Asa Kaplan
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I don’t know about the big trapezoid, but the little lineated piece certainly looks like vascular plant material. Land plant even. I find these in Middle Devonian shaley limestones, even those whose paleoenvironments had paleodepths below normal wave-base.
For a more extensive list of candidate brachiopods, see
http://ftp.maps.canada.ca/pub/nrcan_rncan/publications/ess_sst/122/122462/bu_378.pdf
Among orthotetidines, this publication lists only Schellwienella? cf . S. alternata Weller, 1914, with some good photos on plate 1.
David, nice fossil. If this is definitely from the Madison Limestone then it is Mississippian in age — far too young to host Rafinesquina or Strophomena. I do concur that it is a strophomenide brachiopod, most likely an orthotetidine. This article is a good jumping-off point:
https://imnh.iri.isu.edu/digitalatlas/geo/gsa/papers/gsac1p4.pdf
I’m with Jack — this looks like a Phacopid trilobite, perhaps even Phacops. In WV these are found in Middle Devonian rocks like the Marcellus Shale and the Mahantango Formation. Mahantango and Marcellus trilobites lived about 385 million years ago.
But the Eastern panhandle of WV….aren’t all those shales metamorphosed? Maybe not all, but all the ones I have seen were metamorphosed! No chance of fossils in a rock that has been through that much heat and pressure.
Oh, I see. Thanks, Lisa. I would like to see better support on this website for event subscription, so that updates go out to those folks who intended to attend. Otherwise, let’s leave event functionality to a platform like Eventbrite or even Facebook that can handle the relevant tasks.
Thanksgiving food………..mushroom gravy. I would like to know what we know about mushrooms from the fossil record.
Fossil ID webinar is tonight at 4pm PST / 5pm MST / 6pm CST / 7pm EST, right? at http://idigbio.adobeconnect.com/room
The rock there is either early Cenozoic or else Mesozoic. Ediacarans are out of the question, not only for this reason, but for morphological reasons: no known Ediacaran is spiral- or tube-shaped.
This appears to be the trace of a worm or other creature that fed in a spiral outward from a central starting point. It consumed the sediment whole and released the digested sediment behind it. If it showed a rigid, curved outer shell, then we could talk about what kind of snail or cephalopod shell it is. But since the outlines are wavy and irregular, it is almost certainly a feeding trace.
I don’t know my trace fossil taxonomy well enough to put a genus identification on this fossil, but these lecture notes contain some spiral feeding traces you might take a look at:
http://www.yorku.ca/lbianchi/nats1800/lecture01a.htmlThanks for the tag, EG! I have no idea what this webinar is or where to find it, but I’d like to learn about the lesser-known soft-bodied preservation localities like Blue Island. And maybe a review of some amazing sites that are now off-limits (rather than played out).
Although often mistaken for a trilobite, this is not a fossil at all. You will note that you can crush it with your fingernail.
It is the egg case of a praying mantis from the 2010’s.
Julie @julie-niederkorn, you have opened my eyes! I was assuming the entire fossil to be a pygidium, but now I take your point that it comprises the whole thorax plus the pygidium. And that makes it an excellent match for the thoracopygidium of Thaleops ovata. It also helps explain the outline that appears anterior to the thorax: It’s a cross-section through the cephalon. I note especially the robust right gena. For comparison:
Congrats on your first complete trilobite, Julie 🙂The cephalon appears to belong to some ceraurine trilobite. For example, here is Ceraurus. Note the glabellar lobes and how they’re connected to the other parts of the cephalon.
That pygidium is definitely not Flexicalymene! Note in this photo how triangular Flexicalymene‘s pygidium is, and how it terminates with a prominent bulb on the median lobe with hardly any posterior margin. The pygidium you show has many segments and a broad posterior margin — features typical of order Proetida, not Phacopida (of which Flexicalymene is a member). I was not able to locate an Ordovician trilobite to match your image, but I’ve included below an image of a pygidium that more closely matches the features I see in yours. (This pygidium belongs to Dikelocephalus, which is certainly not the trilobite in your hand.)
https://upload.wikimedia.org/wikipedia/commons/d/df/Flexicalymene_meeki_pygidium_view.JPG
This looks for all the world like a diagenetic oxidation halo around a bar-shaped fossil (crinoid pluricolumnal?), caused by bacterial activity after the death of the animal. Especially given the halos around the other fossils in the same rock.
If this were the Hunsrück Slate, I would give more pause. But since soft-bodied preservation is unheard of anywhere else in the Devonian, and since Appalachia’s Devonian rocks are sufficiently well studied that we would know about instances of soft-bodied preservation, there is no good reason to consider the possibility here. Just a diagenetic halo.
Bruce, the internal molds in the bottom slab appear to be brachiopod as well, probably Athyris or a related genus. Not sure of the species. Love seeing them all in apparent life position.
