzaniu zasięgu ubóstwa na badanym obszarze.
Źródło:
Journal of Agribusiness and Rural Development; 2016, 42, 4
1899-5241
Pojawia się w:
Journal of Agribusiness and Rural Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A herpetotheriid marsupial from the Oligocene of Bugti Hills, Balochistan, Pakistan
Autorzy:
Crochet, J Y
Antoine, P.O.
Benammi, M.
Iqbal, N.
Marivaux, L.
Metais, G.
Welcomme, J.L.
Powiązania:
https://bibliotekanauki.pl/articles/22725.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Bugti Hills
classification
herpetotheriid marsupial
Balochistan
Chitarwata Formation
Pakistan
Oligocene
fossil vertebrate
Asia
Asiadidelphis akbarbugtii
paleontology
Opis:
Didelphimorph marsupials were widely distributed in Asia during the Cenozoic, but their occurrence in the Indian subcontinent has not so far been demonstrated. Here, we describe a new herpetotheriid marsupial Asiadidelphis akbarbugtiisp. nov. from the early Oligocene Bugti Member of the Chitarwata Formation, Bugti Hills, Pakistan. The discovery of the herpetotheriids in the Oligocene of Pakistan represents the most southern occurrence of the family, which was thought to have occurred only to the north of the Alpine−Himalayan Suture. Our data suggest that episodic faunal exchanges occurred between the Asian mainland and the Indian subcontinent during the late Paleogene, and that the southern Asian faunas were not as completely isolated by the Himalayan chain as formerly believed.
Źródło:
Acta Palaeontologica Polonica; 2007, 52, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A laboratory study of pressure distribution and residual settlements in wide grading double layer railway ballast under long-term cyclic loading
Autorzy:
Sysyn, M.
Gerber, U.
Nabochenko, O.
Dehne, S.
Powiązania:
https://bibliotekanauki.pl/articles/1849767.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
podsypka kolejowa
podsypka dwuwarstwowa
zachowanie
obciążenie długotrwałe
obciążenie cykliczne
osiadanie
ciśnienie
rozkład ciśnienia
railway ballast
long-term behaviour
permanent settlement
ballast grading
pressure
pressure distribution
Opis:
Ballast layer has weighty share in the lifecycle costs of railway track. The strict standards and maintenance rules of ballast grading significantly contribute to the ballast costs. One ways to the costs reduction is differential demands to ballast grading for the secondary and low loaded railway lines. Additional one is the different ballast grading over the ballast height. This study presents a full scale laboratory investigation of technical efficiency of such railway ballast under the long-term cyclic loading in comparison with the standard ballast layer. The double layer is presented with standard grading ballast upper layer and bottom sub ballast layer consists of ballast mixture. Pressure distribution under the ballast layer and permanent settlements of the layers are measured during the loading cycles. The reference measurements with standard grading ballast material are carried out. The study shows that initial settlement accumulation of the double layer railway ballast are lower to that of the standard ballast layer. However, the settlements accumulation intensity of the ballast is higher. The analysis of the pressure distribution measurements under the ballast layer and the settlements inside the ballast layer explain the causes of the different settlement accumulation.
Źródło:
Archives of Civil Engineering; 2020, 66, 4; 561-578
1230-2945
Pojawia się w:
Archives of Civil Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A lag in the advancement of biotechnology; reliable control of maize stem borers in Africa
Autorzy:
Samuel, A.O.
Tabbassum, B.
Sharif, M.N.
Bhatti, M.U.
Nasir, I.A.
Husnain, T.
Powiązania:
https://bibliotekanauki.pl/articles/65339.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
climate change
food security
integrated pest management
pest management
pest control
maize
stem
borer
RNAi technology
Opis:
The future of food security in Africa is being severely threatened due to an exponential increase in population, which is almost three times the increase of food production. Maize production is constrained by stem borers which cause significant yield losses. Yield losses can be further compounded by higher temperatures due to climate changes, which are expected to increase the population of maize stem borers. While several methods have been employed in stem borer management, there is still significant damage caused by maize stem borers. This necessitates better control methods including the adoption of recent biotechnological advancement in RNA interference (RNAi) technology. This review highlights evidence of an increase in the stem borer population as well as the foreseen decline in maize production worldwide due to the effects of climatic changes. Furthermore, we have drawn attention to improved methods that have been used to control stem borers in maize production as well as a reluctant acceptance of traditional biotechnology in Africa. Finally, we suggest the application of alternative RNA interference techniques to breed maize for efficient pest control in order to achieve food security, improve nutrition and promote sustainable maize production.
Źródło:
Journal of Plant Protection Research; 2018, 58, 1
1427-4345
Pojawia się w:
Journal of Plant Protection Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A local existence theorem of the solution of the Cauchy problem for BBGKY chain of equations represented in cumulant expansions in the space $E_{\xi}$
Autorzy:
Stashenko, M.O.
Hubal, H.M.
Powiązania:
https://bibliotekanauki.pl/articles/2050194.pdf
Data publikacji:
2004
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
non-symmetrical particle systems
space of sequences of continuous bounded functions
BBGKY chain of equations
cumulant
Opis:
It is proved convergence of solution in cumulant expansions of the initial value problem for BBGKY chain of equations of non-symmetrical one-dimensional system of particles which interact via a short-range potential in the space $E_{\xi}$ of the sequences of continuous bounded functions.
Źródło:
Opuscula Mathematica; 2004, 24, 1; 161-168
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A modified nanoporous stir bar for simultaneous determination of Cu(II) and Cd(II) ions in natural samples prior to flame atomic absorption spectroscopy
Autorzy:
Karimi, M.
Aboufazeli, F.
Zadeh Zhad, H. R. L.
Sadeghi, O.
Najafi, E.
Powiązania:
https://bibliotekanauki.pl/articles/780050.pdf
Data publikacji:
2013
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
stir bar sorptive extraction
nanoporous structure
Cd(II) and Cu(II) determination
FAAS
Opis:
In this work, the application of stir bar sorptive extraction (SBSE), as a fast and conventional method, has been investigated for the simultaneous preconcentration and determination of trace amounts of Cd(II) and Cu(II) ions in natural samples. For this purpose, the surface of stir bar was functionalized by amine functionalized nanoporous silica and characterized by IR spectroscopy, X-ray powder diffraction (XRD), Atomic force microscopy (AFM) and N2 adsorption. In this approach, after the preconcentration of Cd(II) and Cu(II) ions and removing the matrix interferences using modified stir bar, the amounts of these ions were determined in eluent by flame atomic absorption spectroscopy (FAAS). Various parameters on adsorption and elution steps including pH of sample, adsorption kinetic, eluent parameters (type, volume and concentration) and elution time, have been optimized in this study. The limits of detection (LOD) were 1.6 and 13.8 ng mL-1 (recovery of 83.5 and 88.1%) for cadmium and copper ions, respectively. The preconcentration factors were 133 and 137 and the relative standard deviations (RSD) of the method were 5.7 and 4.6% for Cd(II) and Cu(II) ions, respectively. As the key point in this study seems to be stir bar nanoporous structure, the analytical performance of this stir bar was compared to non-porous ones. The accuracy of this novel method has been confirmed using some standard references materials. Finally the potential of this method was investigated by determination of Cd(II) and Cu(II) ions in some real samples with complicated matrixes.
Źródło:
Polish Journal of Chemical Technology; 2013, 15, 2; 86-93
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A modified PWM three intervals control for a matrix converter in real time
Autorzy:
Rezaoui, M. M.
Nezli, L.
Mahmoudi, M. O.
Kouzou, A.
Abu Rub, H.
Powiązania:
https://bibliotekanauki.pl/articles/964019.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
matrix converter [3×5]
THD
PWM three intervals
real time
Opis:
In this paper, the application of the proposed control strategy PWM three intervals with 3×5 matrix converter is presented and analyzed. This control strategy is developed for the control of the multi-phases matrix converter, where the main aim is to ensure the waveform quality of the output voltages and the input currents based on the THD evaluation. Simulation results and real time implementation on dSpace 1103 of 3×5 matrix converter under R-L load are presented for the validation of the proposed control strategy and to clarify the main related advantages.
Źródło:
Archives of Control Sciences; 2014, 24, 1; 85-98
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new approach in separation process evaluation. Efficiency ratio and upgrading curves
Autorzy:
Irannajad, M.
Nuri, O. S.
Allahkarami, E.
Powiązania:
https://bibliotekanauki.pl/articles/110189.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
separation efficiency
mineral processing
selectivity index
process evaluation
efficiency ratio
operation efficiency
Separation Process
Opis:
In mineral processing separation efficiency (SE), operation efficiency (OE), selectivity index (SI) and other indices have been used to evaluate the separation process. Up to now, no study has been conducted on the relationship between the SE, OE and SI indices. In this research, two upgrading curves are proposed based on the above indices for process and selectivity evaluation. The first upgrading curve is based on recovery R, SE, and OE as a function of concentrate grade. This curve has three background lines, including no upgrading line, ideal upgrading line and the ideal mixing line. The proposed upgrading curve is applicable not only for process evaluation by specification of OE and SE, but also for selectivity evaluation with the lowest difference between SE and OE. The curve showed that the recovery value is always greater than the SE and OE values. The parameters of OE, SE and R were used for plotting the upgrading curve as a function of concentrate grade taking into consideration all of them at a time. A new selectivity indicator, namely Efficiency Ratio (ER) as the selectivity parameter, is proposed as the ratio of OE to SE. The ER values fluctuate between 1 and . It can be presented as a function of concentrate and tailing grades (ER = [c(1-t)]/[1(c-t)]). The results showed that ER is insensitive to the feed grade and has the inverse relationship with SI. To measure the separation selectivity, another upgrading curve is proposed based on ER and SI parameters. This curve is divided into seven separation classes for evaluation the class of a separation process from ideal class to no separation one. The results of this research can be useful for separation process evaluation.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 3; 847-857
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new kentriodontine dolphin from the middle Miocene of Portugal
Autorzy:
Lambert, O
Estevens, M.
Smith, R.
Powiązania:
https://bibliotekanauki.pl/articles/22701.pdf
Data publikacji:
2005
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Portugal
Miocene
Odontoceti
Middle Miocene
Lower Tagus Basin
Kentriodontidae
new species
dolphin
Cetacea
new genus
Tagicetus joneti
paleontology
Opis:
A nearly complete skull, a partial left scapula, five lumbar vertebrae, and some fragments of ribs of a medium−sized kentriodontid dolphin (Cetacea, Odontoceti) discovered in the middle Miocene of Setúbal Peninsula, Lower Tagus Basin, Portugal, are herein assigned to a new genus and species, Tagicetus joneti. Within the grade−level family Kentriodontidae, the new taxon is referred to the specifically and ecologically diversified subfamily Kentriodontinae, essentially defined by a well−developed posterolateral projection of the nasal. The elongated rostrum, the constriction of the asymmetric premaxillae at the base of the rostrum, the anteriorly elongated palatines, and the elevated vertex of T. joneti suggest closer affinities with the larger, more derived Macrokentriodon morani, from the middle Miocene of Maryland (USA). Among other features, T. joneti differs from the latter in having more numerous maxillary teeth and shorter zygomatic processes of the squamosals. Besides providing additional indications about the evolutionary trends within the Kentriodontinae, this occurrence constitutes the first record of the subfamily from the east coast of the North Atlantic based on a nearly complete skull. Considering their morphological diversity and wide geographic range, the Kentriodontinae may have constituted one of the dominant groups of Miocene oceanic dolphins.
Źródło:
Acta Palaeontologica Polonica; 2005, 50, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new mammal from the Turonian–Campanian (Upper Cretaceous) Galula Formation, southwestern Tanzania
Autorzy:
O’Connor, P.M.
Krause, D.W.
Stevens, N.J.
Groenke, J.R.
MacPhee, R.D.E.
Kalthoff, D.C.
Roberts, E.M.
Powiązania:
https://bibliotekanauki.pl/articles/20223.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Opis:
We here establish a new mammaliaform genus and species, Galulatherium jenkinsi (Mammalia), from the Upper Cretaceous Galula Formation in the Rukwa Rift Basin of southwestern Tanzania. This represents the first named taxon of a mammaliaform from the entire Late Cretaceous of continental Afro-Arabia, an interval of 34 million years. Preliminary study of the holotypic and only known specimen (a partial dentary) resulted in tentative assignation to the Gondwanatheria, a poorly known, enigmatic clade of Late Cretaceous–Paleogene Gondwanan mammals (Krause et al. 2003). The application of advanced imaging (μCT) and visualization techniques permits a more detailed understanding of key anatomical features of the new taxon. It reveals that the lower dentition consisted of a large, procumbent lower incisor and four cheek teeth, all of which were evergrowing (hypselodont). Importantly, all of the teeth appear devoid of enamel. Comparisons conducted with a range of Mesozoic and selected Cenozoic mammaliaform groups document a number of features (e.g., columnar, enamel-less and evergrowing teeth, with relatively simple occlusal morphology) expressed in Galulatherium that are reminiscent of several distantly related groups, making taxonomic assignment difficult at this time. Herein we retain the provisional referral of Galulatherium (RRBP 02067) to Gondwanatheria; it is most similar to sudamericids such as Lavanify and Bharratherium from the Late Cretaceous of Madagascar and India, respectively, in exhibiting relatively simple, high-crowned, columnar cheek teeth. Other features (e.g., enamel-less dentition) are shared with disparate forms such as the Late Jurassic Fruitafossor and toothed xenarthrans (e.g., sloths), here attributed to convergence. Revised analyses of the depositional context for the holotype place it as having lived sometime between the late Turonian and latest Campanian (roughly 91–72 million years ago). This enhanced geochronological context helps to refine the palaeobiogeographical significance of Galulatherium among Cretaceous mammals in general and those from Gondwanan landmasses specifically.
Źródło:
Acta Palaeontologica Polonica; 2019, 64, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł

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