CURT Posted April 12, 2008 Share Posted April 12, 2008 Yesterday I posted a question about a fossil that I purchased years ago as a pomegranate from the Miocene of Nebraska. Extensive research turned up nothing. Does anyone recognize this thing? Is maybe the data wrong? Any insight would be appreciated. Link to comment Share on other sites More sharing options...
LanceH Posted April 12, 2008 Share Posted April 12, 2008 Reminds me of a crinoid holdfast/bulb thingy. Yesterday I posted a question about a fossil that I purchased years ago as a pomegranate from the Miocene of Nebraska. Extensive research turned up nothing. Does anyone recognize this thing? Is maybe the data wrong? Any insight would be appreciated. Link to comment Share on other sites More sharing options...
Xiphactinus Posted April 12, 2008 Share Posted April 12, 2008 Reminds me of a crinoid holdfast/bulb thingy. ^^^^I agree. Crinoid holdfast. Def not Miocene. Link to comment Share on other sites More sharing options...
RJB Posted April 12, 2008 Share Posted April 12, 2008 Ive either got about a dozen fossil pomagranates, or some crinoid bulb thingys? RB Link to comment Share on other sites More sharing options...
jkfoam Posted April 12, 2008 Share Posted April 12, 2008 Go with the crinoid holdfasts. Thats what you have. JKFoam The Eocene is my favorite Link to comment Share on other sites More sharing options...
Mike Murphy Posted April 12, 2008 Share Posted April 12, 2008 Curt: Each of the respondents is correct in their ID. Here is some further information on the crinoid bulb. The crinoid bulb is referred to as a "plate lobolith" and is associated with scyphocrinid crinoids. These were bulbous structures attached to the distal (attachment) ends of crinoid stems and served as either a float or as a bottom support for the crinoids. These plate loboliths are cosmopolitan and are found in late Silurian (Pridolian age) and early Devonian (Lockhovian age) rocks in Oklahoma (Silurian and Devonian), Tennessee (Devonian), New York (Silurian), West Virginia (Silurian), Malyasia (Silurian), Burma (Silurian), Bohemia (Silurian) and Morocco (Silurian and Devonian). Identified as Camarocrinus sp., paleontologists originally thought that the structures represented the calyx of a cystoid.By the start of the 20th century, however, it was determined that they were crinoidal and were identified as structures from various Scyphocrinites spp because they were found in specific association with Scyphocrinites crowns, calyces and stems. Camarocrinus ulrichi (Schuchert, 1904) is the common form species name for the lobolith structure found in the early Devonian of Oklahoma. Various paleontologists have associated these loboliths with functioning as anchors, filled with water and supporting the crinoids on bottom sediments while other paleontologists associated these loboliths with a planktonic lifestyle because of the internal chambers that likely could be variously filled with gas to provide buoyancy. The varying of gas volume and water in the lobolith would allow the crinoids to follow the nutrient levels in the ocean. The floating is now the dominant theory of the lobolith function. There are commonly specimens of the loboliths for sale on eBay and the internet from various fossil dealers. They are most commonly found concentrated in specific beds in the Henryhouse Formation (Late Silurian) and the Haragan and Bois d'Arc Formations (Early Devonian) of southcentral Oklahoma and in the Silurian and Devonian of southern Morocco (Erfoud and Tafilalet regions). Attached is a publication on fosil crinoids that discusses the loboliths of Scyphocrinites along with a diagram of the structure of the lobolith. I have also attached a diagram of the presumed planktonic mode of life. There is an excellent discussion of the Moroccan Scyphocrinites locations, collection of specimens and photgraphs of the individual loboliths and a plate with loboliths in association with crowns and stems on the Scyphocrinites web page, a Moroccan fossil dealer. The lobolith is also not likely from Nebraska as there are no surface exposures of Silurian or Devonian rocks in Nebraska according to the Nebraska Geological Survey. The appearance of the specimen and the weathering of the specimen indicates that the specimen was probably collected from the early Devonian Bois d'Arc near Fittstown, Oklahoma (Pontotoc County). Most of these lobolith specimens are now collected from the Jennings rock quarry. Many are found partially silicified. Regards, Mike Fossil_Crinoids_Hess.pdf Link to comment Share on other sites More sharing options...
CURT Posted April 12, 2008 Author Share Posted April 12, 2008 Curt:Each of the respondents is correct in their ID. Here is some further information on the crinoid bulb. The crinoid bulb is referred to as a "plate lobolith" and is associated with scyphocrinid crinoids. These were bulbous structures attached to the distal (attachment) ends of crinoid stems and served as either a float or as a bottom support for the crinoids. These plate loboliths are cosmopolitan and are found in late Silurian (Pridolian age) and early Devonian (Lockhovian age) rocks in Oklahoma (Silurian and Devonian), Tennessee (Devonian), New York (Silurian), West Virginia (Silurian), Malyasia (Silurian), Burma (Silurian), Bohemia (Silurian) and Morocco (Silurian and Devonian). Identified as Camarocrinus sp., paleontologists originally thought that the structures represented the calyx of a cystoid.By the start of the 20th century, however, it was determined that they were crinoidal and were identified as structures from various Scyphocrinites spp because they were found in specific association with Scyphocrinites crowns, calyces and stems. Camarocrinus ulrichi (Schuchert, 1904) is the common form species name for the lobolith structure found in the early Devonian of Oklahoma. Various paleontologists have associated these loboliths with functioning as anchors, filled with water and supporting the crinoids on bottom sediments while other paleontologists associated these loboliths with a planktonic lifestyle because of the internal chambers that likely could be variously filled with gas to provide buoyancy. The varying of gas volume and water in the lobolith would allow the crinoids to follow the nutrient levels in the ocean. The floating is now the dominant theory of the lobolith function. There are commonly specimens of the loboliths for sale on eBay and the internet from various fossil dealers. They are most commonly found concentrated in specific beds in the Henryhouse Formation (Late Silurian) and the Haragan and Bois d'Arc Formations (Early Devonian) of southcentral Oklahoma and in the Silurian and Devonian of southern Morocco (Erfoud and Tafilalet regions). Attached is a publication on fosil crinoids that discusses the loboliths of Scyphocrinites along with a diagram of the structure of the lobolith. I have also attached a diagram of the presumed planktonic mode of life. There is an excellent discussion of the Moroccan Scyphocrinites locations, collection of specimens and photgraphs of the individual loboliths and a plate with loboliths in association with crowns and stems on the Scyphocrinites web page, a Moroccan fossil dealer. The lobolith is also not likely from Nebraska as there are no surface exposures of Silurian or Devonian rocks in Nebraska according to the Nebraska Geological Survey. The appearance of the specimen and the weathering of the specimen indicates that the specimen was probably collected from the early Devonian Bois d'Arc near Fittstown, Oklahoma (Pontotoc County). Most of these lobolith specimens are now collected from the Jennings rock quarry. Many are found partially silicified. Regards, Mike Thanks so much to everyone. What a great resource you guys are. Link to comment Share on other sites More sharing options...
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