The rock lying by the roadside did not look like much of interest at first: a rather nondescript limestone, with little more to show to casual observation than a few vague blotches. Anyway, old habits die hard, so I picked it up, licked the surface and put it, and my hand lens, to my eye. The memory of the shock, and the thrill of minor discovery, is still fresh. The little blotches turned out to be the most superb three-dimensionally preserved Nummulites foraminifera that one could hope to see, set in a marvellously revealing natural cement of sparitic calcite. Part of the sample still graces my desk, while the rest has been sacrificed for microscope thin sections for students. Such treasures should not be withheld from the younger generation.
Licking the rock, of course, is part of the geologist’s and palaeontologist’s armoury of tried-and-much-tested techniques used to help survive in the field. Wetting the surface allows fossil and mineral textures to stand out sharply, rather than being lost in the blur of intersecting micro-reflections and micro-refractions that come out of a dry surface. On that day, it brought out the handsome nummulites a treat. The taste, now, was likely merely registered as generically-slightly-dusty and then instantly forgotten; I had always thought it entirely superfluous to identification. But perhaps not so. As we contemporary types develop capabilities in one direction, we might be entirely losing them in another. Go right back to the beginnings of our science, and our ancestors, and their senses, were attuned to different settings. One could then, it seems, literally develop a taste for stratigraphy.
If one was to choose an ancestral stratigrapher, then Giovanni Arduino (1714–1795) would be as good a candidate as any. He was the man who set up the Primary, Secondary and Tertiary ‘orders’ of strata that were ultimately to morph and diversify into what we now know as the Geological Time Scale (together with an offhand mention of a ‘fourth order’ that itself was to evolve – with a few fits and starts – into the Quaternary).
Arduino was a busy man who had to be ‘everywhere at once’, with a number of working personae, although neither he nor his colleagues would include within these the role of theoretical scholar or academic. A mining engineer and surveyor, and self-confessed ‘mineralogist’ – a term in which he cheerfully lumped together a keen interest in minerals, rocks and fossils – he had boundless energy and enthusiasm for practical fieldwork, and a magnificent and marvellously diverse field area – the Veneto of north-east Italy. Stretching from the plains of the Po Delta by Venice through the foothills of the Alps to the north towards the high Dolomites, it was a profitable playground for Arduino, whose expertise was constantly in demand by the local mines, foundries and quarries.
His growing realization that there was an ordered pattern behind the bewildering diversity of rock types of his large playground was not set out in some learned treatise or monograph, but in a couple of letters to a friend who was a scholar and academic. This was the ‘respected professor’ Antonio Vallisnieri of the University of Padua: these representatives of contrasting worlds had become close friends. Arduino supplied Vallisnieri with specimens picked up on his travels, and in the learned professor he found a kindred spirit with whom he could share his enthusiasm and curiosity about all things ‘mineralogical’. Vallisnieri simply published the letters wholesale in 1760 in the local Venetian journal, grandly entitled Nuova raccolta d’ospuscoli scientifici et filologici. There they, and Arduino’s insights, would likely have languished, had not a travelling Swedish mineralogist, Johann Jakob Ferber, come along, realized the significance of Arduino’s study, and paraphrased the important bits into German. This was further translated into French and English, and so they travelled farther afield. Ferber was to Arduino a little as was John Playfair to the brilliant if prolix James Hutton. The rest is history, or rather, stratigraphy.
For Arduino’s letters were exactly that: letters, nicely easy-going as between friends and discursive as you please. While Arduino’s system has now grown gigantic, the original letters have remained in the shade, unknown to anyone except scholars of geological history who could read eighteenth-century Italian. Indeed, they have only in the last year received a full published English translation, thanks to the efforts of Theodore Ell, who also provides useful context to Arduino’s life and work. They make absorbing reading, and are thankfully much shorter, and livelier, than is Hutton’s epic. And within them – particularly in the first letter – Arduino conversationally describes the local rocks, minerals and fossils of the sequence of rocks, that he depicted in that famous – and still impressive – annotated geological field section across the valley of the Agno ‘as far as the highest summits of the Alps above Recoaro’. It is in these initial descriptions that the question of taste looms large.
Once the preliminaries are over – and Arduino shows elegant manners in these, proclaiming himself grieved ‘to be kept from research and contemplation of the productions of the Fossil Kingdom’ and from ‘regular correspondence with Men of Philosophy’ – his list of ‘curious observations’ was unfurled, spiced with those sensory grace-notes. Fossil shells in a mudrock, for instance, and coal fragments, when burned, leave an ash that ‘as soon as it is placed on the tongue, it burns like fire and leaves a flavor equally bitter and urinous; when spat out, it leaves a certain sweetness, and a skinned tongue’. Springs that emerge from a stratum full of marcasite and coal ‘have an acid spicy flavor; vitriolic, yes, but with a certain pleasantness that I cannot describe, like the acidity of wine’. These waters ‘made me far less nauseous than did the waters from the same source that I have tasted here in Vincenza and at Scio’. The white and micaceous sediment from one stratum has no taste in the raw state, he said, but once burnt ‘acquired a flavor, as well as a caustic quality from the calcining of the spar’.
It is a taxonomy of taste – and of sight and smell too, as the specimens are burnt, boiled, dissolved, all reacting in different ways, minutely described. The account as a whole is redolent with a literary flavour that is part alchemy, part sensual experience of rock, part scientific analysis. And, of course, in days when there was no chemical analytical equipment – and indeed no framework of chemistry in any way that we now understand it – it was a sensible means to throw a little light on those enigmatic but useful rocks.
This was taste, therefore, as analytical tool. The whim of some jaded gourmet, or perhaps gourmand, though, can also be thrown into the mix. One can imagine that the shade of the Reverend William Buckland, celebrated Dean of Westminster, dinosaur hunter and man with a mission to eat his way through the animal kingdom, might begin to stir and take an interest at this point. Even the Reverend Buckland though did not, as far as I know, make much headway through the extinct animal kingdom. But, on one notorious occasion, others reputedly did.
The 1951 annual dinner of the Explorers Club in the grand ballroom of the Roosevelt Hotel, New York, had more of a buzz than usual. The promoter of the event, Commander Wendell Phillips Dodge, sent out a press release to say that prehistoric meat would be on the menu. Impresario and one-time agent for the film star Mae West, he knew to be shameless in attracting attention. On the evening the dish was labelled Megatherium, while in the following days the Christian Science Monitor got in on the act. This august journal said that the meat was in fact that of a frozen woolly mammoth, fully a quarter of a million years old, and excavated from one of the far Aleutian islands. It was, it was said, from the private stock of yet another hungry and peripatetic Reverend, Bernard Hubbard, who was also known as the Glacier Priest.
As urban legends go, it had impressive longevity, and persisted for decades, only to be eventually undone by the cold and indigestible light of science. A morsel of the meat, requested by an absent Explorer but never eaten (one can see a spectral Rev. Buckland sorrowfully shaking his head), had found its way into the Yale Peabody Museum of Natural History. In 2014, a couple of curious PhD students, intrigued by the story, decided to put it in for DNA testing. Analysis was not straightforward (slow cooking plays hell with DNA) but enough was found to show that the steak was neither sloth nor mammoth, but quite clearly green turtle.
A sad story, somehow rendered a little more melancholy due to the statement released by the Explorers Club after the debunking, in that they were glad – they averred – that it had not really been a mammoth that had been served, as they would not wish to be associated with serving meat from unsustainable sources (though it is uncertain whether they sought the views of the turtle community on this matter).
If mammoth is off the menu, what about the edibility of other fossils? One might think here of edibility more widely, without a strict focus on the whims and fancies of the human palate and stomach, which arguably has had more than its fair share of attention. One might come full circle to think of who, or what, might wish to eat – for example – a Nummulites. This is genuinely intriguing, particularly when one goes to the more spectacular end of that inherently impressive genus.
Nummulites, in general, must have been like its much smaller foraminifer brethren that live today: essentially a modest amount of protozoan protoplasm bound up within an awful lot of calcium carbonate shell, with at least one of the uses of this shell being to deter those creatures that might wish to snack on the protoplasm. That must work up to a point, but it’s not completely predator-proof. There are animals today that do eat foraminifera – some worms, snails, fish, sea urchins and suchlike. Much of such foraminiferovory is a little like deposit feeding, with the tiny skeletons subsequently excreted as a kind of lime sand. It is not always easy to see if the foraminifera have been eaten by design or by accident, but in at least some instances selective ingestion has been inferred. There are other means of getting into a foraminifer. Some fossil specimens have holes bored into them, some of which show signs of healing, showing that the boring was done while the foraminifer was alive, and not post-mortem. Wholesale crunching has also been suggested, though it takes a little work to discriminate that from wave damage.
But let’s now scale up to the more hulking ancient relatives, pass by the modest giants discovered earlier by idle curiosity (and a hand lens), and head straight towards the top: Nummulites millecaput. Pictures of this monstrous protozoan show it resting on the palm of a hand like a discus, and it could reach 16 centimetres across. The enigmatic name (why a thousand heads?) was given to it by someone who possessed something of an enigmatic name himself, Nérée Boubée, in 1832. Nérée is one of the rarer first names in the French language, being derived either – one must take one’s pick – from a mariner of Greek mythology, who fathered the Nereids, or Saint Nérée, eunuch of the Roman Emperor Domitian. Whatever M. Boubée’s parents might have had in their heads when they saddled the poor infant with this identity, it seems not to have done him irreparable harm. He became an enthusiast, collector and teacher of natural history ‘of insatiable curiosity’ and set up a thriving business selling specimens. Somewhere along the way he found, and named, this monster foram.
What, though, could eat a living rock of this proportion? Some have suggested that its very gigantism was a means of outgrowing potential predators. Most Eocene would-be nummulitovores, in this view, would have regarded this beast with much the same sense of baffled impotence that our house cat displays when a hedgehog passes by. Even the Rev. Buckland, if transported by some time machine to nummulite times, may have wondered where his knife and fork might get purchase.
The importance of this question may be moot, given that Nummulites – common enough at times and in places to be a rock-builder effective enough to catch the eye of an Egyptian pharaoh – nevertheless seems to have been a bit player in the ancient Earth’s food chain. But what if it formed a whole food chain in itself? – or even formed the whole of the Earth’s surface?
This is perhaps the purest and most sublime example of wishful thinking in the annals of palaeontology. Its author was Randolph Kirkpatrick, who in his professional career was assistant keeper of lower invertebrates in the British Museum, from 1886 to 1927. He did some methodical science, and made one or two minor but significant discoveries, such as the discovery of a sponge that secreted a coral-like calcareous skeleton. But then he discovered Nummulites, and made not only a virtue out of its presumed inedibility, but made a planet too.
The Nummulosphere, he called it, and described it in a book of the same title, in 430 pages of prose that, if perhaps not exactly deathless, is attractively assembled, while his evidence is laid out with the utmost clarity. The intentions are set out on the title page, with a quote from Homer’s Odyssey. Kirkpatrick would not, thus, ‘swerve from the truth’ in revealing the declared speech of ‘the ancient one of the sea’. The ocean, Kirkpatrick said, is full of organisms which efficiently extract calcium carbonate and silica from the seawater to create a myriad skeletons, which then go on to become geological strata. Look at thin sections of those ancient strata through a microscope and you will see traces of those skeletons.
Many of them, he went on to say, show the traces of the curved shells and chambers of Nummulites; these were not always obvious, but could be detected with the trained eye. That trained eye then put other rocks under the microscope. With just a little more training, the same shapes could be detected in all of the specimens that Kirkpatrick looked at – including in lavas, granites and even meteorites. The inference was clear. All rocks were the more or less silicified remains of a globe-encircling layer built up by countless generations of nummulites which, indigestible to other organisms, built up to form the Earth’s crust. To critics who said that he did not understand the basics of igneous petrology and the crystallization of minerals from magma, Kirkpatrick quite reasonably replied that that may be so – but he did know his nummulites, and that is what mattered.
‘Crazy old Randolph Kirkpatrick’, Stephen Jay Gould called him in one of his essays. And his ideas were so completely and certifiably bonkers, but also so politely and doggedly expressed, that he did not draw out Gould’s sharpness, but rather an amused sympathy and even a hint of admiration. Even in such extreme alternative hypotheses, Gould suggested, there was food for thought.
 You see what I mean about old habits. I still rarely travel without one.
 Arduino set out his ‘orders’ in the second letter.
 He apparently made a play for a morsel of the embalmed heart of an extinct French monarch, but even if successful, that would have been cheating, taxonomically.
 And therefore real turtle, though mock mammoth.
 Culver and Lipps (2003) discuss the chapter and verse.
 A real word, or at least one invented in published print: Hickman and Lipps (1983).
 Syed et al. (2014).
 Beavington-Penney (2004).
 In The Panda’s Thumb.
Beavington-Penney, S. 2004. Analysis of the effects of abrasion on the test of Palaeonummulites venosus: implications for the origins of nummuloclastic sediments. Palaios, 2, 143–155.
Culver, S. J. and Lipps, J. H. 2003. Predation on and by Foraminifera. In Kelley, P. H., Kowaleski, M. and Hansen, T. A. (eds) Predator-Prey relations in the Fossil Record. Kluwer Academic/Plenum Publishers, New York, pp. 7–32.
Ell, T. 2011. Two letters of Signor Giovanni Arduino, concerning his natural observations: first full English translation. Part 1. Earth Sciences History, 30, 267–286.
Ell, T. 2012. Two letters of Signor Giovanni Arduino, concerning his natural observations: first full English translation. Part 2. Earth Sciences History, 31, 168–192.
Hickman, C. S. and Lipps, J. H. 1983. Foraminiferovory: selective ingestion of foraminifera and test alterations produced by the neogastropod Olivella. Journal of Foraminiferal Research, 12, 145–150.
Kirkpatrick, R. 1916. The Nummulosphere. Part III: The Ocean Floor or Benthoplankton. Lamley & Co, London, 319 pp.
Syed, R., Sarkar, S. and Sengupta, S. 2014. Predatory drilling in Tertiary large foraminifera from India. Current Science, 106, 1130–1133.