Jörg Fröbisch and Kenneth D. Angielczyk of The Field Museum together with Christian A. Sidor from the University of Washington have identified a distant relative of mammals, Kombuisia antarctica, that apparently survived the mass extinction by living in Antarctica.
The new species belongs to a larger group of extinct mammal relatives, called anomodonts, which were widespread and represented the dominant plant eaters of their time. "Members of the group burrowed in the ground, walked the surface and lived in trees," said Fröbisch, the lead author of the study. "However, Kombuisia antarctica, about the size of a small house cat, was considerably different from today's mammals — it likely laid eggs, didn't nurse its young and didn't have fur, and it is uncertain whether it was warm blooded," said Angielczyk, Assistant Curator of Paleomammology at The Field Museum. Kombuisia antarctica was not a direct ancestor of living mammals, but it was among the few lineages of animals that survived at a time when a majority of life forms perished.
Scientists are still debating what caused the end-Permian extinction, but it was likely associated with massive volcanic activity in Siberia that could have triggered global warming. When it served as refuge, Antarctica was located some distance north of its present location, was warmer and wasn't covered with permanent glaciers, said the researchers. The refuge of Kombuisia in Antarctica probably wasn't the result of a seasonal migration but rather a longer-term change that saw the animal's habitat shift southward. Fossil evidence suggests that small and medium sized animals were more successful at surviving the mass extinction than larger animals. They may have engaged in "sleep-or-hide" behaviors like hibernation, torpor and burrowing to survive in a difficult environment.
Earlier work by Fröbisch predicted that animals like Kombuisia antarctica should have existed at this time, based on fossils found in South Africa later in the Triassic Period that were relatives of the animals that lived in Antarctica. "The new discovery fills a gap in the fossil record and contributes to a better understanding of vertebrate survival during the end-Permian mass extinction from a geographic as well as an ecological point of view," Fröbisch said.
The team found the fossils of the new species among specimens collected more than three decades ago from Antarctica that are part of a collection at the American Museum of Natural History. "At the time those fossils were collected, paleontologists working in Antarctica focused on seeking evidence for the existence of a supercontinent, Pangaea, that later split apart to become separate land masses," said Angielczyk. The fossils collected in Antarctica provided some of the first evidence of Pangaea's existence, and further analysis of the fossils can refine our understanding of events that unfolded 250 million years ago.
"Finding fossils in the current harsh conditions of Antarctica is difficult, but worthwhile," said Angielczyk. "The recent establishment of the Robert A. Pritzker Center for Meteoritics and Polar Studies at The Field Museum recognizes the growing importance of the region," he said.
This research is part of a collaborative study of Dr. Jörg Fröbisch (Department of Geology, Field Museum, Chicago), Dr. Kenneth D. Angielczyk (Department of Geology, Field Museum, Chicago), and Dr. Christian A. Sidor (Burke Museum and Department of Biology, University of Washington), which will be published online December 3, 2009 in Naturwissenschaften.
Funding for this research was provided through a Postdoctoral Research Fellowship of the German Research Foundation (Deutsche Forschungsgemeinschaft) to J. Fröbisch and grants of the National Science Foundation to C. A. Sidor.
NOTE: For images, please contact Dr. Jörg Fröbisch at 312-665-7099 or email: email@example.com
Jorg Frobisch | EurekAlert!
Geophysicists and atmospheric scientists partner to track typhoons' seismic footprints
16.02.2018 | Princeton University
NASA finds strongest storms in weakening Tropical Cyclone Sanba
15.02.2018 | NASA/Goddard Space Flight Center
For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.
In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.
But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...
Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.
The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...
Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters
Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
20.02.2018 | Life Sciences
20.02.2018 | Medical Engineering
20.02.2018 | Physics and Astronomy