Rockhead Posted September 4, 2008 Share Posted September 4, 2008 The Dude in the center is most interesting. About 1 3/8" across. Link to comment Share on other sites More sharing options...
Uncle Siphuncle Posted September 4, 2008 Share Posted September 4, 2008 Hey all you Echinerds, take a close look at the center specimen. I dropped by Richard's house and saw this thing yesterday. He said it came from the Glen Rose formation and I've never seen this form in the Kgr before. Definitely not Salenia, not even Phyllacanthus, I have no idea what it is. I'm curious what the experts think. Grüße, Daniel A. Wöhr aus Südtexas "To the motivated go the spoils." Link to comment Share on other sites More sharing options...
Guest N.AL.hunter Posted September 4, 2008 Share Posted September 4, 2008 I am confused... where are the "Crinoids, One W/skin, And Mo"? Link to comment Share on other sites More sharing options...
Auspex Posted September 4, 2008 Share Posted September 4, 2008 I am confused... where are the "Crinoids, One W/skin, And Mo"? Typo; been fixed. "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...
Rockhead Posted September 4, 2008 Author Share Posted September 4, 2008 I am confused... where are the "Crinoids, One W/skin, And Mo"? Yea, I meant echinoids. I guess my tongue got wrapped around my eye tooth and I couldn’t see what I was saying. Thanks for the correction Auspex. Link to comment Share on other sites More sharing options...
Bill Posted September 4, 2008 Share Posted September 4, 2008 Nice finds, is the one in question a flint cast with some test remaining? KOF, Bill. Welcome to the forum, all new members www.ukfossils check it out. Link to comment Share on other sites More sharing options...
Uncle Siphuncle Posted September 4, 2008 Share Posted September 4, 2008 Not flint. It is a limestone mold of the echinoid with part of the test remaining. I'd have to look at it again to decide if it is a low form or a compressed example of a more inflated form. If that thing came out of the Glen Rose, it is unlike anything I've ever seen. Grüße, Daniel A. Wöhr aus Südtexas "To the motivated go the spoils." Link to comment Share on other sites More sharing options...
LanceH Posted September 4, 2008 Share Posted September 4, 2008 The three things in the upper left look like "Porocystis" I've seen on another webpage showing Glen Rose fossils. They are supposedly an "algal fruiting body". The Pennsylvanian brachiopod in the lower right is a transported fossil, prolly from road construction gravel. Link to comment Share on other sites More sharing options...
Frank Posted September 4, 2008 Share Posted September 4, 2008 Hey Richard, do you have any other views and/or closer shots of the oddball echinoid?? Link to comment Share on other sites More sharing options...
Rockhead Posted September 5, 2008 Author Share Posted September 5, 2008 Hey Richard, do you have any other views and/or closer shots of the oddball echinoid?? Frank, I do now. I have tried to match it with one in Charles E. Finsley’s “A Field Guide to Fossils of Texas”, but I only find some to be very similar. If it didn’t have the “Test” (skin) on it, it would just be a nice “Skipper”. It appears to be "flattened" as it is about 1/4" thick. The ones it resembles are all more globular. Link to comment Share on other sites More sharing options...
Auspex Posted September 5, 2008 Share Posted September 5, 2008 All I know is that Dan's excited about it, so I'm going to pay attention! "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...
Mike Murphy Posted September 7, 2008 Share Posted September 7, 2008 The unknown echinoid appears to be about 1" in diameter and appears to have portions of the test preserved as pyrite altered to hematite with the interior remaining as limestone. The preservation is not very good, but there are some important features preserved: a dicyclic apical system surrounding a subcircular periproct, uniserial pore zones on the ambulacra, ambulacra about half as wide as each interambulacra, and single primary tubercles on each interambulacral plate. Based on these features and the depressed nature of the test, the echinoid may represent Orthopsis sp. since Orthopsis has all of these features. Is there any preservation of the shell on the oral surface? This might help further in identification. It is a shame that the features of the plates on the ambulacra aren't preserved. This is a neat echinoid and is certainly a rare find! The echinoids from the Glen Rose are diverse and generally well preserved. Was this specimen from the same zone as the Salenia texana and the Heteraster obliquatus? Regards, Mike Link to comment Share on other sites More sharing options...
Uncle Siphuncle Posted September 7, 2008 Share Posted September 7, 2008 Mike I've attached an image of a well preserved Orthopsis comalensis for comparison. The peristome and apical system look similar in both specimens. Richard's specimen is considerably larger, but I have found one in that size range before. I guess what threw me off is the lack of tubercles on his, but I suppose they could have been worn off as it appears to have been heavily reworked. This species does tend to have a low form test, another attribute consistent with both specimens. Your thoughts? BTW I've poked around in the Kgr a little bit down here and between what I've read and seen in the field, if memory serves the Orthopsis/Globator/Goniopygus zone is about 25 meters stratigraphically above the Salenia texana zone. Grüße, Daniel A. Wöhr aus Südtexas "To the motivated go the spoils." Link to comment Share on other sites More sharing options...
Auspex Posted September 7, 2008 Share Posted September 7, 2008 Looks like an object lesson/reminder of how much difference the state of preservation can make. "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...
Mike Murphy Posted September 7, 2008 Share Posted September 7, 2008 Dan: Thanks for the information on the Glen Rose Goniopygus-Globator-Orthopsis zone. I will have to go back to the localities where I have found Goniopygus specimens and see if I can find some of the Orthopsis comalensis since that is one species that has completely eluded me. Imagine what this specimen might have looked like prior to the weathering with a pyrite or marcasite replaced test. The preservation might have been spectacular as with many of the echinoids from the Pawpaw and Del Rio. Mike Link to comment Share on other sites More sharing options...
Rockhead Posted September 12, 2008 Author Share Posted September 12, 2008 The unknown echinoid appears to be about 1" in diameter and appears to have portions of the test preserved as pyrite altered to hematite with the interior remaining as limestone. The preservation is not very good, but there are some important features preserved: a dicyclic apical system surrounding a subcircular periproct, uniserial pore zones on the ambulacra, ambulacra about half as wide as each interambulacra, and single primary tubercles on each interambulacral plate. Based on these features and the depressed nature of the test, the echinoid may represent Orthopsis sp. since Orthopsis has all of these features. Is there any preservation of the shell on the oral surface? This might help further in identification. It is a shame that the features of the plates on the ambulacra aren't preserved. This is a neat echinoid and is certainly a rare find! The echinoids from the Glen Rose are diverse and generally well preserved. Was this specimen from the same zone as the Salenia texana and the Heteraster obliquatus? Regards, Mike Mike, Thanks for the great run down. The DW is pretty proud of it since she found it. It was on the shore of one of the local lakes in the water being washed to and fro by the waves. It was probable much nicer not long before it was picked up. It was found at a lower stratigraphical layer on the earth than the three selenias, but it was a surface find in a well visited and traveled area. And Dan, that’s a beauty of a speccimon you've got there. Where’d that come from? =) Richard Link to comment Share on other sites More sharing options...
Uncle Siphuncle Posted September 12, 2008 Share Posted September 12, 2008 Richard Comal County, Glen Rose formation Grüße, Daniel A. Wöhr aus Südtexas "To the motivated go the spoils." Link to comment Share on other sites More sharing options...
Rockhead Posted September 12, 2008 Author Share Posted September 12, 2008 RichardComal County, Glen Rose formation Say no more! Link to comment Share on other sites More sharing options...
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