South American floras are famous for their high species diversity. However, because of the undersampled South American plant-fossil record, remarkably little is known about how long this floral richness has existed. The Patagonian region of Argentina is an ideal place to study the history of South American plant diversity: fifty million years ago, Patagonia had humid subtropical forests with luxuriant vegetation, and today some of these forests are beautifully preserved in desert rock exposures accessible to paleontologists.
For this study, which will appear in the June 2005 issue of The American Naturalist, researchers collected more than 4000 specimens of fossil leaves, fruits, seeds, and flowers at a site with outstanding fossil preservation, Laguna del Hunco. Adjusted for sampling effort, the Laguna del Hunco flora, which has produced 186 species, is more diverse than any comparable deposit known elsewhere in the world. Preliminary collections at a second site, Río Pichileufú, show comparable richness. Precise radioisotopic ages, including the first from the Río Pichileufú flora, show it be almost 5 million years younger (47.46 ± 0.05 myr) than Laguna del Hunco (51.91 ± 0.22 myr). Highly diverse floras were present in a warm area of South America by the Eocene and were long lived and areally extensive.
Carrie Olivia Adams | EurekAlert!
Separate brain systems cooperate during learning, study finds
22.02.2018 | Brown University
Maelstroms in the heart
22.02.2018 | Max-Planck-Institut für Dynamik und Selbstorganisation
Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...
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...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
22.02.2018 | Life Sciences
22.02.2018 | Information Technology
22.02.2018 | Health and Medicine