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 Ice cave in Transylvania yields window into region's past
28.04.2017 | National Science Foundation

nachricht Citizen science campaign to aid disaster response
28.04.2017 | 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: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>