Page 33 - Introduction to Paleobiology and The Fossil Record

20 INTRODUCTION TO PALEOBIOLOGY AND THE FOSSIL RECORD
a long-running program of study of dinosaurs
and other fossil groups from the Cretaceous
of Madagascar (Box 1.4).
Field expeditions attract wide attention,
but most paleontological research is done in
the laboratory. Paleontologists may be moti-
vated to study fossils for all kinds of reasons,
and their techniques are as broad as in any
science. Paleontologists work with chemists
to understand how fossils are preserved and
to use fossils to interpret ancient climates and
atmospheres. Paleontologists work with engi-
neers and physicists to understand how
ancient animals moved, and with biologists to
understand how ancient organisms lived
and how they are related to each other.
Paleontologists work with mathematicians
to understand all kinds of aspects of
evolution and events, and the biomechanics
and distribution of ancient organisms. Pale-
ontologists, of course, work with geologists
to understand the sequence and dating of
the rocks, and ancient environments and
climates.
But it seems that, despite centuries of study,
paleobiologists have so much to learn. We
don’t have a complete tree of life; we don’t
know how fast diversifi cations can happen
and why some groups exploded onto the scene
and became successful and others did not; we
don’t know the rules of extinction and mass
extinction; we don’t know how life arose
from non-living matter; we don’t know why
so many animal groups acquired skeletons
500 million years ago; we don’t know why
life moved on to land 450 million years ago;
we don’t know exactly what dinosaurs did;
we don’t know what the common ancestor of
chimps and humans looked like and why the
human lineage split off and evolved so fast to
dominate the world. These are exciting times
indeed for new generations to be entering this
dynamic fi eld of study!
Review questions
1 What kinds of evidence might you look
for to determine the speed and mode of
locomotion of an ancient beetle? Assume
you have fossils of the whole body, includ- Foote, M. & Miller, A.I. 2006. Principles of Paleontol-
ing limbs, of the beetle and its fossilized
tracks.
2 Which of these statements is in the form
of a scientific hypothesis that may be
tested and could be rejected, and which
are non-scientific statements? Note,
scientific hypotheses need not always be
correct; equally, non-scientifi c statements
might well be correct, but cannot be
tested:
• The plant Lepidodendron is known
only from the Carboniferous Period.
• The sabertoothed cat Smilodon ate
plant leaves.
• Tyrannosaurus rex was huge.
• There were two species of Archaeop-
teryx, one larger than the other.
• Evolution did not happen.
• Birds and dinosaurs are close relatives
that share a common ancestor.
3 Do you think scientists should be cautious
and be sure they can never be contra-
dicted, or should they make statements
they believe to be correct, but that can be
rejected on the basis of new evidence?
4 Does paleontology advance by the discov-
ery of new fossils, or by the proposal and
testing of new ideas about evolution and
ancient environments?
5 Should governments invest tax dollars in
paleontological research?
Further reading
Briggs, D.E.G. & Crowther, P.R. 2001. Palaeobiology
II. Blackwell, Oxford.
Bryson, B. 2003. A Short History of Nearly Everything.
Broadway Books, New York.
Buffetaut, E. 1987. A Short History of Vertebrate Pal-
aeontology. Croom Helm, London.
Cowen, R. 2004. The History of Life, 4th edn. Black-
well, Oxford.
Curry Rogers, K. & Forster, C.A. 2001. The last of the
dinosaur titans: a new sauropod from Madagascar.
Nature 412, 530–4.
Curry Rogers, K. & Forster, C.A. 2004. The skull of
Rapetosaurus krausei (Sauropoda: Titanosauria)
from the Late Cretaceous of Madagascar. Journal of
Vertebrate Paleontology 24, 121–44.
Dong Z.-M. & Currie, P.J. 1996. On the discovery of
an oviraptorid skeleton on a nest of eggs at Bayan
Mandahu, Inner Mongolia, People’s Republic of
China. Canadian Journal of Earth Sciences 33,
631–6.
ogy. W.H. Freeman, San Francisco.
Fortey, R. 1999. Life: A Natural History of the First
Four Billion Years of Life on Earth. Vintage Books,
New York.