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Curator of Micropalaeontology's blog

2 Posts tagged with the blaschka_models tag

My work diary of last week, in which members of the public put a valuable part of the collection at risk with their smart phones, tiny floating snails cause a flurry of visitors and microfossils are mentioned on the Test Match Special cricket commentary(!) in a varied week for the curator of micropalaeontology.




First up is a trip across the Museum to the Nature Live Studio with some delicate specimens that will be the subject of my two public talks later in the day. We can't move large items across the Museum during opening hours and, with the galleries filled with summer visitors, this is more than sensible at present.


In the Nature Live Studio with host Tom Simpson - a CT-scan of a Blaschka glass radiolarian model on the screen.


All of the specimens in my care bar the one in the Treasures Gallery are housed behind the scenes, so regular visitors might not even know that we have microfossil collections. A previous head of palaeontology collections calculated that we have as few as 0.001 per cent of our fossil collections on display.


If you haven't been to one yet, the Nature Live events are a great way to bring these parts of our collections out for the public and allow us to talk about our science. The incredibly delicate and unique Blaschka Glass models of radiolarian microfossils are always a big hit, but we have to ask a smart phone-brandishing throng of children and their parents to move away from the specimens after the first show as a mother leans over the barrier and takes a picture on her phone from right above the specimen. We add two extra barriers for the second show!



I've had an enquiry from The Geological Magazine asking me to review a book that I have almost finished reading. I have to think carefully about saying yes or no. Receiving a free copy is the usual bonus for undertaking these tasks but, as I have a copy already, dedicating a lot of time to a review does not seem so appealing.


I decide that I shall send the extra copy to my student in Malaysia but I think I will wait until after she has finished writing up her MSc thesis. Her first chapter arrives today for comment as do some proofs for a book chapter on microfossil models that I have written. Much of the day is spent checking these and providing additional information requested by the editors of the book. It will be about the history of study of microfossils and will have an image of one of our microscope slides on the cover.




The galleries are packed with summer visitors but it is relatively quiet behind the scenes with many staff on annual leave, away on study trips, conferences or fieldwork.


This quieter period is a good time to catch up on some of the documentation backlog so today I finish documenting a new donation, continue to work on a large dataset relating to specimens from the Challenger Collection, and register 30 Former BP Microfossil Collection specimens that are due to go out on loan to the USA.


I spent my first 6 years at the Museum on a temporary contract curating the Former BP Microfossil Collection so it is always satisfying to see it being used by scientists. We have big plans for this collection in the future. However, I feel that I will need to do more than wait for a rare quiet day if I am to meet my part of the databasing targets set by the Museum. We plan to have details of 20 million of our specimens on our website within 5 years.




An enquiry has come in this week about our heteropod collection. These are tiny planktonic gastropods, or literally floating snails. They are of great interest to scientists looking to quantify the effects of ocean acidification because they secrete their shells of calcium carbonate directly from the seawater that they lived in.


Measurement of carbon and oxygen isotopes from fossil examples can give details of the composition of ancient oceans and help to quantify changes over time. I mention the enquiry to staff in the Life Sciences Department and three visitors arrive to look at our collection within a day, including two from the British Antarctic Survey looking to develop projects on ocean acidification.



It is back to documentation again, a task I often save for days when the cricket is on. I am amazed when I hear dinoflagellates mentioned during the Test Match Special commentary. Dinoflagellates are protists that are a major consituent of modern and fossil plankton. We have thousands of glass slides of them here at the Museum within the micropalaeontology collections.


straussii_cookii_montage.jpgNew species of Australian Jurassic dinoflagellate Meiogonyaulax straussii (1-4) and Valvaeodinium cookii (16-20) published by Mantle and Riding (2012). Images courtesy of Dr Jim Riding, British Geological Survey.

A regular visitor to our collections who works at the British Geological Survey in Nottingham has described two new species of Jurassic microfossil from the NW Shelf of Australia and named them strausii and cookii after the former and current England cricket captains and Ashes-winning opening batsmen. It causes much merriment in the Museum microfossil team as another former England Captain, Michael Vaughan, remarks on the radio that they look rather like omelettes.


Cricket is the theme for today as I attend a lunchtime retirement party for a former cricketing colleague at the Science Museum next door. I leave a colleague to take a visitor to lunch but come back to find that he has gone home sick and the visitor is still here with a list of requests that account for the rest of the day...


The Museum radiolarian collection makes up considerably less than 1% of the total microfossil collection but is proving very popular at the moment. Last February we loaned some slides to accompany an exhibition by Irene Kopelman at the Gasworks Gallery and this week I processed a loan for Artist/PhD Researcher Gemma Anderson. Glass models of radiolarians made in 1889 by the father and son partnership of Leopold and Rudolf Blaschka are also being prepared for something special that will be happening later in the year at the Museum.



A scanning electron microscope image of part of the fossil radiolarian residue on loan to Gemma Anderson. The tip of a standard 0.65mm diameter dressmaking pin is included for scale.


Radiolarians are single celled organisms (Protozoa) that secrete tiny skeletons of opaline silica. They are present in the oceans of today from the tropics to the Arctic and live anywhere from near the surface to depths of several hundred metres. They range in size from 0.03mm to 2mm and mainly have a solitary floating lifestyle (planktonic), although some are colonial.


The living cell that produces the skeleton consists of a central mass of cytoplasm surrounded by a peripheral layer called the extracapsulum. Sometimes the extracapsulum contains bubble like structures that aid flotation and occasionally algal symbionts. The cells also produce radiating fine structures called axopodia. In some species these are contractile and may have been used to move organic particles closer to the extracapsulum for digestion.


Fine strands called fusules connect the extracapsulum with the inner capsule and these are unique to the Radiolaria. Modern radiolarians are subdivided based on the microanatomy of the central capsule whereas fossil forms are classified on skeletal characteristics. The living and fossil classification schemes are not intergrated as a result.



A Blaschka glass model of the radiolarian Aulosphaera elegantissima Haeckel, 1862. The central mass of cytoplasm, the axiopoda and the spherical silica shell are magnified about 500 times and reproduced in glass.


A collection of 18 radiolarian and heliozoan Blaschka glass models were acquired by the Museum in 1889. The Blaschkas made 10 different varieties of Radiolaria representing two of the three main subdivisions. They also offered three varieties of Heliozoa (literally sun animals). These look superficially like radiolarians but differ in the arrangement of the pseudo/axo-podia and the cellular structure in the central capsulum.


The illustration of A. elegantissima in Ernst Haeckel's 1862 monograph on the Radiolaria that provded the inspiration for their work.


Radiolarians are very beautiful to look at but are also scientifically significant. The have a long geological record stretching back more than 500 million years to the Cambrian Period. This makes them very useful for determining the age of sedimentary rocks that contain them as well as giving details of past climates and oceanographic conditions.


The Museum's radiolarian collection of 1,500 slides is small but historically very significant. Ernst Haeckel described 2,775 new radiolarian species in his 1887 monograph on the Challenger radiolarians [PDF] but did not define any type specimens. A set of teaching slides made by Haeckel in the Museum collection is the only set of plankton slides available from the Challenger Expedition. Residues in the Ocean Bottom Sediment Collection also contain important comparative specimens that help define Haeckel's species concepts in the absense of type specimens.




A close up of part of the radiolarian residue on loan to Gemma Anderson. It is from Miocene Barbados Marl which is roughly 15 million years old.


It will be very interesting to see the results of Gemma's study; I will comment on this blog with any details. I would also be very excited to see a Blaschka radiolarian model on display in the Museum galleries. I promise a more detailed post on the Museum Blaschka Collection in the future with a very interesting story involving a team of archivists, curators, conservators and exhibition staff (with some C-T scanning too).

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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