If the shells are in shallow water, wave action soon grinds them into sand-sized pieces.
Even if they are not in shallow water, the shells are attacked by worms, sponges, and other animals (Figure 11.5).
A fossil is any remains or trace of an ancient organism.
Fossils include body fossils, left behind when the soft parts have decayed away, as well as trace fossils, such as burrows, tracks, or fossilized waste (feces) (Figure 11.4).
The fossil record also plays a key role in our lives.
Fossil fuels such as coal, gas, and oil formed from the decayed remains of plants and animals that lived millions of years ago. Most fossils are preserved in one of five processes (Figure 11.6): preserved remains, permineralization, molds and casts, replacement, and compression.
Throughout human history, people have discovered fossils and wondered about the creatures that lived long ago.
In ancient times, fossils inspired legends of monsters and other strange creatures.
It would be rare for any of the antelope’s remains to actually be preserved as a fossil.
On the ocean floor, a similar process occurs when clams, oysters, and other shellfish die.
The soft parts quickly decay, and the shells are scattered over the sea floor.
Some of the best-preserved skeletons of land animals are found in the La Brea Tar Pits of Los Angeles, California.
Although the animals trapped in the pits probably suffered a slow, miserable death, their bones were preserved perfectly by the sticky tar.
A storm at sea may shift sediment on the ocean floor, covering and helping to preserve skeletal remains.