Wednesday, April 15, 2009

A Day at the Beach -- Speak Memory

An exercise in memory.

A sunny, warm afternoon in early April on the beach at Fort Lauderdale, this is time well spent, not thinking about the befores or the afters, just sifting idly through the shell debris marking the reach of the tide.

Well, not completely idly. I have this thought – there have to be many sharks cruising off the Florida coast, losing their teeth by the thousands in the course of a lifetime. Despite most of these teeth being lost to the ocean depths, I have to believe some of these modern teeth will wash ashore and hide among the white fragments of shells. Though I do have this goal (still totally unrealized), I am not unaware that other things of interest are hidden here. For one, this erratically coiled, patterned tube, white and yellowish, clearly a shell.

Big, colorful, classically beautiful, complete shells – that’s been the extent of my interest in shells. This is small, inconspicuous, pale, and vaguely scatological. Maybe that last attribute explains why I pocket it (later leaving it on a bureau in the house where I stayed).

With some very desultory research, I conclude this is a worm shell, a shell from a gastropod. I tentatively label it as a Florida Worm Shell (Petaloconchus floridanus) or perhaps an Erect Worm Shell (Petaloconchus erectus). Or, maybe, the correct answer is “none of the above” but I don’t think so.

It took a couple of days, but, drifting out of some opened mental drawer, came a memory of an another object resembling this shell, an object I had not only seen before, but had collected as a marine fossil. “Out of sight, out of mind” is total rubbish if memory is part of the mind. Sure, the memory can be an unreliable guide to what you’ve seen. Sometimes establishing links that aren’t really there. “Yes, yes, that’s just like . . . .” And upon seeing the source of that memory, murmuring, “Oh, never mind.” But, “out of sight” has no bearing on what’s happening in the memory.

Here’s the basis of unbidden memory.

Some 18 months ago, while sifting through some of the fossiliferous material from the Lee Creek Mine piled up in front of the Aurora Fossil Museum (Aurora, NC), this curiosity with its patterned, coiled tubing, showed up, was put into its own baggie, and inserted in a drawer labeled Aurora. Now, another tentative identification. This, I think, is also a worm shell, though fossilized, perhaps a Serpulorbis granifera.

As is usually the case with me, there is some issue with the ID. S. granifera is clearly found in late Pliocene (Chowan River) and early Pleistocene (James City) formations (roughly 1 to 3 million years ago) at Lee Creek. Does it go back farther than that? It’s important, because I thought I was working in material from the Pungo River Formation (mid-Miocene – 10 to 20 million years ago).

Perhaps, this specimen was reworked from its original formation.

Sort of like a memory that turns up where and when you least expect it.

Coda: I am puzzled by the process through which the worm shell became fossilized. The fossilized tube is hollow in spots. Why didn’t it fill completely and the intruding material solidify? Perhaps it did, but now some of the solidified material has crumbled and fallen out as the exposed fossil encountered the elements.

Identification note: The identification of the fossil as Serpulorbis granifera is based on plate 35 in Geology and Paleontology of the Lee Creek Mine, North Carolina, Volume II published in the Smithsonian Contributions to Paleobiology series). I was let down by Moore’s Invertebrate Fossils, finding nothing in it coming close.


  1. i found a worm shell at the beach the other day that looked fossilized as well in the s shape and was told it was merely a type of sea shell worm

  2. The initial find that inspired this post was not fossilized, but the second worm shell discussed above is clearly fossilized. The strongest piece of evidence for that conclusion is where it was found. The color (off white, gray) is another good indicator. That said, what you found could still be a fossil depending upon the beach where you found it and what rock formations might be giving up material to wave action.


Nature Blog Network