The Antarctic is very much the flavour of the month here. To mark the 100th anniversary of Scott reaching the South Pole, a new exhibition opened on 20th Jan at the Museum. The Museum holds over 40,000 items relating to Scott's Terra Nova Expedition of 1910 so I thought I would show you details of one of the treasures that remains hidden from view. A wonderful book of bound documents tells the story of Edward Heron-Allen and Arthur Earland's study of the Terra Nova material; how the collection was acquired, studied and the significance of the discoveries that they made.

The start of the letter from Edward W. Nelson to Arthur Earland prior to the expedition.

In my microfossil Christmas card post I mentioned that Heron-Allen and Earland had worked on material from Scott's Terra Nova Expedition of 1910. Although they had not been on the trip, a letter from crew member and biologist Edward W Nelson (1883-1923) clearly shows that Earland had been in contact before the trip to encourage Nelson to look out for foraminifera. The exhibition at the Museum has a picture of Nelson along with all of the other crew members and outlines some of the scientific research that went on as part of the expedition as well as the expedition to the South Pole.

Part of the Heron-Allen Type Slide Collection from the Terra Nova Expedition material.

The Terra Nova was the ship that carried Scott and his party to the Antarctic and lent its name to the expedition. Samples were collected from the ocean bottom as it travelled from Britain via the Atlantic Ocean to the Antarctic. While in the Antarctic, ocean bottom samples were dredged too, many of which contained the remains of foraminifera. Even while Scott was on his way to and from the South Pole, the Terra Nova was collecting scientific material from Antarctic region.

Heron-Allen's signed personal annotated copy of the 1922 publication with Arthur Earland and part of one of the letters from Sydney Harmer bound next to it.

The Keeper of Zoology at the Museum at the time was Dr Sydney Harmer who had worked with Terra Nova expedition member D. G. Lilley to publish a list of the samples and sampling details. The first set of letters are from Harmer inviting Heron-Allen and Earland to work on the material. They clearly state that the authors will not be paid and that the final work will be edited by Harmer himself. Neither of them were ever officially employed by the museum but had an honorary status and were provided room to work at the Museum.

Portraits of Heron-Allen and Earland now hanging in the Museum micropalaeontology library, The Heron-Allen Library.

Harmer wrote, 'In a group like the foraminifera I imagine that you would have no difficulty in putting on one side enough duplicates to compensate you in some measure for the trouble of working out the collection.' A later letter states 'I am delighted to have placed it in the hands of an enthusiast to whom no trouble seems too great.' A number of years later, Heron-Allen donated his entire foraminiferal collection to the Museum so all of the original samples, the described material and Heron-Allen's slides are now in our care.

This type of information about the acquisition of the collection is very important as it clearly states the agreement between the scientists about how and where the material should be deposited. Heron-Allen was certainly the curator's friend because of the meticulous way he documented and kept relevant archival correspondence and other materials associated with his collections.

Part of one of the illustrations of foraminifera hand drawn by Mary H Brooks.

The receipt for payment for the artwork sent by Mary H. Brooks. It was paid for by Heron-Allen himself.

Heron-Allen's copy of the paper is also annotated in red ink with references to slides in the Museum collections. Heron-Allen constructed a series of 'type slides' for all of the samples that he worked on. For the Terra Nova Expedition these were slides showing good examples of each of the foraminiferal species encountered at each collecting station of the expedition. As a result this library volume is an extremely useful reference to researchers looking at Terra Nova collections and is a great example of the value of the library items that accompany the collections here at the Museum.

Details of some of the 'type slides' from the collection. The material in these slides was being collected by the crew of the Terra Nova from Antarctic waters at the time that Scott was attempting to return from the South Pole.

Some annotations in red made by Heron-Allen that links the published text directly to the 'type slides' illustrated above.

650 species of foraminifera are described in the publication with 46 new to science. Many forms previously described from the Arctic were also recognised in the Antarctic and the previous theory of bipolarity that foraminifera evolved independently in the Arctic and Antarctic was discounted. Many isomorphs (species made of silica where previously found examples were calcareous) were also discovered. A letter in French from the famous foraminiferologist Schlumberger discusses this issue and is also bound into the volume.

It would appear from the correspondence bound into the book after the annotated copy of the paper that the authors had a great many problems in the editorial stage of their publication. There are many letters between Heron-Allen and Harmer discussing issues about the publication proofs. In one letter, Harmer requests that Heron-Allen cuts down the size of the manuscript by reducing the size of the appendices. The volume ends with a poem written by Heron-Allen that starts:

Goodbye old friend our task is over

we bid farewell to the 'Terra Nova'

Henceforth will life be somewhat calmer

For me - 'Eugenie' and Sydney Harmer

The 100th anniversary of the tragic demise of Captain Scott quite rightly makes the headlines. However, it should not be forgotten that the Terra Nova Expedition was responsible for many new scientific discoveries. This amazing volume of hidden treasures is testament to Heron-Allen's meticulous record keeping but also to some of the discoveries that are not normally associated with the Terra Nova Expedition. The new exhibition at the Museum strikes a good balance between telling the story of Captain Scott and highlighting the scientific breakthroughs that resulted from the expedition.

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.

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.

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.

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.

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.

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!

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.

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.