Fossil (DK Eyewitness Books)

73 Pages·2004·23.27 MB·English

by  Paul Taylor

Eyewitness
FOSSIL
Eocene fish
Pleistocene human skull
Eocene gastropods
Cretaceous dinosaur
finger bones
Triassic swimming reptile
Cretaceous
cone (sectioned
and polished)
Ordovician nautiloid
Jurassic brittlestar
(polished and shaped)
Jurassic sea urchin
Cretaceous cone
Pleistocene coral
Carboniferous Eocene
horsetail shark
tooth
Modern
Carboniferous
horsetail
fern
Eyewitness
FOSSIL
Jurassic ammonite Triassic
(carved as a snakestone) dinosaur
footprint
Written by
DR. PAUL D. TAYLOR
Carboniferous
lycopod
Eocene fish
Silurian
brachiopod
Pleistocene
hand ax
Permian tree fern
(sectioned and polished)
Modern
coral
Pliocene scallop
Pleistocene
coral
DK Publishing, Inc.
Cretaceous
opalized
gastropod
Cretaceous
Cretaceous Carboniferous spider opalized bivalve
dinosaur tooth
Jurassic Pleistocene sea urchin
ammonite LONDON, NEW YORK, MELBOURNE,
MUNICH, and DELHI Cretaceous worm tube
Project editor Louise Pritchard
Art editor Alison Anholt-White
Cretaceous bryozoan Senior editor Sophie Mitchell
Senior art editor Julia Harris
Editorial director Sue Unstead
Art director Anne-Marie Bulat
Special photography Colin Keates
(Natural History Museum, London)
Miocene corals
Revised Edition
Managing editors Linda Esposito, Andrew Macintyre
Jurassic coral (sectioned Managing art editor Jane Thomas
and polished) Category publisher Linda Martin
Art director Simon Webb
Editor and reference compiler Clare Hibbert
Art editor Joanna Pocock
Consultant Kim Bryan
Pleistocene
19th-century Production Jenny Jacoby
gastropods
microscope Picture research Celia Dearing
for examining DTP designer Siu Yin Ho
thin sections
U.S. editor Elizabeth Hester
Senior editor Beth Sutinis
Art director Dirk Kaufman
U.S. production Chris Avgherinos
U.S. DTP designer Milos Orlovic
This Eyewitness ® Guide has been conceived by
Dorling Kindersley Limited and Editions Gallimard Silurian
This edition first published in the United States in 2004 sea lily
by DK Publishing, Inc., 375 Hudson Street, New York, NY 10014
08 10 9 8 7 6 5
Copyright © 1990, © 2003, Dorling Kindersley Limited
All rights reserved. No part of this publication may be reproduced,
stored in a retrieval system, or transmitted in any form or by any
means, electronic, mechanical, photocopying, recording or otherwise,
without the prior written permission of the copyright owner.
Published in Great Britain by Dorling Kindersley Limited.
Miocene bat jaws
A catalog record for this book is available from the Library of Congress.
ISBN 13: 978-0-7566-0682-4 (PLC)
ISBN-13: 978-0-7566-0681-7 (ALB)
Color reproduction by Colourscan, Singapore
Printed in China by Toppan Printing Co. (Shenzhen) Ltd.
Discover more at
Slide of thin section of
Carboniferous bryozoans
Modern
magnolia flower
Contents
Jurassic
ammonites
6
Fossils – true and false
8
The making of rocks
Silurian trilobite
10 (mounted as a brooch)
Turning to stone
12 44
The changing world Onto the land
14 46
Early paleontology Sea dragons
16 48
Fossil folklore Fossil giants
18 50
Fossils of the future Discovering dinosaurs
20 52
Remarkable remains Winged wonders
22 54
Corals Mammal variety
24 56
Sea bed dwellers A world apart
26 58
Shells of all shapes Human fossils
28 60
Intelligent mollusks Living fossils
30 62
Animals in armor Fossil hunting
32 64
Arms and spines Did you know?
34 66
Fishes Identifying fossils
36 68
Plants – the pioneers Find out more
40 70
Fossil fuels Glossary
42 72
Out of the water Index
Fossils-true and false
F
ossils are the remains or evidence of animals or
plants that have been preserved naturally. They
range in size from huge dinosaur skeletons to
tiny plants and animals which can only be seen
under a microscope. Most fossils are formed
from the hard parts of animals and plants, such
as shells, bones, teeth, or wood. They may be
virtually unchanged from the originals, or Only BOnes
Bones are often the only
they may be mineral replacements. Animals
remains of animals because they
and plants have also been preserved in peat, are the hardest parts. This is the
fossilized vertebra from the
tar, ice, and amber, the resin of ancient trees.
backbone of an ancient, giant
Eggs, footprints, and burrows can be swimming reptile called a
plesiosaur (pp. 46–47).
fossilized too. The study of fossils, called
WHAT CAn IT Be?
paleontology, shows us that life originated on
Although people have been Trilobite cast and mold
collecting fossils for hundreds of Earth at least 3,500 million years ago. Since then
years, the true nature of them was
there has been a succession of animal and plant
a mystery until relatively recently.
This illustration appeared in an species. Most are now extinct, and only a tiny
Italian book published in 1670.
number have survived as fossils. By studying
these survivors, we can get a
fascinating glimpse of ancient TAkIng sHAPe
Fossils are often found in two
life on Earth.
parts. Sometimes, after burial,
an animal rots away, and leaves a hollow
mold. If the mold is then filled by
sediment (p. 9) it may harden
to form a cast.
Plesiosaur
tooth HArd
TOOTH
Teeth are
often found
as fossils, as
they are made of
rAre delICACy hard material.
Detailed fossils of plants are rare
because they rot away quickly
when they die. In this leaf,
however, even the delicate veins
have been preserved.
PeArly AMMOnITe
The mollusks known as ammonites
(pp. 28-29) are now extinct. They had
hard shells made of a chalky mineral
called aragonite, with a colorful outer
layer of mother-of-pearl. This one has
been preserved almost in its original state.
PreCIOUs WOOd
One kind of fossilization occurs
when chemical changes cause a
mineral to grow, grain by grain, in place
of the original tissues of the animal or
plant. The tissues of this fossilized wood
have been replaced by opal.

UnnATUrAl BUrIAl
This ancient Greek pot, discovered buried in
the ground, is not a fossil. In the past the term
fossil, which means “something dug up,” was
used to describe many things found in the
ground, such as ancient pottery and minerals,
but these are no longer thought of as fossils.
Area where fragments
are missing
AnCIenT TrAIl eAsy MIsTAke
This is the trail of an unknown These are not a fossilized duck’s
animal which moved across the sea head and a human leg! Their
bed millions of years ago. Fossilized evidence shape is pure chance. They
of the activities of an animal, like this trail, is are really lumps of rock
called a trace fossil. called flint nodules, found
in chalk (p. 9). The shapes
of flint nodules can be very
peculiar and are often
mistaken for fossils.
FAlse FOssIl Flint “duck’s head”
This is not a fossil. The tree like growths,
called dendrites, are manganese that
seeped into the rock.
Flint “human leg”
AnIMAl Or VegeTABle?
No - minerals! Minerals are Bunch of grapes
not the remains of an animal Squid-like creature
or plant, and therefore they
are not fossils.
FOssIl FAkes
During the 1720s, at a
PACked TIgHT
Sometimes fossils are found time when the nature of
densely packed because the fossils was unclear, these
animals lived in great “fossils” were carved and
numbers. These small buried in the ground by
ammonites are in people who wanted to fool
limestone (p. 9). a scientist named Johann
Beringer. He was taken in
by the joke and published
descriptions of his find
which resulted in his
humiliation when the
hoax was uncovered.
Beringer’s “Lying Stones”

The making of rocks
T
he many kinds of rocks beneath our feet have been
forming for more than 4,000 million years. The Earth’s
crust is made up of elements. The important ones are FOlded rOCk
Powerful movements in
oxygen, silicon, aluminum, iron, calcium, sodium,
AMeTHysT the Earth’s crust can cause
This is the purple variety potassium, magnesium, and carbon. These combine in rocks to crack and form
of the mineral quartz. If faults, or to buckle,
different ways to form minerals. All rocks are made up of
allowed to grow freely, creating folds like this.
quartz crystals are pointed minerals. Common rock-forming minerals include calcite
and hexagonal (six-sided).
(calcium carbonate), quartz (silicon dioxide), and Distorted
trilobite
feldspars (complex minerals
Mica
Feldspar Quartz containing aluminum, silicon,
calcium, sodium, and
potassium). There are three
groups of rocks: igneous,
metamorphic, and sedimentary.
TWIsTed TrIlOBITe
Metamorphic rocks may contain distorted
fossils such as this trilobite (p. 30) in slate.
Thin
Black mica section of
granite
Glassy quartz
Band
White feldspar rich in Changed
Band quartz
Molten rocks rich in rocks
mica
Igneous rocks are formed High temperatures and
grAnITe by the cooling of molten pressures can change
The speckles in this granite are magma (liquid rock) from rocks into new types
individual minerals. Granite is
deep within the Earth. called metamorphic
an igneous rock formed at
great depths. Sometimes the magma rocks. Marble is a
reaches the surface and metamorphosed
erupts from volcanoes as limestone; slate, a
lava before it cools. Most metamorphosed shale.
often, though, the magma
cools and becomes solid
deep underground.
lAyer UPOn lAyer Band of
The Grand Canyon in Arizona, quartz
formed by the erosion of sandstone
Band of
and limestone, is a natural slice sCHIsT
through the Earth’s crust. The Parallel banding of minerals is silicate
oldest stratum, or layer, is at a common feature of minerals
the bottom, the youngest metamorphic rocks. Schist is
Thin section
at the top. formed from shale or mud.
of schist
One varve
Fine sediment
Coarse sediment
rOCk BAnds
Stratification on a much smaller
scale than the Grand Canyon is
seen in this sedimentary rock.
Each set of one light layer (fine
sediment) and one dark layer
(coarse sediment) is a year’s
accumulation of silt and mud,
called a varve, at the bottom of a
glacier-fed lake. Such well-
defined seasonal bands are rare.

CHAlk ClIFFs
Chalk is a pure white limestone
composed mostly of the skeletons
of tiny marine plants.
COnglOMerATe
This is a coarse
sedimentary rock consisting of
rounded pebbles bound together
by a natural mineral cement.
Conglomerate can look a lot like
manufactured concrete.
Pebble Million years ago
Era Period (mya)
Holocene (epoch) 0.01
Pleistocene (epoch) 2
Pliocene (epoch) 5
Natural cement
Miocene (epoch)
c
oi 24
z
o Oligocene (epoch)
n
e 34
C
Loose
Eocene (epoch)
sand
55
grains
Paleocene (epoch)
65
Sandstone
Cretaceous
142
c
Deposited rocks Quartz ozoi
s Jurassic
e
M
Rocks are continually being eroded, creating grains
Iron-rich
206
which are carried by rivers, by the sea, and by the cement
wind. These grains are deposited, together with Triassic
the remains of animals and plants, as mud, sand, Thin 248
or coarser material. As this sediment is buried section of
deeper by more sediment, it is compacted (pressed sandstone Permian
290
down) and cemented by the growth of minerals to
form a sedimentary rock. Sandstone, for example,
is a sedimentary rock made from cemented sand. Carboniferous
FrOM rOCk TO rOCk 354
As cliffs of sedimentary rocks
are eroded, small pieces of rock Devonian
are deposited on the beach.
c
These will be eroded further FOssIl Clam shell zoi 417
and may eventually form new COnTAIner o
sedimentary rock. Many sedimentary rocks ale Silurian
P
contain hard lumps called 443
concretions or nodules.
These were formed after the
Shell sediment was deposited, Ordovician
fragment often around fossil shells like
this clam (p. 26). 495
Thin Finely broken-up shells
section of Cambrian
limestone
545
Precambrian
FOssIlIFerOUs rOCk
(about seven times longer
Limestone is a sedimentary rock than all the other periods
composed mainly of calcite and a few put together)
other similar carbonate minerals. The
calcite is usually derived from the
broken shells and skeletons of
animals and plants that lived in 4,600
the sea. Larger, more intact shells Fossil (origin of the Earth)
brachiopod
can also be present, and limestones
are therefore good rocks in sTrATIgrAPHICAl COlUMn
which to hunt for fossils. This A series of eras and periods (and
Silurian limestone contains some epochs in the Cenozoic) are used to
fossil brachiopods (pp. 24–25). describe the age of rocks and fossils.