Canal Camels

Twenty-million-year-old camels from the Isthmus of Panama are helping tell the story of the monumental land bridge between North and South America. University of Florida researcher Aldo Rincon and Carlos Jaramillo from the Smithsonian’s Tropical Research Institute, and their colleagues, were surprised to find camel fossils as a result of the recent widening of the Panama Canal (intended to double the canal’s capacity by 2015). Camel fossils have never been found in Panama before. Most likely a predecessor of today’s llamas and guanacos that live in the Andes, these two species of ancient camels, named Aguascalientia panamaensis and Aguascalientia minuta, stood only two to three feet tall; each had a long snout but no hump. “It was like a little dog,” said Jaramillo. Clocking in at 20 million years old, these camels had huge ridged chompers, comparable with those of a crocodile. Teeth like these suggest that they probably ate more than just grass; they likely chowed down on fruit and the tougher leaves of shrubs and trees.

Rincon and Jaramillo’s studies are also very telling of the history of that strip of land known as the Isthmus of Panama. The land bridge connecting North and South America has always been of point of interest to paleontologists because its development meant huge changes in evolutionary history. While providing the connection between North and South America, it closed off another—that between the Atlantic and Pacific oceans. Animals crossed the land bridge, and some went extinct while others adapted and evolved. The new camel fossils are dated to 17 million years before what scientists previously thought was the formation of the land bridge (3.5 million years ago), and 14 million years before the earliest mammals were believed to have crossed between North and South America. Fossils from these ancient species of camel have previously been found in North America, but not in South America until much later. Bruce Patterson, curator of mammals at the Field Museum of Natural History in Chicago, also notes that this find leads paleontologists to hypothesize that Panama was actually part of North America before the formation of the isthmus, because camels didn’t make it into South America until much later. Camels are believed to have originated in Florida and Texas 40-45 million years ago; the Eocene-aged Protylopus, the earliest known camel, was a 4-toed, hoofed animal less than three feet tall.