There are seven specimens of Archaeopteryx; and a
feather. And from what seems not very much a great deal of academic
effort is attempting to discover the origins of bird flight. In
jaundiced moments one speculates that when another specimen is found
another university will be founded to study it. And a second one to
refute the findings of the first.
There are certainly enough academic disciplines involved to start a
couple of faculties - geology, palaeontology, biology, anatomy,
physiology, ecology, aerodynamic engineering, ornithology - the
variety of skills focused on these seven specimens is never ending.
Archaeopteryx probably weighed about 250 grams and had a wing span of
58 cm. To take off it needed to generate more than 9.8 newtons per
kilogram of its body weight to overcome the force of gravity. We may
have the feathers of Archaeopteryx but we do not have a reliable
measurement of its musculature, - their size, strength or efficiency.
This of course can, and does, lead to hugely involved disputes as to
- whether the beast could take off,
- if it took off from the ground,
- or from a tree it had climbed up,
- did it fly or did it glide
- or were its feathers there just to keep it warm.
But before we get to what Archaeopteryx was for we have to go through
much fascinating detail of
- how the fossils were found;
- detailed anatomy of wings and of wing flapping;
- discussion of X-rays taken of birds as they fly;
- which reptiles were the birds ancestor (and was
that the same ancestor as that of Archaeopteryx);
- discussion of homologous and analogous parts in
the wrist of Deinonychus and Archaeopteryx;
- which of the original five fingers are retained
in Archaeopteryx's three digits,
- the significance of a reversed hallux, especially
in relation to tree climbing and perching;
- the evolution and function of feathers;
- the development of "wings" for temperature
regulation and/or flight;
- comparisons between bats, pterosaurs and birds
and their relationship to Archaeopteryx;
- and many other topics which impinge on the study
of these fabulous fossils.
As you can see from my list of the subjects
discussed - which is by no means complete - anyone who understands all
there is to know about Archaeopteryx can claim to know a good fraction
of human knowledge. The author makes a good stab at making the varied
strands of expertise digestible to the intelligent layman, and in the
main succeeds very well.
Having read the book I now know a great deal more than I did before,
and have a better understanding of the areas of controversy. In the
end one will never know unequivocally whether Archaeopteryx could take
off from the ground and fly in and out of the bushes, flapping its
wings as it chased butterflies and dragonflies, but I hope it did. And
if another specimen is found I would love to have a good long look at
it - although I will be at the end of a very long queue!
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