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Curator of Micropalaeontology's blog

20 Posts tagged with the foraminifera tag
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This week a surplus set of plaster microfossil models were transferred to the Department of Geology, University Leicester UK to help with teaching micropalaeontology to undergraduate students. The two sets of models were made by 19th Century scientists d'Orbigny (1802-1857) and Reuss (1811-1873), who were some of the very earliest micropalaeontologists.

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A set of d'Orbigny models from the Museum collections. Some look a dirty brown colour but in fact this is an original feature to show the difference between models based on modern species (white) and fossil ones (brown). This set was previously mounted for display in the Museum galleries.

 

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A drawer of d'Orbigny models of Foraminifera. (Skaters on the Museum ice rink can be seen in the background)

 

The famous French scientist Alcide d'Orbigny quickly recognised the difficulty in portraying his work on microfossils to a wider audience because of the small size of the specimens. He carved scale models of foraminferal microfossils from limestone and these originals are in the Museum national d'Histoire naturelle in Paris. He used these to create plaster replicas that he sold in sets to accompany his publication of the first classification of the Foraminifera which was first published back in 1821.

 

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A 'Plaster Army' of Reuss & Fric models arranged in rows reminiscent of the 'Terracotta Army'.

 

The second set was made by Vaclav Fric (1839-1916) under the supervision of Anton Reuss who was similarly looking to illustrate his classification of the Foraminifera. For more information about these models and other microfossil models at the Museum there is a publication in the Geological Curator. A paper was recently submitted for publication in a Special Publication of the Geological Society as a contribution to a set of papers on the history of study of the Foraminifera.

 

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Some more Reuss & Fric models. The black spots show the openings or 'foramen' common to and therefore giving rise to the name 'Foraminifera'.

 

If these models are so important, why are we letting them go from the Museum? Firstly we already have three registered sets of these models in our collections (some are illustrated above). One of these three sets is is on the salvage list for the Palaeontology Department. This means that these will be some of the first items to be saved from the building should there be some sort of disaster and it is deemed safe to do so.

 

Secondly, the model sets on their way to the University of Leicester were never formally accessioned into the Museum collections so we are able to send them on without having to deaccession them. They are slightly worn as they have previously been used for teaching micropalaeontology to postgraduate students. Currently there are limited opportunities for postgraduate study of micropalaeontology so it is very good to know that a new course is starting at the University of Birmingham in September 2012.

 

I would argue that sending these models to a university to help inspire a new generation of micropalaeontologists is exactly the sort of use that d'Orbigny and Reuss would have wanted for their models rather than for them to sit in a box in a dusty corner of my office...

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A couple of weeks ago we processed a loan to Prof. Dil Joseph and his team at the Department of Electrical and Computer Engineering at the University of Alberta, Edmonton, Canada. They have developed a new method for imaging microfossils under a light microscope called Virtual Reflected Light Microscopy (VRLM). As well as being a novel use for some of our historical residue collections, this potentially provides an interactive method for viewing our collections in 3-D on-line and could greatly aid future users of our collections.

 

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Cindy Wong, Adam Harrison and Dr Dileepan Joseph of the University of Alberta (photo courtesy of Ryan Heise, Communications Officer, Department of Electrical and Computer Engineering at the University of Alberta)

 

VLRM involves photographing microfossils under many different light conditions and from many different angles so that 3-D images can be built up. The team has also developed software to deliver these images to the web via an interactive interface that allows users to digitally manipulate specimens. A demo of VLRM can be found on-line and 3-D images can be obtained with the help of red-cyan glasses.

 

In normal circumstances we would make 2 dimensional images of specimens with either a light microscope or with a scanning electron microscope. These would be sent to enquirers about the collections. If possible, scientists would prefer to visit the Museum as they would normally need to manipulate specimens to see features that would not always be visible from 2 dimensional images. VLRM potentially recreates that visitor interaction with the specimens remotely on-line.

 

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Part of the ocean bottom microfossil residue collection housed in the Department of Palaeontology.

 

The team have borrowed some of our most significant microfossil residues to test their system and develop future applications. These residues come mainly from the H.M.S. Challenger Collection. The Challenger Expedition of 1872-1876 was the first oceanographic voyage. Prior to this, the ocean bottom was completely unexplored so these residues represent a 'first ever glimpse' of the bottom of the worlds oceans.

 

All of the organisms discovered during this first dredging of the ocean bottoms, including the microfossils, were described resulting in many new species being found. The foraminiferal type specimens of many of these species are housed here in the Museum and are frequently consulted by visitors. When a new species is described, a type specimen must be designated and deposited in a recognised museum so that future workers can consult them if neccessary.

 

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A type slide from the Challenger Foraminifera Collection. It is 7.5cm long.

 

As the research is being done in North America, it was topical that we also loaned a residue from the Second Albatross Cruise of 1882. The Albatross was reportedly one of the the first vessels built for oceanographic studies and made its maiden voyage from Washington.

 

Dil Joseph's team in Edmonton have already published on computer aided recognition of foraminifera. It will be very interesting to see how historically significant materials from our collections play a part in future research on this subject. Work on Virtual Reflected Light Microscopy certainly looks to revolutionise how data on microfossil collections will be shared and how we make our collections available in the future.

 

Special thanks to Lil Stevens who processed this loan. She has now joined the full time curatorial staff and is helping out with micropalaeontology curation.

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Microfossils of the day

Posted by Giles Miller Aug 12, 2011

To celebrate the United Nation's Year of Biodiversity last year, the Museum published details of a different species every day on its web site under the title Species of the Day. These records were delivered last week to another web site The Encyclopedia of Life. Each species was chosen and written about by a museum scientist so this week's blog is to point you in the direction of the microfossils which were chosen for their importance in studies on climate change, ocean acidification, north sea oil exploration and the fossil record of sexual reproduction. Follow the links below to find out more about each species and the groups to which they belong.

 

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Emiliania huxleyi

 

Emiliania huxleyi is a coccolithophore which is a unicellular plant that lives in the upper layers of the ocean and forms tiny calcareous coccolith plates like the ones you can see above. These are artificially coloured images from a scanning electron microscope. This very high powered microscope is needed as they are only tens of microns in size and as a result are usually referred to as nannofossils. The ones above are only slightly larger than a thousanth of a millimetre in size. If you were to dip a bucket in the ocean you could find literally tens of thousands of these types of cells. In early summer, E. huxleyi forms enormous blooms across the northwest European shelf that can be seen from space. Coccoliths are susceptible to changes in climate and ocean acidification. This, combined with an excellent fossil record makes them an essential group in the study of recent changes to our oceans and environment.

 

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Harbinia micropapillosa

 

Harbinia micropapillosa is an ostracod, a microscopic crustacean with two calcareous shells. Ostracods can be found in virtually any current aquatic environment and very rarely on land in damp habitats near to water. They have an extensive fossil record because their two shells preserve well as fossils but usually the soft body parts decay soon after death. H. micropapillosa is exceptional because the soft body parts have been preserved in a rock formation that is roughly 140 million years ago. Recent analysis using new techniques has shown the reproductive organs of this ancient organism are identical to those of present day ostracods and suggest that they reproduced using giant sperm back in the Cretaceous period. If you can't wait to find our more about this interesting fossil then follow the link above. However, I will be expanding the story of these important specimens in our collections as the subject of a future blog.

 

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Nannoceratopsis gracilis

 

Nannoceratopsis gracilis is a dinoflagellate cyst from the Jurassic period about 145-200 million years ago. Dinoflagellates are marine photosynthetic algae that play an important role at the base of the food chain and the carbon cycle. At stages throughout their life cycle they form resistant organic cysts that can be found in the fossil record by dissolving suitable rocks in nasty acids like hydroflouric acid. Nannoceratopsis is one of the earliest forms of dinoflagellate cyst so studies of this genus can tell us a lot about the early evolution of dinoflagellates. The shape is also very distinctive and easily recognisable. N. gracilis can be found in rocks 168-185 million years old and can therefore be used, on its own or in association with other fossils, to accurately date rocks.

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Nummulites gizehensis

 

I mentioned Nummulites gizehensis is a member of the Foraminifera in my second blog and showed a picture of the pyramids at Gizeh that are constructed from rocks that contain this species. The genus Nummulites is a member of a group called the "Larger Foraminifera" that build multichambered shells up to 15cm in size despite being a single celled amoeba. The chambers like the ones shown above can only be seen by breaking the shells apart or making specially oriented thin sections of the rocks they are found in. Sometimes symbiotic green algae also lived in the chambers, providing products of photosynthesis to the amoebe while using the shell as protection. N. gizehensis lived during the Middle Eocene epoch about 37-48 million years ago, in shallow marine conditions and can be used as a marker to show the age of rocks that contain them, particularly in the oil region of the Middle East.

 

Finally a big thank you to my former colleagues Jeremy, Susanne and Clive who originally wrote about three of these beautiful microfossil species of the day.

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Working while I sleep

Posted by Giles Miller Jul 6, 2011

Adding details about our specimens to the Museum electronic database and publishing the details on the internet is an important way for us to make sure that our specimens are used to their best potential. This takes up about 20% of my job allocation. As a result I was very happy to leave the office last night and arrive in the next day to find that 5,634 micropalaeontology records had been added to the collections database overnight while I slept.

 

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Details of the overnight import of records to the Museum database with Pelham Miller on the desktop background.

 

 

If this can be done overnight, is there any need to have a curator to do this job?

 

 

If I'm totally honest, 99% of this work didn't happen overnight. Firstly, someone sat and typed what they saw in our registers as part of the "Rapid Data Project" (thank you SJ). Because the data was recorded often in short hand we had to add information to the records, particularly about where the specimens were published and who donated/collected them (thank you Lyndsey).

 

 

Finally we had to check the records to make sure they were accurate. Part of this was done by using lists of microfossil names already published (thank you Micropalaeontology Press). Checking records is not exactly the most stimulating part of my job. However, I do find that this progresses much faster while I listen to Test Match Special!

 

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An example of a collections register including annotations when our specimens have been published in scientific articles.

 

 

The eagle eyed of you may have spotted on the first image that there were over 2,000 errors in the overnight import. This looks serious but they are easy to correct. To maintain data accuracy and consistency across the Museum, the database system (KE Emu) only allows certain terms to be used for some fields. I used "Purchased" instead of "Purchase" and this caused about a thousand of them. The rest of the errors result from incorrect usage of some country names in the Middle East ...

 

 

In the last year we have added about 35,000 micropalaeontological records. I am also managing projects to create records with other Palaeontology Curators. This is on-going and we hope to reach 100,000 records in the next couple of years.

 

 

OK. So you now know that this didn’t really happen overnight while I slept. Even so, it does give a good example of what can be achieved with a little bit of teamwork. If you consider that each curator in our department has an annual target of about 2,000 specimens to add to our on-line database, this project has enormous potential to showcase our collections quickly, easily and accurately.

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What is micropalaeontology?

Posted by Giles Miller Jun 21, 2011

The answer to this question is the straightforward part of this post: palaeontology is the study of fossils and micropalaeontolgy is the study of microfossils. Alas, that’s the easy bit done… what then, are microfossils?

 

I’ll assume that we all know what a fossil is (if not, I recommend starting here) so a microfossil must be a small fossil, right? Actually, this is a harder question to answer than you might think so here are some thoughts on how large a microfossil is, how old they are and how we manage them at the Museum.


Size

There is no agreed size below which a fossil stops being a large fossil and starts becoming a microfossil. Some people arbitrarily say that if you need to use a microscope to view a fossil then you are looking at a microfossil. However, some fossils we consider microfossils measure more than a couple of centimetres in diameter. The rocks that were used to construct the pyramids in Egypt contain microfossils that can be as large as a ten pence piece!


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Photo of Egyptian pyramid courtesy of Bobbie Molloy.


This size delimiting definition also gets slightly difficult to use when you are studying the microscopic parts of a larger organism, for example the fossilised scales of a fish or a minute example of something that is usually larger like a gastropod (e.g. a snail). Most people studying these topics would consider themselves microvertebrate workers or gastropod workers and not micropalaeontologists. However, many micropalaeontologists, like me also study microscopic remains of larger organisms like fish that they find during laboratory preparations for other microscopic remains.


Biological classification

Some people try to restrict micropalaeontology to particular biological groups that are commonly considered microfossils. This can also be open to personal opinion, for example, palynologists study microscopic organic remains like spores, pollen and oceanic plankton – all microscopic in size – but some of them would consider themselves palynologists rather than micropalaeontologists. The Micropalaeontological Society defines its specialist groups to reflect biological classifications of organisms commonly accepted as microfossil groups.


Age

As with size, there is no agreed age beyond which something stops being recently dead and becomes a fossil. With specimens in this narrow window of age (ie 0-10,000 years old) it is virtually impossible to tell how old a microfossil specimen is without carrying out some sort of destructive chemical analysis on it.


Our collections

At the Museum, we mainly follow the Micropalaeontological Society's definition of a microfossil and in the Palaeontology Department we have collections of Foraminifera, Ostracoda, conodonts, Radiolaria, nannofossils and various palynological groups such as the dinoflagellates and spores. In future posts I will introduce each of these microfossil groups as I highlight projects that are currently happening here at the Museum.


My job is to manage all of these collections which number over 750,000 objects. It would be impossible to count the exact number of specimens because some slides and residues contain hundreds of thousands of specimens.


The lack of clarity over what age makes a microfossil causes problems sometimes with deciding where to store specimens in the Museum collections. In the Palaeontology Department we have all the extant (modern) Foraminifera as well as the fossil specimens, so no problem there. However, ostracods are split between our department and the Zoology Department, with us holding the fossils and Zoology the recent (extant) forms. In practise it is very difficult to draw the line between fossil and recent and we certainly have some ostracods that could be in the Zoology Department and probably vice versa.


The majority of the microfossil collections are Foraminifera, which are unicellular animals with a foramen (i.e. an opening, sometimes multiple) that form small shells of calcium carbonate, silica or organic materials. Examples of Foraminifera are shown below, where the field of view of the slide from the Heron-Allen Collection is about 2cm.


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The Heron-Allen Collection

 

I mentioned that some micropalaeontologists like me also work on microscopic fragments of fish (microvertebrates). At the Museum these are kept with the fish collections so they do not come under my ‘jurisdiction’. However, I still study them and some of my most important discoveries have been on this subject as you will find out in the next post to the blog.

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Giles Miller

Giles Miller

Member since: Apr 21, 2010

This is Giles Miller's Curator of Micropalaeontology blog. I make the Museum micropalaeontology collections available to visitors from all over the world, publish articles on the collections, give public talks and occasionally make collections myself.

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