Tuesday, August 10, 2010

Globorotalia truncatulinoides


Globorotalia truncatulinoides (d'Orbigny, 1839) is a planktic foraminifera.

It tolerates a broad range of sea surface temperatures and salinities and occurs in subtropical and transitional water masses. It is a deep-dwelling species which ascends to shallower depths during its reproduction period in winter. In the fossil record it is since the Pleistocene and may be used for studies on climate change of the last 2 mya.

The relative abundance of dextral coiling is higher at lower latitudes.

The specimens shown here are from a sample from the Hebridian Slope off Scotland in the North Atlantic. Northwest of the British Isles, this steep continental slope to depths greater than 2000 m separates the distinct continental shelf of Europe from the deeper Atlantic Ocean. The sample is in the repository of the Scottish Association for Marine Sciences, Oban.

see more foraminifera found at the Hebridian Slope










Umbilical view of a
dextral coiling specimen
















Spiral View

















more images of Globorotalia truncatulinoides at
Laboratório de Microfósseis Calcários,
Rio Grande do Sul, Brasil

Thursday, July 1, 2010

Exhibition Foraminifera of Northern Germany


Opening:
Saturday, 7th of August 2010 at 14.00h

Ice Age Museum Lütjenburg/Germany
www.eiszeitmuseum.de

Foraminifera objects
by artist Anna Mandel
www.annamandel.de

Contact me, if you want to organize an exhibition where you are. Michael:
michael [at] foraminifera.eu

More Info



Tuesday, June 15, 2010

Classical Site: Damery - Fleury-la-Rivière

A classical site for (micro-) paleontological research is the area Damery - Fleury-la-Rivière in the Paris Basin. It is famous for rich fossil beds of Lutetian Age (48.6 - 40.4 mya). In the 19th century pre-evolutionist Jean-Baptiste Lamarck (1744-1829), the author of many first descriptions of species Alcide Dessalines d'Orbigny, Olry Terquem (1797-1886) and others worked on fossil foraminifera of the Paris Basin.

The foraminiferal fauna indicates shallow water, warm marine conditions such as found today in the Red Sea: a great variety, rich ornamented and big foraminifera, a substantial part being Miliolids.






Ornamented Miliolid: Miliola prisca (Terquem, 1882)
















Unornamented, rather large Miliolid: Triloculina trigonula (Lamarck, 1804)

















Trochulina turbo (d'Orbigny, 1826), umbilical side















Trochulina turbo (d'Orbigny, 1826), spiral side













See more images on Fleury-la-Rivière

The sediment-sample was sent by Adrian, Thanks a lot !

Thursday, June 10, 2010

NHM London plans closure of Micropal Research


Sign the E-Petition against the closure plans.

The Natural History Museum London plans to close down its Micropaleontological Research due to budget cuts pronounced by the British Government.

The British Government has spend billions of pounds to help british banks in their risky business. Now they are planing a cut of expenses such as for museums. The NHM trustees and department heads reacted with a financial plan to close the Research on Micropaleontology. Collections shall not be affected.

Read the whole story at NHM Paleonet

Read Nature News on this topic

A petition is under way to bring this sad issue to the public and change plans.

Friday, June 4, 2010

Gulf Oil Disaster affects Foraminifera - some ideas

The Gulf Oil Disaster heavily affects the foraminiferal communities in the Gulf of Mexico.

As a nutrient rich and warm part of worlds oceans the Gulf of Mexico is packed with foraminiferal communities and a high diversity is on record. The Deep Horizon explosion causes the death, migration and misbuilding of billions of foraminifera.

Loosers

1.
Foraminifera depending on coral reefs and mangroves will be heavily affected as the basis of their live will be harmed, diminish or vanish.





Peneroplis reported from the Gulf will be a looser, too big, too complex, living too close to the shore in shallow water.





2.
Benthic Foraminifera living on and above the sediment will die in areas covered by oil.

3.
The toxical chemicals used to disperse the oil and the oil flares will harm or kill all kind of foraminifera whether drifting or living and cause misbuildings as observed with heavy-pollution.

4.
Near shore foraminiferal communities will heavily be affected as the oil will not be taken away as on the shore, but tends to drift to the shore.

5.
Big and complex structured foraminifera, depending on better environmental conditions will be overall the loosers and some species may even die out.


Winners

1.
Deep infaunal foraminifera used to nearly anoxic conditions will at first hand not be affected at all. They may even get the chance to conquer life space left empty by others. Such an effect has been recorded after the Mount Pinatubo ash covered the ocean floor in the surrounding oceans with Reophax. Reophax is in the fossil record since more than 400 Mya and has survived crises as global freezing, meteor impacts ...







30 Mio. year old Reophax from Germany looks the same as recent ones. It is also reported from the Gulf area.








2.
Simple structured and less demanding Foraminifera will overcome the crisis more easily and may temporarily conquer new life space.

Total effects as derived from observations of other crises such at the K/T (=Dinosaur) extinction event

1. The bio-diversity will diminish
2. The size of individuals and richness of ornamentation will be reduced
3. The recovery process will establish new communitarial structures

Total effects due to the short impact time and local limitation from an evolutionary point of view

1. New species are not likely to evolve. The reproduction cycle in warm waters may be short like 3 months, but even over a period of 30-50 years it may not be enough time.

2. Dead areas will be invaded first by foraminifera still alive such as in the sediment or from nearby less affected areas.

3. The heavy pollution by oil and chemicals does most likely not kill all foraminiferal live in the whole Gulf of Mexico. Simple and very tolerant species will most likely take over. Coral reef and mangrove dependant species may die out.

Wednesday, May 26, 2010

Miocene - the genus Florilus

The Miocene epoch lasted from 23.0-5.3 Mya BC and has foraminiferal faunas closely related to recent ones. The genus Florilus is common in Miocene sediments of the shelf. Some authors placed them in Nonion.






Florilus boueanum (d´Orbigny, 1846),
Stade, Germany, Pre North Sea, Middle Miocene

















Florilus boueanum (d´Orbigny, 1846),
Gram, Denmark, Pre North Sea, Miocene








Florilus grateloupi (d´Orbigny, 1826),
Calvert Cliffs Bed 10, Maryland, USA, Miocene











Florilus chesapeakensis Gibson, 1983,
Calvert Cliffs Bed 4-9, Maryland, USA, Miocene

Tuesday, April 13, 2010

Evolution illustrated by foraminifera 1


Natural Selection

The theory of evolution wants to explain how we - meaning all living organisms - came to be in all our complexity and variation. In a group of organisms the environmental conditions will favour some individuals while others will not reproduce as well. If heritable characters are the cause a shift in the frequency of these heritable characters within a population will occur after some generations. This process is called natural selection.

fossil Globigerina sp.
Italy, Pleistocene

Natural selection leads to specific foraminiferal faunas in specific environments

Open Sea offers little nutrition, which makes survival very difficult though competition is low and predators are rare. Many planktonic foraminifers use symbiont algae, who deliver energy through photosynthesis. In return they gives shelter for the little algae in its chambers, which need to be transparent, so that the sunlight may pass. Its globose construction allows up and downward drift in the watercolumn, probably needed to follow food, avoid predators and UV radiation.

recent Globigerinoides ruber from Mexican pacific ocean.

read the whole story at www.foraminifera.eu/evolution.html