| [Thread Prev] | [Thread Next] | [Thread Index] | [Date Prev] | [Date Next] | [Date Index] |
Dear Patricio, > As the traces are not going into the basal plate seems to me that the they should be done in the living shark and not postmortem. Have you consider microwear analysis? These could be "feeding traces" of sharks on other animals as well. Just an idea. I have not had a chance to do microwear analysis or SEM studies of the damaged teeth. I am open to all suggestions and appreciate your reply. Although the pictures I posted on the web do not show much detail in these traces, there is quite a lot there. The shallow grooves are symmetrical in cross section, and fairly uniform in width and depth, not something you would expect from damage or wear related to the shark's feeding activities. In comparison, here's a picture of a tooth of a contemporary but smaller species (/Squalicorax/) that was damaged by the impact of another, similar (serrated) tooth: http://www.oceansofkansas.com/sharks/Kansas/bittooth.jpg /Cretoxyrhina/ teeth (in this specimen and others) were very tough and seldom show evidence of visible wear on the cusps or cutting edges, or breakage while in the sharks jaw. Micro-wear is a subject that has not been extensively studied in /Cretoxyrhina/ so far as I am aware. For the most part, I suspect that their prey was relatively soft-bodied fishes. We do occasionally find the tips of their teeth embedded in the bones of prey species, especially marine reptiles: http://www.oceansofkansas.com/Niobrarasaurus/New%20dino/figure6t.jpg http://www.oceansofkansas.com/Niobrarasaurus/New%20dino/Figure6Tc.jpg Thanks for your comments. Best regards, Mike Everhart Adjunct Curator of Paleontology Sternberg Museum of Natural History Fort Hays State University, Hays, KS www.oceansofkansas.com >Dear Mike, > >As the traces are not going into the basal plate seems to me that the they should be done in the living shark and not postmortem. Have you consider microwear analysis? These could be "feeding traces" of sharks on other animals as well. Just an idea. > >Patricio Dominguez > >----- Mensaje original ----- >De: Mike Everhart <mike@oceansofkansas.com> >Fecha: Martes, Septiembre 13, 2005 3:51 am >Asunto: paleonet Invertebrate feeding traces on fossil shark teeth > > > >>All, >>A small number of fossil shark teeth from the Late Cretaceous >>marine >>deposits in Kansas (Cenomanian-Coniacian) have what appear to be >>feeding >>traces (radula?) of a small invertebrate (gastropod?). I am >>curious to >>know if others have observed similar damage to shark teeeth, and >>to know >>what might be 'feeding' on the enamel of these teeth. >> >>Most of the teeth have been identified as /Cretoxyrhina mantelli/, >>which >>is generally considered to be the largest shark of the time in >>the >>Western Interior Sea. >> >>Pictures of a /Cretoxyrhina/ tooth with feeding traces are shown here: >>http://www.oceansofkansas.com/Temp6.html >> >>Regards, >> >>Mike Everhart >>Adjunct Curator of Paleontology >>Sternberg Museum of Natural History >>Fort Hays State University, Hays, KS >>www.oceansofkansas.com >> >> >> >> >> >> >> >> > > > > > >
Partial index:
