17 mar 2012
Researchers scratching in the sediment during the historic expansion of the Panama Canal say they have discovered the fossils of a small camel with a long snout that roamed the tropical rainforests of the isthmus some 20 million years ago.
The ancient camel had no hump and one of the two species found appeared to stand only about two feet tall, scientists reported in a recently published article in the Journal of Vertebrate Paleontology.
University of Florida researcher Aldo Rincon, a doctoral student in geology, discovered the fossils during the canal’s widening to accommodate hulking new cargo ships that will soon ply the waterway. He and a group of other scientists from Panama, the United States and the Smithsonian Tropical Research Institute also reported finding fossils of ancient marlins, turtles and horses.
“We never expected to find a camel there,” said Smithsonian scientist Carlos Jaramillo, co-author of the journal article. “It’s really, really a surprise.”
Unlike contemporary camels, these had crocodile-like teeth.
“It was like a little dog,” Jaramillo added.
Scientists believe the camels, Aguascalientia panamaensis and Aguascalientia minuta, may have used the sharp teeth as they chomped on lush foliage and fruit.
The find is raising questions about just how long ago the isthmus was created. The discovery of a mammal fossil also could help scientists better understand what happened when present-day North and South America were finally connected.
Geologists and paleontologists have essentially been traveling in the footprint of construction workers who are completing a five-year expansion of the Panama Canal. The $5.2 billion project will allow larger, modern container ships and cruise liners to traverse the canal — doubling the waterway’s capacity by 2015.
The construction work is providing a unique opportunity for researchers to excavate and preserve fossils buried in sediment that are normally hard to uncover beneath the extensive tropical foliage.
Though a relatively small country, Panama carries great scientific importance because it serves as the land bridge connecting North and South America. When that gateway between the continents was created, there was a global sea change: the Pacific and Atlantic oceans were cut off from one another, and a great interchange of animals began, leading some species into extinction and others to adapt.
Researchers have long thought the isthmus was created 3.5 million years ago, but now that scientists have discovered a camel species living in the area about 17 million years earlier, that hypothesis is being questioned.
“It’s pretty unusual to find camel remains that age at that place,” said John Kricher, a biology professor at Wheaton College in Massachusetts who specializes in tropical ecology and is not affiliated with the project. “It certainly is a significant find by any measure. And it rewrites something of mammalian deep time history.”
Plant species are believed to have spread between continents about 45 million years ago, and some animals such as crocodiles and turtles at about 20 million years ago. Mammals, however, didn’t travel over until considerably later — between 1.5 and 3 million years ago, scientists estimate. Why they didn’t is still somewhat of a mystery.
