Eller, Eugene Rudy. (1955). Additional scolecodonts from the Potter Farm formation of the Devonian of Michigan. Annals of the Carnegie Museum. 33(21): 347-386.
61079
Eller, Eugene Rudy
1955
Additional scolecodonts from the Potter Farm formation of the Devonian of Michigan
[From introduction:]
A number of years ago a small fauna of scolecodonts, fossil polychaete jaws, collected by Dr. G. Arthur Copper of the United States National Museum, were studied and the results published (Eller, 1938). From fragments and the type of jaws found it was evident that only a small portion of the fauna was originally described. Subsequent collecting has proved that the formation is extremely rich in scolecodonts. A hand specimen of the limestone, when dissolved in a weak acid solution, will produce scores of jaws, and many in a very fine state of preservation. Even if one jaw in 25 was considered as representing an individual the annelids would far outnumber any other type of invertebrates preserved in the rock. Their presence in such numbers must have been a considerable factor in the competition for food and a living space. The sea bottom was continually being disturbed and reworked by their burrows, a situation that could not be very desirable for the physical comfort of the diverse fauna and flora that wanted to occupy the same area.
Most of the specimens found were single jaws. There were perhaps a hundred specimens, however, consisting of two jaws in articulation. Workers or students only slightly familiar with this field often view with alarm the fact that a single jaw from the complex jaw apparatus is figured generically and specifically. This is especially true of those who chance on an articulated specimen. All workers that have given any serious thought to the subject state in their publications that they are obliged to describe the jaws separately and realize that they do not belong to different species. Again it is well to quote Hinde (1880) where he restated that in the classification he was “thoroughly conscious of its tentative character, as serving for paleontological reference rather than as presenting exact zoological arrangement.”
The Potter Farm formation is probably Tully in age. It has not been correlated very extensively but it contains faunal elements related to those of the Cedar Valley formation of Iowa and the Thunder Bay formation. The specimens were all collected from the ledges by the side of the road about a quarter of a mile south of Four Mile Dam, Alpena County, Michigan.