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Fosil kura-kura raksasa kuno adalah ukuran mobil Smart
Ancient giant turtle fossil was size of Smart car
Date:
May 17, 2012
Source:
North Carolina State University
Summary:
Picture a turtle the size of a Smart car, with a shell
large enough to double as a kiddie pool. Paleontologists have found just such a
specimen -- the fossilized remains of a 60-million-year-old South American
giant that lived in what is now Colombia.
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Picture a turtle the size of a Smart car, with a shell large
enough to double as a kiddie pool. Paleontologists from North Carolina State
University have found just such a specimen -- the fossilized remains of a
60-million-year-old South American giant that lived in what is now Colombia.
The turtle
in question is Carbonemys cofrinii, which means "coal turtle,"
and is part of a group of side-necked turtles known as pelomedusoides. The
fossil was named Carbonemys because it was discovered in 2005 in a coal mine
that was part of northern Colombia's Cerrejon formation. The specimen's skull
measures 24 centimeters, roughly the size of a regulation NFL football. The
shell which was recovered nearby -- and is believed to belong to the same
species -- measures 172 centimeters, or about 5 feet 7 inches, long. That's the
same height as Edwin Cadena, the NC State doctoral student who discovered the
fossil.
"We had
recovered smaller turtle specimens from the site. But after spending about four
days working on uncovering the shell, I realized that this particular turtle
was the biggest anyone had found in this area for this time period -- and it
gave us the first evidence of giantism in freshwater turtles," Cadena
says.
Smaller
relatives of Carbonemys existed alongside dinosaurs. But the giant version
appeared five million years after the dinosaurs vanished, during a period when
giant varieties of many different reptiles -- including Titanoboa
cerrejonensis, the largest snake ever discovered -- lived in this part of South
America. Researchers believe that a combination of changes in the ecosystem,
including fewer predators, a larger habitat area, plentiful food supply and
climate changes, worked together to allow these giant species to survive.
Carbonemys' habitat would have resembled a much warmer modern-day Orinoco or
Amazon River delta.
In addition
to the turtle's huge size, the fossil also shows that this particular turtle
had massive, powerful jaws that would have enabled the omnivore to eat anything
nearby -- from mollusks to smaller turtles or even crocodiles.
Thus far,
only one specimen of this size has been recovered. Dr. Dan Ksepka, NC State
paleontologist and research associate at the North Carolina Museum of Natural
Sciences, believes that this is because a turtle of this size would need a
large territory in order to obtain enough food to survive. "It's like
having one big snapping turtle living in the middle of a lake," says
Ksepka, co-author of the paper describing the find. "That turtle survives
because it has eaten all of the major competitors for resources. We found many
bite-marked shells at this site that show crocodilians preyed on side-necked
turtles. None would have bothered an adult Carbonemys, though -- in fact
smaller crocs would have been easy prey for this behemoth."
The
paleontologists' findings appear in the Journal of Systematic Palaeontology.
Dr. Carlos Jaramillo from the Smithsonian Tropical Research Institute in Panama
and Dr. Jonathan Bloch from the Florida Museum of Natural History contributed
to the work. The research was funded by grants from the Smithsonian Institute
and the National Science Foundation.
Story
Source:
The above
story is based on materials provided by North Carolina State University. Note: Materials may be edited
for content and length.
Journal
Reference:
- Edwin Cadena, Dan Ksepka, Carlos Jaramillo, Jonathan Bloch. New pelomedusoid turtles from the late Palaeocene Cerrejon Formation of Colombia and their implications for phylogeny and body size evolution. Journal of Systematic Palaeontology, 2012 (in press)
