Mike Olive Posted January 18, 2014 Share Posted January 18, 2014 Hello, All: I'm a new member, live in Colorado but, mostly collect fossils on the family ranch in central Texas near Bandera. The rock there is lower Cretaceous limestone. However, I'm mainly interested in some (Edwards Formation?) chert nodules that are scattered here and there all over the ranch. Some of the nodules have fossils. I've looked around the Fossil Forum site and I'm very encouraged. There seems to be lot of expertise, covering many types of fossils. Great. I've been able to identify some of my chert fossils but, not all, not by a long shot. Attached photos show a fossil conical marine gastropod (possibly, genus Nerinea or, Turritella?) that's pretty common on the Olive ranch. I've found dozens of them but, I don't know what the heck I've got. Any ID help would be greatly appreciated. Thanks. Mike Olive Boulder, Colorado Link to comment Share on other sites More sharing options...
RyanNREMTP Posted January 18, 2014 Share Posted January 18, 2014 Closest I can find in my books is Volutomorpha. But it's hard to tell exactly from an impression. Link to comment Share on other sites More sharing options...
Pliosaur Posted January 19, 2014 Share Posted January 19, 2014 I think it might be a shell imprint of maybe conch??? Link to comment Share on other sites More sharing options...
Auspex Posted January 19, 2014 Share Posted January 19, 2014 I think you are on the right track with Turritella (but which one???). Compare here: LINK "There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant “Try to learn something about everything and everything about something.” - Thomas Henry Huxley >Paleontology is an evolving science. >May your wonders never cease! Link to comment Share on other sites More sharing options...
Herb Posted January 21, 2014 Share Posted January 21, 2014 (edited) Closest I can find in my books is Volutomorpha. But it's hard to tell exactly from an impression. I believe also that it is a species of "Volutomorpha. Edited January 21, 2014 by Herb "Absence of evidence is not evidence of absence"_ Carl Sagen No trees were killed in this posting......however, many innocent electrons were diverted from where they originally intended to go. " I think, therefore I collect fossils." _ Me "When you have eliminated the impossible, whatever remains, however improbable, must be the truth."__S. Holmes "can't we all just get along?" Jack Nicholson from Mars Attacks Link to comment Share on other sites More sharing options...
Mike Olive Posted February 2, 2014 Author Share Posted February 2, 2014 Thanks, guys, for the help. I apologize for my photos. I know they aren't the best, and I'm working on that. But, I have to disagree here. I have dozens of these chert fossils featuring the same small, slender, high, turret-like gastropod. And I don't think it's Volutomorpha. First, the shape is wrong, my fossil doesn't have the bulb-like morphology seen in Volutomorpha. Further, the beaded ornamentation isn't identical. Each whorl of my one to 3 inch turreted fossils features a sequence of columns or pillars, these columns being composed of, usually, four beads. As the columns curve around, each is in a vertical line with the columns in the whorls above and, below. The whole thing presents itself almost like an echo of graceful marble columns from ancient Greece, having different levels, curving around a forum. Of course, being chert, it's silica dioxide, not marble but, the resemblance is there. Anyway, as always, I appreciate all ideas that come my way. Tuning into The Fossil Forum is like taking a course on fossils. I'm learning a lot. Thanks. --Mike Olive Link to comment Share on other sites More sharing options...
Taogan Posted February 2, 2014 Share Posted February 2, 2014 Looks like a Cerithiid, if it was European I'd say Exechocirsus, but I haven't been able to find out if that genus is present in the USA. Link to comment Share on other sites More sharing options...
elcoincoin Posted February 2, 2014 Share Posted February 2, 2014 +1 on cerithiid Link to comment Share on other sites More sharing options...
Mike Olive Posted February 3, 2014 Author Share Posted February 3, 2014 Yeah, a cerithiid like Exechocirsus is an interesting idea. I looked over some photos of European examples and, it is pretty close. But, so far, I am unable to find good proof that Exechocirsus occurs in Cretaceous North America. It's a good lead, I'll continue looking.... Mike Olive Link to comment Share on other sites More sharing options...
Herb Posted February 10, 2014 Share Posted February 10, 2014 (edited) here is a comparison photo of your imprint with a Volutimorpha that I have. not perfect but pretty close. Edited February 10, 2014 by Herb "Absence of evidence is not evidence of absence"_ Carl Sagen No trees were killed in this posting......however, many innocent electrons were diverted from where they originally intended to go. " I think, therefore I collect fossils." _ Me "When you have eliminated the impossible, whatever remains, however improbable, must be the truth."__S. Holmes "can't we all just get along?" Jack Nicholson from Mars Attacks Link to comment Share on other sites More sharing options...
Mike Olive Posted February 11, 2014 Author Share Posted February 11, 2014 Thanks, Herb, for showing me the Volutomorpha comparison. You're right, it does make a pretty good fit. These last few days, I have been going over my dozen or so good examples of this fossil. There is a lot more variation than I remembered. Some of the conical spires are, indeed, very slim but, others are are much fatter. And, the beaded pillars do not, necessarily, form a continuous rib up and down the fossil. In some fossils, within a given whorl, each line of beads, each rib, is off-set from ribs in the whorls above and below. I don't understand all this variation. I'm gonna have to take a couple steps backwards, and rethink this. Thanks, again.---Mike Olive Link to comment Share on other sites More sharing options...
Uncle Siphuncle Posted February 11, 2014 Share Posted February 11, 2014 the external molds look consistent with what i've found in edwards limestone cobbles. but i'm not seeing what looks to be chert, common inclusions in the edwards, at least in viewing the pix on my phone. Grüße, Daniel A. Wöhr aus Südtexas "To the motivated go the spoils." Link to comment Share on other sites More sharing options...
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