The South American and Antarctic Peninsula fossil record of Salviniales (water ferns): Its implication for understanding their evolution and past distribution

2021 ◽  
Vol 295 ◽  
pp. 104521
Author(s):  
Facundo De Benedetti ◽  
María C. Zamaloa ◽  
María A. Gandolfo ◽  
Néstor R. Cúneo
Ameghiniana ◽  
2015 ◽  
Vol 52 (1) ◽  
pp. 29 ◽  
Author(s):  
Rodolfo A. García ◽  
Leonardo Salgado ◽  
Mariela S. Fernández ◽  
Ignacio A. Cerda ◽  
Ariana Paulina Carabajal ◽  
...  

1998 ◽  
Vol 11 (4) ◽  
pp. 373 ◽  
Author(s):  
Rosemary A. Askin ◽  
Alicia M. Baldoni

Proteaceous plants were an important component of the high-latitude Late Cretaceous–Paleogene podocarpaceous conifer and Nothofagus forest vegetation growing in high-rainfall temperate conditions. In the southern South America–Antarctic Peninsula region the fossil record of the Proteaceae comprises pollen, leaves, fruits and wood with affinities to the extant subfamilies Grevilleoideae, Proteoideae, and possibly Carnarvonioideae and Persoonioideae. The oldest reported occurrences of Proteaceae in this region are in the middle–late Santonian of the Antarctic Peninsula and include pollen of Proteacidites subscabratus Couper, with the addition in the Campanian of other species of Proteacidites and Propylipollis, Cranwellipollis spp. and Peninsulapollis spp. Diversity of proteaceous pollen increased through the Campanian and Maastrichtian, reflecting the spread of Proteaceae along the Antarctic Peninsula and into South America. Both endemic species and species derived from the Australian region are represented. Compared to coeval Australian assemblages, however, proteaceous diversity remained relatively low. Interestingly, Beauprea-type species (Beaupreaidites spp., Peninsulapollis spp.) are common and varied in the Antarctic Peninsula from Campanian into the Eocene, yet the South American pollen record does not include these forms, except for rare Peninsulapollis gillii. Possibly drier conditions may have discouraged northward migration of this group. South American fossil proteaceous taxa are primarily related to Grevilleoideae, a trend that continues into the modern flora on that continent.


1988 ◽  
Vol 24 (1-4) ◽  
pp. 85-88 ◽  
Author(s):  
E.B. Pereira ◽  
A.W. Setzer ◽  
I.F.A. Cavalcanti

Abstract 222Rn was continuously measured at the Brazilian Antarctic Station (62 oS, 58 oW) during the year of 1986. Baseline radon concentration averaged 0.02 Bq.m-3 with surges peaking at 0.4 Bq.m-3. The data exhibited a characteristic periodicity of about 25 days and a strong positive association with short term fluctuations of atmospheric temperature. No seasonal variation of radon were observed. Interpretation of the radon surges with reference to synoptic charts and weather satellite pictures showed that the continental influence of radon at the Antarctic Peninsula is very small and comes only from the tip of the South American cone.


2016 ◽  
Vol 36 (6) ◽  
pp. e1228657 ◽  
Author(s):  
Guillermo F. Turazzini ◽  
Matías L. Taglioretti ◽  
Raúl O. Gómez

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