The discovery of two new extinct camel species by scientists from the University of Florida and the Smithsonian is casting new light on the history of the tropics, a region containing more than half the world’s biodiversity and some of its most important ecosystems.
Image above: University of Florida doctoral student Aldo Rincon holds the lower jaw of Aguascalietia panamaensis, a newly described species of ancient camel. The 20-million-year-old specimen was recovered from the Las Cascadas formation in Panama. (Photos by Jeff Gage, University of Florida)
Appearing online this week in the Journal of Vertebrate Paleontology, the study is the first published description of a fossil mammal discovered as part of an international project in Panama. Funded with a grant from the National Science Foundation, University of Florida paleontologists and geologists 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.
Florida Museum of Natural History photo by Jeff GageThe discovery extends the distribution of mammals to their southernmost point in the ancient tropics of Central America. The tropics 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, yet little is known of their history because lush vegetation prevents paleontological excavations.
Image above: This lower jaw of Aguascalietia panamaensis, a new species of ancient camel, represents one of the oldest mammals from Panama. Recovered from the Las Cascadas formation, the 20-million-year-old specimen extends the geographic distribution of mammals to their southernmost point.
“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 University of Florida Campus. “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.” Study co-authors are Catalina Suarez and Carlos Jaramillo of the Smithsonian Tropical Research Institute and Jonathan Bloch of the University of Florida.
Researchers described two species of ancient camels that are also the oldest mammals found in Panama: Aguascalietia panamaensis and Aguascalientia minuta. Distinguished from each other mainly by their size, the camels belong to an evolutionary branch of the camel family separate from the one that gave rise to modern camels based on different proportions of teeth and elongated jaws.
“Some descriptions say these are ‘crocodile-like’ camels because they have more elongated snouts than you would expect,” said lead author Aldo Rincon, a UF geology doctoral student. “They were probably browsers in the forests of the ancient tropics. We can say that because the crowns are really short.”
Rincon discovered the fossils in the Las Cascadas formation, unearthing pieces of a jaw belonging to the same animal over a span of two years, he said.
“When I came back to the museum, I started putting everything together and realized, ‘Oh wow, I have a nearly complete jaw,’ ” Rincon said.
The study shows that despite Central America’s close proximity to South America, there was no connection between continents because mammals in the area 20 million years ago all had North American origins. The Isthmus of Panama formed about 15 million years later and the fauna crossed to South America 2.5 to 3 million years ago, MacFadden said.
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.
Researchers will continue excavating deposits from the Panama Canal during construction to widen and straighten the channel and build new locks, expected to continue through 2014. The project is funded by a $3.8 million NSF grant to develop partnerships between the U.S. and Panama and engage the next generation of scientists in paleontological and geological discoveries along the canal.–Source: University of Florida