WHAT IS PALENTOLOGY?
The word 'palaeontology' refers to the study of ancient life. It is derived from the Greek words palaios (ancient) and logos (study)
(Above) A short Youtube clip explaining Palaeontology http://www.youtube.com/watch?v=SEyl2rRa2YY (Fiona Passantino))))))Jjj
WHAT ARE FOSSILS?Fossils are our window into the past. They are evidence of ancient life forms or ancient habitats which have been preserved by natural processes. The word ‘fossil’ comes from the Latin word fossus, which means ‘dug up’.
They can be the actual remains of a once living thing, such as bones or seeds, or even traces of past events such as dinosaur footprints, or the ripple marks on a prehistoric shore. |
(above) A short Youtube clip explaining fossils. http://www.youtube.com/watch?v=3rkGu0BItKM (Fiona Passantino)
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WHY ARE FOSSILS IMPORTANT?Fossils are valuable sources of information
about the Earth's history. They tell us about the organisms that lived on Earth
from the time of the oldest fossils, about 3.8 billion years ago, to the
present. They are a window into the past. Fossils allow palaeontologists
to reconstruct the past, providing important information on life
billions of years ago.
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WHAT CAN FOSSILS TELL US ABOUT THE PAST?Fossils reveal many fascinating facts about
the past. By studying fossils we can learn not only about the creatures and
plants of the distant past, but how they grew, what they ate, how they
interacted, and many aspects of their behaviour.
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HOW ARE FOSSILS FORMED?
(below) A sequence of photos showing the fossilisation process. Photo source: http://www.bbc.co.uk/nature/fossils
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3) As time passes, these sub fossils become buried deeper and
deeper. Sediment continues to build up upon these remains, providing a barrier
of protection. The mud and sand becomes compressed and is now turning into
rock. Chemicals and minerals ooze through the sediment, gradually dissolving
the bone or shell away. A mould or cast is left behind.
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4) In some cases, minerals from the rocks gradually implant
themselves in the bone, shell or wood, changing its chemical composition.
In cases where the original has dissolved away, the minerals can gradually fill
the hollow to create a natural cast of the original. So sometimes a fossil
doesn't contain anything of the original creature except its shape.
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WHERE ARE FOSSILS FOUND?
Fossils can be found all over the world.
Wherever there are living things, fossils can be created. Location plays an
important role in producing fossils, the trick is to be somewhere protected
from scavengers and the elements. The best place and greatest chance of
producing a fossil is on a sea or river bed buried in sand, mud or soil.
Fossils are more common in these areas. The map below, locates the major fossil
sites around the world. It can be seen that fossils in the right location, can
be produced anywhere around the world.
HOW ARE FOSSILS LOCATED?
Finding fossils is a combination of hard work, chance and knowing where to look! Fossils are mostly found where sedimentary rocks of the right age are exposed, such as river valleys, cliffs and hillsides, and human-made exposures such as quarries and road cuttings.
Most of the time, fossils are only partially uncovered on site, then removed individually or in blocks before being taken back to a laboratory. |
HOW ARE FOSSILS EXCAVATED?
After being found, a fossil must be carefully
freed from the rocky matrix that has surrounded it for millions of years.
It must not be damaged. First the fossil is labelled and photographed
and it's position is carefully noted.
Most of the overlying rock is removed by using tools such as picks and shovels. The rock closer to the fossil is removed by using smaller more delicate tools such as trowels, hammers, whisks and dental tools. The exposed fossil is photographed and labeled again. Frequently, only some of the overlying rock is removed at the dig site. The rest of the rock can be removed later, in the lab. Small and large fossils are excavated differently, but both have to be treated very carefully to avoid breaking them. Before removing a crumbling or fragile fossil, a quick-setting glue can be applied to it with a brush or sprayer. Then the fossil can be removed from the surrounding rock. The fossil must be packed very carefully to be moved to the lab. Small fossils can be packed in boxes or bags. Large fossils can be wrapped in paper with a layer of plaster applied. |
TECHNIQUES OF EXCAVATION
Removing and transporting a fossil can take one amateur fossil hunter a matter of minutes, or involve a whole team of palaeontologists working painstakingly over weeks or even months. Every year, major museums send digging parties to rich fossil sites around the globe. In the field, they can face a variety of challenges, from delicate to crumbling rocks to huge lumps of bone that require heavy lifting equipment to transport them. Some bones may even need to be cut into smaller pieces to be transported. Major excavations may use cranes, helicopters, digging machines and even explosives.