Camels with long, crocodile-like snouts once lived near what is now the Panama Canal, suggests a new study.
The camels lived 20 million years ago and are now considered to be among the oldest known animals from Panama.
"They were probably browsers in the forests of the ancient tropics. We can say that because the crowns are really short," lead author Aldo Rincon, a University of Florida geology doctoral student, said in a press release.
Rincon and his team are working with the Panama Canal Authority and scientists at the Smithsonian Tropical Research Institute to make the most of a five-year window of excavations during Panama Canal expansions that began in 2009.
The new fossil camels, Aguascalietia panamaensis and Aguascalientia minuta, extend the distribution of mammals to their southernmost point in the ancient tropics of Central America.
Excavations are often difficult in the tropics because the lush vegetation prevents access. That's not such a bad thing, considering that these species-rich areas contain some of the world's most important ecosystems, including rain forests that regulate climate systems and serve as a vital source of food and medicine.
"We're discovering this fabulous new diversity of animals that lived in Central America that we didn't even know about before," said co-author Bruce MacFadden, vertebrate paleontology curator at the Florida Museum on the UF campus and co-principal investigator on the NSF grant funding the project.
"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."
The two new fossil camels, found in the Las Cascadas formation, belong to an evolutionary branch of the camel family separate from the one that gave rise to modern camels.
Camels belong to a group of even-toed ungulates that includes cattle, goats, sheep, deer, buffalo and pigs. Other fossil mammals discovered in Panama from the early Miocene have been restricted to those also found in North America at the time.
While researchers are sure the ancient camels were herbivores that likely browsed in forests, they are still analyzing seeds and pollen to better understand the environment of the ancient tropics.
"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 four to five million years ago, they dispersed into South America and evolved into the llama, alpaca, guanaco and vicuña."
The study was published in the latest Journal of Vertebrate Paleontology.