Scientists have discovered the first-ever fossil evidence of monkeys
from the North American landmass: a 21-million-year-old specimen that
changes our understanding of the biological history of the continent.
The fossil monkey is closely related to living South American
monkeys, such as capuchins. It somehow made the journey from South
America to North America 15 million years before there was a land bridge
to travel across. The discovery, which was supported by the National
Science Foundation (NSF), adds a layer of complexity to established
theories about the past movement of animals on the continents.
The findings were published today in the journal Nature.
"For a long time, South America -- after its disconnect from
Antarctica -- has been thought of as an island continent," said Jonathan
Bloch, curator of vertebrate paleontology at the Florida Museum of
Natural History and a researcher on the NSF-funded project.
It wasn't until the rise of the Isthmus of Panama, about 4 million
years ago that North and South America were connected and animals could
migrate between the continents -- a major event known as the Great
American Biotic Interchange (GABI).
"This fossil shows us that one of the first waves of GABI happened
about 12 million years before our previous record," Bloch said.
The new discovery raises questions about why monkeys never ventured
farther into North America. One theory is that the monkeys weren't used
to eating the continent's food: They were unwilling to trade South
America's tropical fruits for northern acorns.
"There appears to be potentially a barrier between two forests with very different histories," Bloch said.
The researchers actually discovered several fossils from the specimen
in Panama: seven tiny teeth ("beautiful teeth," Bloch said). They were
uncovered thanks to a once-in-a-century research opportunity created by
the expansion of the Panama Canal. The massive construction project --
widening, deepening and adding new locks to the 100-year-old canal --
required digging directly through fossil deposits.
The rainforests of Panama, like tropical environments worldwide, are some of the most biologically diverse areas on Earth.
"There's a great deal to learn about the evolutionary history through
the fossil record of the tropics," Bloch said. "But with those
beautiful forests comes a downside -- it's incredibly hard to access
rock. And you can't access fossils without rocks."
The Canal expansion solved this problem. Bloch and his colleagues
have spent the last six years collecting and studying fossils, plus
other geological and archeological samples, from the area.
The project was funded through a NSF Partnerships in International Research and Education (PIRE) award. The PIRE program
supports robust global collaborations that generate new scientific
knowledge and educate the next generation of globally engaged scientists
"This Panama Canal project is a stellar example of why PIRE is
important," said Jessica Robin, program director in NSF's Office of
International Science and Engineering. "It leveraged support from both
NSF and institutions in Panama to answer fundamental questions about the
history of our continent, forge strong international partnerships and
train young researchers."
In addition to the Florida Museum of Natural History at the
University of Florida, the Panama Canal PIRE partners included the
Panama campus of the Smithsonian Tropical Research Institute, the New
Mexico Museum of Natural History and Florida State University.
International research collaborators were Panama's Biomuseo, the
Universidad de Panamá and Sociedad Mastozoológica de Panamá.
The Panama Canal PIRE
has led to a quantum leap in our understanding of the land's biological
history, said Bruce MacFadden, distinguished curator of vertebrate
paleontology at the Florida Museum of Natural History and principal
investigator on the PIRE award.
"We've learned a lot about the plants, the marine life, the
vertebrates," MacFadden said. "We're characterizing the ancient
biodiversity of the tropics of the Americas."
The fossil monkey -- a new genus and species, given the name Panamacebus transitus -- is
the latest addition to this knowledge. It's an ancient species that
could help answer questions about our own future, and what might happen
to other species in the wake of a changing climate and increased habitat
"What happens to plants and animals when the planet changes?" Bloch
said. "That is a question we want to know now because it's important to
us. The impossible thing to do is the thing you want to do -- run lots
and lots of experiments."
Luckily, Earth has run those experiments already, with events like
GABI, which had profound effects on plant and animal migration as well
as ocean circulation and global climate. The results are logged in the
That information can help scientists make predictions about how
plants and animals might respond to changes on the planet in the future,
Bloch said. "It helps us think about about how to approach some of the
grand challenges that are here today, in terms of life and the planet."
As part of the Panama Canal PIRE's educational outreach, the fossil teeth of P. transitus will be available for downloading and 3-D printing on MorphoSource.
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