Page 70 - Introduction to Paleobiology and The Fossil Record

Chapter 3

Taphonomy and the quality of

the fossil record

Key points

• Plants and animals with hard tissues are most frequently preserved in the fossil
record.
• Soft tissues usually decay rapidly, but rapid burial or early mineralization may prevent
decay in cases of exceptional preservation.
• Physical and chemical processes may damage hard tissues during transport and
compaction.
• Plants may be preserved as permineralized tissues, coalifi ed compressions, cemented
casts or as hard parts.

• There has been a longstanding debate about the fidelity and quality of the fossil
record.
• The fossil record is clearly affected by the rock record, and apparent rises and falls in
biodiversity can mimic rises and falls in sea level, for example.
• Perhaps the parallel patterns of biodiversity and rock record through time are driven
by a third factor, such as sea-level change, at least at local and regional scales.
• Quantitative studies suggest that knowledge of the fossil record is improving.
• Paleontologists can use phylogenetic trees and fossil records, both largely independent
of each other, to establish congruence between the two data sets, and so gain some
measure of confidence that the fossil record tells the true history of life.

To examine the causes of life, we must first have recourse to death . . . I must also

observe the natural decay and corruption of the human body. Darkness had no effect
upon my fancy; and a churchyard was to me merely the receptacle of bodies deprived
of life, which, from being the seat of beauty and strength, had become food for the
worm. Now I was led to examine the cause and progress of this decay, and forced to
spend days and nights in vaults and charnel-houses.

Mary Shelley (1813) Frankenstein