The Origin and Evolution of Birds?Alan Feduccia (Yale UP, 1996)
In 1980 Alan Feduccia, one of the world?s leading experts on avian evolution
published his The Age of Birds, which was intended to be an overview of
everything that was known about the evolution of birds. It was quite a short
volume, and the impression gained from it was that in fact, apart from a few
restricted areas, very little was known about the phylogeny of modern birds.
The Origin and Evolution of Birds is designedly an updated edition of the
earlier work and it is amazing what has been discovered in the intervening
16 years?the book is now twice the length and although there are some groups
which are still almost entirely unknown in the fossil record, several groups
are now much better understood, and much evidence of other, now extinct
groups, has also emerged.
I found this book to be a fascinating read and a very useful summary of what
is known. Feduccia, as one of the players in academic debate in this area,
of course has his own strongly-held theories, but as they are laid out here
his arguments for, for example, the origin of birds not from dinosaurs, but
from the earlier thecodonts (so that birds and dinosaurs have a common
ancestor, but birds are not dinosaurs), or the origin of flight from small
gliding reptiles, not larger running dinosaurs, seem eminently sensible.
Parts of the book are, however, better written and better organised than
others (one or two chapters seem to have been written by the ?write, paste,
expand on disk? method and are consequently difficult to follow).
An interesting angle on bird evolution that I was completely unaware of is
that it is now thought that the Cretaceous birds which have been discovered
are not modern birds, but belong to an earlier radiation of birds, the
Enanthiornes, which may not have been endothermic, or fully endothermic. (It
is not known whether Archaeopteryx is one of these, or whether it represents
the stem line of birds before the Enanthiornes and the ancestors of modern
birds diverged. Fossil modern birds, except for some Cretaceous
proto-Charadrids, are almost all Tertiary in date, and Feduccia argues that,
apart from the oscine Passerines, which radiated in Miocene, all the
families of birds radiated within a few million years from common
proto-Charadrid stock in the early Tertiary (much like the mammals). Waders
therefore, not ratites or grebes or penguins, are the most ?primitive? birds.
Talking of ratites?in his earlier work Feduccia had opined that the ratites
were polyphyletic; now more evidence has emerged of a ratite ancestor, one
which could fly. Thus it seems that these early ratites radiated all over
the world (the fossils of these birds have been found in North America,
which may be where they originated) and on each continent forgot how to fly
separately (in New Zealand two waves of flying ratites landed, to produce
the Moas and the Kiwis).
At $55US (c $85 ?) this is a rather expensive book, but it is certainly
worth looking out for in libraries, as it is full of fascinating information
such as the topics I?ve outlined and a least a dozen more of equal interest.
It is also a beautifully produced book with hundreds of black and white
illustrations and a magnificent painting on the front cover of the (extinct)
New Zealand Long-legged Owlet-Nightjar, a real cracker.
Dr John Leonard
PO Box 243, Woden,
ACT 2606, AUSTRALIA
"We are not concerned with hopes and fears,
only with the truth as far as our reason permits
us to discover it." Charles Darwin