Portraits of Wildflowers

Perspectives on Nature Photography

The tales that rocks can tell

with 19 comments

rudistid/caprinid fossil. This is an extinct fossil group that was a prolific reef-builder in the Cretaceous, when our local formations were deposited.

Speaking of rocks (as I did yesterday), on February 2nd a couple of miles from home I found a rock with a fossil in it. I assumed the piece of fluted column, which was 2 inches (5cm) in diameter, had come from the stalk of a tree or plant, but as I know nothing about such things I turned to geologist Eric Potter at the University of Texas. He referred my question to paleontologists and the answer came back that this was a “rudistid/caprinid fossil.” That “extinct fossil group… was a prolific reef-builder in the Cretaceous, when our local formations were deposited.” The Cretaceous ended some 65.5 million years ago, so this might be the oldest thing I’ve ever found. For more on this kind of creature, you can read about rudists and caprinids.

On February 26th I came across a different sort of fossil on the opposite side of my neighborhood. This time I could tell that I was looking at shells. Eric Potter confirmed that these were “oysters stacked together in an ‘oyster bank’, very similar to what we have today in our coastal bays. This is a cross-sectional view.”

oysters stacked together in an “oyster bank”, very similar to what we have today in our coastal bays. This is a cross-sectional view.

© 2016 Steven Schwartzman

Written by Steve Schwartzman

March 25, 2016 at 5:00 AM

19 Responses

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  1. Great finds. I must be related as I’ve been described as an old fossil by some of my younger co-workers.

    Steve Gingold

    March 25, 2016 at 5:07 AM

  2. Great finds and great reading too.
    Happy Easter, Steven!


    March 25, 2016 at 5:47 AM

    • It’s not uncommon in central Texas to see clear imprints of small shells in rocks, but these two finds were larger and quite different from those common fossils, so I was happy to come across them both in a single month. I’m glad you enjoyed the reading.

      Happy Easter to you, Dina.

      Steve Schwartzman

      March 25, 2016 at 7:31 AM

  3. Floods in Iowa in ’93 and ’08 exposed a large expanse of fossils below the spillway of a dam. They are fun to explore. Small kids have exciting times there. https://jarphys.wordpress.com/2013/05/04/devonian-fossil-gorge-of-iowa/

    Jim Ruebush

    March 25, 2016 at 7:23 AM

    • I reread your post and at the end I noticed that I’d commented on it three years ago. The year of the worst flooding, 2008, was the very year we visited Iowa, at the end of April. I remember as we drove south along the Mississippi how many flooded places we saw. You’re fortunate to live so close to the Devonian Fossil Beds, where big kids have exciting times too.

      Steve Schwartzman

      March 25, 2016 at 8:11 AM

      • This year so far has not produced major flooding. The snow cover was not deep and melted away in stages. We can still get huge rains through July. Those are more frequent in recent years.

        Jim Ruebush

        March 25, 2016 at 8:51 AM

  4. This appeals to the geologist and paleontologist in me 🙂

    Sherry Lynn Felix

    March 25, 2016 at 8:50 AM

    • I can understand why. I wish I knew more about both fields. In several places I’ve recently photographed abstract patterns in rocks but I usually don’t even know for sure what the rocks are.

      Steve Schwartzman

      March 25, 2016 at 8:58 AM

  5. Thanks for keeping us in wonder.

    Margie Roe

    March 25, 2016 at 2:47 PM

  6. These are exciting finds, Steve. Well done. The chunk with vertical lines in the first shot reminds me of electronic clippers used to shear sheep and in dog grooming. At first glance I thought the second shot was actually of fresh oysters. I have a few marine fossils in rocks from when I lived in NW Queensland. It only rains for about a week every year there so most of the time it is extremely dry and dusty. Once upon a time though, the whole area was an inland sea. So hard to believe when we look at it now!


    March 26, 2016 at 6:04 AM

    • In line with what you’ve said, Eve and I have been working our way through the 36 half-hour episodes of “A New History of Life”:


      Over millions of years the continents have undergone huge shifts in shape and position. Many currently land-locked places once lay under oceans. It’s common in central Texas to see small shells (or their impressions) in rock, but I’d never run across fossils like these two. I wish I knew how to make fossils turn up as frequently as these did.

      Your mention of clippers for animals suddenly reminded me that when I used to go to the barber shop as a kid the barber used a similar device. I haven’t thought about that in decades: see, I’m becoming a fossil too.

      Steve Schwartzman

      March 26, 2016 at 7:58 AM

      • I’m sure they still use these devices on people too, Steve. With your youthful enthusiasm for so many topics, I could never think of you as a fossil! 😀


        March 26, 2016 at 8:02 AM

        • Thanks for your vote of confidence for the un-fossil, Jane. I’m happy to have all my fossils be in rocks.

          Steve Schwartzman

          March 26, 2016 at 8:07 AM

  7. At first I thought you’d uncovered a portion of a Greek or Roman column — or at least a faux column used in more modern architecture. Now, I see a resemblance to the gills of a mushroom.

    Of course, its true identity is far more exciting and interesting. I’ve never seen anything like it, even though I grew accustomed to finding fossilized clams, whelks, and so on up in the Hill Country. I’ve never found an oyster, though. The best I ever found was a fossilized snail-like shell still half-embedded in a limestone outcrop. Both of these are even more remarkable. If I’d found them, I’d still be excited.


    March 26, 2016 at 7:09 AM

    • If I turned up an authentic Greek or Roman column in Austin, that really would be something, and we’d have to rewrite the history books, or assume I’d stumbled on discarded loot that someone had brought back from the Old Word. In any case, as you said, these fossils were exciting enough in their own right. The rock with the oyster shells was too large and heavy to mess with but I kept the other one.

      Steve Schwartzman

      March 26, 2016 at 8:22 AM

  8. That must have been so exciting!


    March 27, 2016 at 2:44 AM

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