Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Encrustation provides clues about ancient seas

25.03.2003


David L. Rodland, a Ph.D. student in Virginia Tech’s Department of Geological Sciences, has been studying encrustation, or the colonization of seashells by other marine organisms that live permanently attached to hard surfaces.



Examples of encrusting organisms (or epibionts) include serpulid and spirorbid worms, bryozoans, barnacles, and algae. Many epibionts produce their own calcareous tubes, shells, or skeletons, which are attached to that surface and may become fossilized along with it. "The encrustation of seashells by epibionts provides a great deal of ecological data or, for fossils, paleoecological, data," Rodland said. "You can count the number and diversity of epibionts on a shell, for example, and see how it changes as a function of shell size. Or you can examine how encrustation varies between different kinds of shells or between the shells collected at different places and under different environmental conditions. Some workers have even suggested that they could be used to estimate the amount of nutrients and plankton available in ancient seas."

At the meeting of the Southeastern Sections of the Geological Society of America (GSA) in Memphis March 12-14, Rodland presented a comparison of the encrustation of a bivalve mollusk (Macoma) with the encrustation of an articulate brachiopod (Bouchardia) from the coast of Brazil. "This is the only tropical / subtropical site where both bivalves and brachiopods occur in abundance in the present day, or at least, the only one we know," Rodland said. "Brachiopods were a common element in Paleozoic fossil beds (>250 million years ago) and so this is the first opportunity we really have to compare brachiopods and bivalves in the modern world."


"As it turns out," he said, "epibionts appear to preferentially colonize the brachiopod Bouchardia, and occur less frequently on the bivalve Macoma. There are a large number of different measures one can use to evaluate the degree of encrustation on a shell, but Bouchardia is always preferred. This may be in part because Macoma lives in the sand, while Bouchardia sits on the surface; but because storms periodically rework everything, some shells get brought back to the surface while others get buried, so they both get encrusted eventually. The composition of the shells may also make a difference to the organisms colonizing them; Macoma is aragonitic while Bouchardia is calcitic."

What does this mean? Bivalves are very common today, while brachiopods were much more common hundreds of millions of years ago, Rodland said. Therefore, differences in the encrustation of each may have implications for the evolution of the organisms that encrust them. "But no one really knows," he said, "because there has been next to no study of brachiopod encrustation, and no one has really compared brachiopods and bivalves in this way before. If you’re trying to measure changes in ocean nutrients through the fossil record of epibionts, this means you have to account for differences between the shells that are getting encrusted in the first place."

David Rodland | EurekAlert!
Further information:
http://www.technews.vt.edu/

More articles from Earth Sciences:

nachricht The Wadden Sea and the Elbe Studied with Zeppelin, Drones and Research Ships
19.09.2017 | Helmholtz-Zentrum Geesthacht - Zentrum für Material- und Küstenforschung

nachricht FotoQuest GO: Citizen science campaign targets land-use change in Austria
19.09.2017 | International Institute for Applied Systems Analysis (IIASA)

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

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...

Im Focus: Silencing bacteria

HZI researchers pave the way for new agents that render hospital pathogens mute

Pathogenic bacteria are becoming resistant to common antibiotics to an ever increasing degree. One of the most difficult germs is Pseudomonas aeruginosa, a...

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

Molecular Force Sensors

20.09.2017 | Life Sciences

Producing electricity during flight

20.09.2017 | Power and Electrical Engineering

Tiny lasers from a gallery of whispers

20.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>