scholarly journals Inoceramid bivalves from the Maastrichtian of the Western Fore-Balkan Mts (Bulgaria)

2020 ◽  
Vol 49 (1) ◽  
pp. 31-52
Author(s):  
Docho Dochev ◽  
Lubomir Metodiev
Keyword(s):  
Taxonomic Descriptions ◽  
Lower Maastrichtian ◽  
Balkan Mountains

Taxonomic descriptions of newly recorded inoceramid species from the Maastrichtian of the Western Fore-Balkan Mountains (Bulgaria) are presented. The following taxa have been determined: Cataceramus subcircularis (Meek, 1876); Cataceramus palliseri (Douglas, 1942); Cataceramus barabini (Morton, 1834); Cataceramus? glendivensis Walaszczyk, Cobban and Harries, 2001; Cataceramus? cf. bebahoensis (Sornay, 1973); Cataceramus aff. goldfussianus (d’Orbigny, 1847); Trochoceramus tenuiplicatus (Tzankov, 1981); Endocostea typica Whitfield, 1880; Endocostea jolkicevi Walaszczyk, Odin and Dhondt, 2002; Endocostea sp. aff. E. coxi (Reyment, 1955); and “Inoceramus” howletti Walaszczyk, Kennedy and Klinger, 2009. The present record allowed two lower Maastrichtian inoceramid zones, namely the Endocostea typica and Trochoceramus radiosus zones, to be indicated. The material allows for correlation with the Northwestern and Boreal areas of Europe and elsewhere.

Review of the ammonite genus Pseudokossmaticeras Spath, 1922 from the uppermost Campanian–lower Maastrichtian in Bulgaria

2021 ◽  
Vol 50 (2) ◽  
pp. 3-33
Author(s):  
Docho Dochev ◽  
Lubomir Metodiev
Keyword(s):  
Lower Maastrichtian ◽  
Balkan Area ◽  
Balkan Mountains

New data on the ammonite genus Pseudokossmaticeras Spath, 1922 have been obtained from several uppermost Campanian–lower Maastrichtian strata of the Fore-Balkan Mountains (Bulgaria). A review of the earlier Bulgarian records of the genus is also presented. The following species are here described and illustrated: Pseudokossmaticeras brandti (Redtenbacher, 1873), P. galicianum (Favre, 1869), P. muratovi Michailov, 1951 and P. tercense (Seunes, 1892). Our newly obtained ammonite records were constrained by the inoceramid zonation that has recently been proposed for successions of the Fore-Balkan area. Hence, the Bulgarian data are of importance for correlation with other occurrences of Pseudokossmaticeras across Europe.

scholarly journals Inoceramid bivalve and dinoflagellate cyst integrated biostratigraphy of the topmost Campanian–Maastrichtian in a part of the Western Fore-Balkan Mountains, northwest Bulgaria

2020 ◽  
Vol 49 (3) ◽  
pp. 39-63
Author(s):  
Polina Pavlishina ◽  
Docho Dochev ◽  
Lubomir Metodiev ◽  
Eliza Vladimirova
Keyword(s):  
Depositional Environment ◽  
Dinoflagellate Cyst ◽  
Lower Upper ◽  
Stratigraphic Subdivision ◽  
First Occurrence ◽  
Lower Maastrichtian ◽  
Marine Productivity ◽  
G Ratio ◽  
Balkan Mountains ◽  
Upper Maastrichtian

We present the inoceramid and dinoflagellate cyst record from the topmost Campanian–Maastrichtian strata of three key sections of the Western Fore-Balkan Mountains, northwest Bulgaria. The following inoceramid zones were recognized: “Inoceramus” redbirdensis Zone, Endocostea typica Zone, Trochoceramus radiosus Zone and “Inoceramus” ianjonaensis Zone. The Campanian/Maastrichtian boundary was tentatively drawn slightly below the first occurrence of Endocostea typica. The uppermost inoceramid assemblage was confined to the lower part of the upper Maastrichtian. Dinoflagellate cyst ranges, as well as the first and the last occurrence events of dinocysts, provided valuable markers for the stratigraphic subdivision of the Maastrichtian. The first occurrence of Microdinium carpentierae was documented in proximity to the Campanian/Maastrichtian boundary. The Cerodinium diebelii Zone was recognized with a stratigraphical range from the lower Maastrichtian to the lower upper Maastrichtian. The last occurrence of Alterbidinium acutulum was recorded in the lower Maastrichtian and used as aid for tracing the lower/upper Maastrichtian substage boundary. The marked domination of delicate chorate dinocysts in all sections and the encountered low P/G ratio values are indicative of stable low-energy depositional environment and oligotrophic conditions, with normal marine productivity and nutrient availability in the basin during the Maastrichtian.

scholarly journals Review of the ammonite genus Pseudokossmaticeras Spath, 1922 from the uppermost Campanian–lower Maastrichtian in Bulgaria

2021 ◽  
Vol 50 (2) ◽  
pp. 3-33
Author(s):  
Docho Dochev ◽  
Lubomir Metodiev
Keyword(s):  
Lower Maastrichtian ◽  
Balkan Area ◽  
Balkan Mountains

New data on the ammonite genus Pseudokossmaticeras Spath, 1922 have been obtained from several uppermost Campanian–lower Maastrichtian strata of the Fore-Balkan Mountains (Bulgaria). A review of the earlier Bulgarian records of the genus is also presented. The following species are here described and illustrated: Pseudokossmaticeras brandti (Redtenbacher, 1873), P. galicianum (Favre, 1869), P. muratovi Michailov, 1951 and P. tercense (Seunes, 1892). Our newly obtained ammonite records were constrained by the inoceramid zonation that has recently been proposed for successions of the Fore-Balkan area. Hence, the Bulgarian data are of importance for correlation with other occurrences of Pseudokossmaticeras across Europe.

Phytoplankton of the Calanus Expeditions in Hudson Bay, 1953 and 1954

1961 ◽  
Vol 18 (1) ◽  
pp. 51-83 ◽  
Author(s):  
Adam Bursa
Keyword(s):  
Surface Wind ◽  
The Arctic ◽  
Phytoplankton Production ◽  
Hudson Bay ◽  
Population Exchange ◽  
Taxonomic Descriptions ◽  
Hydrographic Structure ◽  
Plankton Production ◽  
Water Temperature Data ◽  
Ice Conditions

Phytoplankton samples, collected in 1953 and 1954 by the Calanus expeditions, were examined by the quantitative sedimentation method in an attempt to determine the ecological aspects of phytoplankton production in Hudson Bay and Strait. During the period July to September of both years, water temperature data, and salinity, oxygen and quantitative phytoplankton samples were collected at the surface and from depths of 10, 25, 50 and 100 metres. Numerically, the most abundant, heterogeneous phytoplankton populations were found in the mouth of Hudson Bay. The lower production of phytoplankton in the surface layer can be explained by the greater amplitude of temperature and salinity, dependent upon ice conditions and surface wind drift. The most productive layer was at a depth of 10 m. Large phytoplankton populations in waters supersaturated with oxygen were still found at 25 m, indicating light conditions favourable for photosynthesis. The relatively high plankton production in the area joining Hudson Bay and Hudson Strait is probably due to the hydrographic structure and the supply of nutrients resulting from the mixing of water masses which originate in other geographical areas. The preponderance of diatoms over flagellated groups, which is more marked in Hudson Strait than in Hudson Bay, is typical for the arctic. The composition of phytoplankton in these areas shows a great similarity in the main to that found on both sides of the Atlantic. Apart from locally produced plankton populations, there is a population exchange which follows water movements. To supplement the meagreness of existing taxonomic descriptions, attention is here focussed on the identification of plankters and their individual importance in the general ecology of the phytoplankton.

Taxonomic revision of Hannafordia (Lasiopetaleae: Sterculiaceae (Malvaceae s.l.))

2001 ◽  
Vol 14 (1) ◽  
pp. 101
Author(s):  
C. F. Wilkins ◽  
J. A. Chappill
Keyword(s):  
Chromosome Number ◽  
Taxonomic Revision ◽  
Key Distribution ◽  
Seedling Morphology ◽  
New Subspecies ◽  
Distribution Maps ◽  
Taxonomic Descriptions

Taxonomic revision of the endemic Australian genus Hannafordia F.Muell. identified five taxa, including three recognised species, a new subspecies H. quadrivalvis F.Muell. subsp. recurva C.F.Wilkins and a new subspecific combination H. bissillii F.Muell. subsp. latifolia (E.Pritzel) C.F.Wilkins. Taxonomic descriptions, a key, distribution maps, illustrations, anatomical findings and seed and seedling morphology are presented. A chromosome number of n = 10 is the first published record for the genus.

Myrcia (Myrtaceae) in the state of Paraná, Brazil

Phytotaxa ◽  
2021 ◽  
Vol 486 (1) ◽  
pp. 1-105
Author(s):  
LAURA C. DE LANNOY ◽  
AYRTON I. DE OLIVEIRA ◽  
RENATO GOLDENBERG ◽  
DUANE F. LIMA
Keyword(s):  
South America ◽  
Central America ◽  
Herbarium Specimens ◽  
Vegetation Types ◽  
Northern Limit ◽  
Southern South America ◽  
Taxonomic Descriptions ◽  
Online Databases ◽  
The Caribbean ◽  
Doubtful Species

Myrtaceae is one of the largest families in number of species within the order Myrtales and one of the richest families in Brazil. Myrcia is the fourth largest genus of Myrtaceae, with approximately 770 species distributed from Central America and the Caribbean to southern South America. In Brazil Myrcia is represented by 397 species, of which 309 are endemic. In this study, we present the taxonomic treatment for all species of Myrcia that occur in Paraná state, Brazil. Analyses of herbarium specimens, online databases, and bibliography were performed. Fifty-three species of Myrcia occur in Paraná, distributed in all vegetation types. Twenty-three names were excluded from previous lists of species or listed as doubtful species. Neither of the recorded species is endemic to Paraná, but this state is the southern and northern limit of distribution of six and two species, respectively. We present an identification key, taxonomic descriptions, figures, maps, and comments on phenology, habitat, and morphology for each species.

Campanian-Maastrichtian ammonite and planktonic foraminiferal biostratigraphy from Tercis, France: Implications for defining the stage boundary

1997 ◽  
Vol 71 (3) ◽  
pp. 407-418 ◽  
Author(s):  
Peter Ward ◽  
William Orr
Keyword(s):  
Planktonic Foraminifera ◽  
New Information ◽  
Biogeographic Provinces ◽  
Lower Maastrichtian ◽  
Stratotype Section ◽  
Stratigraphic Ranges ◽  
Excellent Source ◽  
Source Of Information ◽  
Reference Section ◽  
Upper Campanian

The Campanian-Maastrichtian-aged Grande Carriere quarry near Tercis, southwest France, contains a diverse and abundant assemblage of both micro-and macrofossils from a thick sequence of well-exposed limestones. Its fauna is also a mixture of both Boreal and Tethyan Province species. Because of these two traits, the quarry provides an excellent source of information about integrated biostratigraphic events among diverse taxa, as well as providing a reference section for correlation between the two biogeographic provinces. The quarry has recently been proposed as a candidate for the Campanian/Maastrichtian boundary stratotype section, while one ammonite found there, Pachydiscus neubergicus, has been proposed as the index fossil marking the base of the Maastrichtian Stage. We have made collections of Upper Cretaceous ammonites and planktonic foraminifera from limestones exposed in, and near this site, which yield new information about the relative stratigraphic ranges of Upper Campanian and Lower Maastrichtian ammonites and foraminifera.

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