Kane Posted March 27, 2017 Share Posted March 27, 2017 Just ten minutes ago while walking along the river on campus, I came upon this rock with a tube-like piece. The rocks in this river are generally glacial till and more erosion-resistant limestone from the Devonian (Eifelian - Dundee Fm). The tube, about 1.5 inches long, is a bit too straight to be a worm burrow, lacks any of the segments of a crinoid, perhaps too thick to be the edge of a wide spirifer, and it appears next to a brach impression. I just want to be sure if it's geologic or not before I decide whether to keep it. I can try to put the microscope on it later to detect any closer details, and maybe see if I can remove some matrix. But perhaps someone here knows exactly what this is. EDIT: Texture is smooth and somewhat reminiscent to shell material. If it is a brach hinge, it may be sloping away from the edge of the rock as there is no trace of it on the edge. And, if a brach, an odd deposition! ...How to Philosophize with a Hammer Link to comment Share on other sites More sharing options...
GeschWhat Posted March 27, 2017 Share Posted March 27, 2017 Way, way, way out of my realm, but could it be an echinoderm spine? 1 Lori www.areallycrappystory.com/fossils www.facebook.com/fossilpoo Link to comment Share on other sites More sharing options...
westcoast Posted March 27, 2017 Share Posted March 27, 2017 Doesn't look like a brachiopod hinge Link to comment Share on other sites More sharing options...
Kane Posted March 27, 2017 Author Share Posted March 27, 2017 2 minutes ago, GeschWhat said: Way, way, way out of my realm, but could it be an echinoderm spine? I wish! It kind of does resemble an echino spine, though! 1 ...How to Philosophize with a Hammer Link to comment Share on other sites More sharing options...
abyssunder Posted March 28, 2017 Share Posted March 28, 2017 How could it be in a possible transverse section, angular or round? Are productid brachiopods in the Dundee Formation? If yes, it might be a brachiopod spine. It could be also a crinoid spine fragment, although they are more conical than those of brachiopods. I would exclude echinoids. Other pictures, from different angles, are possible? 2 " We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. " Thomas Mann My Library Link to comment Share on other sites More sharing options...
Kane Posted March 28, 2017 Author Share Posted March 28, 2017 Certainly no echninoids in the Dundee Fm (I just wish there were!). Generally, a lot of the brachiopods in this rather thick unit tend to have some larger, less articulated species. The only productid would probably be the Chonetids. The problem with this formation is that there's not been terribly much study of it given its lesser scientific value, and the dearth of distinguishing index fossils apart from some key rugose corals, while many of the rest are found in overlying and underlying units. The only faunal list by unit I've found that is of any value would be "Devonian Rocks of Southeastern Michigan and Northwestern Ohio" by Ehlers, Stumm, and Wright (1951). The pictures I've taken since have not turned out very well, so I will give it a try again later. I plan to return to the site and poke around, too. ...How to Philosophize with a Hammer Link to comment Share on other sites More sharing options...
TqB Posted March 28, 2017 Share Posted March 28, 2017 Any chance it's a smooth orthoconic nautiloid? It seems to have enough taper. Tarquin Link to comment Share on other sites More sharing options...
Kane Posted March 28, 2017 Author Share Posted March 28, 2017 I hadn't thought of that, @TqB, but of the nauts in this unit (which are very few), they all tend to be segmented with a wider taper. Here are a few more pictures. There's a bit of a sharper ridge running along it (second picture, toward the top). The closest match - all visual guesswork, really - is the dorsal view of a Megastrophia sp. hinge, with only the hinge left or the rest buried. But, given that brach hinges will have a lot more flaring toward the beak, if this were just a half near the cardinal extremity, this would be a gigantic specimen (just measured it: 4.5 cm or close to 2 inches). That would make it, if a brach, end to end about 9cm+ / 4 inches+. I don't know anything among the Dundee brachs that large. I just can't figure this one out! ...How to Philosophize with a Hammer Link to comment Share on other sites More sharing options...
TqB Posted March 28, 2017 Share Posted March 28, 2017 With the new photos, it really does look like some annelid tubes (I don't think it's too straight), or even a scaphopod... 1 Tarquin Link to comment Share on other sites More sharing options...
doushantuo Posted March 28, 2017 Share Posted March 28, 2017 It's NOT Plagioglypta, I think Link to comment Share on other sites More sharing options...
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