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NSF PR 97-71 - December 3, 1997
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Strange South American Fossil Mammals Found in Madagascar
and India
A strange group of fossil mammals, heretofore only
known in South America, has been discovered on the
island of Madagascar and in India. The unexpected
discoveries were announced in this week's issue of
the journal Nature by an international
team of researchers. The team was funded by the National
Science Foundation (NSF) and led by paleontologist
David Krause of the State University of New York at
Stony Brook.
The 65-70 million year old mammals, dating from the
Late Cretaceous period, were unrelated to any groups
living today and are known as gondwanatheres. The
discovery of their highly distinctive teeth in such
disparate places as South America, Madagascar and
India has fundamental implications for plate tectonics,
the theory that landmasses move slowly over the face
of the earth and were in different places in the past
than they are today.
Ironically, though the group of mammals was previously
known only to be from Argentina, it was named Gondwanatheria
after the supercontinent of Gondwana, which once included
all of the landmasses of the southern hemisphere.
"These are major discoveries that go far beyond their
obvious significance to paleontologists," says Chris
Maples, program director in NSF's division of earth
sciences, which funded Krause's work. "Krause and
his large-scale, multi-investigator team have provided
an excellent example of the contributions that paleontology
can make to many areas of geoscience, including tectonic
plate positions in Earth's past."
Krause says, "Finding representatives of gondwanatheres
on these three now widely separated landmasses suggests
to us that they were connected in the Late Cretaceous.
A recently proposed geophysical model shows that India
and Madagascar were attached to eastern Antarctica
well into the Cretaceous while South America was attached
to the western end of Antarctica. This discovery supports
that hypothesis with totally independent evidence
derived from the fossil record."
Significantly, gondwanatheres have not been found
in Africa, which lends credence to the research team's
conclusion that Africa was relatively isolated during
the 35 million years of the Late Cretaceous. "It's
not just the mammal evidence that suggests that Africa
was off doing its own thing; the dinosaur evidence
also indicates a high degree of African endemism during
this interval," adds Krause.
Krause has led large-scale NSF-funded paleontological
expeditions to Madagascar for three years. Krause's
team has discovered a spectacular array of well-preserved
and extraordinarily complete skeletal material of
crocodiles, birds, dinosaurs and other backboned animals
in Madagascar. Despite finding only fragmentary remains
of mammals, Krause notes that the mammal specimens
"may not be all that spectacular visually, but they're
extremely important. Scientific significance, just
like beauty, is in the eye of the beholder."
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billion. NSF funds reach all 50 states, through grants
to more than 2,000 universities and institutions nationwide.
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