First North American Monkey fossils are Found in Panama Canal excavation

Seven fossil teeth exposed by the Panama Canal expansion project are the first evidence of a monkey on the North American continent before the Isthmus of Panama connected it to South America 3.5 million years ago. A team including Carlos Jaramillo, staff scientist at the Smithsonian Tropical Research Institute (STRI), published this discovery online in the journal,Nature. They named the new monkey species Panamacebus transitus in honor of Panama and the monkey's movement across the ancient seaway that divided North and South America.

Before the monkey teeth were discovered, the evidence of movement of a mammals from South America are 8.5 - 9 million-year-old fossil remains of giant sloths. The authors of this report suggest two explanations: 

1. That mammal from South America were more adapted to life in the South American derived forests still found in Panama and Costa Rica than to other forest types characteristic of Northern Central America
2. That the lack of exposed fossils deposits throughout Central America means that evidence of these dispersals has yet to be revealed.