We have long used optical telescopes to view distant
objects, both living and non-living, making them easier to identify.
More recently, technology has provided us with telescopes
that record information transmitted over vast distances, allowing us to see distant stars, and even to look back in time as we view the expanding
universe.
Similarly, optical microscopes reveal much more than we
can see with the naked eye, and electron microscopes, of both scanning and
transmission types, make very minute structures visible, although preparation
methods require that care must be taken in interpreting what we see. Advances
have also been made in the analysis of living and non-living materials that
enable us to look at traces of organic chemicals from small samples and, using these
approaches, we can analyse the composition of fragments and
relate these to their origins. The commonplace use of an individual’s DNA in a blood stain is just one example.
Even armed with this information, we need expert analysis of
what we see to make sense of it and this is aided by visual imagery, either
generated by computer technologies, or by the hand of an artist. Artists’
impressions are invaluable in re-creating images of things that are no longer
present and which we therefore have no chance of seeing. An example comes in
the very numerous portrayals of religious scenes, where we are frequently shown
images of Jesus, although we have no record of how He looked. The same goes for
God, the disciples and all the other characters, as well as Heaven and Hell.
Other beings in religious paintings are given a physical
presence that is unlikely or symbolic. The Holy Spirit is frequently depicted as
a white dove, while angels have a characteristic appearance that we all
recognise [1], with bird wings on a human body that also has arms (an example by Tiepolo is shown above). Taken as being real, these angels would
not be able to fly, as the wings of birds have developed from the fore limbs of
their reptile ancestors. With arms already present, the wings of angels, and
the muscles to operate them, must be located quite differently on the body (I’m
not suggesting here that angels do not exist, but that their physical form in
paintings and sculpture means that they cannot fly using their wings). It’s an
example of where artists’ impressions are very useful in creating images that subsequently have "reality".
Another world that fascinates us, and of which we have no
direct knowledge, is that of dinosaurs. We’ve never seen a dinosaur (although
there are some modern-day reptiles, like crocodiles, that give us some clues as
to behaviour), so how do we know what they looked like and how they lived? We
have evidence from which to work, unlike the images created of angels,
where there is no fossil evidence. Bones, skin, muscle attachments, and feathers
(where present) allow us to reconstruct dinosaurs and then put them into an
imaginary landscape. We accept these images, and models based on them, because
we believe what experts tell us (quite rightly?). The images are also
informed by speculation. In Benton’s book on dinosaurs, with its catchy
sub-title [2], we read that the discovery of pigment cells meant that “for the
very first time, we knew the colour patterns of a dinosaur, and could use these
insights to speculate about dinosaurian behaviour”. Can we really gain
information about dinosaur behaviour from colour patterns? Perhaps we can.
Later in the book, Benton describes the swimming of Stenopterygius, an
ancient reptile from the Mesozoic:
Stenopterygius swoops after
a belemnite, an extinct relative of modern squid and octopus. The belemnite has
a fleshy body and fins and swims backwards, just as modern cephalopods do. We
know, too, that it has an ink sac, and so, like its modern relatives, likely
squirts ink when alarmed, and zips off by blasting jets of water through its
siphons. By the time the predator has recovered and snapped a few times at the
ink cloud, the belemnite has long disappeared to safety.
The Stenopterygius is not
too fazed, as this is not an infrequent occurrence, and he lines up to chase
another group of belemnites.
Is the language a little flowery here? Admittedly, the book
was written for a general audience, and books about dinosaurs sell well, but
how critically do we, as members of the public, consider what is said by
popularisers?
Further in Benton’s book [2], the dust cover of which shows Tupandactylus
in flight (see above), we read this about head crests in bird-like dinosaurs:
[It is] suggested that such
prominent head crests and beaks sheathed in keratin as are seen in various
dinosaurs and pterosaurs might have been photoluminescent.. ..[and] we can imagine
the elaborate head crests of Tupandactylus flashing different colours at
dusk, males and females perhaps showing different patterns, and putting on a
spectacular in the crepuscular gloom.
Please note the use of the words “suggested”, “imagine” and
“perhaps” in this quote.
Moving images take artists’ impressions one step further and
we are entertained not only by coloured images of landscapes, but also grunts
and hisses from different dinosaurs. There is a good selection in the video
linked in [3], (complete with an accompanying musical soundtrack to add tension
to each scene). How much of this is supported by evidence? I accept that teeth
marks on bones correspond to the dentition of certain dinosaurs, but the rest
of it?
As we know, dinosaurs are not only important in
palaeontology, but also in entertainment and in retailing. Go into any home
with young children and you will find many dinosaur-related toys, pyjamas,
t-shirts etc. and there is a popular fascination with mythological dinosaurs
like the Loch Ness Monster and Sea Serpents. While there are artists’
impressions based on the sightings of the latter two, that is all we have to go
on and the transformations of known dinosaur types that appear on clothing, or
as toys, may be very far from the creatures that existed hundreds of millions
of years ago. Steve Brusatte, reviewing Bentons’ book (see above) remarks that the
images of dinosaurs it contains are real and can be used by media
professionals, but is this so? Is there a point where palaeontologists can get
a bit carried away with their liaison with the world of entertainment?
One important view of science is that it is based on
falsifiable hypotheses and this is an approach that I have tried to follow in my research. However, falsifiable hypotheses are not possible with extinct
animals (and plants) and, however ingenious our attempts, we are bound to make
suppositions about the effects of time: we can design experiments
that last hundreds of millions of years, but it is impossible to get the
results. It means that palaeontology, including the study of dinosaur fossils,
is a highly-informed guessing game, with some practitioners and artists going
further into the world of imagination than others. Thus, the need for caution.
[1] Roger S. Wotton (in press) Birds and Christian Imagery.
In Winged Worlds (eds. Olga Petri and Michael Guida). London, Routledge.
[2] Michael J. Benton (2021) Dinosaurs: New Visions of a
Lost World. London, Thames & Hudson.
[3] https://www.youtube.com/watch?v=ZzXGSFVbVvU&t=847s&ab_channel=BBCEarth
