Other pages in this set

Page 2

Preview of page 2

Here's a taster:

Body Fossils
Organisms consist of soft tissues, and hard skeletal materials which may be inorganic
When organisms die scavengers may eat them. If they escape this terrible fate, bacteria and fungi
will feed on the organic remains: this is the process of decay. The inorganic materials are
eventually dissolved by groundwater, particularly if it is acidic. A tiny proportion of organisms
undergo processes which preserve them to some extent. Mechanisms of preservation include:
Freezing.…read more

Page 3

Preview of page 3

Here's a taster:

Trace Fossils
Trace fossils are sedimentary structures produced by the activity of organisms, as distinct from the
body fossils which are preserved remains. They include:
Tracks Trails Burrows Borings
Resting place
FOSSIL ASSEMBLAGES
Many organisms are moved by natural processes (such as water currents) after death BEFORE
PRESERVATION. If so, they are said to have suffered postmortem transport. The resulting deposit
of fossils is then referred to as a death assemblage.…read more

Page 4

Preview of page 4

Here's a taster:

TRILOBITES (WOOOOOOOOO)
Exclusively marine, they had an external jointed protein skeleton; the body consisted of three
sections: the cephalon (head), thorax and pygidium (tail). Most were benthic (sea bed) crawlers;
some were shallow burrowers, and others swam. If a species has eyes, there must have been light
to see by, so they must have inhabited shallow water. If it had eyes on the top of its head it must
have been looking up
a lot hence it was on
the sea bed.…read more

Page 5

Preview of page 5

Here's a taster:

A zone fossil used to: determine the relative age/date of rocks or to correlate rocks of the same
age.
Brachiopods
An exclusively marine species, they lived on the sea floor, filtering food from sea water. The shell,
consisting of two valves: a large pedicle valve, and a smaller brachial valve. In most species there
is a hole or foramen in the pedicle valve which allowed the brachiopod to extend its muscular foot
or pedicle (cements it to the sea floor).…read more

Page 6

Preview of page 6

Here's a taster:

Increased surface area hence increased food intake
Bivalves
Includes freshwater and marine species. All are filter feeders. Some live on the sea floor, others
burrow into sediment, 'glue' themselves to rocks or bore their way into driftwood. Some are
capable of short bursts of swimming (just keep swimming right). Shell, consisting of two valves
which are more or less mirror images of one another. The oldest part of each valve forms a tightly
curved 'nose' termed an umbone (or umbo).…read more

Page 7

Preview of page 7

Page 8

Preview of page 8

Page 9

Preview of page 9

Here's a taster:

The coil and chambers (septa) were used as buoyancy to allow the Ammonoid to float. Many
Ammonoids probably lived in the open water of ancient seas, rather than at the sea bottom. Ate
plankton.…read more

Page 10

Preview of page 10

Here's a taster:

Marine conditions
Warm water (best between 25 29°C)
Clear water to allow sunlight through
Shallow water (photic zone)
High energy (breaking waves) aerated
Welloxygenated water
Hard outer skeleton CORALLITE.
SEPTA ­ radial plates grown from corallite wall into the
Coral centre to support the "bag of guts" coral on the top
May grow together in large colonies forming reefs.…read more

Comments

No comments have yet been made

Similar Geology resources:

See all Geology resources »See all resources »