David in Japan Posted October 24, 2018 Share Posted October 24, 2018 Hi TFF friends, how are you? I would like to ask you few questions about a tooth I found last week in Japan. This tooth comes from the late cretaceous (Santonian) Hinoshima formation where I usually go. This formation yield about 13 different species of shark tooth, comprising Ptychodus mammillaris, Hexanchus microdon, Hexanchus sp., Notidanodon dentatus, Sphenodus sp., Echinorhinus wadanohanaensis, Cretalamna appendiculata, Protolamna sp., Squalicorax sp., Cretodus sp., Paranomotodon sp., Dwardius sp., and Synechodus sp. I found this tooth which looks like to be a Cretodus sp. but I would like to have a confirmation. In fact, I have already found Cretodus tooth at the same location but they looked a little bit different. To explain it simply, they just looked like Cretalamna teeth with fold on the crown. The tooth I've found last week, has a lot of long ridges (running from the base of the crown to half of the it) and is more "tougher" (round) than the previous one I have found. Can you confirm me or infirm me the ID? Last question: If this is a Cretodus tooth, how can we explain that this tooth has a lot of ridges but the previous one I've found have "only" fold? Is it pathologic or ontogenic? Thank you very much for your help. David 2 ~~~~~~~~~~~~〇~~~~~~~~~~~~~ Warmest greetings from Kumamoto、 Japan Link to comment Share on other sites More sharing options...
Al Dente Posted October 24, 2018 Share Posted October 24, 2018 Not sure but looks more like a bony fish tooth or even a reptile tooth to me. 2 Link to comment Share on other sites More sharing options...
PaleoRon Posted October 24, 2018 Share Posted October 24, 2018 It does not look like a shark tooth to me. Fish or reptile would be more likely. 2 Link to comment Share on other sites More sharing options...
The Amateur Paleontologist Posted October 24, 2018 Share Posted October 24, 2018 +1 on bony fish tooth - neat one BTW -Christian 1 Opalised fossils are the best: a wonderful mix between paleontology and mineralogy! Q. Where do dinosaurs study? A. At Khaan Academy!... My ResearchGate profile Link to comment Share on other sites More sharing options...
fossilselachian Posted October 24, 2018 Share Posted October 24, 2018 Agree, don't see a Cretodus tooth here. 1 Link to comment Share on other sites More sharing options...
David in Japan Posted October 24, 2018 Author Share Posted October 24, 2018 3 hours ago, Al Dente said: Not sure but looks more like a bony fish tooth or even a reptile tooth to me. 3 hours ago, PaleoRon said: It does not look like a shark tooth to me. Fish or reptile would be more likely. 1 hour ago, The Amateur Paleontologist said: +1 on bony fish tooth - neat one BTW -Christian That is a good surprise. By bony fish, do you mean a kind of Enchodus of some sort? I think it is a neat tooth too. 2 cm high... must have been a big fish. Would love to have a fight with such guy. What made you think fish or reptile? Its more conical shape or the ridges? ~~~~~~~~~~~~〇~~~~~~~~~~~~~ Warmest greetings from Kumamoto、 Japan Link to comment Share on other sites More sharing options...
ynot Posted October 24, 2018 Share Posted October 24, 2018 1 hour ago, David in Japan said: What made you think fish or reptile? Its more conical shape or the ridges? I agree with the others, for both reasons. I am leaning more toward reptile because some pliseasaur teeth shown on TFF have the same appearance. Darwin said: " Man sprang from monkeys." Will Rogers said: " Some of them didn't spring far enough." My Fossil collection - My Mineral collection My favorite thread on TFF. Link to comment Share on other sites More sharing options...
Al Dente Posted October 24, 2018 Share Posted October 24, 2018 2 hours ago, David in Japan said: What made you think fish or reptile? Its more conical shape or the ridges? Most shark tooth enamel has a different texture than this. Hybodont sharks have a different type of enamel on their teeth than most sharks. It is possible this could be from a hybodont shark. Link to comment Share on other sites More sharing options...
Anomotodon Posted October 24, 2018 Share Posted October 24, 2018 I agree with the Hybodont ID (cf. Meristodonoides). Santonian plesiosaur teeth don't have carinae. I am unfamiliar with any bony fish teeth from the Late Cretaceous with similar morphology. Here are some of mine from Albian and Callovian 3 The Tooth Fairy Link to comment Share on other sites More sharing options...
David in Japan Posted October 24, 2018 Author Share Posted October 24, 2018 6 hours ago, Anomotodon said: I agree with the Hybodont ID (cf. Meristodonoides). Santonian plesiosaur teeth don't have carinae. I am unfamiliar with any bony fish teeth from the Late Cretaceous with similar morphology. Here are some of mine from Albian and Callovian 8 hours ago, ynot said: I agree with the others, for both reasons. I am leaning more toward reptile because some pliseasaur teeth shown on TFF have the same appearance. Interesting debate. Does hybodont teeth grows that large? It may be a mistake but i always thought hybodont teeth was smaller. ~~~~~~~~~~~~〇~~~~~~~~~~~~~ Warmest greetings from Kumamoto、 Japan Link to comment Share on other sites More sharing options...
PaleoRon Posted October 24, 2018 Share Posted October 24, 2018 You might want to get in contact with a paleontologist who is familiar with the region you are collecting in. 1 Link to comment Share on other sites More sharing options...
David in Japan Posted October 24, 2018 Author Share Posted October 24, 2018 Will do. Ironically, I found this tooth when I came back from the museum to donate my Heterodontus tooth. 1 ~~~~~~~~~~~~〇~~~~~~~~~~~~~ Warmest greetings from Kumamoto、 Japan Link to comment Share on other sites More sharing options...
Anomotodon Posted October 25, 2018 Share Posted October 25, 2018 Can you post more pictures of the base? Do carinae extend on the "root" part as seen on this picture or is it just matrix? 2 cm is actually fairly big for a hybodont, but size is rarely determining parameter in ID The Tooth Fairy Link to comment Share on other sites More sharing options...
David in Japan Posted October 25, 2018 Author Share Posted October 25, 2018 5 hours ago, Anomotodon said: Can you post more pictures of the base? Do carinae extend on the "root" part as seen on this picture or is it just matrix? 2 cm is actually fairly big for a hybodont, but size is rarely determining parameter in ID The base of the crown is almost round. The carina is extending till the base of the crown but is less and less visible(not as pronounced as a shark tooth were the carinae is sometime expending to the Cusplet). One of the carinae looks more ”sharp” than an other(picture). ~~~~~~~~~~~~〇~~~~~~~~~~~~~ Warmest greetings from Kumamoto、 Japan Link to comment Share on other sites More sharing options...
David in Japan Posted October 25, 2018 Author Share Posted October 25, 2018 Other side. No root visible. 1 ~~~~~~~~~~~~〇~~~~~~~~~~~~~ Warmest greetings from Kumamoto、 Japan Link to comment Share on other sites More sharing options...
NSRhunter Posted October 25, 2018 Share Posted October 25, 2018 Fish or reptilian, maybe plesi? 1 Link to comment Share on other sites More sharing options...
JarrodB Posted October 25, 2018 Share Posted October 25, 2018 I'm getting a reptilian feel on this one. 1 Link to comment Share on other sites More sharing options...
PFOOLEY Posted October 29, 2018 Share Posted October 29, 2018 Great find, David...I am in the reptile camp as well. For your perusal... A review of the Upper Cretaceous marine reptiles from Japan ...and for reference... Features and paleoecological significance of the shark fauna from the Upper Cretaceous Hinoshima Formation, Himenoura Group, Southwest Japan ... . 2 "I am glad I shall never be young without wild country to be young in. Of what avail are forty freedoms without a blank spot on the map?" ~Aldo Leopold (1887-1948) New Mexico Museum of Natural History Bulletins Link to comment Share on other sites More sharing options...
David in Japan Posted October 30, 2018 Author Share Posted October 30, 2018 17 hours ago, PFOOLEY said: Great find, David...I am in the reptile camp as well. For your perusal... A review of the Upper Cretaceous marine reptiles from Japan ...and for reference... Features and paleoecological significance of the shark fauna from the Upper Cretaceous Hinoshima Formation, Himenoura Group, Southwest Japan ... . Thank you very much. I didn't know the second paper you send me existed in English. It will be helpful. I think will will try to have a look at the Satsuma-utsunomiya-ryu(サツマウツノミヤリュウ） found in Kagoshima prefecture (Shishijima). It is a plesiosaur found in the same formation than the one I found my tooth and I will visit the museum before the end of the year to show it to local paleontologists. I am really happy to see how a mis-identified (I was 90% sure of my mistake before creating a thread), generated such great debate. Thank you all, I learned few things but still a lot of mysteries. The more I learn the more I feel idiot. Still very curious about this tooth carina. As @Anomotodon said, this kind of pronounced carina is not visible on tooth from the same age (as far as I saw In the past few days). Really exciting. Thank you all, @JarrodB, @NSRhunter, @PaleoRon, @Al Dente, @ynot, @fossilselachian, @The Amateur Paleontologist, @Anomotodon, @PFOOLEY 1 ~~~~~~~~~~~~〇~~~~~~~~~~~~~ Warmest greetings from Kumamoto、 Japan Link to comment Share on other sites More sharing options...
Anomotodon Posted October 30, 2018 Share Posted October 30, 2018 Actually, now I am also leaning towards a reptile, not plesiosaur (they don't have carinae) but a mosasaur. Best argument would be to prepare it out of the matrix and look at the base to check if the pulpar cavity is open - then it is a reptile Russelosaurina gen. et sp. indet from Santonian Kunitan fm (Sato et al., 2012), enamel is very wrinkly, much like on this tooth 1 The Tooth Fairy Link to comment Share on other sites More sharing options...
David in Japan Posted October 30, 2018 Author Share Posted October 30, 2018 9 hours ago, Anomotodon said: Actually, now I am also leaning towards a reptile, not plesiosaur (they don't have carinae) but a mosasaur. Best argument would be to prepare it out of the matrix and look at the base to check if the pulpar cavity is open - then it is a reptile Russelosaurina gen. et sp. indet from Santonian Kunitan fm (Sato et al., 2012), enamel is very wrinkly, much like on this tooth I would love to clean the base but i think it is way over my skills and i do not want to damage the fossil. Plioplatecarnidae has been found is the same formation. I will have a look. ~~~~~~~~~~~~〇~~~~~~~~~~~~~ Warmest greetings from Kumamoto、 Japan Link to comment Share on other sites More sharing options...
The Amateur Paleontologist Posted October 31, 2018 Share Posted October 31, 2018 (edited) On 25/10/2018 at 8:05 AM, David in Japan said: Looking at your specimen from that side, I'd actually agree with the others on reptile - probably mosasaur... (which in my opinion is even cooler than teleost ) -Christian P.S. @Anomotodon's right, the Sato et al. 2012 paper is a good place to look for further information (e.g. especially the figures showing cranial and dental mosasaur material): Sato etal(2012)_Review of Japanese marine reptiles.pdf Edited October 31, 2018 by The Amateur Paleontologist Opalised fossils are the best: a wonderful mix between paleontology and mineralogy! Q. Where do dinosaurs study? A. At Khaan Academy!... My ResearchGate profile Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now