Introduction to fossil records of avian taxa

pages Rolf A. de By

Many of the more popular bird books state that little is known about prehistoric avian species.   General introductions to prehistoric birds will mention the famous Archaeopteryx, as the oldest known bird genus from the mid-Jurassic, and perhaps will mention some others like the spectacular, fairly recent Moas from New Zealand.

It is true that fossil bird finds are relatively sparse: materials of just over 1000 named species have been found.  The reason for this mainly lies in the fragility of bird tissue, and the problem of its fossil preservation.  Moreover, some finds are eggs or egg shells, footprints and feather imprints, and these materials contribute little to the taxonomic classification of the birds from which they originated.  Many passerine bones have been found, but only a small percentage has been identified to species level.

The problem is aggravated in the historically most abundant group, the passerines: they are usually small, with very delicate skeletal structure, and their skeletons are much alike.  The most important skeletal characteristics in passerine species for classification is the larynx area, but these parts are rarely preserved in fossils.

Yet, much more is known than what the amateur ornithologist is typically aware of.  As a few appetizers, here are some facts that may come as a surprise:

o  forms of Old World Vulture have existed in the New World

o  vice versa, forms of New World Vulture existed in Eurasia

o  fossil parrots and trogons have been found in Europe (for the first, see illustration top right)

o  various forms of flightless auks existed in the northern hemisphere

o  possibly 2000 species of rail have gone extinct with the spread of man on islands throughout the Pacific










psitlep2.jpg (36002 bytes)
Psittacopes lepidus
a species of parrot described from the
early mid-Eocene of Germany in 1998.
  Gerald Mayr, Forschungsinstitut Senckenberg, Germany.