A caddisfly case from the Oligocene of Montana. The case is made of tiny ostracode shells.
Roy Plotnick has another informative post over on Medium. This time he tackles the question "What is a fossil?". If you aren't following him yet, go ahead and click the Follow button. He posts regularly and his posts are very interesting and he'll always leave you thinking...
In a Peanuts comic that had a place of honor on my dorm door, Peppermint Patty is taking an exam and is asked to: “Explain World War II.” Patty incredulously responds: “Explain World War II !?” The last panel, further explains: “Use both sides of the paper, if necessary.” I recently had a similar reaction, when science reporters, interviewing me about my most recent paper, asked me to explain in a few words, “when do bones and teeth become fossils?” Although they are orders of magnitude fewer in number than those written about World War II, nevertheless there are many books and many hundreds of academic papers written about the formation of fossils, the science of taphonomy. Not so simple to answer in a couple of sentences. In addition, it was implicit in their questions, and from one asked by a reviewer of the paper, that the process of fossilization must include some sort of change to the bones and teeth, that they must become “fossilized,” that is, changed to some sort of rock (think of petrified wood).
