Page 10 - Complete Birds of Britain and Europe (DK - RSPB)

INTRODUCTION

EVOLUTION

ost scientists believe birds evolved from dinosaurs.Whether the first
M birds climbed trees and began to glide back to the ground, or ran
along the ground and learned to lift off, is still debated.What we do know
is that, over hundreds of millions of years, birds spread over the globe and
adapted to exploit every habitat except deep underwater. Some species ANCIENT BIRDS
are still evolving separate subspecies today. Gamebirds are ancient, but have
changed little over millions of
years. One group, the grouse,
THE MISSING LINK are adapted to survival on a very
In 1861 a series of fossils were found in simple diet in demanding habitats.
limestone beds in Germany that pointed
to the relationship between dinosaurs SPECIALIZED SPECIES
and birds.The fossilized creature, named There are only five species of
Archaeopteryx, is now viewed as the divers worldwide, all found on
“missing link” because it is very northern lakes and sea coasts.
bird-like in appearance, with well- They have a very specialized
aquatic lifestyle.
developed feathers that are just like
those of a modern bird, and yet still
has many reptilian features such as teeth
ARCHAEOPTERYX in its jaws and a long, flexible, bony tail.
BIRD ANCESTRY
This table shows the relationships between modern can see how different groups split from common
birds (all within the sub-class Neornithes),and their ancestors. Songbirds divided off from the rest
age.Using the branches of the evolutionary tree we more than 100 million years ago.
MILLIONS OF YEARS AGO
150 125 100 75 50 25 0
Ratites,Tinamous
Gamebirds
Neornithes Waterfowl
Button quails
Woodpeckers, Barbets, Honeyguides,Toucans
Jacamars, Puffbirds, Hoopoes, Hornbills,Trogons, Rollers, Bee-eaters,Todies, Motmots, Kingfishers
Colies
Cuckoos, Hoatzin
Parrots
Swifts, Hummingbirds
Turacos, Owls, Nightjars
Pigeons
Cranes, Rails
Sandgrouse, Shorebirds, Gulls,Terns,Auks
Birds of Prey (except New World vultures)
Grebes
Tropicbirds
Gannets, Cormorants
Herons, Ibises, Flamingos, Pelicans, Storks, New World Vultures
Frigatebirds, Penguins, Divers, Petrels,Albatrosses
Songbirds
150 125 100 75 50 25 0

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