Size and Locomotion in Teratorns (Aves: Teratornithidae)

The Auk ◽  
1983 ◽  
Vol 100 (2) ◽  
pp. 390-403 ◽  
Author(s):  
Kenneth E. Campbell ◽  
Eduardo P. Tonni

Abstract The extinct family Teratornithidae contains the world's largest known flying birds. A new method of determining body weights of extinct birds, based on the size of their tibiotarsi, facilitates the estimation of the wing dimensions of these giant birds. An analysis of the bones of the teratorn wing shows that they closely resemble those of condors, suggesting that teratorns flew in a manner similar to these large New World vultures. The bones of the pelvic girdle and hindlimbs indicate that teratorns were probably agile on the ground, though better adapted for walking and stalking than running. We estimate that the largest teratorn, Argentavis magnificens, weighed 80 kg and had a wingspan of 6-8 m. It probably became airborne by spreading its huge wings into the strong, continuous, westerly winds that blew across southern South America before the elevation of the Andes Mountains and, once aloft, flew in the manner of condors.

2012 ◽  
Vol 8 (5) ◽  
pp. 1599-1620 ◽  
Author(s):  
S. Wagner ◽  
I. Fast ◽  
F. Kaspar

Abstract. In this study, we assess how the anthropogenically induced increase in greenhouse gas concentrations affects the climate of central and southern South America. We utilise two regional climate simulations for present day (PD) and pre-industrial (PI) times. These simulations are compared to historical reconstructions in order to investigate the driving processes responsible for climatic changes between the different periods. The regional climate model is validated against observations for both re-analysis data and GCM-driven regional simulations for the second half of the 20th century. Model biases are also taken into account for the interpretation of the model results. The added value of the regional simulation over global-scale modelling relates to a better representation of hydrological processes that are particularly evident in the proximity of the Andes Mountains. Climatic differences between the simulated PD minus PI period agree qualitatively well with proxy-based temperature reconstructions, albeit the regional model overestimates the amplitude of the temperature increase. For precipitation the most important changes between the PD and PI simulation relate to a dipole pattern along the Andes Mountains with increased precipitation over the southern parts and reduced precipitation over the central parts. Here only a few regions show robust similarity with studies based on empirical evidence. However, from a dynamical point-of-view, atmospheric circulation changes related to an increase in high-latitude zonal wind speed simulated by the regional climate model are consistent with numerical modelling studies addressing changes in greenhouse gas concentrations. Our results indicate that besides the direct effect of greenhouse gas changes, large-scale changes in atmospheric circulation and sea surface temperatures also exert an influence on temperature and precipitation changes in southern South America. These combined changes in turn affect the relationship between climate and atmospheric circulation between PD and PI times and should be considered for the statistical reconstruction of climate indices calibrated within present-day climate data.


2019 ◽  
Vol 6 (1) ◽  
pp. 17-21
Author(s):  
Wahid Hussain ◽  
Lal Badshah ◽  
Sayed Afzal Shah ◽  
Farrukh Hussain ◽  
Asghar Ali ◽  
...  

Salvia reflexa Hornem., a member of the New World subgenus Calosphace, ranges from North America to southern South America, Australia, New Zealand, South Africa and Afghanistan in Asia, and still continues to expand its range. Here we report further range expansion for S. reflexa into the tribal areas of Pakistan and hypothesize that it has been introduced from Afghanistan. This represents a new record for the flora of Pakistan.


Author(s):  
Thomas T. Veblen

Although most of the continent of South America is characterized by tropical vegetation, south of the tropic of Capricorn there is a full range of temperate-latitude vegetation types including Mediterranean-type sclerophyll shrublands, grasslands, steppe, xeric woodlands, deciduous forests, and temperate rain forests. Southward along the west coast of South America the vast Atacama desert gives way to the Mediterranean-type shrublands and woodlands of central Chile, and then to increasingly wet forests all the way to Tierra del Fuego at 55°S. To the east of the Andes, these forests are bordered by the vast Patagonian steppe of bunch grasses and short shrubs. The focus of this chapter is on the region of temperate forests occurring along the western side of the southernmost part of South America, south of 33°S. The forests of the southern Andean region, including the coastal mountains as well as the Andes, are presently surrounded by physiognomically and taxonomically distinct vegetation types and have long been isolated from other forest regions. Although small in comparison with the extent of temperate forests of the Northern Hemisphere, this region is one of the largest areas of temperate forest in the Southern Hemisphere and is rich in endemic species. For readers familiar with temperate forests of the Northern Hemisphere, it is difficult to place the temper temperate forests of southern South America into a comparable ecological framework owing both to important differences in the histories of the biotas and to contrasts between the broad climatic patterns of the two hemispheres. There is no forest biome in the Southern Hemisphere that is comparable to the boreal forests of the high latitudes of the Northern Hemisphere. The boreal forests of the latter are dominated by evergreen conifers of needle-leaved trees, mostly in the Pinaceae family, and occur in an extremely continental climate. In contrast, at high latitudes in southern South America, forests are dominated mostly by broadleaved trees such as the southern beech genus (Nothofagus). Evergreen conifers with needle or scaleleaves (from families other than the Pinaceae) are a relatively minor component of these forests.


2016 ◽  
Vol 35 (2) ◽  
pp. 303-345 ◽  
Author(s):  
Robert H. Dott ◽  
Ian W. D. Dalziel

Charles Darwin was a reputable geologist before he achieved biological fame. Most of his geological research was accomplished in southern South America during the voyage of H.M.S. Beagle (1831–1836). Afterward he published four books and several articles about geology and coral atolls and became active in the Geological Society of London. We have followed Darwin's footsteps during our own researches and have been very impressed with his keen observations and inferences. He made some mistakes, however, such as appealing to iceberg rafting to explain erratic boulders and to inundations of the sea to carve valleys. Darwin prepared an important hand-colored geological map of southern South America, which for unknown reasons he did not publish. The distributions of seven map units are shown. These were described in his books wherein he also documented multiple elevated marine terraces on both coasts of South America. While exploring the Andean Cordillera in central Chile and Argentina, he discovered two fossil forests. Darwin developed a tectonic theory involving vertical uplift of the entire continent, which was greatest in the Andes where magma leaked up from a hypothetical subterranean sea of magma to form volcanoes and earthquakes. The theory had little impact and was soon eclipsed by theories involving lateral compression of strata. His and other contemporary theories suffered from a lack of knowledge about the earth's interior. Finally with modern plate tectonic theory involving intense lateral compression across the Andean Cordillera we can explain satisfactorily the geology so carefully documented by Darwin.


Phytotaxa ◽  
2013 ◽  
Vol 105 (1) ◽  
pp. 21
Author(s):  
DANIEL ADOLFO CÁCERES GONZÁLEZ

Bomarea Mirbel (1804: 71; Alstroemeriaceae) includes 122 species (Govaerts 2013) and is divided into four subgenera (Hofreiter & Tillich 2002): Baccata (five species), Bomarea (ca. seventy species), Sphaerine(twelve species) and Wichuraea (eighteen species). Bomarea is distributed from Mexico and the Greater Antilles to southern South America (Gereau 1994). The centre of distribution of the genus is along the Andes from Colombia to Bolivia (Hofreiter 2008).


1982 ◽  
Vol 77 (2) ◽  
pp. 181-188 ◽  
Author(s):  
W. Lobato Paraense

A review of lymnaeid samples collected by the author from 106 localities in Mexico, Cuba, Jamaica, Haiti, Dominican Republic, Puerto Rico, Martinique, Saint Lucia, Guatemala, Costa Rica, Panamá, Ecuador, Peru, Bolivia, Chile, Argentina, Uruguay andBrazil showed that one of them (from Ecuador) belonged to Lymnaea cousini Jousseaume, 1887, and all the others to either L. viatrix Orbigny, 1835 or l. columella Say, 1817. The ranges of L. viatrix and L. columella overlap in Middle America, and in northern and southern South America (Venezuela-Colombia-Ecuador and northeastern Argentina-Uruguay-southernmost Brazil, respectively). L. viatrix was the only species found in Peru west of the Andes and in Chile, and is supposed to have migrated eastward to Argentina via the Negro river basin. The range of L. columella in South America is discontinuous. The species has been recorded from Venezuela, Colombia and Ecuador and, east of the Andes, from latitudes 15º S (central-west Brazil) to 35º S (La Plata, Argentina). Such a gap may be attributed to either introduction from the northern into the southern area, or migration along the unsampled region on the eastern side of the Andes, or extinction in the now vacant area. No lymnaeids have been found so far in Brazil north of latitude 15º S and in the Guianas.


2011 ◽  
Vol 7 (5) ◽  
pp. 2981-3022 ◽  
Author(s):  
S. Wagner ◽  
I. Fast ◽  
F. Kaspar

Abstract. Two simulations with a regional climate model are analyzed for climatic changes between the late 20th century and a pre-industrial period over central and southern South America. The model simulations have been forced with large-scale boundary data from the global simulation performed with a coupled atmosphere-ocean general circulation model. The regional simulations have been carried out on a 0.44° × 0.44° grid (approx. 50 km × 50 km horizontal resolution). The differences in the external forcings are related to a changed greenhouse gas content of the atmosphere, being higher in the present-day simulation. For validation purposes the climate model is analyzed using a five year long simulation between 1993 and 1997 forced with re-analysis data. The climate model reproduces the main climatic features reasonably well, especially when comparing model output co-located with observational station data. However, the comparison between observed and simulated climate is hampered by the sparse meteorological station network in South America. The present-day simulation is compared with the pre-industrial simulation for atmospheric fields of near-surface temperatures, precipitation, sea level pressure and zonal wind. Higher temperatures in the present-day simulation are evident over entire South America, mostly pronounced over the southern region of the Andes Mountains and the Parana basin. During southern winter the higher temperatures prevail over the entire continent, with largest differences over the central Andes Mountains and the Amazonian basin. Precipitation differences show a more heterogeneous pattern, especially over tropical regions. This might be explained by changes in convective processes acting on small scales. During southern summer wetter conditions are evident over the Amazonian and Parana basin in the present-day simulation. Precipitation increases are evident over Patagonia together with decreases to the north along the western slope of the Andes Mountains. During southern winter also a dipole pattern along the Andes Mountains with wetter conditions over the southern parts and drier conditions over the central parts is evident. An interesting feature relates to precipitation changes with changing sign within a few 10th of kilometers along the southern parts of the Andes mountain chain. This pattern can be explained by changes in large-scale circulation related to latitudinal changes of the extratropical southern hemispheric westerlies.


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