OHIO FOSSILS 



Table I. Examples of classification of species in the Linnean system. 



Divisions 



MAN 



DOG 



FROG 



OYSTER 



SCALLOP 



Kingdom 



Animalia 



Animalia 



Animalia 



Animalia 



Animalia 



Phylum 



Chordata 



Chordata 



Chordata 



Mollusca 



Mollusca 



Class 



Mammalia 



Mammalia 



Amphibia 



Pelecypoda 



Pelecypoda 



Order 



Primates 



Carnivora 



Salientia 



Anisomyaria 



Anisomyaria 



Family 



Hominidae 



Canidae 



Ranidae 



Ostreidae 



Pectinidae 



Genus 



Homo 



Canis 



Rana 



Ostrea 



Pecten 



Species 



sapiens 



familiaris 



pipiens 



virginica 



islandicus 



Phylum - Mollusca 



Fig. 3 



The system has many advantages. For example, a doubt- 

 ful specimen may obviously belong in the clams; it can be called 

 a pelecypod until its exact name, i.e. the genus and species to 

 which it belongs, is located. And it will be much more exact to 

 say that the specimen is a pelecypod than to say it is just a fossil. 

 Likewise, if the pelecypod looks like a scallop, it may be 

 possible to say that it belongs in the family Pectinidae, a much 

 more exact statement than just calling it a pelecypod. It may even 

 be so much like a scallop that it can be referred to the same 

 genus; it will be much more exact to say that it is a species of 

 Pecten than to just call it a member of the family Pectinidae. 



CLASSIFICATION AND IDENTIFICATION . Sooner or 

 later, you will want to put a name on each one of your fossils. 

 There are many ways of doing this: you can ask an expert to do 

 it for you and that may be a good way at first. Later, you will 

 want to do the job yourself - there is a certain amount of satis- 

 faction in it. Some of the commoner forms can be identified 

 from the pictures and descriptions in this book; the keys provide 

 a systematic way of doing the work. In case you have never used 

 a key before, the following instructions will start you off. 



USE OF KEYS. You will soon be able to identify your specimens to phylun or class. 

 Once you know you have a brachiopod, for instance, and know its approximate age, for 

 example Silurian (see fig. 4, p. 8), use the "Key to the Commoner Silurian Brachiopods of 

 Ohio" (p. 62) to find out the genus to which your specimen belongs. Start out with No. 1 and 

 decide which one of the two choices fits your specimen. Go on to the number to the right of 

 that choice and decide between the two new possibilities offered. Repeat the process until you 

 come to a name instead of a number. The name should be that of your fossil. Look it up in 

 the text and check with the description and figure to make sure you "keyed" it out correctly. 



Don't be too surprised if your specimen does not "key out. " It may belong to one of the 

 scarcer forms and you may have to hunt it up in more advanced books. References to special- 

 ized books are given in each chapter. Finally, don't hesitate to bring your puzzling specimens 

 to a specialist, but don't give up too easily. Most paleontologists are pretty good-natured about 

 helping out and you may have found something really worthwhile that may interest him. 



