Adventist Youth Honors Answer Book/Nature/Fossils

Fossils
Nature General Conference	Skill Level 2
	Year of Introduction: 1944

Contents

1. Make a collection of at least ten different kinds of fossils and label each with its name and geographic location.

Fossils are found in many places where sedimentary rocks, such as claystones, shales, limestones, and sandstones, are exposed. Only certain sedimentary rocks harbored the appropriate environmental conditions to preserve and yield fossils, which are often concentrated along particular bedding planes within the rocks.

Finding Fossils

Fossils are generally found in sedimentary rock with differentiated strata representing a succession of deposited material.

The occurrence of fossil bearing material depends on environmental factors before and after the time of preservation. After death, the first preserving factor is a rapid burial in water bodies or terrestrial sediment which would help in preserving the specimen. These rocks types are usually termed clastic rock, and are further subdivided into fine, medium and coarse grained material. While fossils can be found in all grain types, more detailed specimens are found in the fine grained material. A second type of burial is in rocks composed of calcium carbonate (limestone) or carbon (coal). The third type of fossil bearing rocks is called chemical rock. Examples include rock salt and phosphate concentrations. The remains of gastropods, algae, vertebrates, and trace fossils are often found in these rocks.

Areas where sedimentary rocks are being eroded include exposed mountainous areas, river banks and beds and engineering features like quarries and road cuts. Generally in appearance, a fossil will be either a different color from the surrounding rock because of the different mineral content, will have a defining shape and texture or a combination of both. Dried up natural lake beds and caves in the form of pitfall traps may contain local and recent fossil fauna for its locality as is the case with Cuddie Springs and Naracoorte Caves in Australia.

Fossils are not to be found in areas of igneous rock (except in some beds between lava flows). In rocks which have undergone metamorphism, they are usually so distorted that they are difficult to recognize or have been destroyed completely.

Artificial exposures, such as road cuts or quarries, can often be good collecting spots, along with continually eroding river or coastal exposures. Coal mining operations often yield excellent fossil plants, but the best ones are to be found not in the coal itself but in the associated sedimentary rock deposits called coal measures.

In hilly regions the best sections are often those exposed at the sides of streams that have cut into the bedrock.

Wave washed sea cliffs and foreshore exposures are often good places to search for fossils, but always be aware of the state of the tides in the area. Never take chances by climbing high cliffs of crumbling rock or clay (many have died attempting it).

Exposures of softer rocks, such as clays and sands, can be good collecting spots. However inland sections tend to degrade rapidly, becoming overgrown, and are lost forever.

Collecting Ethics

To collect fossils, there are various legal realities that must be observed. Permission should be sought before collection begins on private land. Hammering the rocks in national parks and other areas of natural beauty is inappropriate and in most cases is illegal.

Equipment

It is important to have the right kind of field equipment when looking for fossils, and safety should always be an important concern.

A hard hat is essential protection from loose stones that may be dislodged from cliffs above, but keep in mind that a hard hat will not protect the wearer from larger falling rocks. Hard hats are normally a requirement in operational quarries.

Safety goggles and protective gloves are also essential, as rocks can be sharp and dangerous; safety goggles will protect eyes from chips produced while hammering, and gloves protect the hands. No fossil is worth losing an eye for.

A collector need dress appropriately for collecting trips, taking into account the climate and terrain of the area. Sturdy footwear, such as walking or hiking boots with steel toes, are recommended. A hammer, chisel and wrapping materials are the basic equipment required for fossil collecting, along with a well constructed backpack for carrying equipment and fossil finds. The steel of many ordinary hammers is too soft for use on most type of rock. The steel may splinter, and the flying fragments cause injury to the person using the hammer, or others in the vicinity. The hammer should always strike away from the body. The head of a geological hammer or rock pick is made from specially hardened steel designed for use on rocks. The head is either firmly attached to a wooden shaft, or the hammer head and shaft are formed from one piece of steel. The head may have any combination of a square face, a tapered point, or a straight chisel edge. The point of such picks are not meant for striking rock directly, but for tapping rock (such as shale) open along planes and for prying: the hammer end is used for striking.

A convenient weight for a general purpose geological hammer or rock pick is around 1 kg (2 to 3 pounds). For breaking very hard rocks one may need a hammer of between 3 and 6.5 kg (7 and 14 pounds) in weight, with a correspondingly longer and thicker shaft. A hammer that is too heavy is tiring to use and results in unsafe work.

2. Have a brief definition of each of the following in your notebook: Note - terms used in the definitions that are also defined here are in bold type.

a. Geology

Geology is the science and study of the solid matter that constitutes the Earth.

b. Geologic column

Geologic column refers to the orderly and worldwide layercake-like arrangements of sedimentary rocks. Names are assigned to the different layers (from bottom to top): Cambrian, Ordovician, Silurian, Devonian, Mississippian, Pennsylvanian, Permian (these 7 are the Paleozoic), Triassic, Jurassic, Cretaceous (these three are the Mesozoic), Paleocene, Eocene, Oligocene, Miocene, Pliocene, Pleistocene, Holocene (these 7 are the Cenozoic). Each layer is characterized by different kinds of fossils. So, for example, if you wanted to find a dinosaur, you would look in Jurassic or Cretaceous rocks. See "Finding your own dinosaur".

c. Catastrophism

Catastrophism is the idea that Earth has been affected by sudden, short-lived, violent events that were sometimes worldwide in scope.

d. Flood

Term used to identify the major catastrophe that is described in Genesis 6-8, and in 2Peter 3, believed by creationists to have been largely responsible for forming the rocks containing fossils.

e. Fossils

Fossils are the mineralized or otherwise preserved remains or traces (such as footprints) of animals, plants, and other organisms.

f. Paleontology

Paleontology is the study of the history of life on Earth through the examination of plant and animal fossils.

g. Plane of symmetry

Planes of symmetry are an important tool for distinguishing groups of organisms. They are identified if a plane can be drawn that divides an organism into two halves that are mirror images. For example, humans have a single plane of symmetry through the center of the body from head to toe.

h. Paleozoic

Paleozoic rocks generally are the lowest rocks in which fossils of multicellular life forms can be found. Paleozoic rocks contain fossils of trilobites, mollusks, brachiopods, Calamites, crinoids and many other forms.

A Cretaceous ammonite, Discoscaphites iris. Note the complex ammonite suturing pattern on shell in upper left

i. Mesozoic

Mesozoic rocks generally lie above Paleozoic rocks and are characterized by fossils of ammonites, flowering plants and dinosaurs, among others.

j. Cenozoic

Cenozoic rocks generally lie above Mesozoic rocks and may contain fossils of flowering plants, mammals, clam or snail shells and other forms.

k. Pleistocene

These deposits typify the sediments and fossils resulting from the extensive ice sheets that covered the earth after the flood.

A large Devonian trilobite, Phacops moroccensis

l. Ammonite

An ammonite (see photo) is a type of coiled nautilus-like cephalopod mollusk with elaborate sutures in its shell.

m. Trilobite

Trilobites (see photo) are extinct arthropods (see definition) that occur in Paleozoic rocks. The name refers to the three lobes into which the body is partitioned.

Fossil crinoid columnals. Each small disk is a single crystal of calcite.

n. Crinoid

Crinoids, also known as "sea lilies" or "feather-stars", are marine animals with five-fold symmetry. There are only a few hundred known modern forms, but crinoids were much more numerous both in species and numbers before the flood. Some thick limestone beds are entirely made up of disarticulated crinoid fragments (see photo).

A Strophomenid brachiopod. Note the plane of symmetry (white mark) bisects the valves.

o. Arthropods

Organisms with hard exoskeletons and jointed appendages such as insects and crustacea.

p. Calamites

A fossil made when sediment filled the hollow stem of a plant related to modern horsetails (Equisetum).

q. Snails

Snails (Gastropoda) are mollusks that typically have a single valve that exhibits spiral growth about a central axis.

r. Clams

Clams (Pelecypoda) are mollusks that typically have two-part shells, with a plane of symmetry between the two valves. The class has 30,000 species, including scallops, clams, oysters and mussels.

s. Brachiopods

Brachiopods (see photo) are two-shelled marine animals superficially resembling clams, but with a plane of symmetry that divides the valves in half.

t. Dinosaur

A dinosaur is a member of an extinct reptile group characterized by having a open acetabulum (hip socket) and any of a variety of other features. They are found exclusively in Mesozoic rocks.

u. Mammoth

A mammoth is an extinct Pleistocene proboscidean (elephants and their extinct relatives), often with long curved tusks and, in northern species, a covering of long hair.

v. Mastodon

A Mastodon is also an extinct Pleistocene proboscidean; they resembled, but were distinct from, the woolly mammoth, but differed in tooth structure among other things.

w. Mammal

A fossil mammal includes any fossil remains that belonged to an organism that had hair, produced milk and bore live young (except monotremes). Dogs, cats, mice and horses are mammals.

x. Vertebrate

A vertebrate is any organism that contains a backbone of articulated vertebrae. Vertebrate Paleontologists are scientists that study vertebrate fossils, like dinosaurs.

y. Mollusk

a Mollusk is any of a diverse group of invertebrate (no backbone) animals that often have hard outer shells. This group includes clams, snails, cephalopods (octopus, squid, ammonites), and other less familiar forms.

3. Visit a museum where fossils are on display and make a written or oral report of your trip.

Most museums of natural history will have a fossil collection, and even small museums are likely to have a few. If you do not know of such a museum in your area, the Internet is your friend. Try searching for "fossil," "museum," and the name of your locality. If you are still unsure, get a list of local museums and call them. They will be happy to tell you if they have fossils on display, and if they do not, they may be able to direct you to a museum that does. One such online museum is the Southwestern Adventist University dinosaur museum.

After the visit, have your Pathfinders either write their reports or present one orally. This would be a great topic for worship during your club's opening exercises, or during a campout.

4. Describe the process of the proper removal of delicate specimens. Tell how a skeleton of a dinosaur or other gigantic fossil would be removed. Why should beginners not remove such specimens? What should be done by the beginner when he finds what is obviously a valuable fossil?

Removal of delicate specimens

For extracting fossils from harder rocks, a sturdy mallet and cold steel chisels may also be required. Usually one needs a range of chisels in size from small ones with a sharp edge of about 1 cm (quarter of an inch), to much larger and heavier chisels. A broad-bladed chisel is often very useful for splitting rocks along their bedding plane.

Different types of rocks will break differently and a beginner should put in a little practice, getting the feel for a particular type of rock before he or she starts hammering out fossils. It is all too easy to ruin a specimen with one ill-placed blow of a hammer.

Extracting a specimen that is embedded in solid rock may prove to be a long and difficult process. Before attempting to extract a specimen, the collector should make sure that it is feasible to remove it without destroying or damaging it. Leaving sufficient rock beneath the specimen to protect it from fracturing; excess matrix can be trimmed at a later time.

For soft sediments and unconsolidated deposits, such as sands, silts and clays, a spade and a flat-bladed trowel or stout bladed knife may be the most useful tools for clearing the area around a fossil. Brushes are also useful for removing loose sediment from around fossils.

A sieve is used to separate fossils from sands and gravels. A smaller mesh is required in order to avoid losing small fossils. One practical difficulty with using sieves in the field is that they easily become clogged, especially when the material sieved has a high moisture content. However, under dry weather conditions the more durable fossils, such as teeth and bones, can be quickly and easily sieved out of loose sands. Shaking the sieve is always liable to damage or destroy fragile fossils.

If there is water available, such as on a beach or next to a stream, the material containing the fossils can be sieved wet and the matrix gradually washed away. Wet sieving is a technique that is frequently used for the collection of small mammalian fossils, and by using this technique even the smallest specimens may be recovered.

Removing gigantic fossils

Occasionally, large fragile specimens may need to be surrounded and supported using a jacket of plaster before their removal from the rock: This protects the fossil, protecting it from shattering and damaging.

Casting

If a fossil is to be left in situ, a cast may be produced, using plaster of paris or latex. Careful treatment of the surface must be done first to avoid leaving the casting material to deface the specimen. While not preserving every detail, such a cast is inexpensive, easier to transport, causes less damage to the environment, and leaves the fossil in place for others to enjoy. Subtle fossils which are preserved solely as impressions in sandy layers, such as the Ediacaran fossils, are usually sampled by means of a cast, which shows up detail more clearly than the rock itself.

Valuable fossils

If you find an obviously valuable fossil, you should contact a professional. It is too easy to ruin a fossil by attempting to remove it yourself. Leave the extraction in the hands of an experienced collector. If you find such a fossil on public land, contact the authority responsible for the land. The fossil belongs to them, and they have the right to decide what to do with it. To find a professional, contact a museum or a local university. If they do not have one on staff, they will be able to refer you to one.

5. Explain the difference in the account scientists give for the presence of fossils as related by evolutionists and creationists.

Evolutionists and creationists both agree that fossils are formed when a creature is quickly buried in sediment. They disagree on how long ago this happened. Evolutionists believe most fossils were made millions of years ago. Creationists believe that nearly all fossils were made during Noah's flood less than 10,000 years ago.

6. From the Bible and writings of Ellen G. White cite statements to explain the origin of the following: a. Coal b. Petroleum c. Fossils d. Limestone

From Patriarchs and Prophets, pp 107, 108

Everywhere were strewn the dead bodies of men and beasts. The Lord would not permit these to remain to decompose and pollute the air, therefore He made of the earth a vast burial ground. A violent wind which was caused to blow for the purpose of drying up the waters, moved them with great force, in some instances even carrying away the tops of the mountains and heaping up trees, rocks, and earth above the bodies of the dead. At this time immense forests were buried. These have since been changed to coal, forming the extensive coal beds that now exist, and also yielding large quantities of oil. The coal and oil frequently ignite and burn beneath the surface of the earth. Thus rocks are heated, limestone is burned, and iron ore melted.

The Bible itself offers no explicit explanation of coal, petroleum, fossils, or limestone, though it does contain the story of Noah's flood (see Genesis chapters 6-9). In this account, the whole earth is covered by water, and all life, except those in the ark, is lost. The Biblical account of creation rejects the notion of hundred of millions of years of evolution, stating with clarity that God created the world in six days. In Genesis chapter 5, the Bible also provides genealogies of the Patriarchs, including their ages when they had children and when they died. From this, and from other historical records, the Bible sets the age of the Earth at about 6000 years.