Geology museums of Britain: The Natural History Museum, London (Part 2) – reading the evidence
Jon Trevelyan (UK)
From natural history to Earth history
In Part 1, we considered a deceptively simple question: what should a great natural-history museum do with a great collection?
The Natural History Museum provided no simple answer. In some galleries, magnificent specimens dominate; elsewhere, screens, models, reconstructions and interactive displays play a much larger role. Neither approach is necessarily right or wrong. An extraordinary fossil may need little assistance to attract attention, but interpretation can reveal evidence that an inexperienced visitor would otherwise miss.
Geology makes the problem more complicated. A mineral, fossil, meteorite or piece of volcanic rock can be placed in a case. But geology is also concerned with processes operating across extraordinary scales of space and time: minerals crystallise, volcanoes erupt, continents move, oceans open and close, mountains rise and are eroded, and the history of the Earth extends back approximately 4.5 billion years.
How do you put any of that in a museum? The geological galleries at South Kensington are particularly interesting, because much of them occupies the former Geological Museum. Developed separately from the natural-history collections in Waterhouse’s building, it became one of Britain’s principal public showcases for geology, before its incorporation into the Natural History Museum.
The difference can still be sensed physically. Entering the Earth Galleries from the Waterhouse building brings a dramatic change of atmosphere. Traditional architecture and specimen cases give way to a long escalator, apparently carrying visitors into an enormous metallic globe (Fig. 1).
The globe is not a geological specimen and does not pretend to be one. It is theatre – an architectural device announcing the scale of the subject ahead. In this case, that seems entirely appropriate. The Earth itself cannot be placed in a display case.
The entrance also introduces the central question of this second part. Once we have travelled through the globe, should geology be explained principally through rocks, minerals and fossils, or through the diagrams, models and reconstructions needed to explain the processes that produced them?
It cannot sensibly be one or the other. An earthquake cannot be displayed, although rocks deformed along a fault and instruments recording seismic waves can. Nor can we watch the Atlantic opening or India colliding with Asia. Plate tectonics necessarily requires maps, diagrams, models and/or animation.
Minerals present almost the opposite problem. A beautiful crystal may command attention without explanation, yet the ordered arrangement of atoms responsible for many of its properties cannot be seen with the naked eye.
Fossils lie somewhere between the two. An ammonite or dinosaur skeleton is a physical object, but its greater significance may lie in what it tells us about an extinct organism, an ancient environment or evolutionary change. Even the sediment surrounding a fossil may form part of the evidence. Geological museums, therefore, have to move repeatedly between object and process.
That is the central theme of Part 2. We will begin with the materials from which rocks are constructed, move through evidence of geological processes and vanished environments, and eventually enter the history of life preserved in the fossil record. Along the way are crystals, gemstones, fossil trees and footprints, dinosaur skeletons, mass-mortality deposits and Archaeopteryx, one of the most famous fossils ever discovered. What matters is not simply that these objects are impressive. Each is evidence from which part of the Earth’s history can be reconstructed.
That slightly changes the question raised in Part 1. A geological object without interpretation may be beautiful or impressive, but scientifically almost mute to the non-specialist. Interpretation without the object risks becoming little different from a textbook, website or documentary. The best geological displays combine the two: they show us the evidence and help us to read it.
However, before examining how successfully the Earth Galleries achieve that, we need to understand the rather unusual institution from which they developed. Behind the metallic globe lies the legacy of Britain’s former national Geological Museum.
The Geological Museum and its legacy
The Earth Galleries have an institutional history quite different from that of the Natural History Museum’s original collections. Whereas Richard Owen’s ambition was to make the natural world accessible to the public through a great national collection, the former Geological Museum developed from the practical concerns of the Geological Survey and the industrial needs of nineteenth-century Britain.
Under Henry De la Beche, geology was not simply a means of reconstructing the Earth’s distant past. It was also essential to understanding the distribution of coal, ores, building stones and other economically important materials. The institution that eventually became the Geological Museum reflected those concerns from its beginnings (see box: From Geological Museum to Earth Galleries).
However, the Geological Museum gradually developed a much wider educational purpose. Exhibitions such as The Story of the Earth, Britain Before Man and British Fossils increasingly combined original specimens with reconstructions, diagrams and explanatory displays. By the later twentieth century, interactive techniques were also becoming part of the visitor experience.
This is important to the argument running through this two-part article. The tension between displaying geological objects and explaining geological processes did not originate with the modern Earth Galleries. It was already being addressed by an institution whose principal responsibility was to communicate geology to the public.
The incorporation of the Geological Museum into the Natural History Museum consequently brought together two different traditions. One developed from the great natural-history collections associated with Owen; the other from the geological investigations and practical concerns associated with De la Beche.
Both traditions survive in the modern museum, although the Earth Galleries now approach geology on a much broader scale than the original Museum of Economic Geology.
| From Geological Museum to Earth Galleries |
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| The geological galleries now forming part of the Natural History Museum have a history extending back beyond the building in which they are housed. The Museum of Economic Geology was established in 1841 under Henry De la Beche, the first director of the Geological Survey. Its purpose reflected the practical importance of geology to nineteenth-century Britain: rocks, minerals, ores and building materials were not merely scientific curiosities, but resources of enormous industrial and economic significance. In 1851, the institution moved to Jermyn Street as the Museum of Practical Geology. As the Geological Survey expanded its mapping and investigation of Britain, the museum provided a public face for its work. A new Geological Museum opened in Exhibition Road in 1935. Its galleries presented minerals, rocks, fossils, economic resources and the geological history of Britain. During the later twentieth century, increasingly ambitious exhibitions combined specimens with reconstructions, graphics and eventually interactive technology. The Geological Survey moved its headquarters to Keyworth in 1980. Five years later, the Geological Museum was incorporated into the Natural History Museum. The palaeontological research collections of the Geological Survey went to Keyworth, rather than transferring wholesale to the Natural History Museum, but the Exhibition Road building and substantial geological collections became part of the neighbouring institution. The galleries were subsequently extensively redeveloped. The Earth Galleries, opened in the 1990s, transformed much of the former Geological Museum into exhibitions concerned with the materials, processes and history of the planet. The result is unusual: today’s Natural History Museum incorporates not only the collections and traditions of the institution founded in South Kensington under Richard Owen, but also the legacy of Britain’s former national Geological Museum. |
Something of that older geological identity survives in the building itself. A particularly striking example is a table top made from ornamental marbles excavated from tombs beside the Appian Way. The different stones were valued because polishing revealed colours and patterns that made them desirable decorative materials.
Even the surrounding floor is geological. Its grey Carboniferous limestone from Wirksworth in Derbyshire contains abundant fossil fragments, including sections through crinoid stems. A building material beneath the feet of visitors is simultaneously a record of an ancient marine environment (Fig. 2).
The building itself, therefore, preserves something of the institution’s original purpose. Its decorative stones demonstrate how geological materials become part of everyday life, while the fossils within them remind us that even building materials can preserve evidence of an ancient environment.
The modern Earth Galleries have a much wider purpose: their subject is the planet itself – what it is made from, how it works and how it has changed. But behind the modern displays remains the collection and tradition of the former Geological Museum.
That becomes especially apparent in Earth’s Treasures, where, after the theatrical journey through the giant globe, the emphasis returns firmly to physical objects: the minerals from which rocks are made.
Earth’s Treasures – when the objects are enough
After the theatrical entrance to the Earth Galleries, Earth’s Treasures provides a change of pace. Here, there is no need to simulate an earthquake or animate the movement of tectonic plates. Much of the subject can simply be placed in front of the visitor.
Minerals are particularly well suited to museum display. Crystals possess shape, colour, transparency, lustre and symmetry that can be appreciated before we know anything about their chemistry or origin. But appearance is only the beginning. Most rocks are aggregates of minerals, and a comparatively small number of mineral groups account for much of the Earth’s crust.
The gallery begins by connecting familiar rock-forming minerals with the rocks they produce. This is specimen-led interpretation in its simplest form. The explanation tells us what to notice while the minerals themselves remain at the centre of the display (Fig. 3).
Rocks also record what has happened to them. Metamorphism occurs when existing rocks are altered by increased temperature and pressure, without being completely melted. Minerals may recrystallise, new minerals can grow, and the texture of the rock can be reorganised (Fig. 4).
The rock provides the evidence, but interpretation is necessary, because we cannot see the conditions under which it formed. Geologists infer them from the minerals and structures that survive.
Minerals take us to an even less accessible scale. Their outward form ultimately reflects the ordered arrangement of atoms within them – something no visitor can see with the naked eye. Here, a model genuinely adds something that the specimen cannot provide (Fig. 5).
The models make the invisible visible without replacing the objects they are intended to explain (see box: What is a mineral – and why does crystal structure matter?).
| What is a mineral – and why does crystal structure matter? |
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| A mineral is a naturally occurring solid, with a characteristic chemical composition and an ordered internal structure. That last characteristic is particularly important: the atoms or ions are arranged in a repeating three-dimensional pattern. This internal arrangement is the crystal structure. Crystal structure helps determine many of the properties by which minerals can be recognised. It influences crystal form, cleavage, hardness and optical behaviour. Therefore, two specimens can tell us something about processes occurring on a scale far below anything visible to the naked eye. Chemistry matters too. Some minerals have relatively simple compositions, while others permit considerable substitution of one element for another within their crystal structures. Small quantities of particular elements can also profoundly affect colour. This helps explain why identifying a mineral by colour alone can be unreliable. Quartz, for example, occurs in several colours, while retaining the same fundamental crystal structure and chemical composition, silicon dioxide. Its purple variety is amethyst (Fig. 8, below). Minerals, therefore, connect several different scales of geology. Their crystals may be large enough to hold, yet their visible properties ultimately depend on atomic arrangements measured on an extraordinarily small scale. For the museum visitor, models of crystal structures can consequently perform a useful role. They do not substitute for the mineral specimen; they explain something about it that the specimen itself cannot directly show. |
One of the most elegant demonstrations of the connection between internal structure and visible behaviour is Iceland spar, an exceptionally transparent variety of calcite. Light passing through it is split into two rays, so an object viewed through a suitable crystal can appear doubled (Fig. 6).
Minerals have, of course, attracted people for reasons extending beyond science. Colour, transparency and brilliance have made some varieties desirable as gemstones. The gallery demonstrates the transformation particularly well, by placing natural minerals beside cut and polished examples (Fig. 7).
Yet some specimens need no lapidary work – or elaborate museum interpretation – to command attention. A large mass of amethyst is an obvious example (Fig. 8).
For the argument running through these articles, the amethyst is useful precisely because it presents the opposite problem from an earthquake. Nobody needs to explain why it is worth looking at. Interpretation becomes important after the specimen has attracted attention.
The Blue John vase takes us one step further, from geological material to human use (Fig. 9).
This provides a pleasing connection with the Museum of Economic Geology. Minerals and rocks have always been more than scientific specimens: they provide metals, building materials, gemstones and decorative stone.
Taken together, Earth’s Treasures strikes the balance particularly well. The specimens provide the attraction and the evidence; labels and models explain properties that cannot necessarily be seen.
But geology becomes still more interesting when rocks preserve evidence not simply of what they are, but of what happened. A tree is buried and turned to stone. Waves leave ripples across sand. An animal walks over wet sediment. Lava cools and contracts. The processes disappear. Their traces remain. That is the territory of Lasting Impressions.
Lasting Impressions – rocks as records of processes
However, minerals tell us what rocks are made from. Much of geology depends on a different question: what happened?
A rock can preserve evidence of an environment that disappeared millions of years ago. Sedimentary structures may record moving water, fossils the organisms that lived there, and igneous textures the cooling of molten rock. The object in the museum case can, therefore, be the surviving record of an event or process. Lasting Impressions explores this particularly well.
One of its most immediately attractive specimens is a petrified tree from Arizona. About 215 million years ago, during the Triassic, it was part of a living tree. After burial, mineral-rich water permeated the wood and minerals progressively replaced the original material, while preserving its structure (Fig. 10).
The polished surface makes the transformation particularly easy to understand. Growth rings remain recognisable, allowing us to move mentally from the stone in the gallery to a tree growing in a Triassic landscape.
Elsewhere, the evidence requires closer examination. A sandstone slab from Cheshire preserves ripple marks formed in shallow water about 240 million years ago. Crossing the same surface are footprints attributed to Chirotherium, a trace-fossil name applied to distinctive tracks made by Triassic archosaurs (Fig. 11).
This single surface, therefore, preserves two kinds of evidence. The ripples record a physical process; the footprints record behaviour. The animal itself need not be preserved for us to know that it was there (see box: Reading the evidence – fossils, traces and events).
| Reading the evidence – fossils, traces and events |
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| Fossils are often imagined as the preserved remains of organisms: a shell, bone, tooth, leaf or piece of wood. These are body fossils, preserving some part of the organism itself. But the geological record contains other kinds of evidence. Trace fossils preserve the activity of organisms, rather than their bodies. Footprints show that an animal crossed a surface; burrows record animals moving or living within sediment; feeding traces can preserve interactions with food; and coprolites are fossilised faeces. A trace may, therefore, reveal behaviour that the skeleton of the animal cannot. Rocks can also preserve evidence of the environment in which organisms lived. Ripple marks may indicate moving water, while sedimentary structures can record currents, waves, drying, erosion and deposition. The way fossils occur together can be equally important. A concentration of bones or shells may represent animals that lived together, material transported from elsewhere, or organisms brought together by a flood, drought or other event. Determining what happened between an organism’s death and its eventual preservation is part of taphonomy. This means that the surrounding rock should not simply be regarded as material to be removed to expose a fossil. Its sediment, structures, and the position and condition of the fossils within it may all contain evidence. Therefore, a geological specimen can preserve far more than an object. Properly read, it may record an organism, its behaviour, its environment and sometimes even the event that led to its preservation. |
Not every lasting impression involves life. A basalt column from Fingal’s Cave on Staffa records an entirely physical process. As basaltic lava cooled and contracted, fractures propagated through it to produce the regular polygonal columns for which the island is famous (Fig. 12).
Here, the division of labour between object and explanation is particularly clear. The column is the evidence; interpretation reconstructs the process responsible for its form.
An orbicular rock from Alderney presents a more enigmatic example. Its conspicuous rounded structures formed as minerals crystallised in roughly concentric layers, but the processes responsible for producing such rocks are still not completely understood (Fig. 13).
That uncertainty is worth preserving. Museums understandably explain objects, but science does not always provide a complete explanation. Sometimes, an object remains interesting, precisely because questions about it are unresolved.
The final example returns us to fossils. An ammonite from Lyme Regis has been cut and polished, revealing the internal construction of a shell that externally would appear as a familiar coil (Fig. 14).
The chambers can be seen directly. From their arrangement, together with evidence from other cephalopods, palaeontologists can reconstruct something of the growth and biology of an animal that disappeared tens of millions of years ago.
These specimens make the essential point without requiring a lengthy summary. The petrified tree records mineralisation; the sandstone preserves water and an animal’s movement; the basalt records cooling; the orbicular rock an incompletely understood history of crystallisation; and the ammonite the construction of an extinct animal’s shell.
A geological collection is, therefore, not merely an assortment of named rocks and fossils. Its objects are records of change. That becomes still more important when we turn to palaeontology. Some fossils are spectacular enough to become museum showpieces; others acquire their importance only when their anatomy, context or relationship with other specimens is investigated.
The Natural History Museum contains examples of both. Two dinosaur skeletons provide an unusually good comparison: one is among the most complete Stegosaurus specimens ever discovered; the other is much smaller, but helped museum scientists recognise an entirely new genus and species. Together, they take us from spectacle to science.
From spectacle to science
Some fossils possess an advantage that most geological specimens do not: they are spectacular before anyone explains them.
A large dinosaur skeleton is the obvious example. Even a visitor with little knowledge of palaeontology can recognise an animal, appreciate its proportions, and begin to imagine the living creature represented by the bones. The Natural History Museum has few better examples than ‘Sophie’, its remarkably complete skeleton of Stegosaurus stenops.
Discovered in Wyoming in 2003, Sophie dates from the Late Jurassic, about 150 million years ago. Despite the name, the sex of the animal is unknown: the skeleton was named after the daughter of the private donor, whose support enabled the museum to acquire it.
Its completeness is particularly important. Dinosaur skeletons are frequently reconstructed from incomplete remains, with missing elements represented by casts or inferred from related specimens. Sophie lacks comparatively little (Fig. 15).
Sophie illustrates particularly well one of the arguments made in Part 1. Some specimens need little assistance to persuade visitors to look. The plates along the back, small skull, powerful limbs and formidable tail make the skeleton immediately compelling.
But ‘let the specimen speak for itself’ can only take us so far. Interpretation allows us to move from recognising a Stegosaurus, to asking how it walked and fed, how rapidly it grew and what functions its plates and tail performed. Its completeness also has scientific value, because anatomical relationships can be studied within a single individual, rather than reconstructed from several incomplete skeletons. Here, spectacle and science begin with the same object.
A much smaller dinosaur demonstrates the point from the opposite direction. Enigmacursor mollyborthwickae cannot compete with Sophie for visual impact. It was a relatively, small plant-eating dinosaur from the Late Jurassic Morrison Formation of the western United States. Its importance lies instead in what scientists discovered from the specimen (Fig. 16).
The contrast is useful. Sophie is immediately spectacular; Enigmacursor requires more explanation before its importance becomes apparent. Yet, both demonstrate why a natural-history collection is more than an assortment of objects worth looking at. The specimens are evidence.
Much palaeontological work begins after a fossil has been collected. Bones are prepared, described and measured; anatomical features are compared with other specimens; geological age and provenance are established; and classifications are tested as new evidence appears. A scientifically important fossil, therefore, need not be visually extraordinary.
Enigmacursor bridges the worlds of exhibition and research particularly well. It is a public display, but it is also evidence from which Natural History Museum scientists recognised an animal previously unknown to science. Sophie provides the converse example: the completeness that makes it such an impressive exhibit, also increases its scientific value.
Together, the two dinosaurs provide a natural transition from the geological processes considered so far, to something else that fossils record: change in organisms through time.
A single fossil can tell us about an individual animal. Placed alongside fossils of different ages and different organisms, it can contribute to the reconstruction of something vastly larger – the history of life.
No museum could tell that history comprehensively. Life has existed for billions of years; groups have appeared, diversified and disappeared, ecosystems have been transformed, and extinction has repeatedly reshaped the biosphere.
The Natural History Museum nevertheless attempts an extraordinary condensation of that story in a gallery with a surprisingly understated name: From the Beginning. It contains some of the museum’s most interesting palaeontological material. Yet, it is remarkably easy to overlook.
From the Beginning – attempting the history of life
If Sophie and Enigmacursor demonstrate what can be learned from individual fossils, From the Beginning attempts something far more ambitious. Its subject is the changing history of life itself.
That presents a different problem from displaying minerals. A crystal can be appreciated as an individual object; the significance of a fossil often depends on its relationship with organisms that came before and after it. A gallery about evolution, therefore, has to do more than assemble impressive specimens. It has to create connections through time.
Curiously, From the Beginning does not advertise its importance particularly loudly. On my visit, I found it relatively easy to overlook. Its subdued lighting creates a very different atmosphere from Hintze Hall or the theatrical entrance to the Earth Galleries, while its title gives little indication of the extraordinary story within.
That is unfortunate, because the gallery addresses one of the largest questions a natural-history museum can attempt: how did the diversity of life around us arise from a much more distant and very different past?
The story begins long before dinosaurs. By the Cambrian Period, more than 500 million years ago, marine ecosystems contained animals representing a remarkable variety of body plans. The Cambrian diversification is sometimes described as an ‘explosion’, although the term should not imply that complex animal life appeared instantaneously (Fig. 17).
This is one of the strengths of arranging a gallery around the history of life, rather than spectacular individual specimens. Importance is not determined by size.
It also introduces a difficulty. Fossils do not form a neat sequence in which one organism conveniently turns into another. Evolution is a branching process: lineages divide, diversify and disappear, while the fossil record preserves only a small and uneven sample of the organisms that once lived.
Trilobites illustrate another strength of the fossil record. Their mineralised exoskeletons are familiar fossils, but specimens can preserve much more than the appearance of the animal. Cast-off exoskeletons record moulting, tracks preserve movement and, under exceptional circumstances, normally soft structures can still survive (Fig. 18).
Evolutionary history also depends on comparison between different organisms. One classic example is Eusthenopteron foordi, a Late Devonian lobe-finned fish from Canada. Its paired fins contained substantial internal bones, an arrangement important in understanding the origin of the tetrapod limb (Fig. 19).
It would be tempting to describe Eusthenopteron as a creature halfway between a fish and a land vertebrate. That would be memorable, but misleading. Its importance lies instead in helping us understand how structures already present in fishes could be modified during the evolution of tetrapod limbs (see box: Evolution is not a ladder).
| Evolution is not a ladder |
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| Evolution is often illustrated as a sequence: one organism appears to change progressively into another, until a familiar modern animal is reached. The reality is much more like a branching tree. Populations diverge and separate lineages develop. Some branches diversify enormously; others remain relatively restricted; most eventually become extinct. Modern organisms occupy the surviving tips of some branches, rather than the top of an evolutionary ladder. This is important when interpreting so-called ‘transitional fossils’. A fossil such as Eusthenopteron should not be imagined simply as a fish caught in the process of becoming an amphibian (Fig. 19, above). It belonged to a lineage of lobe-finned fishes sharing anatomical features with the broader group from which tetrapods evolved. Its fin skeleton helps palaeontologists understand how structures already present in fishes could be modified during the evolution of limbs. The same principle applies to Archaeopteryx, encountered later in the gallery (Fig. Fig. 22, below). It combines feathers and wings with anatomical characteristics inherited from small theropod dinosaurs. Its importance does not depend on being exactly halfway between a dinosaur and a modern bird. Transitional fossils are valuable, because they preserve combinations of characteristics that help reconstruct evolutionary relationships and the sequence in which anatomical changes occurred. The tree continues to branch. There is no predetermined destination and no inevitable progression towards human beings or any other modern organism. |
Evolutionary change also transformed the planet itself. By the Carboniferous, extensive swamp forests contained giant lycopsids, horsetail relatives and seed ferns. In waterlogged environments, dead vegetation accumulated faster than it could completely decay; burial and geological alteration eventually converted some of that material into coal (Fig. 20).
Here, geology and biology become part of the same story. Organisms respond to their environments, but they can also transform them and leave geological consequences extending far beyond their own lifetimes.
Vertebrates on land underwent another important change. Early tetrapods retained a reproductive connection with water, whereas the amniotic egg allowed one major lineage to reproduce away from standing water and exploit terrestrial environments more extensively (Fig. 21).
Hundreds of millions of years of biological change cannot be compressed into a gallery without considerable selection and simplification. But this is precisely where interpretation becomes essential. Eusthenopteron does not explain the origin of tetrapods merely by being displayed; a Carboniferous plant does not by itself explain coal formation; and a reptile skeleton cannot demonstrate the significance of the amniotic egg.
The specimens provide the evidence. The museum has to explain the relationships between them. And evolutionary history is only one kind of story that fossils preserve. Sometimes, they capture something much more immediate: a school of fish dying together, mammals swept into an accumulation by a flood, or bones left within the sediment in which they were buried.
Instead of changes extending across millions of years, these fossils can preserve moments in vanished worlds.
Great transitions in the history of life
The fossils considered so far demonstrate that evolution is not a procession from simple organisms towards more ‘advanced’ ones. It is a branching history in which existing structures are modified, lineages diversify, and most eventually disappear.
We have already seen this in Eusthenopteron, the Carboniferous forests and the amniotic egg. There is no need to repeat those stories here. Instead, one of the most celebrated fossils in the Natural History Museum allows us to examine another major transition: the origin of birds.
Archaeopteryx lithographica comes from the Late Jurassic limestones of Solnhofen in Germany, approximately 147 million years old. Its fame rests on an extraordinary combination of characteristics. The animal possessed well-developed feathers and wings, but its skeleton also retained teeth, clawed fingers and a long bony tail (Fig. 22).
When the first specimens became known in the nineteenth century, this combination of apparently reptilian and avian characteristics was remarkable. Today, numerous discoveries of feathered dinosaurs have placed Archaeopteryx within a much richer evolutionary context. Feathers are no longer regarded as a uniquely avian feature that appeared suddenly with the first birds. The fossil has not changed. Its scientific context has.
That is one reason historic museum collections remain scientifically important. A specimen collected generations ago can acquire new significance, when later discoveries change our understanding of the organisms around it. Rather than being a fixed illustration of an established fact, it remains evidence capable of being reinterpreted.
Comparison between specimens is equally important. Elsewhere in the gallery, the skulls of a giant crocodilian and a large predatory dinosaur provide a particularly dramatic example (Fig. 23).
Both animals were formidable predators and both possessed powerful jaws and large teeth. Yet similarity of function does not necessarily imply a particularly close evolutionary relationship. Crocodilians and dinosaurs occupy different branches of the archosaur tree, and their respective histories produced very different animals, capable of solving some of the same problems in superficially similar ways.
This is where a large natural-history collection becomes especially valuable. An isolated specimen can reveal a great deal, but comparison allows different questions to be asked. Which characteristics are shared? Which differ? Do similarities reflect common ancestry, or did comparable features evolve independently? How did particular structures change through time?
Archaeopteryx provides an especially powerful demonstration. Feathers, wings, teeth, fingers and tail are not separate curiosities. Their combination within one animal helps palaeontologists reconstruct the evolutionary history linking birds with theropod dinosaurs.
The value of From the Beginning, therefore, lies not simply in the quality of its individual fossils, impressive though many are. Its greater achievement is the opportunity to place those objects within relationships extending across deep time.
But fossils do not record only evolutionary change unfolding over millions of years. Sometimes, they preserve something much more immediate: animals dying together as an environment deteriorated, bones accumulated by a flood, or remains transported, scavenged and buried within sediment.
That is, evolution gives us the long history. Some fossil deposits give us something closer to a snapshot. To understand those, the question changes from “how did life change?” to “what happened here?”.
Fossils as moments in vanished worlds
The evolutionary history explored in From the Beginning operates across immense spans of time. However, some fossils preserve evidence of something much more immediate: an event that may have lasted only days, hours or even minutes.
This is where palaeontology becomes rather like forensic investigation. Finding the fossils is only the beginning. Did the animals die where they lived? Were their remains transported? Were carcasses scavenged or bones sorted by flowing water? How long did they remain exposed before burial?
Questions such as these form part of taphonomy: the study of what happens to organisms between death and their eventual discovery as fossils. One particularly evocative example comes from Dura Den in Fife, where numerous Devonian fish occur together (Fig. 24).
An isolated Holoptychius could tell us about the anatomy of the fish. A concentration of individuals raises a different question: why did so many die together? The museum interprets the assemblage as a school caught as a freshwater lake dried during hot weather. The slab consequently becomes more than a collection of fish fossils. It is evidence interpreted as the aftermath of environmental deterioration about 370 million years ago.
The distinction between observation and interpretation matters. We can observe that numerous fish occur together; explaining why requires evidence from their condition, distribution, surrounding sediment and geological setting. The reconstruction is an interpretation derived from that evidence, rather than something directly preserved in the rock.
A rather different assemblage comes from the famous Late Miocene locality of Pikermi in Greece (Fig. 25). Again, the association is important. Identifying the individual animals tells us something about the mammals inhabiting the region. Understanding why their remains occur together can tell us something about the processes operating after their deaths.
We should not assume that animals preserved together necessarily lived and died together. Rivers can transport carcasses, currents can sort bones, scavengers can scatter skeletons and older remains can be reworked into younger deposits. Therefore, what palaeontologists eventually discover may record a complicated history between death and burial. That becomes particularly apparent when bones remain within the sediment in which they accumulated (Fig. 26).
Such a specimen may initially seem less impressive than a complete mounted skeleton. Individual bones overlap, some may be broken, and there is no recognisable animal standing before us. Scientifically, however, that apparent disorder can be part of the evidence. The orientation of bones may reveal water movement; weathering can indicate exposure before burial; tooth marks may record scavenging; and the surrounding sediment can help reconstruct the environment in which the remains accumulated.
Removing every bone from the rock and arranging the best examples neatly in a case could, therefore, destroy part of the story.
This has an important implication for fossil collecting. A fossil without reliable information about where it came from loses some of its scientific value. Locality, geological horizon and association with other fossils may matter almost as much as the specimen itself.
For the amateur collector, the lesson is particularly useful. Identification – what have I found? – is only the first question. Others should follow. What rock did it come from? How old is it? What occurs alongside it? What environment does the sediment represent? Why might the fossil have been preserved there?
The Dura Den and Pikermi assemblages demonstrate the difference. Neither interpretation results simply from identifying the animals. It comes from treating the fossils and their geological context together.
There is also something striking about the contrast in timescale. The Holoptychius assemblage is approximately 370 million years old, yet the event it is interpreted as recording may have been brief. A lake shrank, conditions deteriorated and fish died. Their remains were buried and eventually became part of the geological record.
Deep time can make Earth history seem remote. Fossil assemblages can do the opposite. A drought, flood or death is understandable on a human timescale, even when its evidence survives from a world hundreds of millions of years old. Therefore, these specimens reinforce one of the strongest lessons of the Earth Galleries. The surrounding rock is not merely packaging for the fossil. It is part of the evidence.
But fossils have another history as well. Once discovered, they become objects of human interpretation, and those interpretations change as new evidence appears. Few examples demonstrate that more vividly than dinosaurs. The nineteenth-century Crystal Palace Iguanodon and modern dinosaur research represent very different stages in our attempt to reconstruct animals that nobody has ever seen alive.
Dinosaurs, mammals and changing interpretations
Fossils do not simply record the history of life. Once discovered, they acquire another history: the history of our attempts to understand them.
That history matters because palaeontological reconstruction is necessarily based on incomplete evidence. Scientists compare specimens, identify shared and differing anatomical features, and use those observations to reconstruct relationships and vanished organisms. As new fossils are discovered, interpretations can change.
Mammals provide a useful example. The early Palaeogene mammal Phenacodus had a relatively generalised body form, including feet very different from the highly specialised limbs of many later hoofed mammals (Fig. 27). Modern horses stand on a single functional digit, while other hoofed mammals have evolved different patterns of reduction and specialisation. Phenacodus, by contrast, retained five toes, although the central digit had become increasingly important.
It is tempting to arrange such fossils in a straight-line, culminating in a modern animal. But, as we have already seen, evolution does not work that way. Phenacodus is more useful as evidence of the diversity of early mammals and as a point of comparison with more specialised forms.
This is one of the great advantages of a large museum collection. A single fossil can tell us a great deal, but comparison allows different questions to be asked. Which characteristics are shared? Which vary? How do anatomical structures change through time? Do similarities reflect common ancestry or adaptation to similar ways of life?
Dinosaurs provide an even more striking demonstration, because their appearance in museums has changed dramatically since they were first recognised. Richard Owen named Dinosauria in 1842, when the known remains were fragmentary by modern standards. Any attempt to reconstruct the complete animals, therefore, required considerable inference. Among the most famous results were the prehistoric-animal models created by Benjamin Waterhouse Hawkins, with Owen’s scientific advice, for the Crystal Palace Park in the 1850s (see also Geology museums of Britain: The Crystal Palace dinosaurs – the birth of scientific reconstruction).
Their Iguanodon was a massive, heavily built quadruped. A conical bone now recognised as a thumb spike was placed on its nose. To modern eyes, the reconstruction is dramatically wrong. That is precisely what makes it so interesting.
The Crystal Palace Iguanodon was not an absurd invention. It was a serious attempt to reconstruct an extinct animal from the evidence then available. As more complete skeletons were discovered, the evidence changed and so did the reconstruction. The supposed nasal horn became a thumb spike, while ideas about posture, locomotion and the overall appearance of the animal were repeatedly revised.
A modern bronze reproduction of the Crystal Palace model in the museum’s Nature and Us gallery consequently records an important stage in the history of palaeontology (Fig. 28).
The ammonite beneath it provides an interesting counterpart. Its first history belongs to the living animal and the sediment in which its shell was preserved. Its second belongs to people: fossils can become scientific specimens, collectors’ objects, decoration and cultural symbols.
The Iguanodon model makes an especially important point. Reconstructions are hypotheses. Modern palaeontologists have vastly more comparative material and far more sophisticated methods than Owen and Hawkins possessed, but the underlying problem remains. Nobody has seen a living non-avian dinosaur. Its appearance and behaviour have to be reconstructed from evidence, and new evidence can alter the result.
The specimens encountered throughout these galleries demonstrate this repeatedly. Sophie’s completeness allows Stegosaurus anatomy to be investigated unusually well. Enigmacursor shows that a fossil can still lead researchers to recognise a dinosaur previously unknown to science. Archaeopteryx has acquired a much richer evolutionary context through subsequent discoveries of feathered dinosaurs. Phenacodus can be compared with other mammals as the history of their diversification is reconstructed.
The fossils themselves have not changed. What changes is our ability to read the evidence.
That may be one of the most important lessons offered by the Natural History Museum’s geological and palaeontological collections. A museum is not simply somewhere established scientific facts are illustrated by attractive objects. The objects are part of the evidence from which those conclusions were reached – and against which new interpretations must be tested.
This also brings us back to the question running through both parts of this article. Geology cannot be displayed through specimens alone. We can place a crystal, fossil or piece of basalt in a case, but not evolution, continental drift or hundreds of millions of years of environmental change. Models, reconstructions and explanatory text are, therefore, indispensable.
The most successful interpretation, however, continually returns us to the evidence. A crystal structure helps us understand the mineral. An explanation of columnar jointing helps us read the basalt. A reconstruction of a drought helps explain a concentration of fossil fish. An evolutionary diagram gives meaning to anatomical characteristics preserved in a fossil.
Interpretation works best, not when it competes with the objects, but when it makes us look at them more closely. That leaves one final question: judged on that basis, how successfully does the Natural History Museum tell the story of the Earth?
Telling the story of the Earth
At the beginning of Part 1, I asked what a great natural-history museum should do with a great collection. After working through these galleries, I think the answer is more complicated than I initially suggested.
My own preference remains firmly with specimens. I go to a natural-history museum principally to see things that I cannot readily see elsewhere: fossils, minerals, skeletons, meteorites and the other physical evidence from which our understanding of the natural world has been constructed. No screen or reconstruction can entirely replace standing in front of an original object.
But the Earth Galleries demonstrate why that preference cannot become a simple rule that more specimens and less interpretation must always produce a better museum.
Geology makes that impossible. A mineral can be displayed; an earthquake cannot. A fossil can be displayed; evolution cannot. We can place a piece of basalt in a case, but not the cooling and contraction that produced its columnar jointing. Continental drift, mountain building, erosion, extinction, and the opening and closing of oceans operate across distances and timescales that no museum visitor can observe directly. Therefore, interpretation is indispensable.
That helps explain the theatrical globe through which visitors enter the Earth Galleries. It is not geological evidence, but it performs a useful function: it changes the scale of our thinking. The subject is not simply a crystal, ammonite or dinosaur bone. It is the Earth.
The strongest displays then bring us back from that enormous scale to the evidence. Earth’s Treasures does this particularly well. Minerals are inherently attractive objects, but crystal models reveal structures too small to see and Iceland spar demonstrates how internal structure affects optical behaviour. The Blue John vase adds another dimension, connecting geology with human use and with the economic-geology origins of the institution.
In Lasting Impressions, the specimens have to be read. The petrified tree preserves biological structure transformed by mineralisation. Ripple marks record moving water and the footprints crossing them the passage of an animal. The basalt column records cooling lava. The sectioned ammonite exposes the construction of a shell that would otherwise remain hidden. Here, interpretation does not compete with the specimens. It makes us look at them more closely.
The same principle applies to palaeontology. A trilobite moult, the fin skeleton of Eusthenopteron, a mass of fossil fish or the feathered skeleton of Archaeopteryx becomes more informative when its significance is explained. No single fossil can show evolution or reconstruct an extinct ecosystem. Collections allow evidence to be compared across time.
This also clarifies some of the reservations I expressed in Part 1. The problem is not interpretation itself, and certainly not technology simply because it is technology. Models, films, graphics and interactive displays can be essential when the subject cannot be represented by an object. They may also engage audiences – particularly children – in ways that traditional displays do not. Nor is a cabinet crowded with poorly explained specimens automatically superior. A hundred objects without sufficient context can amount to little more than a catalogue in three dimensions.
The more useful distinction is between interpretation that directs attention towards the evidence and interpretation that becomes the attraction itself. At its best, the Natural History Museum is exceptionally good at the former. Why does calcite produce a double image? How were footprints preserved on ripple-marked sandstone? Why did those fish die together? What does the skeleton within a lobe-finned fish tell us? Why does Archaeopteryx combine feathers with teeth and a long bony tail?
Each question begins with an object and opens a much larger story.
The collections are equally important when they are not on display. Sophie is a magnificent exhibit, but her unusually complete skeleton is also scientific evidence. Enigmacursor mollyborthwickae provides an even clearer demonstration: a specimen now displayed to the public contributed to the recognition of a new genus and species in 2025. A museum collection is, therefore, not simply an archive of discoveries already made. It remains material from which new discoveries can emerge.
The Crystal Palace Iguanodon adds another lesson. Its nineteenth-century appearance now seems extraordinary, but Waterhouse Hawkins and Richard Owen were attempting to reconstruct an extinct animal from the evidence available to them. Later discoveries changed that reconstruction.
Reconstructions remain hypotheses. New evidence can change them. A natural-history museum consequently does something more interesting than present established facts. Properly used, its specimens demonstrate how we know. A fossil is evidence; our explanation of it is an interpretation that remains open to revision.
Across these two parts of the article, the Natural History Museum has, therefore, presented something of a paradox. It possesses collections of extraordinary scale, although only a tiny proportion can ever be exhibited. Some of its most successful displays depend largely on the power of the objects themselves; others require substantial interpretation, because the processes being explained cannot possibly be placed in a case.
There are things I would change. I would give Britain’s own fossil record a much more substantial presence. I would make From the Beginning easier to find and, where practicable, easier to see in terms of lighting. I would sometimes reduce the amount visitors are expected to read from walls and screens. And where the museum possesses specimens capable of carrying much of the story themselves, I would have confidence in them.
But those criticisms should not obscure what an extraordinary institution this remains.
Its collections encompass evidence from the structure of minerals to the evolution of life, and from events lasting moments, to processes operating over billions of years. Behind the galleries are scientific collections that continue to support research; in front of them are millions of visitors encountering objects that most would otherwise never see.
Richard Owen wanted the public to encounter and understand the natural world. Henry De la Beche sought to collect and investigate geology and demonstrate its usefulness. The institutions they helped create have changed almost beyond recognition, but something of both ambitions survives at South Kensington.
So, after the two parts of this article, I would modify the question with which we began. The choice is not really between specimens and interpretation, or between Victorian cabinets and interactive galleries.
The more important question is: what is the interpretation for? If it overwhelms the object, the visitor may reasonably wonder whether the same information could have been obtained from a book, website or television programme.
But if it sends us back to the object – to notice the structure of a crystal, a ripple beneath a footprint, feathers surrounding a dinosaur-like skeleton or the apparently chaotic accumulation of bones left by an ancient event – it has accomplished something much more valuable.
It has taught us how to look at evidence.
That, ultimately, may be the distinctive thing a great natural-history museum can do: preserve the evidence, allow scientists to investigate it, explain what we currently think it means, and place at least some of it in front of the rest of us.
The Natural History Museum does not always strike that balance in the way I would choose. But when it does, there are few better places in which to encounter the history of the Earth.
| About the museum |
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| Address: Cromwell Rd, South Kensington, London SW7 5BD Website: https://www.nhm.ac.uk/ |
| OTHER PARTS IN THIS ARTICLE |
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| Geology museums of Britain: The Natural History Museum, London (Part 1) – what should a great museum show? |
| Geology museums of Britain: The Natural History Museum, London (Part 2) – reading the evidence |