mikecable Posted April 27, 2013 Share Posted April 27, 2013 Orbitolina texana is an index fossil for the Lower Glen Rose formation of the Trinity Group. (I wouldn't know this without the help of Erich Rose and Dan Woehr, and I wouldn't have found these fossils without Dan's help.) Not much to look at visually, but an important fossil, so I thought I would post this. Plus it gives me a chance to play with some new gear, and also to demonstrate to my sixth grade students how amateurs can engage in real science. The Upper and Lower Glen Rose have been differentiated by a one foot layer of Corbula shells (Marion Whitney, Some New Pelecypoda from the Glen Rose Formation of Texas, J. Paleontology, Vol. 26, p. 697 (Sept. 1952). I haven't identified that layer. But Dan informed me of the Orbitolina texana zone as being a marker for the echinoid producing layer of the lower Glen Rose. If anyone would like to chime in with info on the Corbula layer I would love to know more. Site picture. I don't know if the overlaying member is the Upper Glen Rose or just a distinctive bed in the Lower Glen Rose. I didn't have time to investigate that layer, and since the site is more than a three hour drive I won't be checking this weekend. in situ picture of Orbitolina texana. I've seen them described as discs, plates, etc. In cross-section they look like tiny flying saucers. Some close up pics. Not much to look at, but since I went to the trouble to sieve them and photograph them I thought I would post this. If you want to know more The Foraminiferal Genus Orbitolina in North America Finally some evidence that Orbitolina texana identifies the echinoid zone of the Lower Glen Rose. A nice Leptosalenia texana. Found at this very site. I'm feeling scientific. Link to comment Share on other sites More sharing options...
mikecable Posted April 27, 2013 Author Share Posted April 27, 2013 (edited) Accidental, but you can see one of the tiny flying saucers named Orbitolina texana diving into the mouth of the above echinoid. I'm feeling whimsical, but I can't help thinking of Raquel Welch in Fantastic Voyage. Edited April 27, 2013 by mikecable Link to comment Share on other sites More sharing options...
Uncle Siphuncle Posted April 27, 2013 Share Posted April 27, 2013 glad you enjoyed the Kgr, mike. above the leptosalenia zone is upper glen rose; below it, the lower. orbitolina shows up in lots of marly zones in the Kgr. whenever i see these forams, i slow down and look for echs as they are often found together. 1 Grüße, Daniel A. Wöhr aus Südtexas "To the motivated go the spoils." Link to comment Share on other sites More sharing options...
mikecable Posted April 27, 2013 Author Share Posted April 27, 2013 glad you enjoyed the Kgr, mike. above the leptosalenia zone is upper glen rose; below it, the lower. orbitolina shows up in lots of marly zones in the Kgr. whenever i see these forams, i slow down and look for echs as they are often found together. I enjoyed both sites, but I truly took joy from identifying a foram, albeit a large one. I still don't know if I'm a geek, a nerd, or both. But sometimes when I get excited by small things like this my students share my joy. I can't help but think that's a good thing. Link to comment Share on other sites More sharing options...
mikecable Posted April 27, 2013 Author Share Posted April 27, 2013 Accidental, but you can see one of the tiny flying saucers named Orbitolina texana diving into the mouth of the above echinoid. I'm feeling whimsical, but I can't help thinking of Raquel Welch in Fantastic Voyage. Link to comment Share on other sites More sharing options...
Uncle Siphuncle Posted April 27, 2013 Share Posted April 27, 2013 micros have their allure...and wives don't mind them entering the house as much as macros! Grüße, Daniel A. Wöhr aus Südtexas "To the motivated go the spoils." Link to comment Share on other sites More sharing options...
mikecable Posted April 27, 2013 Author Share Posted April 27, 2013 micros have their allure...and wives don't mind them entering the house as much as macros! Not so sure on that one my brother. I was drying matrix just this week in the oven. Didn't make me popular. On the flip side, I was criticized for tasting something in a green tea bottle in the fridge. Turned out to be some sort of apple cider vinegar concoction for hair care. Didn't taste like tea. Link to comment Share on other sites More sharing options...
JohnJ Posted April 28, 2013 Share Posted April 28, 2013 Not so sure on that one my brother. I was drying matrix just this week in the oven. Didn't make me popular. On the flip side, I was criticized for tasting something in a green tea bottle in the fridge. Turned out to be some sort of apple cider vinegar concoction for hair care. Didn't taste like tea. ...shudder... Mike, your spacecraft has taken a turn for the worse...the mouth is on the opposite side. However, the association of the foram and the echinoid is classic and still beautiful. The human mind has the ability to believe anything is true. - JJ Link to comment Share on other sites More sharing options...
mikecable Posted April 28, 2013 Author Share Posted April 28, 2013 ...shudder... Mike, your spacecraft has taken a turn for the worse...the mouth is on the opposite side. However, the association of the foram and the echinoid is classic and still beautiful. I don't know how I made that newbie mistake. Thanks for the correction. Link to comment Share on other sites More sharing options...
JamieLynn Posted November 11, 2013 Share Posted November 11, 2013 (edited) doing research on the orbitolina and saw this post- How big can they get? I found what looks exactly like the ones in your picture in Round Rock creek just north of Austin. But it is 3" in diameter. Slightly indented on one side. Could it possibly be an orbitolina? It seems they are only an inch or less across typically. It is possible that it is just a piece of perfectly round saucer shaped limestone......I'll get pics of it tomorrow. Edited; the more I look at it I'm pretty sure it's just a rock. hopefull newbie.... Edited November 11, 2013 by JamieLynn www.fossil-quest.com Link to comment Share on other sites More sharing options...
Jersey Posted November 13, 2013 Share Posted November 13, 2013 Interesting foram. My preference of the saucer-shaped forams, though, is Nummulites which I believe gets even larger and which makes up part of the pyramids (http://en.wikipedia.org/wiki/Nummulite ). Link to comment Share on other sites More sharing options...
Herb Posted November 22, 2013 Share Posted November 22, 2013 The biggest Orbitolina I have is about 10-13mm, Nummulites about 30-35mm in dia. Possibly a sand dollar? I have them from 10mm to 100mm in diameter. "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...
Herb Posted November 22, 2013 Share Posted November 22, 2013 It's obvious Mike, from the picture, that Raquel has all the attributes of a fine microbiologist. "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...
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