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Curator of Micropalaeontology's blog

5 Posts tagged with the pattersoncypris_micropapillosa tag
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My diary this week is illustrated by an item from behind the scenes at the Museum for each day. The week's events include:

  • an offer of an important historical collection for sale
  • work towards digitising an amazing collection of marine plankton pictures
  • hosting an old friend from Brazil
  • a recent donation appearing in a publication
  • preparation for a session on the scanning electron microscope

 

Monday

Below is an example from our collection of a slide made by the famous slide mounter Charles Elcock in 1880. Slides made by Elcock fetch as much as £350 on the open market so it was very exciting to be approached by a dealer to see if we wanted to acquire his foraminiferal collection and archive. Unfortunately the asking price was significantly more than we can afford.

Elcock_DSC3569.jpgA slide from our collections made by Charles Elcock in 1880.

 

We regularly buy specimens, and in fact some of my colleagues recently purchased specimens at the Munich Rock and Fossil Show. As far as I know, the last item bought for the micropalaeontology collection was a conodont animal back in the late 1980s.

 

At the very least this collection offer makes me realise the monetary value placed on historical items in the collection that I look after.

 

Tuesday

Below is a scanning electron microscope image of a coccolith, part of a collection of over 6,000 images taken by my former colleague Dr Jeremy Young and his collaborators.

207-23-syra. molischii_SU_blog.jpgScanning electron microscope image of the coccolith Syracosphaera molischii.


Recently graduated micropalaeontology Masters student Kelly Smith is visiting today to help us work up the data on this collection so that we can make information and images available via our website. Because their distribution is controlled largely by temperature, coccoliths in ancient sediments have been used to provide details of past climate change.

 

Coccoliths make their tiny calcareous shells by precipitating calcium carbonate from seawater so their present-day distribution may have been affected by acidification of the oceans relating to the burning of fossil fuels.

 

Wednesday

In 20 years at the Museum I have met a lot of people from all over the world, some of whom have visited regularly and subsequently become good friends. I first met Prof. Dermeval do Carmo of the University of Brasilia, Brazil, shortly after I arrived at the Museum. We have enjoyed a long collaboration that has included working together on publications, teaching collections management in Brazil, fieldwork and even holidays. He is visiting with a large, empty suitcase to to pick up the last of the scientific papers identified as duplicate by some of our volunteers.

 

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The Brazilian Cretaceous non-marine ostracod Pattersoncypris micropapillosa.

 

Today's picture is the exceptionally preserved Brazilian Cretaceous non-marine ostracod Pattersoncypris micropapillosa. Dermeval has recently reclassified the genus under the name Harbinia and is on his way to China to look at the type material for this genus. Species related to Pattersoncypris/Harbinia are used to provide information on rock ages and environments of deposition for oil exploration offshore Brazil and W Africa. For more details about their evolutionary significance, see my post on What microfossils tell us about sex in the Cretaceous.

 

Thursday

Today's scanning electron microscope image is the holotype of a new species of planktonic foraminifera Dentoglobigerina juxtabinaiensis, donated last summer and published last month in the Journal of Foraminiferal Research by University of Leeds PhD student Lyndsey Fox and her supervisor Prof. Bridget Wade.

 

The Museum collection contains many type specimens that ultimately define the concept for each species. As a result, types are some of our most requested specimens by visitors or for loan.

 

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The holotype of a new species of planktonic foraminifera, Dentoglobigerina juxtabinaiensis.


This species is Miocene in age (roughly 13.5-17 million years old) and was recovered from an International Ocean Discovery Programme core taken from the Pacific Ocean near the equator. Foraminifera, like the coccoliths mentioned earlier, are important indicators of ocean condition and climate, so this unusually well-preserved material is an important contribution to their study. Now the paper has been published I am able to register the details in our database and these will go live on our website in a couple of weeks.

 

Friday

I have a scanning electron microscope session booked next week as I have been approached by a colleague at the British Geological Survey who is preparing a chapter for a field guide on Jurassic ostracods. He would like some images of some of our ostracod type specimens from the Kimmeridge Clay Formation of Dorset.

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The ostracod Mandelstamia maculata from the Jurassic Kimmeridge Clay of Dorset.

 

Each specimen must be carefully removed from the slides that house them using a fine paint brush and glued to a small aluminium stub about 1cm in diameter. These will be coated in a fine layer of gold-palladium before being placed in the scanning electron microscope chamber next week for photography.

 

It proves very difficult to identify the relevant specimens as the original publication is pre-scanning electron microscope times and the images taken down a binocular microscope are less than clear. Publishing new, clearer illustrations of each of these type specimens will add considerable scientific value to our collections.

 

This selection of specimens has hopefully shown the historical, scientific and monetary value of our collections while showing that they are also relevant to important topical issues such as climate change and oil exploration.

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Some of the Museum's most important ostracod specimens were re-examined recently using synchrotron technology. The results published in the journal Science showed that these very delicate but exquisitely preserved fossils gave evidence for reproduction using giant sperm back in the Cretaceous period about 100 million years ago.

 

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A scanning electron microscope of an exceptionally preserved ostracod from Brazil showing details of unusually preserved soft body parts.

 

From images obtained by scanning electron microscope we have known since the 1970s that the Cretaceous ostracod Harbinia micropapillosa was almost identical in body form to modern day examples. Usually ostracods, microscopic crustaceans that inhabit aquatic environments, leave only their calcareous shells in the fossil record. However, these exceptional fossils from Brazil include details of their organic soft body parts not normally fossilised.

 

These specimens were first found by legendary evolutionary biologist Dr Colin Patterson while he was studying the fossil fish from the same rock formation. He passed them to Dr Ray Bate who published them under the name Pattersoncypris. However, some ostracod workers now believe that they should be classified under the name Harbinia which was first described by a Chinese worker in 1959 and therefore takes naming priority.

 

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The European Synchrotron Research Facility (ESRF) at Grenoble in France.

 

In 2007 we had a request by Dr Renate Matzke-Karasz (University of Munich) and a group of co-workers to take our specimens to Grenoble in France to have them analysed in the synchrotron beam ID19. A synchrotron is a giant ring where electrons are accelerated to great speeds and then bent into a circular path by magnets. Strong magents are used which cause the electron beam to deviate and at this point a very bright, intense synchrotron x-ray is emitted. Sometimes synchrotrons are referred to as diamond light sources as a result. These very intense synchrotron x-rays are then focussed into a beam which can be used for analysis at a sub micrometer scale ideal for our microfossils.

 

Some types of modern day ostracods are well known for their use of giant sperm in reproduction. Dr Matzke-Karasz and her co-workers were interested to see if our fossil specimens (Robin Smith thesis collection) contained any evidence for giant sperm or the organs responsible for its production and storage. As the curator of the specimens it was my job to transport them safely to Grenoble and to handle them while they were being analysed. I also took part in the analysis which went on all day and all night for two days. Fortunately we did get some sleep as there were four of us. We took it in turns with two of us analysing the fossils and two analysing the comparative modern specimens in 6 hour shifts.

 

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Positioning the specimen so that it is aligned with the beam. (Don't worry about the scary red lines. The beam was only switched on when we were all safely out of the room!).

 

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Dr Radka Symonova (then at Charles University, Czech Republic), Renate, Dr Paul Tafforeau (ESRF) and Dr Robin Smith (Lake Biwa Museum, Japan) examining some early scans in our experimental cabin home for the two days.

 

The specimens were placed in the beam and then rotated 180 degrees while 1500 x-ray cross sections were taken at regular intervals. These x-ray images were then combined together using specially designed software to produce 3-dimensional images (Holotomographic reconstructions). Although we could immediately see evidence for important internal structures while we were analysing the specimens, a lot of work was still required to produce the final results. The slices that make these 3-dimensional images were analysed for internal structures by Renate and her team back in Germany. Artificial colours were painstakingly added to each slice by hand to show these structures more clearly.

 

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One of the x-ray cross sections of a fossil specimen before it was combined into a 3-dimensional image.

 

The results clearly showed differences between males and females. The males had distinctive tubes in the position where modern day ostracods have  a sperm pump called a Zenker's Organ. The females had inflated sacks in the position where modern day ostracods have sperm receptacles. These are only inflated once they have been impregnated with giant sperm. Our results had shown that this reproductive strategy had been in place more than 100 million years ago.

 

 

Video of a female specimen of Harbinia micropapillosa. The orange sacks are the sperm receptacles.

 

So why is this important? As I showed in the dinosaur exhibition blog item, it is vital to know how organisms reproduce so that you can correctly interpret their fossil record and distribution in modern day environments. Ostracods are often restricted to particular environments and can be useful indicators of changes in climate. This particular ostracod species is common in Cretaceous non-marine sediments offshore Brazil and is therefore of interest to oil exploration companies as a marker for key rock formations.

 

Reproduction with giant sperm is not just restricted to the ostracods as other organisms including fruit flies and some types of frog also use this strategy. The evolutionary significance and history of this type of reproductive strategy is still unclear. What is certain is that specimens in the Museum collections show that this was also happening over 100 million years ago!

 

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Some acrylic palm of the hand sized scale models produced from the 3-D synchrotron scans and used at the "Science Uncovered" event.

 

 

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I have lost track of the number of times I have explained to people what I do and they have replied that they had no idea that this type of work was going on behind the scenes at the Natural History Museum. On Friday 23rd September it was our chance to take centre stage in the galleries in Science Uncovered, the largest 'show and tell' the Museum has ever put on.

 

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Using a large plasma screen to bring tiny fossils to life (Photo by Kevin Webb and copyright Natural History Museum)

 

Explaining about microfossils can be a difficult task considering their size and relative unpopularity compared to the dinosaurs and early human fossils that were being displayed on the tables less than 10 metres away. I have previously taken part in science communication events like these and found that microscopes have been a big draw to get the crowds in. This time at Science Uncovered, I found that a large plasma screen showing some eye catching videos and images were more a effective communication tool than ever before. Members of the public were drawn towards the screen to see what I had to say about my subject.

 

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Showing a video of a living ostracod on the giant plasma screen (Photo by Kevin Webb and copyright Natural History Museum)

 

I won't say too much at the moment about what I was talking about other than I was introducing some recent studies on some of our most important ostracod collections. I intend to make that research project the subject of a future blog entitled 'What microfossils tell us about sex in the Cretaceous'.

 

The important theme to this evening was to show the relevance of our collections and research to every day life and showcase to members of the public our science. The ostracods I showed are vital to exploration offshore Brazil and West Africa in areas where oil is being found. Knowledge of the reproductive strategies of ostracods is also vital to interpreting, not just the modern day distribution of ostracods but also the fossil record. Ostracods can give detailed information about past environments (see the Ockley dinosaur blog) and are increasingly being used to interpret past climates.

 

 

A video of the living ostracod Eucypris virens. This is related to the fossil examples that I was showing. (Video courtesy of Dave Horne, Queen Mary College, University of London)

 

It is quite tiring speaking about your subject non-stop for any period of time and my voice was quite dry after an hour. I remember taking part in a similar public event entitled the 'Fossil Road Show' back in the late 1990s and losing my voice completely by the end of the day. Fortunately this time we were using a rota system that changed the staff and specimens on the Palaeontology Station every hour. After my hour was finished I was quite disappointed to be stopping and wished that I could have carried on for longer.

 

Another minor disappointment was that I did not see other aspects of the event and get the chance to fully see what my colleagues from around the museum had to say.

 

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Some scale models of the Cretaceous ostracod Harbinia micropapillosa and my badge.

 

I do have one momento from the event; a badge with 'I'm a scientist.... talk to me'. Guardian journalist Camila Rus joked that some Museum staff had intended to wear their badges on their commute to and from work. I'm not sure this would work considering the almost complete lack of action of fellow passengers when my Natasha wore her 'Please give up your seat, I'm pregnant' badge. What I do know is that large plasma screen was an enormous help to me at 'Science Uncovered' and made my job of explaining my science much easier.

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Two upcoming events will enable you to see the original specimens and the scale models of the ostracod that showed evidence of sexual reproduction through the use of giant sperm 140 million years ago.

 

At Science Uncovered on 23 September (see flyer below for details), I'll be on the Palaeontology table from 16.00-17.00. And, a few days before, at 14.30 on 19 September I'll also be taking part in the 'Microscopic sex' talk for Nature Live in the Attenborough Studio in the Darwin Centre.

 

I hope to see you at one or the other (or both!).

 

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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.



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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