Part 7

Material from separate localities should be kept in individual cloth or paper bags, and the collector should take every precaution to keep the labels with their respective fossils. Remember that a fossil without a locality is hardly worth the paper it is wrapped in.

The collector should always ask the land owner’s permission before entering or collecting on private property. One should respect all property, especially livestock and fences, and leave the area cleaner than when entered. If these precautions are observed, future collectors will probably be welcome to return for additional collecting.

CLEANING AND PREPARATION OF FOSSILS

It is usually necessary to do the final cleaning and preparation of fossils at home or in the laboratory, for most fossils brought in from the field require considerable preparation before they are ready for display.

Excess matrix should be carefully removed with hammer and chisel; blows should always be directed away from the fossil. Smaller tools (needles, tweezers, and awls) should be used in the final preparation stage, and one should work carefully to avoid damaging the specimen. Before starting the final cleaning, it will be helpful to place the fossils in water and let them soak overnight. This will loosen much of the excess rock, and most of the softer material can then be removed with a small scrub brush or tooth brush. Mounted needles can be used to clean more delicate specimens or around the smaller structures of larger fossils. It may be advisable to use the magnifying glass when working with small fossils or with delicate surface structures of larger specimens.

Broken fossils can be repaired with clear plastic household cement, and specimens that are crumbling may be coated with pure white shellac, thinned collodion, or clear nail polish. The latter is preferred as it is not as likely to crack. Fragments of bone are particularly apt to crumble upon exposure to the air. This type of fossil is normally quite fragile and should be excavated with great care and shellaced as soon as dry.

Dilute hydrochloric acid may be used in removing silicified fossils from a calcareous matrix. The material to be etched should be placed in a pottery or glass container and covered with water. Acid should then be added to the water very slowly and until large numbers of bubbles are given off. Each time the bubbling ceases, more acid should be added and this process should be repeated until the fossil is free of matrix. This procedure should be carried on in a well-ventilated place, and the acid should be handled with extreme caution. Hydrochloric acid can cause damage or serious injury and the fumes are extremely corrosive.

HOW FOSSILS ARE NAMED

In order to get the maximum pleasure out of fossil collecting, most amateur paleontologists want to identify and classify the fossils that they have collected. This requires some knowledge of how fossils are classified and how they receive their scientific names.

THE SCIENCE OF CLASSIFICATION

The number of organisms, both living and extinct, is so great that some system of classification is needed to link them all together. Many fossils bear distinct similarities to plants and animals that are living today, and for this reason paleontological classification is similar to that used to classify modern organisms. This system, known as the system of binomial nomenclature, was first used consistently in 1758 by Linné (or Linnaeus), an early Swedish naturalist.

Scientific names established in accordance with the principles of binomial nomenclature consist of two parts: the generic (or genus) name and the trivial name. These names are commonly derived from Greek or Latin words which are usually descriptive of the organism or fossil being named. They may, however, be derived from the names of people or places, and in such instances the names are always Latinized. Greek or Latin is used because they are “dead” languages and not subject to change. They are also “international” languages in that scientists all over the world can use the same names regardless of what language they write in. The system of binomial nomenclature has led to the development of the science of taxonomy, the systematic classification and naming of plants and animals according to their relationships.

THE UNITS OF CLASSIFICATION

The world of organic life has been divided into the plant and animal kingdoms. These kingdoms have been further divided into larger divisions called phyla (from the Greek word phylon, a race). Each phylum is composed of organisms with certain characteristics in common. For example, all animals with a spinal cord (or notochord) are assigned to the phylum Chordata.

The phylum is reduced to smaller divisions called classes, classes are divided into orders, orders into families, families into genera, and each genus is divided into still smaller units called species. A species may be further reduced to subspecies, varieties, or other subspecific categories, but these need not concern us in a publication of this nature.

The following table illustrates the use of binomial nomenclature in the classification of man, a clam, and a dog.

Unit Man Dog Clam Kingdom Animalia Animalia Animalia Phylum Chordata Chordata Mollusca Class Mammalia Mammalia Pelecypoda Order Primates Carnivora Eulamellibranchia Family Hominidae Canidae Veneridae Genus Homo Canis Venus Species sapiens familiaris mercenaria

The generic name and the trivial name constitute the scientific name of a species and according to this system of classification the scientific name of all living men is Homo sapiens. It is obvious that there are many variations among individual men, but all men have certain general characteristics in common and are therefore placed in the same species.

In a scientific name, the generic name is always started with a capital letter and the trivial name with a small letter. Both names must be italicized or underlined.

The name of the author (the person who first described the fossil) usually appears following the scientific name. The date of the scientific publication containing the original description of the fossil is often placed after the author. For example:

Turrilites worthensis Adkins and Winton 1920

With the large numbers of plants and animals that are living today, plus those of the past, random naming would result in much confusion. For this reason scientists have established strict rules that must be followed when a specimen is named. The strict application of these rules enables scientists in all parts of the world to assign scientific names without fear of duplication.

IDENTIFICATION OF FOSSILS

The beginning collector is usually content to know if his specimen is a clam or a snail or a fern or a palm leaf. But as the collection grows, it becomes increasingly desirable to know the scientific name of each fossil.

When he starts to identify fossils it may be helpful to show them to a geology teacher if a college or university is nearby. Most teachers are glad to be of help and will probably have similar specimens in their own collections. As all colleges do not have geology departments, a list of institutions with geologists on their faculties is included at the end of this section of the handbook (p. 27). In addition, many of the science teachers in the public schools are familiar with fossils and can give helpful suggestions as to how to classify material.

Museums are also good places from which to get help. If the museum has a geological collection, it will be most helpful to compare specimens with the fossils in their collections and to ask the museum personnel for advice. In addition to the above sources of information, local professional geologists are usually familiar with the geology of the local area and the paleontological literature of the region.

Possibly local librarians can recommend books, encyclopedias, or other publications that will be of help. Members of a local rock and mineral club, if one is available, are another source of information. Many times these collectors can pass along good ideas and tell exactly which books to consult.

After books or journals describing the fossils of the area have been located, the collected specimens should be closely compared with any illustrations that are shown. Each fossil should be examined carefully, its more characteristic features noted, and it should again be compared with the illustrations and descriptions in the book. The phylum or class to which the specimen belongs should be determined first. For example, the genus and species of a certain fossil may not be known, but it looks like a snail and accordingly it is named a gastropod (for class Gastropoda, the snail class), and this is, at least, a start in determining the scientific name of that particular fossil. The descriptive material in the text of each reference will usually point out the more detailed features which will be diagnostic of the genus or species.