Codes Posted May 22, 2023 Share Posted May 22, 2023 Can anyone help? I sent the pictures off and they are pretty sure it’s a femur bone from a mosasaur. Does that look right? Found on private land along the Missouri River in South Dakota. Appreciate the help. Link to comment Share on other sites More sharing options...
JohnJ Posted May 23, 2023 Share Posted May 23, 2023 The open cell structure of the bone is quite unlike typical mosasaur bone preservation. Sent pictures off to who? What feature suggested 'mosasaur femur' to them? The human mind has the ability to believe anything is true. - JJ Link to comment Share on other sites More sharing options...
Codes Posted May 23, 2023 Author Share Posted May 23, 2023 The Mammoth Site in South Dakota 1 Link to comment Share on other sites More sharing options...
Troodon Posted May 23, 2023 Share Posted May 23, 2023 Can you be more specific as to locality do we can determine if its Mesozoic or Cenozoic. County? Link to comment Share on other sites More sharing options...
Codes Posted May 23, 2023 Author Share Posted May 23, 2023 Charles Mix County, South Dakota Link to comment Share on other sites More sharing options...
Troodon Posted May 23, 2023 Share Posted May 23, 2023 Cannot help with an ID not a marine expert. Can you confirm it was Kp? Kp: Pierre shale Q...: Quaternary Link to comment Share on other sites More sharing options...
Codes Posted May 23, 2023 Author Share Posted May 23, 2023 Q according to that map Link to comment Share on other sites More sharing options...
Troodon Posted May 23, 2023 Share Posted May 23, 2023 If its Quaternary it's more recent and certainly not mosasaur Link to comment Share on other sites More sharing options...
Codes Posted May 23, 2023 Author Share Posted May 23, 2023 Maybe I read the map wrong. I circled the general area Link to comment Share on other sites More sharing options...
Troodon Posted May 23, 2023 Share Posted May 23, 2023 Thats Pierre Shale...will let expert in that deposit chime in Link to comment Share on other sites More sharing options...
Codes Posted May 23, 2023 Author Share Posted May 23, 2023 My bad and thank you Link to comment Share on other sites More sharing options...
Jared C Posted May 24, 2023 Share Posted May 24, 2023 it appears from the photos that your bone is hollow, is that right? Mosasaurs (and other marine reptiles) have dense bones, hollow bones are a feature more famously present in dinosaurs. If indeed hollow, you might have a specimen from a "bloat and float" dinosaur on your hands, which would be very interesting 1 “Not only is the universe stranger than we think, it is stranger than we can think” -Werner Heisenberg Link to comment Share on other sites More sharing options...
Codes Posted May 24, 2023 Author Share Posted May 24, 2023 Boat and float? Sorry don’t know that term Link to comment Share on other sites More sharing options...
mamlambo Posted May 24, 2023 Share Posted May 24, 2023 From what I understand "bloat and float" is when a dead carcass bloats up from decomposition gasses and ends up in a river or the ocean and the floats a distance before descending to the bottom where the fossil is found. It is one theory as to how land animal fossils (dinosaur in this case) sometimes end up in marine settings. 1 Link to comment Share on other sites More sharing options...
pachy-pleuro-whatnot-odon Posted May 24, 2023 Share Posted May 24, 2023 Interesting specimen! Apart from the fact that the bone appears to be hollow, it doesn't appear to have the right shape for a mosasaur propodial either. That's because their propodial bones are usually quite flat and stubby. Plesiosaurs, of course, are found in Pierre Shale as well. And while their propodial bones have a more cancellous inner portion (such as can be seen in the specimen from Sandsend, Whitby, below) that may have eroded out somehow, the hollow seen in the photographs appears too small for that. The bone also appears too rectangular for the usually well-rounded plesiosaur diaphyses. In addition, while the bone does appear to have an obvious rounded femural head on one side, I'd say the lowered, flat surface right next to it, is a combination more typically encountered as articular joint in land-based animals rather than marine creatures. That's because in marine animals, the arms and legs form a less tight coupling with the pelvic and pectoral girdles, due to a reduced need for structural support. As such, I'm on the "bloat & float"-camp. 3 'There's nothing like millions of years of really frustrating trial and error to give a species moral fibre and, in some cases, backbone' -- Terry Pratchett Link to comment Share on other sites More sharing options...
doushantuo Posted May 24, 2023 Share Posted May 24, 2023 (edited) some of you may like: Microanatomical and Histological Features in the Long Bones of Mosasaurine Mosasaurs (Reptilia, Squamata) – Implications for Aquatic Adaptation and Growth Rates Alexandra Houssaye, Johan Lindgren, Rodrigo Pellegrini, Andrew H. Lee, Damien Germain, Michael J. Polcyn PLoS ONE 8(10): e76741. doi:10.1371/journal.pone.0076741 size 17 MB file.pdf Edited May 24, 2023 by doushantuo 2 1 Link to comment Share on other sites More sharing options...
Troodon Posted May 24, 2023 Share Posted May 24, 2023 Not aware of any float and bloat dinosaurs being found in the Pierre Shale, especially that far east. Would be interesting and the School of Mines in Rapid City would be a good place to comment on it. Link to comment Share on other sites More sharing options...
Codes Posted May 24, 2023 Author Share Posted May 24, 2023 That is who looked at it. They went to school there and now work at the mammoth site. 1 Link to comment Share on other sites More sharing options...
Troodon Posted May 24, 2023 Share Posted May 24, 2023 Actually has some of the look of a Tibia from a Hadrosaurid but cannot say its one because of where it was found and comments from S of M Link to comment Share on other sites More sharing options...
Codes Posted May 24, 2023 Author Share Posted May 24, 2023 Dr. Darrin Pagnac at the South Dakota School of Mines and Technology is who looked at the pics. He said by the looks of the rocks it’s most likely a beat femur from a mostarus Link to comment Share on other sites More sharing options...
JohnJ Posted May 24, 2023 Share Posted May 24, 2023 1 hour ago, Codes said: Dr. Darrin Pagnac at the South Dakota School of Mines and Technology is who looked at the pics. He said by the looks of the rocks it’s most likely a beat femur from a mostarus What pictures did you send to him? The second and last image you posted above are taken at the most useful 90° angles. Additional photos taken at 90° could be helpful. The human mind has the ability to believe anything is true. - JJ Link to comment Share on other sites More sharing options...
Codes Posted May 24, 2023 Author Share Posted May 24, 2023 (edited) These exact photos Edited May 24, 2023 by Codes 1 Link to comment Share on other sites More sharing options...
doushantuo Posted May 24, 2023 Share Posted May 24, 2023 (edited) that would be this Darren Pagnac PALAIOS (2017) 32 (5): 330–336. https://doi.org/10.2110/palo.2016.090 Edited May 24, 2023 by doushantuo Link to comment Share on other sites More sharing options...
doushantuo Posted May 24, 2023 Share Posted May 24, 2023 Dare I say it? I see some similarity withTylosaurine quadrates Link to comment Share on other sites More sharing options...
Codes Posted May 24, 2023 Author Share Posted May 24, 2023 Sorry I’m a rookie. Why do you say… do I dare say it? Link to comment Share on other sites More sharing options...
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