erose Posted July 11, 2012 Share Posted July 11, 2012 So I'm sorting through my Walnut Formation, Fredericksburg Group, heart urchins. These are mid Albian (Lower Cretaceous) and I have them from a wide area of Central Texas. I've sorted them out and determined they are most likely the genus Heteraster. That's all good since genus is what I usually settle for. But some of them are fairly well preserved and I think I should be able to get them to species level. I read the books and look at the pictures and I still get confused. I see at least six species listed: H. adkinsi Lambert, H. bohmi (de Loriol), H. bosei (Lambert), H. electus (Cragin), H. mexicana (Cotteau) and H. texanus (Roemer). These are all listed for the Fredericksburg Group but not necessarily all Walnut. H. texanus has been my catch all for these but now I see subtle variation amongst them. Are there any easy distinctions I should be following? Link to comment Share on other sites More sharing options...
Uncle Siphuncle Posted July 11, 2012 Share Posted July 11, 2012 keep me posted as i have the same dilemma. some are clearly higher form than others. i've heard that h. tex and h. mex were merged under h. tex, but consider that heresay till someone produces a paper. i'm a lumper as opposed to a splitter, and have similar taxonomic confusion with hemiasters/mecasters, macrasters... Grüße, Daniel A. Wöhr aus Südtexas "To the motivated go the spoils." Link to comment Share on other sites More sharing options...
erose Posted July 11, 2012 Author Share Posted July 11, 2012 The HGMS book is almost useless. But it is still the only thing close to being comprehensive. I have tried to use the various "keys" they provide for genera but there is just enough inconsistency from the key to the individual descriptions to make for confusion. Finsley's Fossils of Texas is better but not as comprehensive. Whenever possible I dig up the original description but most of those have poor illustrations and descriptions are not thorough. We have heard numerous rumors of a new Texas Echinoid guide for years now. But it's always "not finished because something new was found." I would be happy with anything that improved on the current situation, complete or not. And very much agreed lumping is easier and probably better. Link to comment Share on other sites More sharing options...
Uncle Siphuncle Posted July 11, 2012 Share Posted July 11, 2012 I'd like to see a standardized format followed for echs which lists the diagnostic features in the same order every time, with data populated for each attribute. At that point I think we could key things out with more certainty. Grüße, Daniel A. Wöhr aus Südtexas "To the motivated go the spoils." Link to comment Share on other sites More sharing options...
erose Posted July 11, 2012 Author Share Posted July 11, 2012 I'd like to see a standardized format followed for echs which lists the diagnostic features in the same order every time, with data populated for each attribute. At that point I think we could key things out with more certainty. Exactly. And the same orientation for all photographs or drawings with either consistent scale or easy to read scale bars. When I was with the NYPS I wrote field guides and geo/paleo articles. I enjoyed it a great deal and one of my favorite projects was a large (50 pages) field guide for Big Brook. Various members contributed photos of fossils, text chapters, and illustrations and I did the geo research and double checked the IDs as best I could. It one a first place award from AFMS for that year and we still revised and improved it for later use. It was a lot of work but very fulfilling when finished, even without the award. I know a great deal more about working with photos and such now. The paleo community had something like this in the works with Keith Minor's Cretaceous Fossils web site. I had been taking photos of various east coast fossils to add just before they shut it down. Again we still await the rumored Ammonite publication. If we could make this happen for echinoids I would be happy to act as the assembly editor. I am not an expert on echinoids, nor do I have an extensive collection, but I would happily act as the clearing house/collection point and do whatever was needed to get the material prepared. We would just need someone else to follow through with the taxonomy. I'm probably off my gourd in suggesting this...don't tell my wife. Link to comment Share on other sites More sharing options...
Uncle Siphuncle Posted July 12, 2012 Share Posted July 12, 2012 I've heard rumors of Frank Holterhoff and Neil Immega independently wanting to revise the ech book....no progress yet. If Frank does it, he wants to photo many of my echs. Keith Minor is a friend of mine too...I guess the K.com site just became overwhelming for him (dang shame too), especially with his K ammonite treatise he's working on. He's been to my house to photograph stuff a couple weekends, and the last time he shot nearly 5000 frames...it will be way cool to see this magnum opus once finished...... Grüße, Daniel A. Wöhr aus Südtexas "To the motivated go the spoils." Link to comment Share on other sites More sharing options...
gwestbrook Posted July 17, 2012 Share Posted July 17, 2012 Man! If you two are having problems IDing Echinoids then I have no hope. lol! Link to comment Share on other sites More sharing options...
erose Posted July 17, 2012 Author Share Posted July 17, 2012 (edited) Man! If you two are having problems IDing Echinoids then I have no hope. lol! Don't fret. I'm trying to get down to species level, but in truth, if you can get them to genus you are doing quite well. Some of us just get a bit obsessed... Even after three decades of serious collecting I still consider every ID I make tentative. There are so many variables and every time you think you have all the necessary information you learn of yet a new species or genus or some scientist turns it all upside down. And if the earlier work was done by a splitter then well, all bets are off. And the lumpers didn't make things much easier as well. I read the descriptions, look at the pictures and try my best to understand the differences between this species and the other. Some times it finally clicks like just the other day when I finally figured out the one distinct difference between two "Salenias" found in the Glen Rose and often together. There are a number of differences but most of them are just variations on common attributes. But there was one difference that was easy to see: The position of the apical opening in relation to the ambs. In Hyposalenia phillipsae the opening is centered between the ambs and for Leptosalenia texana its always aligned with one amb. It's like one has it's little hat cocked to the side and one doesn't. Edited July 17, 2012 by erose Link to comment Share on other sites More sharing options...
Uncle Siphuncle Posted July 17, 2012 Share Posted July 17, 2012 i just learned sumpin! thx e Grüße, Daniel A. Wöhr aus Südtexas "To the motivated go the spoils." Link to comment Share on other sites More sharing options...
erose Posted July 17, 2012 Author Share Posted July 17, 2012 i just learned sumpin! thx e Yes, that is the kind of notation we need in the next Texas echinoid book. Link to comment Share on other sites More sharing options...
gwestbrook Posted July 19, 2012 Share Posted July 19, 2012 Don't fret. I'm trying to get down to species level, but in truth, if you can get them to genus you are doing quite well. Some of us just get a bit obsessed... Even after three decades of serious collecting I still consider every ID I make tentative. There are so many variables and every time you think you have all the necessary information you learn of yet a new species or genus or some scientist turns it all upside down. And if the earlier work was done by a splitter then well, all bets are off. And the lumpers didn't make things much easier as well. I read the descriptions, look at the pictures and try my best to understand the differences between this species and the other. Some times it finally clicks like just the other day when I finally figured out the one distinct difference between two "Salenias" found in the Glen Rose and often together. There are a number of differences but most of them are just variations on common attributes. But there was one difference that was easy to see: The position of the apical opening in relation to the ambs. In Hyposalenia phillipsae the opening is centered between the ambs and for Leptosalenia texana its always aligned with one amb. It's like one has it's little hat cocked to the side and one doesn't. Have you seen this site? http://www.nhm.ac.uk/nature-online/life/other-invertebrates/science-echinoids/index.html I'm sure you have, but I just found it for the first time. Link to comment Share on other sites More sharing options...
gwestbrook Posted July 19, 2012 Share Posted July 19, 2012 The regulars drive me nuts. I think I am finally able to tell the difference between Salenia mexicana and Salenia texana. but that's about the extent of my knowledge of echinoid ID down to species. Lol! Link to comment Share on other sites More sharing options...
erose Posted July 19, 2012 Author Share Posted July 19, 2012 (edited) The regulars drive me nuts. I think I am finally able to tell the difference between Salenia mexicana and Salenia texana. but that's about the extent of my knowledge of echinoid ID down to species. Lol! Yep, I know that web site. It helps sometimes and is a good reference for current papers and such. I'm always adding to my lists of ID criteria for echs. Often the formation helps with eliminating possibilities (S.texana is Glen Rose & S. mexicana occurs in the younger Fredericksburg group) but other things like knowing that Phymosoma never has perforate tubercules while a Tetragramma always does helps. But for that, it also means you need a fairly well preserved specimen. Right now I am working my way through a bunch of Glen Rose and Walnut Formation echinoids and doing better than I had hoped at sorting them out...with the exception of those darn HETER-######-TERS! Edited July 19, 2012 by erose Link to comment Share on other sites More sharing options...
gwestbrook Posted July 19, 2012 Share Posted July 19, 2012 (edited) lol! Well, good luck on it all. I'll keep plugging away trying to learn what I can. I really like the echinoids, especially the ones that are in good shape. The more intricate and ornate the better. I would like to find some of the cidaroid types but I know I will have to do some traveling to do that. Here are a few of the better ones I've found in Callahan, Mills and Scurry Counties. SE Callahan County Mills County Scurry County (Fluvanna) Edited July 19, 2012 by gwestbrook Link to comment Share on other sites More sharing options...
erose Posted July 20, 2012 Author Share Posted July 20, 2012 Very nice gwestbrook. Tell me how do you discern Salenia texana from S. mexicana? I've gone by size and formation but would like to know other aspects to look for. Link to comment Share on other sites More sharing options...
gwestbrook Posted July 21, 2012 Share Posted July 21, 2012 (edited) Very nice gwestbrook. Tell me how do you discern Salenia texana from S. mexicana? I've gone by size and formation but would like to know other aspects to look for. Well, I read one paper (I think it was a paper referenced on this site with a link) that simply said, "the apical disk in the S. texana looks like a plain 10-gallon hat and the apical disk on the S. mexicana looks like an ornate Mexican sombrero". So, judging by the ornamentality of the apical disk is the main way I identify them. I've noticed that the apical disk one one species is fairly even all around and on the other species it has a scalloped appearance, the latter being the S. mexican, I'm assuming. Very simplistic, I know. I'm sure I could be wrong, though. Edited July 21, 2012 by gwestbrook Link to comment Share on other sites More sharing options...
erose Posted July 21, 2012 Author Share Posted July 21, 2012 Well, I read one paper (I think it was a paper referenced on this site with a link) that simply said, "the apical disk in the S. texana looks like a plain 10-gallon hat and the apical disk on the S. mexicana looks like an ornate Mexican sombrero". So, judging by the ornamentality of the apical disk is the main way I identify them. I've noticed that the apical disk one one species is fairly even all around and on the other species it has a scalloped appearance, the latter being the S. mexican, I'm assuming. Very simplistic, I know. I'm sure I could be wrong, though. I've read the same descriptions and then when I laid all the specimens out I see a continuos spectrum from ornate to plain and from smooth-edged to scalloped. Sometimes I had to wait until I had a couple of extra-well preserved specimens to be sure. But this also gets into the questions of stratigraphic ranges for various species. Some of the books have such wide ranges and others are very limited. Link to comment Share on other sites More sharing options...
gwestbrook Posted July 21, 2012 Share Posted July 21, 2012 At this point I've only found 6 or 7 of the Salenia types, so I haven't been able to detect such a broad spectrum with respect to the apical disc. Mine all come from just two formations as well, so that also narrows down the variation quite a bit. I'm pretty sure I have 2 or 3 of each of the texana and mexicana species. The very first echinoid I found after getting back into the hunt after so many years was a Salenia texana that I found at that first location in Callahan County. When I first saw it we were looking in the shade of some scrub oaks and I first thought it was an acorn cap and nearly threw it to the side. lol! Link to comment Share on other sites More sharing options...
Solittletime Posted December 27, 2013 Share Posted December 27, 2013 I realize that it has been a long time since posts to this topic were made, However, I am working very hard on a new book on Cretaceous Texas echinoids. Interestingly, the last several days I have been pulling out what little hair I have left trying to figure out the Heterasters. As a result, I am a little amused and also relieved to read some of your old comments. I totally agree with the comments about the poor and in fact contradictory descriptions. I have just discovered that there is a paper which was presented at the Geological Society of American meeting in 2009. The reference is Miller, Justin, Paper No. 10-4 Preliminary revision of Heteraster (Echinoidea) from the Lower Cretaceous of Texas. Basically, he concludes, and I certainly concur, that H. adkinsi, H. bohmi, and H. mexicanus are all synonyms of H. texanus. As I said, I am working very hard to bring this book to fruition, but there is a lot of material to cover. I am making color pictures of the aboral, adoral (if needed), lateral, and posterior (in the case of irregulars) and also describing the unique features of each specimen with text. In some cases I am also using simple statistical approaches to differentiate closely related species. I believe that I have used this approach effectively in defining the Macrasters. However, sometimes, and this is true of the Heterasters and some of the Salenia, the latter effort is impeded by the lack of adequate sample sizes. Dan Woehr is helping me with the Anacacho I am telling you all this as I would like to enlist your much needed help and collaboration. I would also appreciate your input as this project progresses. I am very very new to Fossil Forum so I hope you see this and reply. Link to comment Share on other sites More sharing options...
Herb Posted December 28, 2013 Share Posted December 28, 2013 Have you seen this site? http://www.nhm.ac.uk/nature-online/life/other-invertebrates/science-echinoids/index.html I'm sure you have, but I just found it for the first time. beautiful specimen "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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