Are You Collecting for The Future?

This article was published in the July 2012 issue of Rockwatch Magazine – the club for young geologists.

What does your geological collection represent?

It’s a big question, and it could be a number of different things: the geology of the country, area or town you live in, a set of beautiful colourful and fascinating objects that please you when you look at them or a wealth of scientific knowledge just sitting there ready to be unlocked.

My collection represents my childhood, my fascination with beautiful natural objects and the realisation of the wonderous, boundless knowledge that can be gained from each and every specimen. My collection represents the journey I took to become who I am today (although I still have far to go!).

To me, the meaning of my collection is something very personal, but other collections – like at the Natural History Museum in London and its great mineral gallery – may mean something entirely different. I see the past few hundred years of scientific discovery embedded in those rows of cabinets, and the histories of the people who donated specimens to the museum in the vast corridors of storage behind the scenes.

Collections mean different things to different people too. People will value collections differently and for many reasons, but not just in monetary terms.

Take Sir Arthur Russell, the 6th Baronet of Swallowfield Park near Reading who lived from 1878 to 1964. He was fascinated by minerals from a young age, and at 8 years old he had already visited his first working mine. From then on, he was hooked. His passion lay in piecing together a collection that represented the whole mineralogy of Great Britain and Ireland, and managed to create one of the most comprehensive collections of British minerals to date. His collection became extremely important and well known, and after his death even universities all the way across the Atlantic in the USA wanted part of his collection!

The collection meant everything to him: “It is my earnest hope and desire that this collection upon which I have bestowed so much loving care and so much of my life shall remain intact and be well cared for wherever it finds a resting place”, a quote from Sir Arthur Russell. Arthur’s collection now resides at the Natural History Museum in London in the hope that it would be kept in perpetuity, meaning that it will remain here forever.

The task of keeping objects in the way they were donated is harder than it sounds because all objects and materials will change over time, no matter how careful you are. This type of change is called degradation, and is caused simply by factors such as wear and tear through use, the storage environment (such as high or low temperatures or humidity – the amount of water in the air relative to the temperature) or the amount of light something is exposed to. These factors can cause changes such as breakage, crumbling or fading which alter the condition of the object relative to its original state in which it was given to the museum.

To help slow the process of degradation (a practice called conservation) museums come up with ideas to assess how the material’s condition has changed compared to the state it was originally documented in, and use this to decide how to conserve the material.

Think about your collections. Do you think they will last 100 years and end up in a museum? If so, what might you do to help make sure people can appreciate them like you do, and see the full value of your collections?

See or on how to collect responsibly, or ask your local museum how to best care for your specimens when you get them home. If you would like to know more about the work I am doing take a look at .


Sir Arthur Russell and the Preservation of a National Collection

This article was Published in the Geologists Association Magazine in June 2012 (Vol 11 No. 2).

I started collecting at a very early age. I was a toddler when I began to pick up my first rocks from the beach with my mum and dad, seven when I created my first properly displayed geological collection and eight when I won my first prize with Rockwatch for my ‘mineral museum’.

Sir Arthur Russell (1878-1964), the 6th Baronet of Swallowfield Park near Reading also began collecting at a very young age and by the time he was eight years old had visited his first working mine, a trip that helped develop a hobby and a passion that would stay with him for the next 78 years of his life. His stunning collection evolved into one of the most significant British regional mineral collections to date, comprising approximately 13,000 specimens and is one of the Natural History Museum’s largest and most significant stand-alone collections.

Russell collected almost half of the specimens himself; developing relationships with owners of other mineral collections and workers at important geological sites where he acquired many scientifically significant specimens that otherwise might never have been publicly available. Today, many of the localities he collected at have disappeared; consequently Russell’s specimens hold integral information on the geology, geography and cultural history of these sites.

The collection was left with the Natural History Museum in London on his death, as requested by Russell – to the great annoyance of other institutions, such as Harvard. In his will, he conditioned that the collection be stored in perpetuity, together in its original ten oak cabinets with his cataloguing system. The association of Russell’s original cabinets, labelling and cataloguing system mean that his collection does not only represent a near complete record of the mineralogy of the British Isles at the time of assimilation, but also an important historical and cultural resource.

The practice of keeping an object ‘in perpetuity’ is complex. To preserve something exactly as it is for ever is impossible, a problem all conservators and curators will be intimately familiar with. In heritage collections it is a fact that objects will become more fragile with time and the institution holding them will do their best to ensure the object is in the best condition relative to its original state. This process may involve preventive conservation measures to ensure that the possibility of degradation is limited.

To a casual visitor, it may be difficult to imagine the need to conserve a mineralogical collection. The truth is however that some minerals do degrade, sometimes causing catastrophic damage to the specimen or even to those around it. Because of the nature of the Russell Collection, this kind of damage may not only have implications for the scientific integrity of a specimen, but also the historical context. Mineral degradation can affect associated labels, rendering them unreadable, or worse, completely disintegrating them. In the case of Russell’s collection, part of its uniqueness lies in the labels handwritten by Russell himself in his characteristic script, so preventing loss of any aspect of his collection is essential.

In a climate where museums are under tough economic pressure, with severe cuts to funding and staff it may be more difficult than ever for museums to ensure that collections receive the care they need. Without heritage collections we would lack essential information that forms part of the basis of our extensive knowledge of the world today. What makes a collection such as Russell’s so unique is the range of values that can be associated with it – scientific, historical, educational, cultural, aesthetic and inspirational. It not only provides a significant mineralogical resource for researchers across the world, but also a historical record of people and places, that without the collection we may have known much less about.

Looking back to my own collection, (although far from the stunning host of Russell’s specimens!) it provided me with the notion that I wanted to work in museums with other geological collections. Since being introduced to The Russell Collection, it has inspired me to continue to pursue my aim through studying an MRes in Heritage Science at UCL and I am now about to embark on a project focusing on Russell’s Collection at the Natural History Museum. Through the project I hope to learn much more about museums and how to care for collections as well as how to contribute to the preservation and awareness of our great national geological resources.

For more information on The Russell Collection, The Natural History Museum or the work I am doing please visit: , , or

My Experience at the Natural History Museum: What IS information?

To many heritage professionals, ‘information’ is a quality that is intrinsic to an object. In some ways it may also be considered a value, but here we hit upon a slight conceptual barrier when, to my mind and a few others in the field of heritage studies and philosophy, a value cannot be intrinsic. Value is something that is attributed to an object, whether that be an artwork, a fragment of a medieval pitcher or a mineral specimen. To me, this means that there can be no intrinsic value of an object. If something is not used, kept or even possibly known about, it has no value to anyone. However, if something is then discovered we can immediately put a perceived value onto that object. This may even be the perception that because it has been hidden or lost for any number of years that it therefore must be important, and hence valuable. It’s almost like the ‘philosophical’ question of whether there is a sound if a tree falls and there is no one to hear it. Apart from an object that has lain forgotten about does not generally make any vibrations which is perceived as sound, or in our case value. Ahem.

Anyway, what I was trying to say was that ‘information’ is not always such an easy concept to grasp either.

And the idea that ‘information’ is not an easy concept to grasp was actually something I found difficult to understand too.

So where are we going here?

Basically, I wanted to give you a little flavour of one of the conceptual landmines that are impeding my safe transit across the field of value studies and in the process of doing so, understand things a little clearer myself!

What alerted me to this little philosophical conundrum, was the first day or so of starting part of my masters project at the Natural History Museum in London. For those of you that have not read CSI, but for Museums, you may need a little filling in at this point.

I am currently studying an MRes Heritage Science at University College London, where my project focuses around the identification and understanding of values associated with geological collections. My interest in the subject sprung from my lifelong interest in geology and geological collections which culminated in a degree in geology from the University of Edinburgh. Combine this with the wish to work in museums and a long term interest in history and archaeology and Poof! You get an MRes in Heritage Science on Geological Collections: Identifying Unique Values. To see an earlier version of the project and the poster to go with it see:

In working with the Russell Collection at the NHM, I wanted to assess the extend to which the collection could be used to further quantify values identified through questionnaire data. I hypothesised that certain elements of collections could be seen as components that relate specifically to certain values, such as research notes relating to a personal value, physical damage relating to aesthetic value, locality data relating to cultural value (if just one example) and finally labels relating to ‘information’ value.

Unfortunately, the flaw with this is that I do not yet have the analysed data from the questionnaires telling me the values associated with collections. However, this is why I needed a hypothesis, and the above is therefore something I am going to test. Which is also where we came to our other little friend, ‘information’:

Is ‘information’ a value? Is ‘information’ just a big word which encompasses a lot of other little intricacies of an object or specimen which are essential to its existence (intrinsic property?). How do you go about measuring ‘information’?

Well, first off, I decided that within the scope of this project there is so many times you need to use the word ‘information’, but little to define in any way what people mean by it – especially when you are asking mineralogists, petrologists, palaeontologists, curators, conservators, academics and industry professionals. So I asked the question: “what does the term ‘information’ mean to you?” in the questionnaire to see if there is any common ground between them.

While analysing responses, I was perusing the Russell Collection with my supervisor at the NHM and discussing what changes to various important ‘components’ of specimens could affect the way values are perceived. What we knew was that in geological collections the label is extremely important. Without the label a geological specimen is almost useless. To be able to assign any importance or future use to the specimen there needs to be a locality associated with the specimen and ideally an identification as well. This is an incredibly easy concept to entertain for anyone familiar with geological collections and something that generally doesn’t even need to be explained. However, try explaining this to someone who is familiar with other heritage collections – art, archives, furniture etc. and you find you hit a few stumbling blocks.

Information is something carried by all objects. In many instances in heritage collections this information is easily accessible, such as in a painting, the style, brushwork and paints will usually give clues as to the time period and possibly artist who painted it. A document in an archive will have the paper or parchment, the ink and the writing or pictures on it by which to identify it. Anyone who has watched Antiques Roadshow or similar will be familiar with experts identifying the time period, make and sometimes maker of an object through simple observation of a random object.

For something mentioned above to be missing ‘information’, physical damage to the object obviously causes the most harm. Crucial ‘information’ such as a key word on a document, the makers mark on a cabinet or chemically degraded paints could all affect the ‘information’ stored in the object. However, with a rock or mineral specimen such physical damage may not be important or cause any important loss of ‘information’. If the label was in some way not present though, this would cause significant problems for the value of the specimen – whether that be scientific, historic, or educational.

To conclude, ‘information’ can be complicated, and I am very much looking forward to finding out what comes out of the questionnaire and the rest of my time at the NHM. No doubt I will also be blogging about some of the other experiences I have in the process!

Geodiversity and A Sense of ‘Place’

Maybe it’s why I have such an attachment to Turner and van Dyck. Maybe it’s why I did geology. But it’s certainly why I want to work with natural heritage and the outdoors.
I have always had a strong sense of ‘place’ in the landscape. I was raised in a town in East Lothian, a beautiful area of Scotland with rolling hills, great Carboniferous geology and a strong sense of history in the archaeology of the area. I also spent a lot of time across Scotland looking at rocks in various place as well as visiting many castles and historic houses and gardens as a child with my mum. Later when studying geology at university we had at least one long field trip a year, many of which were to Scotland and all of which were to stunning areas of natural beauty. I think this helped develop a strong sense of ‘place’ in me, in completely natural and ‘untouched’ environments of which you find many in Scotland, and therefore remains somewhere I think I will always want to return to.
So it is no surprise that artists who paint landscapes make me feel so happy when I look at them. I can stare for ages at the scenes, a moment captured in time, which encapsulates parts of the natural and human landscape at the time, and implies that the people working the land are as intrinsic to it as the trees and the rivers that run through them. Interestingly enough, Geoscientist (the fellowship magazine of the Geological Society) also had an article this month that touched on the subject of painting the dynamic and geological landscapes of the 19th century. The article focuses on Thomas Moran, who was different from Turner or van Dyck in that he painted landscapes generally devoid of human interactions, focusing on the natural forces that shaped the landscape such as water and wind. It was also due to his personal interest in geology that made him delve into the realms of his artistic subject, and I think that oddly enough the interpretation of the natural forces in his paintings make the environments almost more surreal, and some have compared his paintings to Dante’s Inferno and his journey through hell. But don’t let this put anyone off who fancies a quick jaunt into the geological countryside! I think that in communicating the actions of natural forces in creating the landscape at that time – and still probably today – it gives the onlooker a sense of wonder and awe.

Geodiversity is extremely important. It describes the diversity within abiotic nature and gives it a name with which people can relate to the idea that it is important. Biodiversity is a ‘buzz’ word and wherever it is used people will automatically feel that this ‘place’ is to be conserved. What about the geology of the area? Not only the geology but the records of the geomorphological processes that have created the landscape we see today on top of which the archaeology produced by our ancestors has barely scraped the surface. Without this diversity we would not be able to live on this planet. It describes the beginning of the Earth and life on the planet; the massive processes that have formed our continents and oceans; the minerals, rocks and fossils that hold out mineral wealth in the form of ore and fossil fuel resources; the climates the planet endures many of which we have learned to thrive in such as rivers, coastal environments, glaciation, deserts and finally the record of continual processes like weathering and formation of soils.

We value these diverse materials, landforms and processes in many ways as the resources that the Earth’s geodiversity gives us is used in every aspect of life from manufacturing almost everything to art materials (and inspiration) to household goods like toothpaste, plaster and of course fuel. We therefore value these resources for their economic and functional purposes, and in tune with this for their research purposes – without research into these materials we would not have these resources to exploit and use in out daily lives. With research also comes education, we need to pass on our knowledge of these resources to future generations and hope that they can get even more information out of these than we previously have. We have already discussed how artists have used landscapes as inspiration for many works of art, but  the aesthetics of geodiversity can extend to tourism – many people travel from all over the world to climb mountains in Scotland and other areas across the world – but the landscape is also of importance to the people who live there all year round. As I began this piece, the landscape and ‘place’ of my area of Scotland is very important to me and holds lots of great memories of which the geology is an intrinsic part of them. Therefore we also associate with these areas cultural values, across the world there are geologically important sites that attract spiritual value to landscapes or forms such as Uluru in Australia or the North American Indians to areas of Central North America. This links with the history of the people who have been associated with the landscape through time, recorded in our history books as well as archaeological remains (as I mentioned are present in my local area too). People interact directly with the landscapes they are attached to and many like to collect pieces of their ‘place’ to keep with them at all times. I think all humans have minor cases of kleptomania, but some definitely more than others. People who collect part of our geodiversity do not have to assign meaning to the objects, and definitely do not have to alter the object in any way from the original state in which it was found. This makes geological collections very different from other collections in that they are still very much part of the landscape they came from when they have been in a collection for 100 years or 2.

In my personal collection, a lot of the specimens are from places I have been and collected them from in Scotland, making the majority of the collection Scottish and attached to that ‘place’. Some of the material has been bought or given to me by other collectors, but the main value to me is that I have personally found many of the specimens. Other famous collections and collectors have specific interests that can sometimes be related to a specific ‘place’ such as Arthur Russell’s collection held at the Natural History Museum in London (NHM). His collection represents Britain’s mineralogy and holds many of the best examples of British minerals. I am currently working with this collection and I always get more excited and awed when I remember that these amazing minerals are from where I live, or better still from somewhere I know and have been in Scotland. I recently got very over excited when I found a (not even particularly visually stunning) specimen that was from the area of my geology dissertation on the Isle of Skye and part of the metasomatic zone around the large granite intrusion of Beinn an Dubhaich at the centre of my area. Funnily enough, of all the visually stunning and historically important specimens I have held and worked with in his collection so far, that is the one I remember the most.

Some museums do capitalise on local collections, such as Wanlockhead Museum of Lead Mining in the Leadhills, Scotland which not only helps you discover the geology of the surrounding area (including getting down to do a bit of gold panning) but it also has the mine and the old miners homes open to the public to help visitors understand and connect to the entire history and culture of the area. As a child I visited Wanlockhead many times and always thoroughly enjoyed it. The National Museum of Scotland in Edinburgh houses a vast mineral collection, not much of which is now on display since the renovation and opening last summer. I know from discussion with the research curator of mineralogy there that the collections held, studied and continually collected are focused on Scottish material but this is not reflected well in the public displays of the museum. The museum’s public display focuses on educating the public about the formation of the Earth and the geological processes that have shaped it since then. The gallery is very good in my opinion and has some great specimens on display, but personally I feel that the museum is missing out on a fantastic opportunity to get people involved in what’s out in their back yards! Edinburgh especially has fantastic geology on its doorstep (Arthur’s Seat) and by simply connecting visitors with what’s right there in front of them could easily give them more inspiration to go out and learn more about it. I know from Russell’s collection at the NHM that Scotland has a wealth of beautiful and fascinating minerals and rocks out there – so why don’t we see them?

I can’t answer the question now, but I can’t help but feel that we could learn a lot from understanding the links between ‘place’ and geological collections better – and even between other ‘places’ and heritage collections. Is there anything to gain from better linking together collections with localities to benefit collection’s management, educational and scientific point of view? Lets hope someone finds out soon!

Mass Extinctions, Lagerstatten, the Cambrian Explosion and Hominids’ obsession with Fossils: Part Four

Part Four: Hominid Evolution and Fossil Collecting

Humans are in a world of their own. There are many common questions now of the sociological implications of the old humanoids, how did they interact and split duties? What was the early evolution of them like? What did they eat? How did they interact with the environment? When did they begin to influence it? I do not have the answers to any of these questions, but here is a very brief note on their evolution, with respect to climate change and speciation.

The fact that human evolution happened at the same time as major climatic deterioration through glaciations and global cooling has prompted questions on the extent that the two events are causally related, including the driving forces in hominid evolution. An issue that needs to be taken into account (not including the complexity of climatic interactions with life) is that of the fossil record, the reliability of dating methods and major tendency for the whole human evolutionary story to shift and change with every new find. Therefore, it is important to remember that correlations mean associations between factors and not necessarily causality. In addition if there is a lack of correlation it does not mean that there is no inter linking of associations. What is important is not only whether climate and hominid evolution are related but the nature of the mechanisms involved.

The lower the minimum or modal temperature, the higher probability of hominid extinction. Therefore, there is a distinct correlation between extinction and climate but not with speciation and climate, so that other primary factors control the first appearance of taxa. It has been found that species diversity varies somewhat with climate, but not in a robust manner. There is a difference in Homo to Australopithecus, where Homo vary positively (more) with low temperature and the latter negatively (less), so that the Australopithecus are more temperature sensitive than Homo. However it may also be the case that species diversity is a measure that shows how ecological changes determine the way in which speciation and extinction interact. When speciation is measured in relation to climatic stability a number of relationships can be observed. It was found that, unsurprisingly, the more stable the climate, the more hominid species. When split into groups of Homo and Australopithecus, it was found that Australopithecus were good with stable climates, but that Homo showed less speciation. There was not a very strong relationship between climatic stability and extinction with hominids, showing the more stable the climate the less extinction.

Climate is likely to be an important element in any model of evolutionary change, that goes hand in hand with competition. When climatic change occurs, it means that it operates through competition. The change will alter the nature, abundance and distribution of environments and resources within the areas initiating changes in the competitive relationships between species. It is these altered competitive relationships that are likely to lead to evolutionary consequences. The consequences might be extinction, speciation rising from reduced intra-community competition or the opening of new ecological opportunities. However, even with this interpretation of the effects of climate change, it is clear that this is not sufficient to describe the changes in speciation, diversity and extinction of taxa. So, it is probable that these effects are locally important effects of competition, but not from climate change as a global effect.

To finish with a flourish, as I promised at the beginning of this four part blog series, I will attempt to reel the palaeo-madness back in towards a more ‘cultural heritage’ alignment. Prehistoric Fossil Collectors by Ken McNamara, details the fascination that we, as species of hominids have had with fossils. Specifically, with the common sea urchin. When alive, the sea urchin can be beautiful, and their shells when washed up on the beach and non-fossilised are beautiful enough to see. However, it seems that the five pointed star that holds so much symbolism in many human cultures for hundreds (maybe thousands) of years can be traced back all the way to the Ordovician, 450 million years ago.

The earliest evidence we have of Homo collecting these trinkets is 400,000 years ago with Homo heidelbergensis where a hand axe has a fossil echinoid displayed on the side. Other usages of the fossils have been placement in graves, as necklaces with holes drilled through the middle, adorning windows and doors or homes and churches and many others.

It could be that in some cases these stars were thought to have some sort of spiritual significance, a trinket to ward off the Devil or to help them in the afterlife. Personally, I think that alongside these possibilities may be the fact that they were pretty, and formed a simple way to adorn the grave of a loved one much as we may do today, without any specific meaning having to be attached to the fossils. In many ways, we are pre-disposed to enjoy beautiful items, especially those with symmetry, which has many connotations for our own bodies, the legs, arms and neck/head symbolised in the five points.

What interests me is the idea that 400,000 years ago our ancestors picked up fossils and cherished them in some way. The practice could go back further, and I think would undoubtedly extend to other fossils. We find even as children that we are drawn to these objects without understanding what they are or have been, but maybe there is something in all of us that wants to understand how we got here. I love the fact that fossils and fossil collecting have been important for so long, and hope that we continue to understand the value of looking at rocks and understanding them in the future.

Recommended Reading:

Foley, R A, (1994), Speciation, extinction and climate change in hominid evolution, Journal of Human Evolution, 26, Available online:

Science and Heritage: Seeking a Sustainable Future

Here is an article I wrote for Museums and Heritage Online Comment section recently, addressing the students’ role in the future of the heritage sector:

“Heritage science is an emerging field. It combines many disciplines that really come together with two main purposes… both scientific and social… and engage[s] a range of disciplines to do that effectively.” Professor May Cassar, Director for the Centre for Sustainable Heritage at University College London (UCL) and Director of the AHRC/EPSRC Science and Heritage Programme.

Dr Matija Strlič, Senior Lecturer and Course Director of the MRes Heritage Science at UCL, explains: “Heritage science is about understanding heritage on various levels, the knowledge of the stories that the object can tell from a chemical level to a personal one but also something that spreads over to an interdisciplinary understanding of heritage management.”

Until recently, the science of heritage was disparate and fragmented. The field was in decline with less research funding available from the European Commission. This matter began to be addressed towards the end of the 20th century when pan European conferences began to be held on the subject of science and heritage.  Independently, the House of Lords Science and Technology Select Committee chose to consider Science and Heritage in their 2005/6 programme of inquiries.

Prof. Cassar stresses how the heritage sector was lucky to have an inquiry shine a light on heritage science, particularly the issue of declining resources in the sector. This was preventing knowledge and expertise from being effectively passed on to new generations. The inquiry did not only coin the term ‘heritage science’ but its recommendations encouraged the development of courses to train and develop younger heritage professionals to deal with the demographic time bomb in the sector.

Prof. Cassar says: “All courses in the heritage sector should aim to extend the research and evidence base to enable better decisions on heritage management and use of resources.” Courses should challenge the ‘hands-off’ approach; heritage science should be open to as wide an audience as possible. But how useful are university courses in heritage science compared to professional experience?

Gabrielle Beentjes has been a senior conservator at the National Archives of the Netherlands for over four years and currently studies heritage science part-time at Masters level. She feels that the course is extremely useful to the heritage sector and especially for someone at her professional level. “It makes the heritage sector more aware of the possibilities of science,” she says, and hopes in the future to be more involved in co-ordinating and stimulating research through the skills the course has taught her.

According to Dr Strlič, “the biggest benefit courses will bring to the sector is that of a broad view of important research questions, and the ability of graduates to question, identify and answer real research needs in the field”.

But what is the future for the students of heritage science? In an age of austerity do new graduates fit into a sector that is littered with budget cuts?

Dr Strlič feels that it would be wise for heritage institutions to build capacity now, to embrace more conservation practitioners, including heritage scientists, in the future. Prof. Cassar notes that for this to happen, the heritage sector will, in the future, need to rely on itself more as the Government has been singularly lacking in moral leadership.

In an age of austerity, prospects for graduates might seem grim, but it is hoped that the heritage sector sees enough merit in the need for heritage science. With fresh approaches, it can look to itself for moral guidance and to provide new opportunities.

Mass Extinctions, Lagerstatten, the Cambrian Explosion and Hominids’ Obsession with Fossils: Part One

So I have been debating what next to blog about and since I have recently been touching on subjects close to my heart at university – discussed in Showing off about Science and 12 Top tips for doing your Geology Mapping Dissertation –  I thought I could briefly touch on some other interesting things I worked on.

The topic of today’s post will be on palaeontology. Because of the vastness of the subject area covered in the heading, I thought it might be good to split it up into several parts in a series. The content will be drawn exclusively from notes leading up to my exam, and only edited a little.

To end the series on a timely note, I will discuss an interesting article in this month’s Geoscientist magazine, of the Geological Society, which looks at fossil collecting through the millennia and provides a very appropriate link to heritage in the process.

Part One: A Broad Introduction to the Fossilisation process and Exceptional Preservation

Understanding the completeness of the fossil record is essential for understanding evolution over long timescales, particularly when comparing biological groups that have different preservation histories. Studies have now veered from the original ‘collecting as much of the record as possible’, and have focused on getting as much data as possible from current fossils and using these for more ‘in depth’ research questions. Now we consider the adequacy of a (sedimentary rock) bed’s suitability to address a specific evolutionary question and the detail that can be acquired from a specific (fossil) specimen.

Consider this new form of questioning in relation to mixing of successive generations of fossils within one bed, and then, the original spatial distribution of a single generation of fossils within one bed. Fossils from one bed might contain very good (exceptionally preserved) fossils but these are highly biased and do not reflect the original morphologic and species distribution of the environment. On the other hand, ‘normally’ preserved specimens through as series of beds might show a complete ‘evolutionary’ series but still be biased by changes in habitat among successive beds. For example, within a single bed there can be changes in the morphological aspects of a species is down to evolution, or just the local environmental change at the time.

Fossils of such specimens as Cambrian Ediacaran fauna are so rarely preserved that it is a great window into past life, however, preservation is usually so far spaced stratigraphically and geographically that there are no good comparisons: fossils are generally environment specific or too ‘wide’ that evolutionary continuums are extremely incomplete. However, well preserved fossils such as common corals (scleractinian), echinoids and molluscs have a high (>50%) preservation rate and therefore provide a great representation of the range of environments and evolutionary processes through time.

Because sedimentation rates are so slow, it is common to find multiple generations of an organism (taxa) within one bed. This can be thought of as ‘time averaging’ of their remains but shows that the organisms were non contemporaneous (didn’t live together) and the phenomenon is pervasive in the fossil record. This is why so many fossils are re-orientated when fossilised and not in their original positions. If the sedimentation rate is so slow that it encompasses environmental change, then remains of more than one habitat can become mixed up. Therefore, a group of fossils from a time averaged deposit is unlikely to be a good ‘census’ model. It is useful to see the range of organisms that were alive over an amount of time out of interest, but not much use in research. Generally this doesn’t happen in areas of high sediment accumulation such as deltas, lagoons and lakes. This is why for seasonal variations etc. only foraminifera are useful, as the deep sea sediments of plankton will deposit continually and record each change. But, in these circumstances there are little high resolution or exceptionally preserved specimens.

This process of time averaging generally also encompasses spatial averaging too, because most population patches migrate and shift over time. Spatial mixing from post-mortem transport does not seem to pose a significant bias for many groups. It is generally easier now to recognise a species that has moved significantly from where it belongs (by using physical characteristics/species comparison). Fossil species assemblages that we don’t think came from a depositional area are more likely to arise from individual behaviour of an organism during its lifetime, or from time averaging of individuals whose environmental boundaries shifted over time.

It cannot be assumed that ‘normal’ samples of the fossil record from one geological time period are comparable to another period or that a species has a constant preservation potential over its entire evolutionary duration. This is down to the numerous plate tectonic movements, changes in climate (causing differences in dissolution rates of skeletons etc.), acquisition of different bio-minerals through time and the evolution of taxa that destroy remains of others (which may affect distributions within different periods). These biases are mainly important when trying to link patterns on large stretches of geological time.

When there is a ‘time gap’ in the sedimentary record (an unconformity) there is likely to be either a layer of no ‘hard part’ fossils, abundant time averaged hard parts or a thin layer of highly damaged hard parts over the discontinuity. This is because in times of no deposition there is less preservation by burial and more abrasion and erosion to erase the fossils completely or ‘mess them up’. Land surfaces are more likely to produce sedimentary gaps that other areas where there is less erosion. Deep sea environments are prone to burial and subduction and therefore we have most of our sea knowledge from shallow sea and lake deposits. In general, ‘normal’ fossils of average preservation and abundance need to be traced over a regional area to track a single habitat and can cover a large chunk of geological time. Increasing the length of time also increases the amount of gaps encountered in the fossil record. Small gaps from tidal rise and fall are easily pieced together, but larger gaps of sea level rise and fall have significantly more uncertainty as they affect a larger area, and coupled with species migration may cause problems for a palaeontologist.

Problems with preservation of fossils can be limited with further understanding of the fossilisation processes. Knowledge of the environments from geological, stratigraphical and chemical data can help determine the climate and habitat that the organism lived and was preserved in. This is then useful for possibilities of further degradation and movement after its death. This also helps when a species may have individually migrated for a purpose, as collective samples may prove. The knowledge of how sediments deposit themselves in different environments and at what time periods is extremely useful and can stop time accumulation biases. The ‘normal’ sites, however incomplete and un-well preserved they may be, can still provide an extremely good idea of the fossil environment and habitat and with increasing data we can change and adapt this knowledge all the time.

Recommended Reading:

Butterfield, N J, (2003), Exceptional Fossil Preservation and the Cambrian Explosion, Integrative and Comparative Biology, 43(1), Available online: