These fossils are from the Devonian period which was known as "The Age of Fish." For you Christians, it is called "The Fifth Day."
From Genesis 1:20;
And God said, Let the waters bring forth abundantly the moving creature that hath life,
23; And the evening and the morning were The Fifth Day.
For an extremely informative academic report on the geological data of the area, Union College of Schenectady put out this document: