Use of Fossil Fish Scales in Micropaleontology

Abstract

Fossil fish remains are abundantly represented in the marine sedimentary rocks of California. Certain shaly formations are littered with dismembered parts of fish, for example scales and single bones, though few other fossils are found in them. Up to the present time, these fossils have not been utilized in geological and paleontological work in California. An attempt has been made by the author to collect a variety of distinguishable fossils of this kind and to determine to what degree these scale assemblages differ in different stratigraphic units. Approximately 75 distinct types of scale have been found, and the more important ones are illustrated in this paper. The present report is preliminary in many respects. Only a small number of genera are definitely determined. No names are given to the new forms at present. Instead, the genera are designated by number, the species by letter. It is hoped that the illustrations and identifications will nevertheless be of use to paleontologists. A general outline for work on fish scales and a description of the technique employed in the study of this kind of material was given by Camp and Hanna (Methods in Paleontology, 1937, p. 127). The methods described by these authors can be readily adapted to individual needs.