Investigating Fossils. Wilson J. Wall

Strictly speaking it is a descendent of the assumed extinct lineage which was rediscovered, rather than the same species. This is, of course, the Coelacanth. This astonishing story started in December 1938 when Marjorie Courtney‐Latimer was on a trip to the dockside of East London in the Eastern Cape of South Africa, to see what the trawlers had brought up by way of specimens for the East London Museum of which she was a curator. On this particular occasion what she found was a 1.5 m, 57.7 kg fish that was already a day out of water. It had been caught at the mouth of the Chaluma river, just south of East London. Through many trials and tribulations it became apparent that this was a fish representing a lineage that had been supposed extinct for 80 million years. Identification came a few days later as a member of the Coelacanthiformes, a group previously considered extinct. Even more astonishing was that this put it into the Crossopterygii, the otherwise extinct group of lobe‐finned fish. This particular species was described and appropriately named Latimeria chalumnae (Greenwood 1988). Such a find is a very rare occurrence as it was not a rediscovery of a species, or even just a new discovery of a previously unknown species, this was finding a group of fish that were well known from the fossil record and assumed to have disappeared millions of years previously. If L. chalumnae had been discovered in the eighteenth or nineteenth century, this would have been used as a demonstration by biblical literalists and supporters, that the fossil record was of species still extant, but not yet found. There are two points to be made about this, the first is that the oxymoron ‘living fossil’ is misleading and the other is that as far as we know L. chalumnae was not represented in the fossil record, it was the lineage which had survived, rather than the species. Another such surviving ancient lineage is the Tuatara, Sphenodon punctatus, from New Zealand. This has been the subject of a quite recent debate regarding the status of a living fossil and the very concept of a ‘living fossil’ as a useful idea, rather than a confusing one (Vaux et al. 2019).

      The situation with the Coelacanth is a very unusual event, although really not so surprising when you consider the numbers involved. As there are generally regarded as being something between 1.5 and 4.5 million species extant on the planet (there are very good biological reasons for this wide range) while through the whole Phanerozoic aeon, which is approximately 541 million years, we have so far found fossils of only about 250 000 different species. This also demonstrates something else; we have no idea of the level of biodiversity for most of the past. We can only surmise what the range of animal and plant species were. There is certainly no reason to believe that the biodiversity was significantly less than it is now. The number and range of species in any ecology will determine the stability as well as the complexity of the population. It is for this reason we have to assume that in the past biological radiations have occurred to fill ecological niches adding to both the complexity and the stability of the system. The complexity and diversity present in the palaeontological ecosystem are reflected in the rate at which dinosaurs are being discovered. In 2019, there were more than 30 new species described and based on mathematical models, this is a small fraction of the potential, with anything up to 70% still to be discovered.

There is no reason to believe that fossilisation is a process only of the past, sedimentation is taking place all the time, with concomitant rock formation, so there should be fossil formation at the same time. Since we do not have a continuous collection of recent fossils from extinct species such as Dodo, Great Auk or Quagga, we can reasonably assume that using a fossil record as a determinant of species numbers is likely to lead us far from the true number. We can, however, make a calculated guess at the diversity from looking at modern ecosystems of the same broad type as we would have expected in any similar area in ancient geological time.

      With the developing interest in palaeontology among the general population and the apparently human tendency to collect things, fossils have become ever more important. They have developed an importance, from a scientific point of view, in helping us understand the way species develop and lineages change, or like the clade of Crossopterygian fish, pass through time largely unaltered. Studying fossils can even help with developing completely new ideas and lines of reasoning, such as how birds originated. As part of this they can help immensely in understanding the biggest and most important questions in biology; evolution and the development of modern species.

      At the same time, the human urge to collect and make sense of material goods, stamps, coins or fossils has meant that they have become of far greater commercial importance than would have been dreamt of 100 years ago. Wealthy collectors can pay large sums of money for rare and exotic fossils, probably far more than their scientific value merits. This can in itself generate problems, such as scientifically valuable fossils being removed from public view and scientific research. Another problem that can arise is that in the base commercial environment within which we live, it is seen as quite in order to generate chimaeric, or even just plain fraudulent, fossils for sale. Of course, this is not new or confined to fossils. Neither is it a phenomenon limited to areas where the outcome of discovery would be predominantly embarrassment, like faked paintings. When Isaac Newton joined the Royal Mint and supervised the recoinage of Britain in 1696 (there was no paper money), it was estimated that between 10 and 20% of the coins in circulation were counterfeit. Even these examples can be seen as relatively minor compared with the wholesale perversion of scientific knowledge when fraud in science takes place.

Some forms of scientific fraud can be seen as relatively harmless, motivated purely by money, this would be where a fossil has been embellished to make it more valuable, but has little intrinsic palaeontological interest. When wholesale fraud takes place, which disrupts the flow of knowledge, then the fraud becomes far more serious. Strangely, the currency of knowledge is held as of less importance than the currency of gold where this sort of fraud is concerned. Interestingly biological fraud has appeared in many different and sometimes surprising places. An example of financially motivated biological fraud is described in the broadly autobiographical book Papillon by Henri Charriere (1970). In this book he describes how, having escaped to British Guiana (now Guyana), he produced an apparently hermaphrodite butterfly by putting male wings on a female body. He further describes how he then sold the specimen to an American for $500. All this took pace in 1941 when the median annual salary for an American was just under $1000. Even then, during World War II, such productions were a profitable enterprise. It is worth considering the problem of a specimen that is genuine, but is so outlandish that it was thought it might have been a hoax. This was the situation as it occurred with the Platypus, Ornithorhynchus anatinus. When a dried specimen was looked at in detail and first described in 1799, it was thought that it might be a hoax. Such composite animals had been known to have been produced by skilful taxidermists in the far east as representations of mythical creatures (Moyal 2004).

      In an era when data can be promulgated very quickly, retractions and rebuttals do not necessarily have the same weight as the original message. In these circumstances, fossil fraud can have far greater repercussions than simply questionable science or making dishonest money. Fraudulent fossils may become part of a spurious line of reasoning about creation or evolution and no amount of denial of the obvious lack of veracity of the image of, say, a fossilised giant will counter the belief systems of the ignorant.

      Knowledge of fossils cannot be given a start date, as soon as man came into contact with suitable geological areas fossils would have been seen. The cognitive recognition of them being biological in origin may well have come later, certainly as soon as writing became more than simple accountancy. It seems that in the ancient world around the Mediterranean it was easy to slot some of the large bones of fossilised mammals into the mythology, labelling them as being the skeletons of ancient giants and warriors. Because fossils are not confined to one area of the planet, it has taxed the minds of all nations to find an answer to how obviously marine species come to be found so far up mountains. It was only later that people started asking questions about the process of fossilisation itself. The process of fossilisation does take a great deal of understanding and to some extent speculation, since even for short fossilisation periods, it is still far too long when compared to a human lifetime.

      Understanding the biological, rather than mineralogical, origin of fossils was a first step in a practical attempt to explain the process of fossilisation. To turn biological material, which everyone knows decays, into a form of rock as solid and stable as any rock, was difficult to comprehend. Once this was understood,