Novelties inAdiantum(Pteridaceae) from South America

Unenlagiinae revisited: dromaeosaurid theropods from South America.

Over the past two decades, the record of South American unenlagiine dromaeosaurids was substantially increased both in quantity as well as in quality of specimens. Here is presented a summary review of the South American record for these theropods.Unenlagia comahuensis, Unenlagia paynemili, and Neuquenraptor argentinus come from the Portezuelo Formation, the former genus being the most complete...

Phenolic Composition of Propolis from China and from South America

Flavonoids and other phenolic compounds were determined in 15 samples of propolis originating from China, from Brazil, and from Uruguay. A total of 24 compounds were identified using mainly HPLC and a few other analytical methods. The most abundant com­ pounds found were benzoic acid and benzaldehyde derivatives, flavones, flavonols. and flavanones. 80% of the samples contained at least 22 g/10...

Archaeology of South America

19th century South America

This basic socio-cultural framework, with all its inherent ambivalences and contradictions, emerged during the colonial era and exercised a deep and lasting impact on the political, economic and social structure of the new South American nations. Only after many decades was the impact blurred by the action of other external influences, change occurring from within, and a growing sense of nation...

Evolutionary novelties

How novel traits arise in organisms has long been a major problem in biology. Indeed, the sharpest critiques of Darwin's theory of evolution by natural selection often centered on explaining how novel body parts arose. In his response to The Origin of Species, St. George J. Mivart challenged Darwin to explain the origin of evolutionary novelties such as the mammary gland, asking if it was "conc...