We geologists have such notions of time and its vastness. The two of us experience this all the time. We routinely visit Sloan Gorge in Woodstock. That’s a canyon where there are Devonian aged sandstones that expose the deposits of ancient streams, perhaps many of them. We look up at the ledges there and see the cross sections of their many channels. What thoughts those visits do inspire. When you walk along a modern stream you instinctively have the notion that it is something that will last forever. How could that stream have not always been right there? How could that stream ever disappear? Could there have been a very first flow of water? Will there ever be a last? No, of course not, none of those things could possibly be; after all a stream is forever and ever. Isn’t that obvious? Stand by the banks of a nearby river and think about this yourself.

From Sloan Gorge we gaze upwards and see a slope that rises up to the top of the Catskill Front. That slope and those mountains have always been there. Haven’t they? And they always will be there. Right? Well – no – those thoughts are false, all of them. We geologists have been seriously studying our science for centuries now and we have learned that streams come – and they go. Even mountains do not last, they slowly erode away. In fact, we don’t think that anything is forever- not a stream, not a mountain – perhaps not even our universe.

That takes us to looking at populations of an ancient form of invertebrate animal. That’s a shellfish called Mucrospirifer. Take a look at our illustration. Mucrospirifer is one of those Catskills area fossils that you really should know. They are very common and have a remarkable morphology. They are members of a group of creatures called the brachiopods. Like clams they have two shells but that’s where the resemblance ends. Their internal anatomies do not resemble, in any way, those of clams. These are simply two very different types of animals.

Our focus today is on how common Mucrospirifer must have once been. We often see strata densely littered with their fossils. We travel back in time to the Catskills region  of 385 million years ago and imagine ourselves drifting across an ancient Devonian seafloor looking down on hundreds of Mucropirifers. Each sits down there facing upwards with their shells open just a bit. They are, all of them, drawing in seawater and sifting out from it bits of food. They are called filter feeders, a peaceable and most reliable way of life for a simple invertebrate. They always had lots of food and few predators. No wonder there were so many of them. 

We continue our swim and pass across endless colonies of these creatures. If their heart beats made any sounds at all then there would be a continuous low roar. We look again and simply cannot imagine that Mucrospirifer will ever pass from this Earth. We think that they will last forever and ever. And, indeed, generations after generations pass by and so do centuries and then millennia and there they are, continuing to be.

But even longer amounts of time pass by and then a time comes when we notice that there are fewer of them, and later fewer still. What is happening? We will never know why but Mucrospirifer was going extinct. There comes, finally, a day, an hour, a minute and a second when we hear the last heartbeat of the last Mucrospirifer. Their time has come.

This too, someday, will also happen to our own species.

Contact the authors at randjtitus@prodigy.net. Join their facebook page “The Catskill geologist.” Read their blogs at “thecatskillgeologist.com.”