Benthic foraminifera, ostracods and radiolarians from the Lachman Crags Member (Santa Marta Formation), upper Santonian-lower Campanian (Upper Cretaceous) of James Ross Island, Antarctica

2013 ◽  
Vol 16 (2) ◽  
pp. 181-196 ◽  
Author(s):  
Leonardo Santos Florisbal ◽  
Karlos Guilherme Diemer Kochhann ◽  
Simone Baecker-Fauth ◽  
Gerson Fauth ◽  
Marta Cláudia Viviers ◽  
...  
2005 ◽  
Vol 17 (2) ◽  
pp. 267-280 ◽  
Author(s):  
MARCELA CICHOWOLSKI ◽  
ALFREDO AMBROSIO ◽  
ANDREA CONCHEYRO

To date, Cretaceous nautilids from the Antarctic Peninsula have received little attention and only a single species had been reported, Eutrephoceras simile Spath, from Seymour, Snow Hill, and James Ross islands. Currently, it is considered a synonym of Eutrephoceras subplicatum (Steinmann), which has also been described from the Upper Cretaceous of central Chile, southern Argentina and Angola. Here, we report and describe E. subplicatum in detail, based on specimens from the Lower Campanian–Maastrichtian of Vega, Seymour and James Ross islands, presenting, for the first time, embryonic conch features related to the palaeoecology of these organisms. The nauta of this species had a diameter of approximately 30 mm with 5–6 septa. In addition, we describe a new species, Eutrephoceras antarcticum, and one specimen assigned to the same genus in open nomenclature, both recovered from the Lower Campanian beds of James Ross Island.


Author(s):  
Consorti L

The intertidal area of carbonate platform hosts a complex array of ecological networks in which microbials, algae, cyanobacteria and benthic foraminifera coexist. Being influenced by the amplitude of tides, intertidal areas frequently experience episodes of extreme conditions, including hypersaline waters and elevate daily temperatures. An interesting record of Upper Cretaceous fossil benthic foraminifera found within the intertidal facies of Apennine Carbonate Platform is presented and discussed. Two local gatherings of juvenile Scandonea and adult Rotalispira maxima suggest that the intertidal area was frequently colonized by benthic foraminifera. The results show that these populations of foraminifera were able to tolerate periods of extreme salinity and temperature for reproduction or feeding purposes.


2020 ◽  
pp. 57-67
Author(s):  
Felix Schlagintweit ◽  
Koorosh Rashidi

new larger benthic foraminifera is described as Broeckinella hensoni from the upper Maastrichtian Tar-bur Formation of SW Iran (Zagros Zone). In comparison to the type species of the genus, Broeckinella arabica Henson, which also occurs in the Tarbur Formation, the new species has distinctly larger dimensions (e.g., size and thickness of test, chamber height). The first record of a microspheric specimen of B. arabica shows previously unrecorded annular chambers in the final test stage. Therefore, the generic diagnosis is herein emended. In the Tarbur Formation, both B. hensoni n. sp. and B. arabica occur in foraminiferal-algal wackestones. However, B. arabica occurs in a wider range of microfacies, including packstones and grainstones. It is assumed that Broeckinella originated in the Upper Cretaceous with Broeckinella neumannae Gendrot. The upper Albian Broeckinella aragonensis Peybernès is herein transferred to the porcellaneous genus Peneroplis Montfort.


1993 ◽  
Vol 67 (5) ◽  
pp. 828-849 ◽  
Author(s):  
W. J. Kennedy ◽  
W. A. Cobban

The Merchantville Formation of New Jersey, Maryland, and Delaware yields a distinctive assemblage of upper lower Campanian ammonites: Pachydiscus (Pachydiscus) sp., Pseudoschloenbachia cf. P. chispaensis Adkins, 1929, Placenticeras placenta (DeKay, 1828), Texanites (Texanites) sp., Menabites (Delawarella) delawarensis (Morton, 1830c), M. (D.) vanuxemi (Morton, 1830c), Menabites (Bererella) sp., Submortoniceras punctatum Collignon, 1948, S. uddeni Young, 1963, Cryptotexanites paedomorphicus n. gen. and sp., Glyptoxoceras sp., Chesapeakella nodatum n. gen. and sp., Baculites haresi Reeside, 1927, and Scaphites (Scaphites) hippocrepis (DeKay, 1828) III of Cobban, 1969. Elements of the fauna occur in the Gulf Coast and Western Interior regions of the United States, in Western Europe, and in Madagascar and provide a basis for correlation at this level.


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