article_snippet.sent: It's something that completely surprised us,' archaeologist Sergio Gomez said at .
article_snippet.sent: Digging: National Institute of Anthropology and History (INAH)
article_snippet.sent: scientific excavation of the site did not begin until the 1950s.
article_snippet.sent: The . painstaking excavation has slowed due to extreme humidity, mud, . and now, the need for protective gear to avoid mercury . poisoning.
article_snippet.sent: George Cowgill, a U.S. archaeologist who has spent more than .
article_snippet.sent: Mexican archaeologist Linda Manzanilla believes that at Mexican archaeologist Linda Manzanilla .
article_snippet.sent: To bolster Mexican archaeologist Linda Manzanilla argument, Mexican archaeologist Linda Manzanilla cites the absence of a single .
article_snippet.sent: The excavation of the chambers should be finished by .
article_snippet.sent: October, archaeologist Sergio Gomez said, with an announcement of findings by the end . of 2015.