As I related in yesterday's post, once I began to explore the creek where I had found the tracks from a river otter, I realized it had numerous fossilized seashells almost anywhere I would look. It was obvious the seafloor at that time must have teemed with animal life. This photo is a good example of what I am talking about. First of all, you can see that it is not what you would call rock in the normal sense. It appears to be a conglomeration of (for lack of a better word) dollops of mud containing the remains of sea creatures that have loosely fused together and hardened. The sea snail shell on the left is larger than it first appears, approaching the size of a tennis ball. It may be a moon snail, but I should mention I know little about sea shells. The most noticeable impression of what appears to have been a turret snail is a type of creature that was most common among the fossils I saw. If you look closely, you will notice numerous other small forms of sea life.
This lump of mud had a higher sand content than the previous image. Right away, attention is drawn to the bivalve at the top with well-defined ridges along the edge. I have no idea what type of shell it is. Just below this shell, the edge of another creature, perhaps a tube worm, is partially exposed. To the right of that is mostly disintegrated impression of another shell. Below that is the shell of what could be a "modern" bay scallop with prominent ribbing emerging from the mud.
The majority of the stream bed was what you would normally expect to see, consisting of small rocks and sand. Many of the fossils were interspersed among the regular rocks.
There was a section of the creek whose appearance was quite a bit different - the sluice-like area also shown in a photo yesterday. The stream bed in the "normal" areas had either already completely eroded through the fossil layer or had not encountered it yet. The section shown here was extremely smooth but revealed fissures that will eventually allow the breakdown of this layer. It put me in mind of a cave painting.
The most tantalizing find was this impression. Whatever made the impression was long gone, but left behind was the outline of what appears to be an extremely large turret-type shell. The large oak leaf on the left provides a good standard of scale. Including the stem, it is probably in excess of six inches, making the impression somewhere between twelve and eighteen inches. How would you like to have that in your shell collection?
To be continued...