Researchers from the University of Florida said the two species of ancient camels, dubbed Aguascalietia panamaensis and Aguascalientia minuta, are the oldest mammals found in Panama.
Their discovery extends the distribution of mammals to their southernmost point in the ancient tropics of Central America, a university release reported Wednesday.
"We're discovering this fabulous new diversity of animals that lived in Central America that we didn't even know about before," study co-author Bruce MacFadden, vertebrate paleontology curator at the Florida Museum on the UF campus, said.
"The family originated about 30 million years ago and they're found widespread throughout North America, but prior to this discovery, they were unknown south of Mexico."
Despite Central America's close proximity to South America, there was no connection between continents until the Isthmus of Panama formed, researchers said.
"People think of camels as being in the Old World, but their distribution in the past is different than what we know today," MacFadden said. "The ancestors of llamas originated in North America and then when the land bridge formed about 4 to 5 million years ago, they dispersed into South America and evolved into the llama, alpaca, guanaco and vicuna."
Paleontologists and geologists are working with the Panama Canal Authority and scientists at the Smithsonian Tropical Research Institute to conduct excavations during a five-year window of opportunity created by the Panama Canal expansions that began in 2009.