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 in
Contact: Cheryl Dybas
National Science Foundation