Writing systems in South America?

long story short, if there have been any writing system in South America made by natives, it might have been destroyed by the Jesuits.

HerneHunter states:

Curiosamente do mesmo Estado da Paraíba, surgiram diversas menções acerca da existência de um tipo de escrita, desenvolvida pelos indígenas da região, e que teria sido empregados em livros, fabricados com papel de entre-casca de árvores e encadernados em madeira dura. Esta história, que a primeira vista pode ser tachada como fantasiosa, consta de várias obras e comunicações jesuítas, e está referida no livro do pesquisador inglês Robert Southey, "História do Brazil", conforme pode ser verificado na edição publicada pela Melhoramentos em 1977, onde encontra-se relatado que os livros teriam sido "feitos por inspiração demoníaca, com caracteres ensinados pelo Diabo", razão porque os jesuítas trataram de destruir aqueles "livros malditos". O que vem de encontro a citação do Padre Simão de Vasconcelos, de que na entrada da cidade da Paraíba existia uma pedra muito antiga, incrustada num penedo, coberta por sinais que tinham sido feitos por "inspiração demoníaca", como consta em sua "Crônica da Companhia de Jesus".

Translated:

Curiously, in the same State of Paraíba, there appeared various references to the existence of a type of writing, developed by the indigenous people of the region, and that had been stored in books, made with paper of tree bark and bound in hard wood. This story, which at first sight could be taken as fantastic, consists of various Jesuit works and communications, and is referenced in the book of the English researcher Robert Southey, "History of Brazil," as can be verified in the edition published by Melhoramentos in 1977, where one finds it related that the books had been "made by demonic inspiration, with characters taught by the Devil," the reason why the jesuits tried to destroy those "evil books." What comes against the citation of Father Simon of Vasconcelos, is that in the entrance of the city of Paraíba there was a very ancient stone, embedded in a rock, covered with signs that had been made by "demonic inspiration," as stated in his "Chronicle of the Company of Jesus."

When you look across history, pretty much any society with enough trade to require bookeeping and stratified enough to support kings will have developed (or borrowed) some kind of writing.

The Advanced culture in Peru and the Andes in South America was too isolated from other such societies to borrow their systems, so what they came up with on their own was probably the world's most interesting (if not practical) writing system: Quipu, which consisted of strings colored and knotted strategically to communicate information (numeric certianly, but many argue much more).

The only other pre-columbian drawings in South America I'm aware of are the Nazca lines from southern Peru. They are rather odd, in that they cannot really be properly appreciated from ground level (although there were typically hills nearby from which they could be appreciated by their creators). There are a lot of theories about what they were for, but few of them include information storage, like you'd get with a proper writing system.

The reason for this being the only writing system known in South America is probably relatively simple: The Andean area contained South America's only real advanced civiliation (The Inca by Pizarro's time).

This Wikipedia page has a nice overview on pre-columbian writing systems in mesoamerica. These are true writing systems, capable of representing spoken language. Some of them have been deciphered and translated.

Additionally, there are two other systems from outside mesoamerica, the Andean quipu and the Ojibwa wiigwaasabak, that may also represent writing systems, but ones that are dramatically different than any currently in use, and may be proto-writing rather than actual writing. Regrettably, not enough examples of either remain to adequately translate.