Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Plant fossils give first real picture of earliest Neotropical rainforests

19.10.2009
A team of researchers including a University of Florida paleontologist has used a rich cache of plant fossils discovered in Colombia to provide the first reliable evidence of how Neotropical rainforests looked 58 million years ago.

Researchers from the Smithsonian Institution and UF, among others, found that many of the dominant plant families existing in today’s Neotropical rainforests — including legumes, palms, avocado and banana — have maintained their ecological dominance despite major changes in South America’s climate and geological structure.

The study, which appears this week in the online edition of the Proceedings of the National Academy of Sciences, examined more than 2,000 megafossil specimens, some nearly 10 feet long, from the Cerrejón Formation in northern Colombia. The fossils are from the Paleocene epoch, which occurred in the 5- to 7-million-year period following the massive extinction event responsible for the demise of the dinosaurs.

“Neotropical rainforests have an almost nonexistent fossil record,” said study co-author Fabiany Herrera, a graduate student at the Florida Museum of Natural History on the UF campus. “These specimens allow us to actually test hypotheses about their origins for the first time ever.”

Herrera said the new specimens, discovered in 2003, also provide information for future studies that promise to provide an even stronger understanding of the plants that formed the earliest Neotropical communities.

Many previous assumptions and hypotheses on the earliest rainforests are based on studies of pollen fossils, which did not provide information about climate, forest structure, leaf morphology or insect herbivory.

The new study provides evidence Neotropical rainforests were warmer and wetter in the late Paleocene than today but were composed of the same plant families that now thrive in rainforests. “We have the fossils to prove this,” Herrera said. “It is also intriguing that while the Cerrejón rainforest shows many of the characteristics of modern equivalents, plant diversity is lower.”

The site, one of the world’s largest open-pit coal mines, also yielded the fossil for the giant snake known as Titanoboa, described by UF scientists earlier this year.

“These new plant fossils show us that the forest during the time of Titanoboa, 58 million years ago, was similar in many ways to that of today,” said Florida Museum vertebrate paleontologist Jonathan Bloch, who described Titanoboa but was not part of the rainforest study. “Like Titanoboa, which is clearly related to living boas and anacondas, the ancient forest of northern Colombia had similar families of plants as we see today in that ecosystem. The foundations of the Neotropical rainforests were there 58 million years ago.”

Megafossils found at the Cerrejón site made it possible to use leaf structure to identify specimens down to the genus level. This resolution allowed the identification of plant genera that still exist in Neotropical rainforests. With pollen fossils, specimens can be categorized only to the family level.

Researchers were surprised by the relative lack of diversity found in the Paleocene rainforest, Herrera said. Statistical analyses showed that the plant communities found in the Cerrejón Formation were 60 percent to 80 percent less diverse than those of modern Neotropical rainforests. Evidence of herbivory also showed a low diversity level among insects.

The study’s authors say the relative lack of diversity indicates either the beginning of rainforest species diversification or the recovery of existing species from the Cretaceous extinction event.

The researchers estimate the Paleocene rainforest received about 126 inches of rainfall annually and had an average annual temperature greater than 86 degrees. The Titanoboa study, which used different methods, estimated an average temperature between 89 and 91 degrees. Today the region’s temperatures average about 81 degrees.

Herrera is now comparing fossils from the Cerrejón site to specimens from other Paleocene sites in Colombia to see how far the early rainforest extended geographically. He is also examining fossils from a Cretaceous site to determine differences in composition before and after the extinction event.

Fabiany Herrera | EurekAlert!
Further information:
http://www.ufl.edu

More articles from Earth Sciences:

nachricht In times of climate change: What a lake’s colour can tell about its condition
21.09.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)

nachricht Did marine sponges trigger the ‘Cambrian explosion’ through ‘ecosystem engineering’?
21.09.2017 | Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

Im Focus: Fast, convenient & standardized: New lab innovation for automated tissue engineering & drug

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Comet or asteroid? Hubble discovers that a unique object is a binary

21.09.2017 | Physics and Astronomy

Cnidarians remotely control bacteria

21.09.2017 | Life Sciences

Monitoring the heart's mitochondria to predict cardiac arrest?

21.09.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>